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HomeMy WebLinkAbout2011-12-31_COMPREHENSIVE WATER RESOURCE MANAGEMENT PLAN PART 2Nine Mile South Fork 9.0 Nine Mile South fork 9.1 General Description of Drainage Area Figure 9.1 depicts the drainage area to the South Fork of Nine Mile' Creek and the individual subwatersheds within this area. The Nine Mile South Fork drainage basin is located in the southwest corner of Edina and includes a small portion of Eden Prairie. Several land- locked lakes are located within this drainage basin, including Arrowhead Lake and Indianhead Lake. These areas would become tributary to the South Fork of Nine Mile Creek only under extreme flooding circumstances (storms greater than the 100 -year frequency storm event). 9.1.1 -Drainage Patterns The stormwater system within.this drainage area is comprised of storm sewers, ditches, overland flow paths, wetlands, and ponding basins. The Nine Mile South Fork drainage basin has been divided into several major watersheds based on the drainage patterns. These major watersheds are depicted in Figure 9.2. Each major watershed has been further delineated into many subwatersheds. The naming convention for each subwatershed is based on the major watershed it is located.within. Table 9.1 lists each major watershed and the associated subwatershed naming convention. Table 9.1 Major Watersheds within the Nine Mile South Fork Drainage Basin Major Watershed Subwatershed Naming Convention # of Subwatersheds Drainage Area (acres) Arrowhead Lake AH ## 31 178 Indianhead IH ## 12 107 Pawnee Pond PA ## 13 39 . -Eden Prairie EP ## 2 204 BraemarArena /Public Works BA ## 4 25 Nine Mile South Fork NMSB ## 92 775 9.1.1.1 Arrowhead Lake The Arrowhead Lake watershed extends: north of T.H-. 62 and is bordered on the west side by T.H. 169 and generally °bordered on the east and south side by Indian HiIN'Road /Pass. The` 178 -acre watershed is comprised of mainly single. family residential land use, however portions of T.H. 62 and the T.H. 62 /T.H. 169 intersection are tributary -to the lake. Within the watershed there are three stormwater detention basins that ultimately drain to Arrowhead Lake. Arrowhead -Lake is a lan& . locked basin covering approximately 22 acres. Barr Engineering Company 9 -1 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina.SWMP FINAL DRAFT 121511REV.docx 9.1.1.2 Indianhead Lake The Indianhead Lake watershed is located southeast of Arrowhead Lake. Within the 107 -acre watershed, there are two stormwater detention basins and Indianhead Lake. The residential watershed ultimately drains to Indianhead Lake via storm sewer networks and overland flow channels. Indianhead Lake is a land- locked basin covering approximately 14 acres. 9.1.1.3 Pawnee Pond The Pawnee Pond watershed is approximately 39 acres. The watershed is a residential area consisting of two stormwater detention basins, Pawnee Pond and a smaller basin east of the intersection of Apache Road and Sally Lane. The Pawnee Pond is located directly north of Apache Road, bordered by Indian Way West on the west, Pawnee Road on the east, and Indian Hills Road on the north. The normal elevation of Pawnee Pond is controlled at Elevation 862 MSL by a pumped outlet. The outflow from Pawnee Pond flows westerly through a cross - culvert beneath T.H. 169, south on the west side of T.H. 169 and ultimately into the Braemar Branch of Nine Mile Creek. 9.1.1.4 Eden Prairie The Eden Prairie watershed consists of approximately 204 acres of land west of T.H. 169 that drains to the South Fork of Nine Mile Creek via the Braemar Branch of Nine Mile Creek. Stormwater runoff from this area flows through a succession of storm sewer systems and ponding basins, eventually outleting to the drainageway that drains south along the west side of T.H. 169. The Eden Prairie watershed boundaries were based on the watershed divides from the Nine Mile Creek Watershed District Water Management Plan (May 1996). Land use within this area consists mainly of industrial and office property. 9.1.1.5 Braemar Arena /Public Works The Braemar Arena/Public Works watershed includes drainage from the south parking lot of the Braemar Arena, Braemar Boulevard, and the Public Works and Public Safety Training Site. The remaining portion of the Braemar Sports Complex parking lot that does not drain to the south drains westerly to the T.H. 169 drainage system. The 25 -acre Braemar Arena/Public Works watershed drains southward through a storm sewer system to a 0.24 -acre stormwater detention pond. The normal water level of this detention pond is controlled at Elevation 846 MSL, by a 24 -inch diameter outlet pipe that discharges southerly into the floodplain of the South Fork of Nine Mile Creek. 9.1.1.6 Nine Mile South Fork The Nine Mile South Fork watershed is comprised of 92 subwatersheds that drains through the drainage system of the Braemar Golf Course, ultimately discharging to the South Fork of Nine Mile Creek. The 775 -acre watershed encompasses a wide range of land uses, including residential, industrial, wetlands, open area/park, and the golf course. The storm water system throughout this area is characterized by storm sewer, ditches, ponds, and overland flow networks. The extent of the Nine Mile South Fork watershed spans west of T.H. 169, where drainage from the Washington Avenue storm sewer system combines with flows from the Eden Prairie and Pawnee Pond Barr Engineering Company 9 -2 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx watersheds. This stormwater flows easterly under T.H. 169 through a large culvert, located midway between Hamilton Road and-West 69'h Street, and discharges into the Braemar Branch of Nine Mile Creek. The Braemar Branch drains southward through Braemar. Park towards the Braemar Golf Course. The Braemar Branch flows through several ponding basins on the west side of the golf course before discharging into the South Fork. Stormwater from the remaining portion of the Nine Mile South Fork watershed flows through a series of storm -sewer pipes, wetlands, and ponds on the eastern side of the Braemar Golf Course before reaching the South Fork of Nine Mile Creek. 9.2 Stormwater System Analysis and Results. 9.2.1 Hydrologic /Hydraulic Modeling Results The 10 -year and 100 -year frequency flood analyses were performed for the Nine Mile South Fork Watershed. The 10 -year analysis was based on a' /z -hour storm of 1.65 inches of rain. The 100 -year analysis was based on a 24 -hour storm event of 6 inches of rain. Table 9.2 presents the watershed information and the results for the 10 -year and 100 -year hydrologic analyses. The results of the I0- year, and 100 -year frequency hydraulic analyses for the Nine Mile South Fork drainage area are summarized in Table 9.3 and Table 9.4. The column headings in Table 9.3 are defined as follows: Node /Subwatershed ID-XP -SWMM node identification label. Each XP -SWMM node represents a manhole, catchbasin, pond, or other junction within the stormwater system. Downstream Conduit— References the pipe downstream of the node in the storm sewer system. Flood Elevation —The maximum water elevation reached in the given pond/manhole for each referenced storm event (mean sea level). In some cases, an additional flood elevation'has:been given in parenthesis. This flood elevation reflects the 100 -year flood elevation of Nine Mile Creek, per the Nine Mile Creek Watershed Management Plan, May 1996. Peak Outflow Rate -The peak discharge rate (cfs) from a given ponding basin for each referenced storm event. The peak outflow rates reflect the combined discharge from the pond through the outlet structure and any overflow. NWL —The normal water level in the ponding basin (mean sea level). The'normal water levels for the ponding basins were assumed to be at the outlet pipe invert or at the downstream control elevation. Flood Bounce —The fluctuation of the water level within a given pond for each referenced storm event. Volume Stored —The maximum volume (acre -ft) of water that was stored in the ponding basin during the storm event. The volume represents the live storage volume only. Barr Engineering Company 9 -3 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFnEdina SWMP FINAL DRAFT 12151IREV.docx Table 9.4 summarizes the conveyance system data used in the model and the model results for the storm sewer system within the Nine Mile South Fork drainage area. The peak flows through each conveyance system for the 10 -year and 100 -year frequency storm events are listed in the table. The values presented represent the peak flow rate through each pipe system only and does not reflect the combined total flow from an upstream node to the downstream node when overflow from a manhole /pond occurs. Figure 9.3 graphically represents the results of the 10 -year and 100 -year frequency hydraulic analyses. The figure depicts the Nine Mile South Fork drainage area boundary, subwatershed boundaries, the modeled storm sewer network, surcharge conditions for the XP -SWMM nodes (typically manholes), and the flood prone areas identified in the modeling analyses. One of the objectives of the hydraulic analyses was to evaluate the level of service provided by the current storm sewer system. The level of service of the system was examined by determining the surcharge conditions of the manholes and catch basins within the storm sewer system during the 10 -year and 100 -year frequency storm events. An XP -SWMM node was considered surcharged if the hydraulic grade line at that node breached the ground surface (rim elevation). Surcharging is typically the result of limited downstream capacity and tailwater impacts. The XP -SWMM nodes depicted on Figure 9.3 were color coded based on the resulting surcharge conditions. The green nodes signify no surcharging occurred during the 100 -year or 10 -year storm event, the yellow nodes indicate surcharging during the 100 -year event, and the red nodes identify that surcharging is likely to occur during both a 100 -year and 10 -year frequency storm event. Figure 9.3 illustrates that several XP -SWMM nodes within the Nine Mile South Fork drainage area are predicted to experience surcharged conditions during both the 10 -year and 100 -year frequency storm events. This indicates a probability greater than 10 percent in any year that the system will be overburdened and unable to meet the desired level of service at these locations. These manhole and catch basin are more likely to experience inundation during the smaller, more frequent storm events of various durations. Another objective of the hydraulic analysis was to evaluate the level of protection offered by the current stormwater system. Level of protection is defined as the capacity provided by a municipal drainage system (in terms of pipe capacity and overland overflow capacity) to prevent property damage and assure a reasonable degree of public safety following a rainstorm. A 100 -year frequency event is recommended as a standard for design of stormwater management basins. To evaluate the level of protection of the stormwater system within the Nine Mile South Fork drainage area, the 100 -year frequency flood elevations for the ponding basins and depressed areas were compared to the low elevations of structures surrounding each basin. The low elevations were initially determined using 2 -foot topographic information and aerial imagery in ArcView. Where 100 -year flood levels of the ponding areas appeared to potentially threaten structures, low house elevations were obtained through field surveys. The areas that were predicted to flood and threaten structures during the 100 -year frequency storm event are highlighted in Figure 9.3. Discussion and recommended implementation considerations for these areas are included in Section 9.3. Barr Engineering Company 9 -4 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 9.2.2 Water Quality Modeling Results The effectiveness of the stormwater system in removing stormwater pollutants such as phosphorus was analyzed using the P8 water quality model. The P8 model simulates the hydrology and phosphorus loads introduced from the watershed of each pond and the transport of phosphorus throughout the stormwater system. Since site - specific data on pollutant wash -off rates and sediment characteristics were not available, it was necessary to make assumptions based on national average values. Due to such assumptions and lack of in -lake water quality data for model calibration, the modeling results were analyzed based on the percent of phosphorus removal that occurred and not based on actual phosphorus concentrations. Figure 8.4 depicts the results of the water quality modeling for the Nine Mile South Fork drainage basin. The figure shows the fraction of total phosphorus removal for each water body as well as the cumulative total phosphorus removal in the watershed. The individual water bodies are colored various shades of blue, indicating the percent of the total annual mass of phosphorus entering the water body that is removed (through settling). It is important to note that the percent of phosphorus removal is based on total phosphorus, including phosphorus in the soluble form. Therefore, the removal rates in downstream ponds will likely decrease due to the large soluble fraction of incoming phosphorus that was unsettleable in upstream ponds. The watersheds are depicted in various shades of gray, indicating the cumulative total phosphorus removal achieved. The cumulative percent removal represents the percent of the total annual mass of phosphorus entering the watershed that is removed in the pond and all upstream ponds. Ponds that had an average annual total phosphorus removal rate of 60 percent or greater, under average climatic conditions, were considered to be performing well. For those ponds with total phosphorus removal below 60 percent, the permanent pool storage volume was analyzed to determine if additional capacity is necessary. Based on recommendations from the MPCA publication Protecting Water Quality in Urban Areas, March 2000, the permanent pool for detention ponds should be equal to or greater than the runoff from a 2.0 -inch rainfall, in addition to the sediment storage for at least 25 years of sediment accumulation. For ponds with less than 60 percent total phosphorus removal, the recommended storage volume was calculated for each pond within the drainage basin and compared to the existing permanent pool storage volume. 9.3 Implementation Considerations The XP -SWMM hydrologic and hydraulic modeling analyses and P8 water quality analysis helped to identify locations throughout the watershed where improvements to the City's stormwater management system may be warranted. The following sections discuss potential mitigation alternatives that were identified as part of the 2003 modeling analyses. As opportunities to address the identified flooding issues and water quality improvements arise, such as street reconstruction projects or public facilities improvements, the City will use a comprehensive approach to stormwater management. The comprehensive approach will include consideration of infiltration or volume retention practices to address flooding and /or water quality improvements, reduction of impervious Barr Engineering Company 9 -5 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFTNEdina SWMP FINAL DRAFT 121511REV.docx surfaces, increased storm sewer capacity where necessary to alleviate flooding, construction and /or expansion of water quality basins, and implementation of other stormwater BMPs to reduce pollutant loading to downstream waterbodies. 9.3.1 Flood Protection Projects The 2003 hydrologic and hydraulic modeling analysis identified several locations within the Nine Mile South Fork drainage basin where the 100 -year level of protection is not provided by the current stormwater system. The problem areas identified in 2003 are discussed below. As part of the 2003 modeling analysis, potential corrective measures were identified for the problem areas for purposes of developing planning -level cost estimates. These preliminary corrective measures are also discussed below. As the City evaluates the flooding issues and potential system modifications in these areas, consideration will be given to other potential system modifications, including implementation of stormwater infiltration or volume retention practices, where soils are conducive. 9.3.1.1 6309 Post Lane (AH 31) A depression area exists in the backyard area of 6309 Post Lane. The depression area receives stormwater from a direct watershed of 1.7 acres. Stormwater collected in the depression area enters a 30 -inch storm sewer system through a catchbasin located at the low point of the backyard. Upstream of the backyard depression area, the 30 -inch system receives stormwater from the T.H. 62 and T.H. 169 interchange and discharge from the Arrowhead Pointe pond (AH_4). During intense rain storms, such as the 100 -year frequency event, the capacity of the 30 -inch system is limited from upstream drainage, preventing the backyard area from being drained. Under current conditions, the 100 -year frequency flood elevation in the backyard depression area is 883.4 MSL. This flood elevation is above the low entry of the home at 6309 Post Lane, surveyed at 880.6 MSL. To alleviate the flooding of the backyard area, it is necessary to restrict the flow in the 30 -inch system from upstream drainage areas during the time period of the backyard inundation. Currently, stormwater from the T.H. 62 and T.H. 169 interchange is collected in a series of ditches and enters the 30 -inch storm sewer system through a flared end section on the north side of T.H. 62 (subwatershed AH_25) and a catchbasin/manhole inlet on the southeast side of the interchange (subwatershed AH_29). To retard the flow in the 30 -inch system during the time period of the backyard inundation, it is recommended that a control structure be installed at the catchbasin/manhole inlet in the ditch southeast of the T.H. 62 and T.H. 169 interchange (node AH_29). The control structure should consist of a 6 -inch orifice at elevation 882 MSL to allow low flows through during smaller storm events and to allow the ditches to completely drain. A 6 -foot weir at elevation 887 MSL will restrict high flows through the system during the time period of the backyard inundation and take advantage of available temporary storage in the highway ditches. In addition, it is recommended that the control structure from the Arrowhead Pointe pond (AH_4) be modified to restrict flow from the pond during the time period of the backyard inundation. It is Barr Engineering Company 9 -6 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFTNEdina SWMP FINAL DRAFT 12151IREV.docx recommended that the control structure consist of a 4 -inch diameter orifice at elevation 884 MSL and a 6 -foot weir at elevation 887 MSL. With implementation of these recommendations, the resulting 100 -year frequency flood elevation in the backyard depression area is 880.5 MSL, below the.-low entry elevation at 6309 Post Lane. 9.3.1.2 Braemar Golf Course (NMSB_62) The predicted 100 -year flood elevation of the NMSB_62 watershed is 840.9 MSL. Based on the 6 -foot topographic information from the City, it appears that this flood level will impact the Executive Course clubhouse at the Braemar Golf Course. Anecdotal information suggests this structure has been affected by flood waters in the. past. 9.3.1.3 Paiute Pass & Sally Lane Intersection (NMS B_83, NMSB_84) The storm sewer system at the Paiute Pass and Sally Lane intersection collects, stormwater from a total drainage area of approximately 27 acres. The system discharges'into the Braemar Branch, West of Sally Lane, via two 24 -inch pipes. During the 10 -year and 100 -year storm events, the Paiute Pass /Sally Lane intersection is inundated with stormwater and ponding occurs. Based on topographic information from the City, ponding will occur in this intersection to Elevation 863.6 MSL. As water levels rise higher than this, water will begin to encroach upon the homes west of Sally Lane (7000, 7004, 7008 Sally Lane) and eventually flow to the Braemar Ditch via overland flow. It is recommended that the topography of this area be examined in further detail and a controlled positive overflow path be constructed between the homes if necessary to ensure the homes are protected from flood waters. 9.3.1.4 7009 & 7013 Sally Lane Backyard Depression Area.(NMSB_70) A backyard depression area exists behind the homes along Sally Lane and Paiute Pass. A 12 -inch piped outlet exists from this area, draining northward and connecting to the system along Paiute Pass. During the 100 -year storm event, the predicted flood elevation reaches 864.5 MSL, assuming an overland flow channel from this area. Based on topographic information from the City, this flood elevation encroaches upon the homes at 7009 and 7013 Sally Lane. It is recommended that the topography of this area be further examined to determine the elevation at which the flooded area will drain <west toward Sally Lane via overland flow. If necessary, a controlled positive overflow should be constructed between the homes to prevent flood water from damaging the structures. 9.3.2 Construction/Upgrade of Water Quality Basins The 2003 P8 modeling analysis indicated that. the annual removal .of total phosphorus from several ponds in the Nine Mile South Fork drainage area was predicted to be below the desired 60 percent removal rate, under average year conditions. For those ponds with total phosphorus removal below 60 percent, the permanent pool storage volume was analyzed to determine if additional capacity is necessary. The ponds that exhibited deficiencies in total phosphorus removal and permanent pool volume are listed below, along with recommended pond upgrades. Barr Engineering Company 9 -7 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx Construction of new or expansion of existing water quality basins is one method to increase the pollutant removal achieved prior to stormwater reaching downstream waterbodies. Many additional techniques are available to reduce pollutant loading, including impervious surface reduction or disconnection, implementation of infiltration or volume retention BMPs, installation of underground stormwater treatment structures and sump manholes and other good housekeeping practices such as street sweeping. As opportunities arise, the City will consider all of these options to reduce the volume and improve the quality of stormwater runoff. 9.3.2.1 NMSB_3 & NMSB_2 Pond NMSB_3 is located on the Braemar Golf Course, southeast of the intersection of Valley View Road and Braemar Boulevard. This pond receives stormwater from an immediate watershed of approximately 21 acres, as well as discharge from the Braemar Branch, which drains an area of approximately 259 acres and flow from Pond NMSB_33 to the east. The pond is a Type 5 wetland and was assumed to have an average depth of 4 feet. Pond NMSB_2 is downstream of Pond NMSB_3, connected by a 30 -inch equalizer pipe. Pond NMSB_2 receives stormwater from an immediate watershed of approximately 5 acres, as well as flow from the upstream NMSB_3. This pond is also a Type 5 wetland and was assumed to have an average depth of 4 feet. The annual removal of total phosphorus from these two ponds was predicted to be below 60 percent based on the modeling results. Consequently, the MPCA recommended permanent pool storage volume for these ponds was calculated and compared with the existing dead storage volume. For the permanent pool volume analysis, the two ponds were considered as one. Based on this assumption, it was determined that the ponds are deficient in dead storage volume. It is recommended that an additional 1.2 acre -feet of dead storage volume be provided to these two ponds to meet the MPCA design criteria for detention basins. 9.3.2.2 NMSB_12 Pond NMSB_12 is located on the Braemar Golf Course, approximately 700 feet southwest of the clubhouse. The pond receives stormwater runoff from the direct watershed of approximately 12 acres, in addition to flow from the upstream wetland NMSB_56. Based on the wetland inventory, the pond is a Type 5 wetland, and was assumed to have an average depth of 4 feet. Based on this depth assumption and the pond area from the 2 -foot topographic information, the current permanent pool storage volume is greater than the MPCA recommended storage volume for detention ponds. It is recommended that the basin be maintained on a regular basis to ensure the removal efficiency is provided and maintained. 9.3.2.3 NMSB_86 Pond NMSB_86 is located on the Braemar Golf Course, directly south of the clubhouse parking lot. Pond NMSB_86 is a small pond that receives stormwater runoff from a direct watershed of approximately 21 acres, as well as discharge from the upstream pond (NMSB_57). The pond discharges directly to the South Fork of Nine Mile Creek via a 30 -inch pipe. The annual removal of total phosphorus from Pond NMSB_86 was predicted to be well below 60 percent based on the Barr Engineering Company 9 -8 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx modeling results. Based on the MPCA recommended storage volume for detention basins, there is not an adequate amount of permanent pool storage in this basin. It is recommended that an additional 0.15 acre -feet of dead storage volume be provided to meet the MPCA design criteria for detention basins. 9.3.2.4 NMSB_7 Pond NMSB_7 is located on the Braemar Golf Course, on the north side of Braemar Boulevard. Pond NMSB_7 is a small detention pond that receives stormwater runoff from a 2.4 -acre watershed, in addition to discharge from an upstream wetland (NMSB_90). Pond NMSB_7 discharges to Pond NMSB_85 via a 24 -inch pipe. Pond NMSB_7 was assumed to be shallow, with an average depth of 2.3 feet, based on Braemar Golf Course design plans. Based on this depth assumption and the pond area from the 2 -foot topographic information, the current permanent pool storage volume was calculated to be 0.6 acre -feet. This permanent pool storage volume is greater than the MPCA recommended storage volume for detention ponds. However, because the water quality modeling results indicate that the total phosphorus removal in Pond NMSB_7 is below desired removal levels, it is recommended that the depth of the pond be increased to a depth of 4 feet to improve removal efficiency. 9.3.2.5 NMSB_85 Pond NMSB_85 is located on the Braemar Golf Course, downstream of Pond NMSB_7, on the north side of Braemar Boulevard. Pond NMSB_85 receives stormwater runoff from a 67.5 -acre watershed, as well as discharge from Pond NMSB_85 and discharge from a backyard depression area northeast of the intersection of Gleason Road and Dewey Hill Road (NMSB_15). Based on the wetlands inventory, the pond is a Type 5, and was assumed to have an average depth of 4 feet. Based on this depth assumption and the pond area from the 2 -foot topographic data, the current permanent pool storage volume is 1.3 acre -feet. This storage volume is less than the MPCA recommended permanent pool storage volume for detention basins. It is recommended that an additional 1.2 acre - feet of dead storage volume be provided to meet the MPCA design criteria for detention basins. Barr Engineering Company 9 -9 P: \Mpls\23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx i i !Minnetonka EP_1 Eden Prairie EP_2 1 AHT12 ; AH_23 � AH_25 AH_26 1H_28 AH_3 AH_32 _ 62 PA_1 �R P� 92 PA_8 PA_4 P—A NMSB_9 NMSB_ SWIM- S B_ MM AHN AHLt rroxhead Lake A. 1' It .< MA IH_3 f NMS _6 Indran IH_14 \ ' ^•5� IH_8 NSB_7 �H_18 NMSB12.1 � IH_11 NMSB 22 NMSB_1 SB. NMSB_3 IH_42 NMSB_34 NMSB_26 ________.� `f 1,:7y0�� NMSB_2 NMSB�27 A NMSB_43 U NMSB_3 r � /NMS11BMfS3 B _32 NMSB_37 i _� � N"MSBT29 NMSB3 NM� SB 25 _ N� di NMSB_31 EMS OKLA CIE. 9-UM BMW_ l ' 169 i [:gip �A\,�t� 1 [ ile C'�•erk St ttt�1 u 6 u u t Bloomington o e r� Cn • !��•URPURAI�, • 188fl City of Edina Boundary Roads /Highways Creek /Stream Lake /Wetland Nine Mile Creek - South C3 Fork Drainage Basin Subwatershed Imagery Source: Aerials Express, 2008 O Feet 1,200 0 1,200 Meters 400 0 400 Figure 9.1 NINE MILE CREEK SOUTH FORK DRAINAGE BASIN Comprehensive Water Resource Management Plan City of Edina, Minnesota Minnetonka Eden Prairie v 'v UI JILU 2 22 Eden Prairie 169 I Arrowhead cake Brapmer Apna/ rublic Works Indianhend Lake s2 AW �p •ter'. ��� ad 4, J K Nine Mile reek South F6rk Bloomington -A,,. r 'A �1 t Imagery Source: Aerials Express, 2008 O Feet 1.200 0 1,200 Meters 400 0 400 Figure 9.2 NINE MILE CREEK SOUTH FORK MAJOR WATERSHEDS Comprehensive Water Resource Management Plan City of Edina, Minnesota {n City of Edina Boundary Roads /Highways Creek /Stream Lake /Wetland C3 Nine Mile Creek South Fork Drainage Basin C3 Major Watershed C3 Subwatershed Imagery Source: Aerials Express, 2008 O Feet 1.200 0 1,200 Meters 400 0 400 Figure 9.2 NINE MILE CREEK SOUTH FORK MAJOR WATERSHEDS Comprehensive Water Resource Management Plan City of Edina, Minnesota _---- _ - -� —_ Minnetonka_' Eden Prairie EP_2B EP_ 1 �1 b Indiun &end Lake IH 1 IF NMSB_90 f Vina'�l�lE/�"" ;� OWL% GEM-% % f e Mile Creek yot�tli F� I I Bloomington I Imagery Source: Aerials Express, 2008 O Percent TP Removal in Water Body* This number represents the percent of the total annual mass of phosphorus entering the water body that is removed. j� 0 - 25% (Poor /No Removal) 25 - 40% (Moderate Removal) - 40 - 60% (Good Removal) _ 60 - 100% (Excellent Removal) Cumulative TP Removal in Watershed* This number represents the percent of the total annual mass of phosphorus entering the watershed and upstream watersheds that is removed in the pond and all upstream ponds. _ 25 - 40% (Moderate Removal) 40 - 60% (Good Removal) 60 - 100% (Excellent Removal) "Data based on results of P8 modeling. Area Draining Directly to the South Fork of Nine Mile Creek Flow Direction 0 Feet 1,200 0 1,200 Meters 400 0 400 Figure 9.4 NINE MILE CREEK SOUTH FORK WATER QUALITY MODELING RESULTS Comprehensive Water Resource Management Plan City of Edina, Minnesota Minnetonka •--------------------------- ----- --------�. )212 Eden Prairie Figure 9.3 NINE MILE CREEK SOUTH FORK HYDRAULIC MODEL RESULTS Comprehensive Water Resource Management Plan City of Edina, Minnesota City of Edina Boundary Potential Flooding During Roads /Highways 100 -Year Frequency Event Creek/Stream Pipes o Manhole Lake /Wetland Manhole Surcharge During C3 Nine Mile Creek South ° Fork Drains 100 -Year Frequency Event Drainage Basin g Manhole Surcharged During g g C3Subwatershed 10 -Year Frequency q y Event Feet 400 0 400 800 Meters N 120 0 120 240 �4 IOU GLEASON CT VE HILLS RD ' •0 .. •1 . •% •. C �iTATE H:yy NO 62 .fir .o • �4Z- - Row's m A F 0 •� 1�C gl!!114Y1i • - � . 0 qG( Moe • � AFR _ oe 1 99 do N � gRgN RD r• ( •7 INDIAN WA w�• 0 (NEST . � RO W • � W Tam IIIIIIIIIIEII� '0 No moop • "° 0 VW 0 s NfFST T/< BMW —_ LVFST TR t o•C •• °' SAMOFL - • MU SIOJX I* • TR • QUO \S • •� vow �y v F� \ \yZF P \ G4J!kJ • . %w C", WF Z �IJ1'IL`L'�C/ 0 PAWTE CIR GMA r n TE P% o ��� s i o 17 4.0 • LEY RD � BE, jI 0• O� a � A, 0• o • v -0 � YP��P � � �• 0 �• Oi�: CO CM'Yn2't*'" 0 0 RD NO MAR T rl;1f�C.� � • p•9CPI wuc+q� ,• •0 EMU 9• 0 m w z 0 o. :1 d 6 EMARARENA 0�9 , 0 • �d• WNW M sue• ffm MEW • m (a MU 951 4 1 ,I EE U IH 15 44e4file Creek iJ GM o�L9D 9L3 MW SCOTIA MARK sC,1kp,1)R l Cs 0 ,PA IR amp BRAFBUJ<N II OII�I RD NIVr.7l 4 0 Iff LOCH MOOR K Gm ..0 2sss ,J zsas NMSB NA1SB 57 F Bloomington TRALEE SCHEY OP EMS 0 0 lRi 1p, zsas jr 2sss ,J zsas NMSB NA1SB 57 F Bloomington TRALEE SCHEY OP EMS 0 0 lRi 1p, zsas Table 9.2 Waters he& Modeling Results for Subwatersheds in the Nine Mile South Fork Drainage Basin (Revised 12 /2006) Watershed Information 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 =Hour Event Watershed ID Total Area . (ac) % Impervious Area Peak Runoff Rate ;(cfs) Total Volume Runoff (ac -ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) AH_1 50.1 54 226.1 18.5. 1.1 154.4 H_ 10 1.9 12 9.1 % 0:5 0.8 5.9 x.11_11 1.3 21 6.2 0.5 1.2 6.8 AR 12 1.5 20 7.1 0.4 0.9 5.3 H 13 4.3 0 17.3 1.3 0.9 6.8 H 15 1.2 20 5.6 0.4 1.0 4`:0 `H 16 0.4 20 2.2 0.2 1.3 3.1 �, H_17 4.9 20 21".7 1.4 0.8 11.7 AH 18 2.3 21 10.7 0.7 1.0 7.4 AH 19 6.4 20 26.8 1.8 0.7 13.4 AH-20 '6A 8 29.3 1.6 0.7 15.4 AH-21 6.9 9 31.4 1.7 .0.7 15.1 8.6 8 3&0 2.1 0.6 13.5 _22 23 5.9 17 26.8 1.7 0.8 15.0 AH-24 3.3 28 14.6 1.0 0.9 9.1 _25 4.6 44 21.2 1.9 1.3 15.4 H 26 4.2 19 18.8 1.2 0.8 10.2 AH 27 1.5 20 6.7 0.4 0.8 4.1 AH 28 4.8 50 22.7 2.1 1.4 19.5 AH-29 5.9 41 28.4 2.5 1.3 25.7 AH 3 6.3 41 30.7 2.4 1.2 33.2 AH 30 4.1 20 18.4 1.1 0.8 10.6 AH 31 1.7 20 8.1 0.5 0.9 6.4 AH 32 7.1 50 32.4 3.1 1.3 23.5 AH _33 3.1 50 15.0 1.4 1.4 13.6 H_4 1.1 30 5.4 0.5 1.3 5:5 AH 5 3.7 20 16.0 1.0 0.7 8.3 AIL6 13.0 28 59.0 4.3 1.0 39.3 AH 7 5.6 50 26.5 2.5 1.3 21.3 AH-8 0.6 30 3.1 0.3 1.3 3.7 _9 5.2 43 25.0 2.0 1.2 22.7 BA -1 4.4 51' 20.5 1.6 1.1 16.2 13A 3.1 80 13.9 1.3 1.4 9.3 A_3 9.5 7 39.5 2.3 0.6 14.7 A_6 7.8 9 35.4 2.1 0.8 18.1 EP -1 95.5 80 320.8 41.2 1.3 135.5 P_2 123.7 71 296.0 50.5 1.2 101.6 H_1 38.2 48 167.5 13.5 1.0 1'07.8 H 10 6.6 16 29.3 1.8 0.7 14.6 H_11 2.7 26 11.7 0.8 0.8 6.8 H_12 6.3 20 26.2 1.7 0.7 13.0 H_13 5.1 16 22.9 1.4 0.7 '11.9 H 14 5.0 32 22.3 1.6 '1.0 14.5 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\NineM[Le_SWMM_hydraulic_ output_ 2006UPDATE _final_NWL_verification.xls NMSB Runoff Results UPDATE Table 9.2 Watershed Modeling Results for Subwatersheds in the Nine Mile South Fork Drainage Basin (Revised 12/2006) Watershed Information 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Watershed ID Total Area (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) H_15 2.9 20 13.6 0.8 0.8 8.6 IH_3 18.4 11 73.5 4.7 0.6 28.3 H_5 1.4 20 6.5 0.4 0.8 4.3 H_6 15.1 15 67.1 4.0 0.7 33.1 H_7 1.0 20 4.5 0.3 0.9 3.7 H_8 4.7 20 21.2 1.3 0.8 11.7 MSB_10 0.3 4 1.1 0.1 0.5 0.3 MSB_11 1.4 2 6.5 0.4 0.8 4.8 MSB_12 11.7 8 50.0 3.0 0.6 17.1 MSB_13 8.1 1 16 35.8 2.2 0.7 18.1 SB_14 5.9 20 26.2 1.8 0.9 14.7 SB_15 2.4 20 10.8 0.7 0.8 6.5 SB_16 2.8 19 12.3 0.8 0.7 6.5 MSB_17 7.6 19 34.2 2.1 0.8 18.7 NMSB_18 8.0 20 10.0 1.8 0.4 3.7 MSB_19 6.9 20 30.8 1.9 0.8 16.9 SB_2 4.9 29 21.3 1.5 0.8 12.7 SB_20 11.6 5 41.7 2.7 0.5 12.3 SB_21 1.4 21 4.9 0.4 0.6 2.3 SB_22 9.3 20 36.9 2.7 0.8 18.2 MSB_23 7.6 20 32.3 2.1 0.7 16.6 MSB_24 2.0 50 9.5 0.8 1.3 11.9 MSB_25 1.4 20 6.6 0.4 0.9 5.3 SB_26 6.7 20 26.7 1.8 0.7 12.9 SB_27 4.0 20 18.4 1.1 0.8 11.7 SB_28 2.4 20 7.4 0.6 0.6 3.3 SB_29 3.2 20 9.2 0.8 0.6 4.0 SB_3 20.7 10 46.8 4.9 0.5 19.9 MSB_30 15.4 20 57.9 4.3 0.7 27.2 MSB_31 5.0 19 23.4 1.4 0.8 14.9 SB_32 6.6 20 28.3 1.8 0.7 14.7 SB_33 4.8 10 20.5 1.2 0.6 6.3 SB_34 8.3 16 34.6 2.2 0.7 15.9 SB_35 3.1 15 12.4 0.8 0.6 5.3 MSB_36 3.9 19 17.1 1.1 0.8 8.9 SB_37 4.7 20 21.4 1.3 0.8 12.6 MSB_38 1.3 20 5.8 0.4 0.7 3.2 MSB_39 5.1 20 23.4 1.4 0.8 14.6 SB_4 17.9 14 74.1 5.5 0.9 40.6 MSB_40 3.4 18 15.6 1.0 0.8 9.3 SB_41 6.0 8 22.4 1.5 0.5 7.5 MSB_42 4.5 16 21.0 1.2 0.8 13.3 NMSB 43 6.7 16 28.2 1.8 0.7 13.2 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\NineMlLe_SWMM_hydraulic_ output_ 2006UPDATE _final_NWL_verification.xls NMSB Runoff Results UPDATE 3 Table 9.2 Watershed Modeling Results for Subwatersheds in the Nine Mile South Fork Drainage Basin (Revised 12 /2006) Watershed Information 100 -Year Storm Results 24- Hour,Event 10 -Year Storm Results 1/2 -Hour Event Watershed ID Total Area (ac) % Impervious Area Peak Runoff Rate. (cfs) "Total Volume Runoff (ac -ft)' Peak Runoff Rate (cfs) Total Volume ` Runoff (ac -ft) NMSB 44 0.6 3 2.8 0.1 0.7 .2;1, NMSB' 45 20.5 • 5 44.1 4.7 0.4 12.8 NMSB 46 1.2 50 . 5.7 0.4' 1.1 6.6 MSB_47 ' 2.7 2 I.1.8 0.6 0.6 4.5 NMSB 49 0.6 43 '2.8 0.2 1.1 3.3 NMSB _5 , .. 24:6 6 27.4 4.8 0.2 10:0 . MSB_50 ": ,;. 19 '52 9.1 0.7 1.2 11.1 NMSB 51, 3.4 50 16.4 1.3 1.2 18.5 NMSB 52 _5:3" 26 24.8 1.6 0.9 15.4 NMSB-56 27.4, 8 83.5 6.4 0.5 27.6 NMSB 57 20.6 15 -81.0. 5.4. 0.6 35.5 NMSB 58 3.6 20 16.7 1.0 0.8 11.6 NMSB 59 3.8 20 17.5 1.1 0.8 NMSB-6 1.7 14 7.6 0.4 0.7 3.9 SB 61 2.3 80 10.2 1:0 1.4 9.2 NMSB 62 7.3 6, 23.1 1.7 0.5 6.7 . NMSB 63 2.7 50 13.1 1.0 1.2 16.2 MSB_64 2.7 50 13.1 1.0 1.2 16.0 NMSB-65- 1.3 50 6.4 0.5 1.2 8.3 MSB 66 10.0 19 39.8 2.7 03 19.0 NMSB 67 5:8 12 26.0 1.5 0.7" 12.9 SB_68 4.8 80 21.7 2.1 1.4 22.5 __ NMSB 69 6.5 15 28.2 2.1 1.0 17:9 T4MSBj 2.4 16 10.4 0.7 0.9 5.2 SB -70 2.9 17 13.2 0.8 0.8 7.6 NMSB-71 5.6 50 26.9 2.1 1.2 31.0 NMSB 72 8.4, 17 34.8 2.3 03 16.1 NMSB 73 - 69.6 74 218.5 29:0 1.2 87.2 NMS 1174 , . 0.7 22 3.3 ` 0.2 1.1 4.0 NM-S-B-75 1.6 20 7.3 0.4 0.8 4.6 NMSB 76 1.4 16, 6.5 0.6 1.2 7.6 NMSB 77 4.5 10 20.3 1.4 0.8 7.0 NMSB 78 5.6 20 24.4 1.6 0.8 13.0 14MSB 79 1.2 23 5.5 0:3 0.9 ' 5.1 NMSB_8 9.8 16 39.8 3.1 0.9 19.1 NMSB 80 0.5 63 2.4 0.2 1.3 4.0 NMSB-81 0.6 50 2.8 0.2 1.2 3.3 NMSB-82 2.6 16 11.3 0.7 0.7 5.4 NMSB 83 10.7 20 36.7 2.9 0.6 16.7 NMSB-84 3.1 20 14.1 0.9 0.8 8.8 NMSB-85 16.7 9 56.2 4.5 0.6 19.7 MSB_86 20.7 2 37.0 4.5 0.3 8.3 NMSB .87 8.8 75 42.2 3.7 1.3 37.3 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\NineMlle_SWMM_ hydraulic_ output_ 2006UPDATE _final_NWL_verification.xls - NMSB Runoff Results UPDATE Table 9.2 Watershed Modeling Results for Subwatersheds in the Nine Mile South Fork Drainage Basin (Revised 12/2006) Watershed Information 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Watershed ID Total Area (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) NMSB_88 1.8 72 8.7 0.7 1.4 12.3 MSB_90 29.8 35 118.2 9.4 0.8 65.5 NMSB_91 2.4 20 11.0 0.7 0.8 7.1 SB_92 0.4 19 1.7 0.1 0.8 1.3 SB_93 0.9 28 4.3 0.3 1.0 4.5 MSB_94 4.7 20 19.1 1.3 0.7 9.4 MSB_95 5.9 20 25.8 1.6 0.7 13.8 MSB_96 1.6 21 7.3 0.5 0.8 4.7 SB_97 6.8 17 26.8 1.8 0.7 12.2 SB_98 0.9 20 4.0 0.2 0.8 2.4 SB_99 4.4 20 19.1 1.2 0.7 9.9 PA-1 7.6 37 35.6 2.5 1.0 27.3 A_10 2.2 20 10.5 0.6 0.8 7.4 A_11 1.0 20 4.6 0.3 0.9 3.8 A_12 2.1 20 9.4 0.6 0.9 8.4 A_13 0.6 21 2.7 0.2 0.9 2.2 A_2 1.6 17 7.4 0.4 0.8 4.3 A_3 8.6 12 36.6 2.2 0.6 15.6 A_4 1.5 20 6.8 0.4 0.8 4.5 A_5 2.6 20 12.3 0.7 0.8 8.8 A_6 3.9 26 17.6 1.2 0.9 11.3 A_7 1.5 20 6.9 0.4 1.0 5.3 A_8 3.9 20 17.1 1.1 0.7 9.1 A 9 1.7 20 8.2 0.5 0.9 6.6 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\NineMlLe_SWMM_ hydraulic_ output_ 2006UPDATE _final_NWL_verification.xls NMSB Runoff Results UPDATE Table 9.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in the Nine Mile South Fork (Revised 12/2006). Subwatershed or Node „ Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (fl) Type of Storage' NWL (ft) Flood Bounce (ft) Flood Elevation (ft) NWL (ft) Flood Bounce (ft) 513 365p 874.9 8733 514 366p 874.9 street 873.7 516 368p 872.6 869.7 519 370p 887.0 887.0 520 371p 887.8 887.7 521 372p 891.5 891.4 523 374 •869.8 869.5 534 382p 879.1. 874.5 536 384p 879.3 street 874.1 537 385p 878.5 873.0 539 387p 874.7 869.9 541 389p 868.2 866.7 543 3900 881'i 877.3 546 393p 868.8 868.2 548 1948p 869.2 868.3 549 395p 868.3 868.0 552 397p 884.3 884.3 . 553 398p 883.5 883.5 555 399p 882.0 879.0 560 402p 946.4 946.1 561 403p 878.3 876.5 564 405p 883.8 881.8 565 406p 883.2 881.4 566 407 •880.5 879.1 570 409p 882.1 879.5 571 2092p 884.7 882.1 575 413p 887.6 887.7 576 414p 887.6 887.7 578 416p 887.6 887.2 580 418p 886.8 886.0 581 419p 885.4 884.0 1034 81 1p 890.5 890.4 1035 812p 876.3 876.3 1036 813p 868.8 868.8 1037 814p 868.1 868.1 1038 815p 868.0 867.9 ,1042 818p 866.9 866.4 1043 819p 864.3 864.3 1045 822p 863.6 862.7 1047 823p 863.6 860.9 1048 824p 863.6 860.9 1049 825p 863.6 860.9 1052 828p 863.6 860.9 1053 829p 863.6 860.9 1059 overland to NMSB_W 851.0 851:0 1060 833p 854.4 856.4 1061 834p 855.5 856.6 1062 835 .869.6 864.4 1063 836 877.9 874.4 1064 837p 878.6 878.3 1068 .840p 881.4 880.6 1071 overland to NMSB_W 844.8 844.8 1073 overland to NMSB_W 844.8 842.8 1075 844p 860.2 860.2 1077 overland to NMSB_W 845.0 844.9 1078 846p 856.5 856.9 1080 848p 883.3 880.0 1081 849p 883.9 879.8 1083 851P 882.6 879.2 1085 853p 879.6 879.2 1092 859p 958.2 957.9 1093 860p 942.2 939.7 1094 861p 930.4 930.3 1095 862p 901.8 901.7 1096 863 -886.3 886.0 1098 868p 878.8 street 874.5 1100 866p 895.2 895.2 1101 867p 881.4 878.6 PAMpbN23 MNt2T23271072 Edim Water Resources Mgmt Plan UpdaIc\WorkFilestQAQC Model for PondWimMll. a _SWMM_hydmulic_mtpm_2006UPDATE_f al_NWI, -, riri©limn is NMSB Node Resulu UPDATE Table 9.3 Hydraulic Modeling Results for XPSWMM Subwatersheds /Nodes in the Nine Mile South Fork (Revised 12/2006). Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft) Type of Storage' NWL (ft) Flood Bounce (f) Flood Elevation (ft) NWL (ft) Flood Bounce (ft) 1102 869p 878.2 874.2 1103 870p 877.1 873.6 1104 871p 875.2 1 872.3 1105 872p 870.3 869.4 1106 873p 869.6 868.6 1109 876p 863.7 860.9 1111 overland to NMSB_85 847.2 845.3 1256 992p 883.7 883.7 1257 993p 871.7 870.8 1260 995p 844.3 844.2 1261 3254p 844.2 844.1 1593 1274p 889.2 888.1 1644 1354p 875.6 875.3 1651 1360p 884.9 884.7 1654 1608p 890.6 889.7 1656 1363p 894.5 894.4 1872 1516p 840.5 837.9 1879 1520p 869.8 864.1 1880 1521p 888.7 888.4 1881 1522p 918.4 918.7 1883 1607p 854.7 854.4 1885 1524p 856.0 855.7 1886 1606p 856.7 856.5 1932 1618p 883.9 883.4 2076 to Braemar Branch 869.7 869.1 2078 to Braemar Branch 854.7 852.7 2081 1650p 853A 853.7 2082 to Braemar Branch 852.0 851.2 2204 1755p 864.9 864.1 2205 1756p 865.4 864.4 2209 1759p 844.9 844.1 2242 1790p 857.8 852.2 2244 1791p 860.1 856.6 2246 1794p 876.0 874.7 2247 1795p 877.3 876.4 2344 to Braemar Branch 857.0 853.9 2400 1945p 888.2 892.7 2401 1946p 885.5 885.1 2402 2541p 880.0 879.6 2405 2106p 869.0 867.9 2407 2108p 870.6 870.6 2409 2105p 868.9 870.0 2437 1978p 889.6 886.3 2571 2115p 886.4 885.3 2596 2102p 871.3 870.3 2599 outfall to T.H. 169 886.2 886.2 2601 outfall to T.H. 169 883.7 883.6 2603 2086p 885.8 883.1 2604 2098p 886.4 883.9 2605 2095p 886.7 884.1 2613 outfall to Creek 832.9 829.8 2619 2123p 841.8 838.1 2622 2125p 843.9 841.3 2628 ditch 843.2 841.6 2633 outfall to Creek 832.9 827.2 2637 2085p 886.6 884.4 2640 overland to AH_25 893.8 893.7 2641 2091 p 888.2 885.0 2643 2088p 884.2 881.6 2644 2096p 887.0 882.3 2646 ditch west of T.H. 169 866.3 864.1 2647 2107p 868.3 867.4 2648 ditch west of T.H. 169 866.8 865.1 2649 2109p 869.6 870.8 2650 ditch west of T.H. 169 866.9 866.4 2652 ditch west of T.H. 169 877.8 877.7 2653 2111 882.7 882.9 2655 2113 886.9 887.8 P:\Mpb\23 MN\27\23271072 Edina Wafer Resources Mgmt Plan Update \WorkFiIm\QAQC Model fm PondWincMlte_SWMM hydmulic output 2006UPDATE _fmal_NWL_vaificmion.xls NMSB Nodc Rauhs UPDATE Table 9.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in the Nine Mile South Fork (Revised 12/2006). Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft) Type of Storage' NWL (ft) Flood Bounce (ft) Flood Elevation (ft) NWL (ft) Flood Bounce (ft) 2656 2114p 886.0 887.5 2657 ditch west of T.H. 169 884.1 883.9 2659 2117p 868.7 1 868.7 2660 2118p 867.1 hwy ditch 863.1 4.0 867.3 863.1 4.1 2661 ditch west of T.H. 169 866.1 862.9 2673 2521p 882.1 881.0 2676 2524 875.8 876.0 2677 2525p 872.9 873.4 2679 2527p 878.5 878.7 2694 2621p 845.1 844.5 2695 2622p 846.3 845.4 2704 ditch west of T.H. 169 889.1 888.3 2727 2183p 872.6 870.8 2728 2180p 872.7 872.5 2729 2182p 873.0 873.0 2730 2181p 874.3 874.3 2731 2540p 866.8 866.2 2733 2244p 841.1 838.0 2868 3189p 886.8 885.6 2869 3188p 886.8 885.6 2870 3186p 886.9 885.6 2871 3187p 887.0 885.7 2874 3251p 844.1 844.0 2875 3253p 844.0 843.9 2947 3287p 887.0 884.3 2951 outfatl to Creek 833.1 833.2 AH I landlocked 878.3 lake 875.8 2.5 876.4 875.8 0.6 A11_3 3191_p 887.1 hwy ditch 881.2 5.9 885.7 881.2 4.6 AF L4 2087p 888.2 pond 885.5 2.7 886.6 885.5 1.1 AH_5 408p 881.8 street 879.1 AH 6 404p 884.3 pond 880.0 4.3 882.1 880.0 2.1 AH 7 2119p 888.7 hwy ditch 884.4 4.2 888.0 884.4 3.5 AH 8 41 1p 886.1 884.9 AH_9 1365p 888.9 parking lot 885.5 3.4 888.2 885.5 2.7 BA-1 2049p 877.7 876.5 BA-2 2033p 893.9 888.2 BA_3 1793p 872.7 866.3 BA-6 3289p 851.4 pond 846.0 5.4 847.2 846.0 1.2 EP -1 2190p 872.7 ponds 865.4 7.4 871.1 865.4 5.7 ER -2 2155p 890.6 ponds 886.0 4.6 887.1 886.0 1.1 M-1 landlocked 864.6 lake 862.7 1.9 863.2 862.7 0.5 Hi_3 360p 872.5 depression 863.9 8.6 869.1 863.9 5.2 IH 5 367p 874.9 871.1 iH_6 363p 874.9 street 873.5 Ri_7 369p 874.8 street 874.7 IH_8 1355p 893.9 893.7 PA_I 2100p 868.0 pond 864.0 4.0 863.6 862.0 1.6 PA-2 landlocked 887.0 b d 881.3 5.7 884.7 881.3 3.4 PA-3 396p 877.4 street 871.8 PA-4 388p 873.1 869.0 PA_5 392p 891.9 891.9 PA-6 381p 877.0 pond 872.5 4.5 874.3 872.5 1.8 PA_7 391p 879.8 depression 874.5 5.3 877.4 874.5 2.9 PA -8 386p 877.9 871.6 PA_9 landlocked 888.9 depression 885.0 3.9 886.5 885.0 1.5 AH_10 401p 953.5 952.0 AH_II 417p 887.5 887.2 AH 12 3288p 887.0 6 d 884.1 2.9 885.2 884.1 1.1 AH 13 412p 887.9 school yard 885.7 2.2 887.4 885.7 1.7 AH 15 415p 887.6 887.3 AH 16 1272p 884.2 882.1 AH 17 1364p 899.3 899.2 AH I8 2090p 891.4 891.1 AH 19 1362p 885.2 885.0 AK -20 1361p 885.3 885.1 AH 21 400p 884.6 880.8 AM -22 1359p 882.2 881.9 AH 23 1275p 890.0 888.4 PAMpls\23 MN\27\23271072 Edina Water Resources Mgm1 Plan Update \WorkFitc \QAQC Model for PondVJi=MlLe_SWMM hydraulic output 2006UPDATE _rinal_NWL_vmifimlion.xls NMSB Node Results UPDATE Table 9.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in the Nine Mile South Fork (Revised 12/2006). Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft) Type of Storage' NWL (ft) Flood Bounce (ft) Flood Elevation (ft) NWL (ft) Flood Boone (ft) AH_24 1273p 891.1 889.7 AH_25 2097p 887.0 hwy ditch 878.7 8.3 884.3 878.7 5.6 AH_26 2094p 905.0 905.1 AH_27 landlocked 894.5 b d 893.5 1.0 894.3 893.5 0.8 AH_28 2093p 886.7 hwy ditch 881.6 5.1 884.8 881.6 3.2 AH_29 2098p 887.2 hwy ditch 884.0 3.2 885.2 884.0 1.2 AH_30 1977p 905.2 street 898.8 AH_31 2139p 883.4 b d 875.8 7.6 880.9 875.8 5.1 AH_32 2104p 886.6 hwy ditch 880.7 5.9 884.2 880.7 3.6 AH_33 3190p 886.8 885.5 IH_IO 1944p 892.3 892.4 IH_11 373p 874.2 873.9 1H_12 1353p 880.3 880.1 1H_13 362p 880.2 879.1 Hi-14 2501 p 874.9 pond 869.8 5.0 871.9 869.8 2.0 IH_15 1357p 923.5 920.2 PA 10 380p 894.5 894.5 PA_ll landlocked 884.0 b d 879.4 1 4.6 882.3 879.4 2.9 PA_12 383p 879.5 street 874.6 PA_13 landlocked 890.1 b d 887.8 2.3 889.3 887.8 1.5 NMSB-2 2131p 843.7 pond 840.2 3.5 843.0 841.7 1.3 NMSB-3 2130p 844.9 pond 840.2 4.7 844.1 841.7 2.4 NMSB-4 Braemar Branch 850.0 848.1 NMSB _5 2531p 840.9 pond 835.6 5.3 838.1 835.6 2.5 NMSB-6 2120p 841.9 pond 835.6 6.3 841.2 835.6 5.6 NMSB-7 2536p 842.4 pond 836.3 6.1 839.3 836.3 3.0 NMSB _8 overland to NMSB 90 844.9 pond 842.4 2.5 843.6 842.4 1.2 NMSB-10 1515p 840.0 837.8 NMSB_I 1 1519P 842.3 841.8 NMSB_12 2133p 832.9 pond 826.9 6.0 827.8 826.0 1.8 NMSB-13 875p 869.1 street 862.9 NMSB-14 877p 856.1 858.1 NMSB-15 994p 844.7 b d 841.8 2.9 842.6 841.8 0.8 NMSB-16 3291p 844.5 NMSB-17 3255p 844.4 NMSB 18 864p 880.3 876.3 NMSB-19 1557p 903.3 901.1 NMSB 20 2620p 848.1 depression 843.5 4.5 846.3 843.5 2.7 NMSB 21 865p 943.3 943.2 NMSB-22 1652p 881.0 street 876.4 NMSB_23 850p 884.6 street 879.7 NMSB-24 2529p 876.8 hwy ditch 875.0 1.8 875.7 875.0 0.7 NMSB-25 1523p 929.4 929.6 NMSB_26 854p 878.8 870.0 8.8 871.4 870.0 1.5 NMSB-27 852p 880.7 b d 871.2 9.5 878.9 871.2 7.8 NMSB_28 855p 875.4 869.4 NMSB_29 856p 872.6 867.9 NMSB-30 874p 869.6 street 868.7 NMSB 31 857p 866.2 865.1 NMSB 32 843p 862.1 862.0 NMSB 33 27 (inlettoutlet) 844.9 pond 840.2 4.7 844.1 841.7 2.4 NMSB-34 847p 873.2 b d 866.9 6.3 869.0 866.9 2.1 NMSB_35 2522p 883.6 street 881.9 NMSB 36 842p 849.0 848.3 NMSB_37 845p 858.2 street 858.1 NMSB 38 858p 977.4 977.3 NMSB 39 832p 853.9 856.4 NMSB-40 841p 846.9 847.0 NMSB-41 2124p 843.5 depression 838.0 5.5 842.8 838.0 4.8 NMSB 42 831p 854.6 850.8 NMSB 43 1525p 856.8 856.7 NMSB _44 1517p 841.8 838.1 NMSB 45 1528p 847.7 depression 840.2 7.5 847.2 840.0 7.2 NMSB 46 1647p 858.6 hwy ditch 854.1 4.6 863.9 854.1 9.8 NMSB 47 1514p 840.6 838.1 NMSB 49 1646 870.5 871.9 NMSB-50 164 864.0 h ditch 862.8 1.2 863.9 1 862.8 1.1 NMSB 51 2526p 876.7 1 877.0 P:XMplst23 MNt27123271072 Edina Water Resource Mgmt Plan Update %WorkFilm\QAQC Model for PondWineMlLi�_ SWMM hydraulic output 2006UPDATE _rmat_NWf_vuirwion.als NMSB Node Raulm UPDATE bi Table 9.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in the Nine Mile South Fork (Revised 12/2006). Subwatershed or Node' Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft) Type of Storage' NWL (ft) Flood Bounce (ft) Flood Elevation (ft) NWL (fl) Flood Bounce (fl) ' NMSB-52 1883p 858.2 854.2 NMSB-56 21320 839.5 831.4 NMSB 57 2137p 839.3 pond 835.6 3.7 837.8 835.6 1 2.2 NMSB 58 991P 897.3 897.1 NMSB-59 landlocked 866.3 b d 859.4 6.9 864.7` 859.4 5.3 NMSB 61 261 1p 884.3 884.2 NMSB-62 2502p 840.9 hwy ditch 835.6 5.3 837.9. 835.6 2.3 NMSB-63 2530p 870.2 hw 'ditch 865.0 5.3 869.5 865.0 4.5 , NMSB-64 1965p 864.3 hwy ditch 857.2 7.0 866.2 857.2 9.0 NMSB, 65. 1963p: 862.7 hwy ditch 855.7 7.0 865.5 ' -855.7 9.8 NMSB 66 816p 868.0 867.8 NMSB,67, ' 810p 910.9 street 905.2 NMSB 68. 2610. ,886.4 886.5 NMSB 69 Braemar Branch 860.0, 855.5 NMSB-,70 821p 864.5 b d 857.3 7.2 863.8 857.3 6.5 NMSB'711 " 1753p 863.1 863.0 NMSB 72 820p, 864.3 864.2 NMSB 73 2122p 866.1 ditch 856.0 10.1 859.7 856.0 3.7 NMSB-74 1751p 861.6 857.6 NMSB-75 817P 872.6 street 868.6 NMSB'76 1752p 863.0 862.1 NMSB-77 Braemar Branch 860.6 ditch 857.6 NMSB 78 809P 863.9 864.1 NMSB 79 2134p 867.1 866.2 NMSB-80 2523p 877.3 877.5 NMSB-81 1964p 863.2 865.7 NMSB-82 838p 880.3 ditch 875.0 5.3 8795 875.0 1 4.5 NMSB-83 826p 863.6 street 860.9 NMSB-94 830p 863.6 street 860.9 NMSB-85 2121p 842.2 pond 836.3 5.9 8385 836.0 2.5 NMSB 86 2136 833.5 pond 828.4 5.1 833.0 828.4 4.6 NMSB 87 1757p 866.7 ditch 863.0 3.7 .865.8 863.0 2.8 NMSB 88 2528p 879.8 880.1 NMSB_W 2720p 844.9 wetland 839.0 5.9 842.6 839.0 3.5 NMSB-91 1949p 869.6 865.7 3.9' 868.4 865.7 2.7 NMSB 92 394p 869.0 868.3 NMSB 93 2110p 882.9 883.0 NMSB 94 2116p 872.0 871.9 NMSB 95 1951p 871.2 871.1 NMSB-96 1950p 871.4 870.6 NMSB 97 1952p 871.5 871.1 NMSB-98 2112 894.5 894.4 NMSB 99 2103p 871.4 depression 1 867.7 1 3.7 870.1 867.7 1 2.3 1 byd = backyard depression r. P:VApls\23 MN\27\23271072 Edina Water Reso- Mgml Plan Updalc \WmkFilcs\QAQC Model for PmchNi =Mn.e_SWMM_hydraulic_oulput- 2006UPDATE_final_NW L verifimlionaLs NMSB Node Raulls UPDATE Table 9.4 Conduit Modeling Results for Subwatersheds In the Nine Mile South Fork Drainage Basin (Revised 1212006). Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimension (R) Roughness Coefficient Upstream Invert Elevation (ft) Downstream Invert Elevation (ft) Conduit Length (ft) Slope IOOY Peak flow through Conduit (cfs) l0Y Peak Flow through Conduit (cfs) 365p 513 514 Circular 1.25 0.024 869.11 868.79 47 0.68 3.7 -3.2 367p IH 5 516 Circular 2 0.024 868.21 864.18 29.5 13.66 24.6 19.0 368p 516 ilt_1 Circular 2 0.024 864.18 863 167.7 1 0.70 24.6 19.0 373p IILI1 523 Circular 1.75 0.013 872.89 868.23 166.2 2.80 21.8 16.9 374p 523 IH_I Circular 2 0.024 868.23 863.04 100 5.19 21.8 16.9 380p PA_10 PA-6 Circular 1 0.024 887.5 876.42 166 6.67 6.2 2.5 381 PA-6 534 Circular 1 0.013 872.5 872.23 139 0.19 5.3 3.1 382p 534 PA-12 Circular 1.25 0.013 871.23 870.84 28 1.39 5.3 3.2 383 PA-12 536 Circular 1.5 0.013 870.84 870.75 22 0.41 10.1 10.6 394p 536 537 Circular 1.5 0.013 870.75 870.01 164.2 0.45 10.8 8.6 385p 537 PA-8 Circular 1.5 0.013 870.01 869.09 230 0.40 10.8 8.7 386 PA_8 539 Circular 1.75 0.013 869.09 868.48 146.8 0.42 22.4 16.1 387p 539 PA_4 Circular 1.75 0.013 868.48 866.93 44 3.52 22.4 16.2 388 PA-4 541 Circular 1.75 0.013 866.93 863.61 116 2.86 29.1 20.2 390p 543 PA-12 Circular 1 0.013 872.33 871.34 99 1.00 6.2 5.8 391 PA-7 543 Circular 1.25 0.013 1 874.5 873.5 99 1.01 -7.6 4.7 393p 546 NMSB 92 Circular 1.5 0.013 1 866.57 866.38 48 0.40 -5.6 -3.0 394p NMSB_92 548 Circular 1.5 0.013 866.38 865.96 118 0.36 -4.6 -1.9 395p 549 546 Circular 1.5 0.013 866.98 866.57 115 0.36 -5.6 -3.0 397p 552 553 Circular 1.25 0.024 884.32 883.52 67 1.19 0.0 0.0 398p 553 AH_I Circular 1.25 0.024 883.52 874.83 94 9.24 0.0 0.0 400 AK-21 AFl_I Circular 1.5 0.024 877.91 874.83 47.3 6.51 20.3 15.1 401 AH_IO 560 Circular 1 0.013 951.3 949.2 48 4.38 9.1 5.9 402p 560 561 Circular 1 0.024 945.7 873.43 1 245.5 29.44 9.1 5.9 403p 561 AR-1 Circular 2 0.013 871.54 871.5 20 0.20 9.1 5.9 404p AFL6 564 Circular 1.75 0.013 880 879.64 62 0.58 12.1 11.7 405p 564 565 Circular 1.75 0.013 879.64 877.78 304 0.61 12.1 11.7 406p 565 566 Circular 1.75 0.013 877.78 876.28 250 0.60 15.9 14.4 407p 566 AIL Circular 1.75 0.013 876.28 874.69 272 0.58 15.9 14.4 409p 570 AH_5 Circular 2.5 0.013 872.96 872.63 31 1.06 40.2 35.5 411p AH_8 AH_6 Circular 2.5 0.024 879.42 877.74 156 1.08 30.0 32.6 412 AH_13 575 Circular 1.5 0.024 885.66 884.77 115 0.77 5.7 6.3 413p 575 576 Circular 1.5 0.013 884.77 1 883.94 160 0.52 5.8 6.6 414p 576 AI L15 Circular 1.5 0.013 883.94 883.48 90 0.51 5.8 6.8 415 AH_15 578 Circular 1.5 0.013 883.29 882.95 19 1.79 6.4 7.4 416p 578 AFl_11 Circular 15 0.013 882.95 882.2 28.5 2.63 6.6 7.5 417 AH_11 580 Circular 15 0.013 882.2 882.2 14.5 0.00 15.8 16.2 418p 580 581 Circular 2 0.024 879.02 879.11 104 -0.09 15.8 16.2 419p 581 AI-1_6 Circular 2 0.024 879.11 879 147 1 0.07 15.8 16.2 809p NMSB_78 1032 Circular 1.25 0.024 860.7 856.2 182 2.47 4.7 6.7 810p NMSB_67 1034 Circular 1 0.013 902.96 886.43 184 8.98 11.9 10.4 817p NMSB_75 1042 Circular 1 0.013 867.38 863.24 207 2.00 5.8 3.6 818p 1042 1043 Circular 1 0.013 863.14 858.82 216 2.00 3.9 3.6 821p NMSB 70 1045 Circular 1 0.013 857.3 856.34 180 0.53 3.7 4.1 828p 1052 1053 Circular 1 0.013 855.46 855.02 41.7 1.06 4.9 5.6 832p NMSB_39 1059 Circular 3 0.013 851 850.44 70 0.80 30.1 22.0 833 1060 NMSB_39 Circular 1.75 0.013 851.23 851 24 0.96 IS.0 7.8 834 1061 1060 Circular 1.75 0.013 851.58 851.23 36 0.97 15.0 7.6 835 1062 1061 Circular 1.25 0.013 863.9 851.58 220 5.60 15.0 6.0 PAMpls\23 MN\27\23271072 Edina Water Resources Mgt Plan Update \WorkFilu\QAQC Model for Pond\NineMa c_SWMM-hydnulic_output 2006 UPDATE -FLnaLNWL-verifimtim.xta NMSB_CondWiRmulu UPDATE Table 9.4 Conduit Modeling Results for Subwatersheds In the Nine Mile South Fork Drainage Basin (Revised 12/2666). Conduit ID - Upstream Node Downstream Node Conduit Shape Conduit Dimensions* (ft) Roughness Coefficient Upstream Invert Elevation (ft) Downstream Invert Elevation (ft) Conduit Length (ft) Slope IOOY Peak Flow through Conduit (cfs) IOY Peak Flow through Conduit (cfs) 836p 1063 1062 Circular l 0.013 873.52 863.9 78'. 12.33 13.4 5.9 840p 1068 NMSB_82 Circular 1 0.013 879.34- 879 36" 0.94 4.7 3.5 843p NMSB 32 1075 Circular 1,25 0.013 856.45 855.26 73 1.63 11.6 11.7 845p NMSB_37 1078 Circular 1.75 0.013 851.93 851.21 77.7 0.93 19.0 15.7 946p 1078 1077 Circular 2 0.024 851.21 844.47 123 5.48 10 15.7 847p NMSB 34 1080 Circular 1.25 0.013 881.16 877 128 3.25 -4.9 0.0 848p 1080 1081 Circular 1.25 0.013 877 876.83 103 0.17. 4.8 -3.7 849p 1081 NMSB 23 Circular 1.75 0.013 876.83 875.96 274 0.32 13.8 -4.6 850p NMSB 23 1083 Circular 2 0.013 875.96 873.53 118.8 2.05 26.2 13.7 851P 1083 NMSB 27 Circular 2 0.013 873.53 871.16 185 1.28 1 26.2 13.7 852p NMSB 27 1085 Circular 2.5 0.013 871.16 870.44 140 0.51 15.3 11.1 854p NMSB 26 NMSB 28 Crcular 3 0.013 869.95 867.36 423 0.61 56.7 25.7 855p NMSB28 NMSB29 Circular 3 0.013 867.36 866.46 273 0.33 64.1 29.0 856p NMSB29 NMSB_31 Circular 3 0.013 866.46 859.44 431 1.63 73.2 34.5 858p NMSB 38 1092 Circular 1 0.013 976.85 961.03 120 13.18 5.9 3.2 859P 1092 1093 Circular 1 0.024 957.52 937.5 110 18.20. 5.9 4.1 861p 1094_ 1095 Circular 1.25 0.013 930 902 .134.1 20.88 5.8 3.2 862p 1095 1096 Circular 1.25 0.013 901.25 888.07 160 8.24 5.8 3.1 863p 1096 NMSB_18 Circular 1 0.013 885.56 875.86 147 6.60 5.8 3.2 864p NMSB_18 1098 Circular 1.5 0.013 875.86 872.11 29 12.93 15.8 6.5 865p NMSB_21 1100 Circular 1 0.013 942.96 894.77 128 37.65 4.9 2.3 866p 1100 1101 Circular 1 0.013 894.77 878.25 91 18.15 4.9 2.6 867p 1101 1098 Circular 1 0.013 878.25 872.11 137 4.48: 4.9 2.6 868p 1098 1102 Circular 2.5 0.013. 872.11 872.02 27.3 • 0.33 37.8 253 969p 1102 1103 Circular 2.5 0.013 872.02 871.62 97 0.41 37.8 25.4 870p, 1103 1104 _ Circular: 2.5 0.013 871.62 870.85 175 0.44 37.8 25.4 871p 1104 1105 Circular - 2.25 0.013- 870.85 865.47 289.7 1.86 37.8 25.2 875. NMSB_13 1109 Circular 3 0.013 857.38 854.91 225 1.10 95.2 59.8 876p 1109 NMSB_14 Circular 3 0.013 854.91 851.5 310 1.10 95.2 59.9 977p NMSB_14 1111 Circular 3 0.013 851.5 843.96 260 2.90 97.4 70.9 992p 1256 1257 Circular 1 0.013 880.06 865.29 158 9.35 9.7 10.0 993p 1257 NMSB_59 Circular l 0.013 865.29 860.17 73 7.01 9.6 10.0 994p NMSB_15 1260 Circular l 0.024 842.78 842.17 152.7 0.40 0.9 0.0 1272 AH_16 AH_6 Circular -2 0.024 878.48 877.92 156 0.36 -7.7 3.9 1273 AH_24 1593 Circular 1.5 0.013 888.1 886.68 164 0.87 10.5 9.1 1274p 1593 A]-L4 Circular 1.5 0.013 886.68 885.7 69.5 1.41 10.5 9.1 1353 IH_12 1644 Circular 1 0.013 873.83 873.21 33.2 1.87. 10.1 10.1 1354p 1644 •111_11 Circular 1.75 0.013 873.03 872.89 32 0.44 10.2 10.1 1356p 1647 IH_8 Circular 1 0.013 889.42 886.96 24.7 9.96 1.7 -2.1 1362 AH_19 1651 'Circular 1.25 .0.013 879 878.21 .85. 0.93 7.8 8.4 1364 AH_17 1656 Circular 1 0.013 893.4 888.46 .61.5 .8.03 9.7 .9.9. 1365 AH_9 565 Circular 1.25 0.013 885.5 884.9 62 '" 0.97 10.8 9.6 15140 NMSB_47 NMSB_57' " Arch 38 "x57" 0.024 836.3 835.5 40 2.00 80.1 38.2. 1515p NMSB_10 NMSB 57 .. Circular 1 . 0.024 836.35 836.11 27 0.89 - 2.7 0.8 1516 1872 NMSB 10 Circular 1 0.024 836.76 836.35 29 1.41 2.7 0.8 1517 NMSB•44 NMSB 5 Circular 1 0.024 835.32 834.52 32 2.50 4.6 3.7 1521 .1880'. 1879' Circular 1 0.024 887.98 860 131 21.36 - 6.6 5.8 1522 1881' 1880 CircuLv - I 0.024 917.88 887.98 77.8 38.43 6.6 5.5 1523 NMSB 25 1881 Circular 1 0.013 927.28 923 109.5 3.91 6.6 5.3 PAMp1st23 MNt27t23271072 Edina Wata Rao NIS= Plan Update WorkFila\QAQC Model for Pond\N ineMUA-$ WMM_ hydmuhc_ outpue_ 2006UPDATBfuud- NWI._verifiatim.xls NMSB ConduitRaulu UPDATE Table 9.4 Conduit Modeling Results for Subwatersheds In the Nine Mile South Fork Drainage Basin (Revised 12/2006). Conduit [D Upstream Node Downstream Node Conduit Shape Conduit Dimensions' (ft) Roughness Coefficient Upstream invert Elevation (ft) Downstream Invert Elevation (ft) Conduit Length (ft) Slope IOOY Peak Flow through Conduit (cfs) IOY Peak Flow through Conduit (cfs) 1646p NMSB 49 2076 Circular 1 0.013 869.11 869.01 64 0.16 2.8 3.2 1647p NMSB_46 2078 Circular 2 0.013 854.06 852.28 106 1.68 33.8 20.8 1649p NMSB_50 2081 Circular 2 0.013 862.77 850.58 154 7.92 39.5 40.4 1650p 2081 2082 Circular 3 0.013 850.58 850.5 10 0.80 39.5 40.3 1751p NMSB_74 2194 Circular 2.5 0.013 856.13 856.09 42 0.10 14.4 4.4 1752p NMSB_76 2196 Circular 2.25 0.013 856.1 855.89 23.9 0.88 49.3 52.1 1755p 2204 NMSB_71 Circular 2.25 0.013 859.12 856.46 304 0.88 21.1 23.4 1756p 2205 2204 Circular 2 0.013 860 859.12 12.5 7.04 18.2 23.1 1757p NMSB37 2205 Circular 2 0.024 863 860 75 4.00 18.2 23.1 1793 BA-3 2244 Circular 2.25 0.013 865.14 852.74 200.5 6.18 70.8 41.9 1794p 2246 BA-3 Circular 2.25 0.013 871.32 869.41 1 219.7 0.87 34.2 25.0 1944p iH_10 2400 Circular 2 0.013 891.51 887 30 15.03 29.3 14.7 1945p 2400 2401 Circular 2 0.013 887 884.53 35 7.06 29.3 14.6 1946p 2401 2402 Circular 2 0.013 884.53 878.98 50 11.10 29.3 14.6 1948p 548 NMSB 91 Circular 1.25 0.013 865.96 865.73 70 0.33 4.6 2.1 1949p NMSB_91 2405 Circular 1.75 0.013 865.73 865.46 31 0.87 18.0 14.0 1950p NMSB 96 2407 Circular 2 0.013 1 866.82 866.61 31 0.68 19.2 12.9 1951p NMSB_95 2409 Circular 1 0.013 866.86 865.79 31 3.45 9.7 8.6 1963p NMSB_65 NMSB 46 Circular 2 0.013 856.8 855.74 210 0.50 28.7 20.6 1964p NMSB_81 NMSB_65 Circular 2 0.013 856.8 855.74 18 5.89 23.5 21.1 1965p NMSB 64 NMSB31 Circular 2 0.013 857.22 856.8 100 0.42 20.8 18.5 1977 AH 30 2437 Circular 1.25 0.013 898.05 885.03 186 7.00 17.7 11.1 1978p 2437 AH_3 Circular 1.5 0.013 882.82 882.75 31 0.23 17.7 10.4 2033 BA-2 2247 Circular 1.25 0.013 887.5 870 333.7 5.24 13.8 9.3 204 BA_1 2247 Circular 2.25 0.013 874.9 870 53.6 9.14 20.5 16.0 2085p 2637 AH_32 Circular 1.5 0.013 880.95 880.7 23 1.09 6.9 10.3 2086p 2603 571 1 Circular 2.5 0.013 876 873.45 110 2.32 33.8 31.6 2087p AI L4 2644 Circular 1 0.013 883.41 885.5 18 -11.61 4.0 3.1 2088p 2643 AH_31 Circular 2.5 0.013 873.4 873.05 74 0.47 37.6 34.4 209 AH_18 2641 Circular 1.25 0.013 890.59 883.17 56.2 13.20 10.4 7.2 2092p 571 2643 Circular 2.5 0.013 873.45 873.4 25 0.20 33.8 31.6 2093 AH_28 2637 Circular 1.5 0.024 881.59 881.59 30 0.00 6.9 10.3 2094 AH 26 2640 Circular 2 0.013 898.13 893.39 27 17.56 18.8 10.5 2095p 2605 2604 Circular 2.5 0.013 877.5 876.32 177 0.67 19.9 23.9 2096p, 2644 2643 Circular 1.25 0.013 882 881.55 15 3.00 5.3 4.1 2097 AH 25 2605 Circular 2.5 0.013 878.67 877.5 145 0.81 19.9 31.2 2098 AR-29 2603 Circular 2.5 0.013 876.32 876 148 0.22 32.4 30.6 2100p PA-1 549 Circular 1.5 0.013 867 866.96 10 0.40 -3.5 -3.5 2102p 2596 NMSB 97 Circular 1 0.013 867.94 867.56 36 1.06 5.3 -5.4 2103p NMSB 99 2596 Circular 1 0.013 867.73 867.94 20 -1.05 5.3 -5.4 2104 AH_32 2604 Circular 2 0.013 880.68 880 300 0.23 16.4 12.2 2105p 2409 2646 Circular 1.25 0.013 865.79 863.35 118 2.07 9.7 9.3 2106p 2405 2647 Circular 1.75 0.013 865.46 865.09 49 0.76 18.0 14.0 2107p 2647 2648 Circular 1.75 0.013 865.09 864.43 69 0.96 18.0 15.2 2108p 2407 2649 Circular 2 0.013 866.61 866.4 49 0.43 19.2 12.9 2109p 2649 2650 Circular 2 0.013 866.4 865.95 68 0.66 19.2 12.9 21 10p NMSB 93 2653 Circular l 0.013 879.36 878.84 34 1.53 3.7 2.4 2111 2653 2652 Circular 1 O.Ol3 878.84 877.59 120 1.04 3.7 2.4 2112 NMSB_98 2655 Circular 1 0.013 894.17 886.07 43 1 18.84 4.0 2.4 PAMpls\23 MM27\23271072 Edina Water Resources Mgrat Plan Updzte\WorkFil a\QAQC Model for PoudWi=MDt SWNBUydraulic_output 2006UPDATF fmaL NWL voifi ti=xls NMS11_Conduitl1mulr UPDATE e Table 9.4 Conduit Modeling Results for Subwatersheds In the Nine Mile South Fork Drainage Basin (Revised 12/2006). Conduit ID Upstream Node Downstream Node. Conduit Shape Conduit Dimensions « (ft) Roughness. Coefficient Upstream Invert Elevation (ft) Downstream Invert Elevation (ft) Conduit Length (ft) Slope IOOY Peak Flow through Conduit (cfs) :IOY Peak Flow through Conduit (cfs) . 2113p 2655 2656 Circular 1 0.013 886.07 884.28 57 3.14 4.0 - 2.4 2115p 2571 AH_8 Circular 2.5 0.013 880.18 880.52 28 -1.21 27.4 29.8 2116p NMSB-94 2659 Circular 1 0.013 867.68 864.77 82 3.55 1 7.8 7.4 2117p 2659 2660 Circular l 0.013 864.77 863.11 49 3.39 7.8 7.6 2118p 2660 2661 Circular' 1.25 0.013 863.11 862.2 70 1.30 7.8 8.2 211 AH 7 AH_25 Circular 2 0.024 884.42. 883.6 412 0.20 11.1 8.2 2121p NMSB-85 NMSB_47 Arch 38 "x57" 0.024 836 836.3 100 0.30 76.6 35,0 2122p NMSB 73 2663 Arch 72" eq 0.013 856.03 855.42 200 0.31 346.1 .127.4 2124p NMSB 41 NMSB I1 Circular 1 0.013 838 837.09 85 1.07 4.9 4.8 2125p 2622, NMSB 7 7Circular 2 0.013 837.93 836.3 240 0.68 20.2 20.2 '2133 NMSB-12 2633 Circular 4 0.024 825.87 825.56 26 1.19 61.2 18.1 2136p NMSB 86 NMSB -1 Circular 2.5 0.024 828.4 828.3 250 0.04 , 20.1 19.2 2139p AH_31 570 Circular 2.5 0.013 873.05 872.96 132.5 0.07 1 40.2 35.5 2155 EP-2 2704. Circular 1.5 0.024 888.59 888.33 20 1.30 8.3 0.0 218Qp 2728 2727 Circular 1.25 0.013 872.52 870.77 175 1.00 -0.4 OA 2183p 2727 BA_3 Circular 1.5 0.013 870.77 870.48 29 1.00 2.1 0.0 2501 11­1_14 513 Circular 1 0.024 869.83 869.11 89.5 0.80 3.7 -3.2 2502p NMSB-62 1872 Circular 1 0.024 837 836.76 17 1.41 2.7 0.8 2521 p 2673 1068 Circular 1 0.013 879.58 879.34 30 0.80 4.7 3.5 2522p NMSB-35, 2673 Circular 1 0.013 879.96 879.58 48 039 4.7 -3.5 2523p NMSB_80 2676 Circular 1 0.013 876.88 876.04 28 3.00 2.4 4.0 2524p 2676 2677 Circular 2 0.013 875.43 872.44 189 1.58 2.4 4.3 2525p 2677 NMSB 63 Circular 3 0.013 870.8 870.33 65 0.72 27.5 34.0 2526p NMSB 51 2677 Circular 2 0.013 875.39 870.8 100 4.59 25.1 30.5 2527p 2679 NMSB _51 Circular 2 0.013 877.69 875.39 175 1.31 8.7 12.3 2528p NMSB 88 2679 Circular 2 0.013 878.81 877.71 64 1.72 8.7 12.3 2529p NMSB_24 NMSB_W. Circular- 1.5 0.013 875 861.08 177 7.86 9.0 16.2 2530p NMSB-63 NMSB-50 Circular 2 0.013 864.95 1 863.69 178 0.71 30.6 2815 2540p 2731 IH_1 - Circular 3 0.024 865 861.7 160 2.06 29.3 .14.6 2541p 2402 .2731 Circular 2 0.013 878.98 865 190 7.36 29.3. 14.6 2610p NMSB_68 2599 Circular 2 0.013 884.78 884.51 16.00 1.7 21.7 22.5 261 Ip NMSB 61 2601 Circular 1.5 0.013 883.01 882.47 65.00 0.8 10.2 9.2 262Dp NMSB-20 2695 Circular '. 1.25 0.013 843.52 843.32 40 0.50 10.7 8.4 2622p 2695 2694 ' Circular 1.25 0.013 843.32 843:14 36 0.50 10.7 8.4 2702p NMSB_85 2619 Circular ' 1 0.013 836.6 836.07 21 2.52 4.1 3.6 2720p NMSB_90 2622 Circular 2 0.013 839.02 837.93 160 0.68.- 20.2 20.2 3254p 1261 NMSB-17 -_ Circular 1 0.013 841.4 841.17 35 0.66 -2.5 -2.7 396 PA-3 PA-1 Circular 1.25 0.013 _ 867.8 863.37 177 2.50 14.8 13.1 816p NMSB-66 1040 Circular 1 0.013 862.37 860.97 235 0.60 5.5 5.5 2101 -2595 549 Circular - 0.66 0.010 867.5 867.5 - 5 0.00 0.6 0.6 2091p 2641 2603 ' :Circular 1 0.013 876.27 876 8 3.38 9.7 6.8 2123p 2619 Circular' 1 0.013 836.07 835.32. 30 2.50 4.1 3.6 1883p NMSB_52 - -NMSB-44 2344 Rectangular 6 0.012 852.1 851.9 108.3 0.18 420.2 219.4 1528p NMSB 45 .1893 Circular • 6 0.024 839.11 838.76 70 0.50 281.7 216.3 1759p 2209 `2210 Circular . 2 0.013 843.02 842.9 24 0.50 0.7 8.4 1795p 2247 2246 Circular 2.25 0.013 871 871.32 218.7 -0.15 30.6 25.1 2241_p - NMSB-85 2733 Circular_ 1 0.024 836.8 837.79 40 -2.48 3.0 0.9 2244 2733 NMSB 47 Cuciflar 1 0.013 837.79 836.3 39 3.82 '' 3.0 0.9 2532_p NMSB_l5 2687 -" Circular .: 1 0.008 841.8 837.75 270 1.50 8.4 6.5 P:N7pls\2.l MNI27\21271072 Edina Water Raomcea Mgmt Plan Upd=c W.AFdatQAQC Modd far PmdWineMILA- SWMhLh1'd aulic_ output_ 2006UPDATE _fmaLNWL�vaificmionatb NMSB_ConduitRauln UPDATE Table 9.4 Conduit Modeling Results for Subwatersheds in the Nine Mile South Fork Drainage Basin (Revised 12/2006). Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimensions* (ft) Roughness Coefficient Upstream Invert Elevation (ft) Downstream Inver Elevation Ele (ft) Conduit Length (ft) Slope IOOY Peak Flow through Conduit (cfs) IOY Peak Flow through Conduit (cfs) 3186p 2870 2869 Circular 3 0.013 881.06 881.01 35.1 0.14 21.1 26.8 3187p 2871 2870 Circular 3 0.013 881.13 881.06 92.8 0.08 21.1 30.1 3188_p 2869 2868 Circular 3 0.013 881.01 880.89 13.7 0.88 21.1 24.8 3189p 2868 AH_33 Circular 3 0.013 880.89 880.46 110.5 0.39 21.1 23.0 3190 AH_33 2571 Circular 2.5 0.013 880.46 880.18 40 0.70 27.4 29.8 3191p AH 3 2871 Circular 3 0.013 881.15 881.13 28.5 0.07 21.1 32.1 3287p 2947 Ali-25 Circular 1.5 0.024 882.6 881.59 87 1.16 3.6 4.6 3288p 2947 Circular I 0.013 884.1 882.6 106 1.42 3.7 4.6 3289 B.-6 2951 Circular 2 0.009 846 832 360 3.89 35.7 45.2 360p IH_3 II-I_1 Circular 1.5 0.024 863.85 862.85 312 1 0.32 9.3 6.4 362p Q%13 11-1_1 Circular 1.25 0.024 873.27 863 116.7 8.80 12.4 11.9 363p IH_6 1Ii_14 Circular 1 0.024 869.57 869.32 30.5 0.82 5.0 5.5 366p 514 H-lL5 Circular 1.5 0.024 868.79 868.21 107.2 0.54 10.5 10.5 369 11-1_7 514 Circular 1.5 0.024 870 868.79 34 3.56 12.6 13.1 370p 519 IH_7 Circular 1.5 0.024 880.89 870 184 5.92 14.7 15.6 371p 520 519 Circular 1.5 0.024 882.51 880.89 50 3.24 13.7 15.9 372p 521 520 Circular 1 0.013 885.41 882.51 110 2.64 7.9 7.9 389p 541 PA-1 Circular 1.75 0.013 863.61 863.26 9.5 3.68 26.7 20.2 392 PA-5 543 Circular 1 0.013 882.88 876.55 331 1.91 7.4 6.9 399p 555 AH_1 Circular 3 0.024 876.3 874.8 31.2 4.81 77.4 41.9 408p AH_5 AH_I Circular 2.5 0.013 872.63 872.3 213 0.15 51.0 38.8 811p 1034 1035 Circular 1 0.013 886.07 869.1 190 8.93 10.7 9.6 812p 1035 1036 Circular 1 0.013 868.6 863.48 132 3.88 8.2 8.2 813p 1036 1037 Circular I 0.013 863.48 862.74 54.5 1.36 3.8 3.8 814p 1037 1038 Circular 1 0.013 862.74 862.46 29 0.97 2.7 2.7 815p 1038 NMSB 66 Circular l 0.013 862.46 862.37 35.5 0.25 1 3.0 -2.9 819p 1043 NMSB_72 Circular l 0.013 858.82 858.52 28 1.07 1.9 -2.3 820p NMSB 72 1045 Circular 1.25 0.013 858.28 856.34 125 1.55 9.0 11.2 822p 1045 1047 Circular 1.25 0.013 856.34 854.59 135.3 1.29 8.8 9.1 823p 1047 1048 Circular 1.25 0.013 854.59 854.59 28.7 0.00 5.2 5.0 824p 1048 1049 Circular 1.25 0.013 854.59 854.35 22 1.09 6.0 4.6 825p 1049 NMSB_83 Circular 1.5 0.013 854.35 854.17 29.1 0.62 10.4 5.3 826p NMSB 83 1051 Circular 2 0.024 854.17 852.93 213 0.58 16.3 18.9 827p 1047 1052 Circular 1 0.013 854.59 855.46 24.7 -3.52 1 4.5 5.8 829p 1053 NMSB_84 Circular 1.5 0.013 855.02 853.94 91.2 1.18 4.9 5.6 830p NMSB 84 1055 Circular 2 0.024 853.94 853.29 168 0.39 17.5 20.4 831p NMSB 42 1057 Circular 2 0.024 848.5 846.7 50 3.60 32.7 20.6 837p 1064 1063 Circular 1 0.013 874.7 873.52 133 0.89 6.1 5.0 838p NMSB_82 1064 Circular 1 0.013 875 874.7 38.5 0.78 6.0 5.0 841 p NMSB 40 1071 Circular 1 0.013 844.91 844.26 31.2 2.08 4.7 4.4 842p NMSB 36 1073 Circular 1.5 0.024 842.52 842.34 20 0.90 21.0 10.0 844p 1075 NMSB 37 Circular 1.25 0.013 855.18 852.48 153 1.76 1 11.4 11.2 853p 1085 NMSB_26 Circular 1 0.013 871.77 871.5 5 5.40 19.7 13.5 857p NMSB 31 1090 Circular 1.5 0.013 859.44 840.39 132 14.43 36.2 43.1 860p 1093 1094 Circular 1 0.024 937 934.55 122.4 2.00 4.4 3.2 872p 1105 1106 Circular 2.25 0.013 865.47 862.82 100 2.65 29.0 25.2 873p 1106 NMSB_30 Circular 2 0.013 862.82 860.8 52 3.88 23.4 23.9 874p NMSB_30 NMSB_13 Circular 2.5 0.013 860.8 857.38 524 0.65 49.4 45.5 991 p NMSB 58 1256 Circular 1 0.013 894.1 880.06 109 12.88 11.6 11.6 P:\Mpls\23 MM27\23271072 Edim Water Resources Mgmt Plan Update \W"kFila\QAQC Model fm Pond \NineMQ.e -SWMMJrydrnulic_ouiput 2006UPDATEjma1_NWLverifiwtiou.xts NMSB ConduitR -1U UPDATE 6 Table 9.4 Conduit Modeling Results for Subwatersheds In the Nine Mile South Fork Drainage Basin (Revised 12/2006). Conduit ID Upstream Node 995p 1260 1275p AH_23 1355p IH_8 1357p IFLI5 135 AH_22 1360p 1651 1361 AH_20 1363p 1656 1519p NMSB_11 . 1520p 1879 1524p 1885 1525p NMSB_43 1557 NMSB 19 1606p 1886 1607p 1883 1608p 1654 1618p 1932 1652p NMSB22 1753p NMSB_71 1790p 2242 1791p 2244 1952p NMSB_97 2114p 2656 2120p NMSB 6 2130p NMSB 3 2131p NMSB 2 2132p NMSB_56 2134p NMSB 79 2137p NMSB 57 2181p 2730 2182p 2729 2190 EP_1 2531p NMSB_5 2535p NMSB_62 2536p NMSB_? ' 2621p 2694 2700p NMSB 3 1 2874 3253 L325 3255 NM3291 ff NM P:\Mpls\23 MN\27\23271072 Fdim Water It atnttas Mgmt Plan Update \WmtFila\QAQC Model for Pond\NiwMRe_SWM&hydmulic_ output_ 2006UPDA7F _fuw1_NWl�verificetim.xls NMSB ConduitRmulo UPDATE Southwest Ponds 10.0 Southwest Ponds (Dewey Hill Road Area) 10.1 General Description of Drainage Area Figure 10.1 depicts the drainage area to the Southwest Ponds drainage basin and the individual subwatersheds within this area. The Southwest Ponds watershed is located in southwest Edina, bordered by West 70`h Street to the north, West 78`h Street to the south, Gleason Road on the west, and the SOO Line railroad on the east. The drainage basin encompasses approximately 461 acres that ultimately drain to the South Fork of Nine Mile Creek south of West 78`h Street. 10.1.1 Drainage Patterns The stormwater system within this drainage area is comprised of storm sewers, ditches, overland flow paths, wetlands, and ponding basins. The Southwest Ponds drainage basin has been divided into two major watersheds based on the drainage patterns. These major watersheds are depicted in Figure 10.2. Each major watershed has been further delineated into numerous subwatersheds. The naming convention for each subwatershed is based on the major watershed it is located within. Table 10.1 lists each major watershed and the associated subwatershed naming convention. Table 10.1 Major Watersheds within the Southwest Ponds Drainage Basin Major Watershed Subwatershed Naming Convention # of Subwatersheds Drainage Area (acres) Southwest Ponds SWP ## 65 411 Nine Mile- 494 NM494 ## 7 50 10.1.1.1 Southwest Ponds The Southwest Ponds watershed encompasses approximately 411 acres. The land use within the watershed is mainly low and medium density residential, in addition to the commercial and industrial area on the eastern portion of the watershed along Cahill Road and Lewis Park. The watershed is characterized by a series of ponding basins, that ultimately outlet to the South Fork of Nine Mile Creek via a storm sewer system that travels southward from the intersection of West 78th Street and Delaney Boulevard and discharges into a detention pond north of Interstate 494. Discharge from this detention pond flows beneath Interstate 494 and enters the South Fork of Nine Mile Creek. 10.1.1.2 Nine Mile 494 The Nine Mile 494 watershed encompasses approximately 50 acres. The land use within the watershed is mainly low and medium density residential. There is one stormwater detention basin within the watershed. The watershed ultimately drains to the South Fork of Nine Mile Creek through a storm sewer system that discharges to the Creek just southeast of the intersection of Marth Court and West 78th Street, on the north side of Interstate 494 Barr Engineering Company 10 -1 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 10.2Stormwater System Analysis and Results 10.2.1 Hydrologic /Hydraulic Modeling Results The 10 -year and 100 -year frequency flood analyses were performed for the Southwest Ponds drainage basin. The 10 -year analysis was based on a'' /� -hour storm of 1.65 inches of rain. The 100 -year analysis was based on a 24 -hour storm event of 6 inches of rain. Table 10.2 presents the watershed information and the results for the 10 -year and 100 -year frequency hydrologic analyses for the Southwest Ponds basin. The results of the 10 -year and I00 -year frequency hydraulic analysis for the Southwest Ponds drainage basin are summarized in Table 10.3 and Table 10.4. The column headings in Table 10.3 are defined as follows: Node /Subwatershed ID—XP -SWMM node identification label. Each XP -SWMM node represents a manhole, catchbasin, pond, or other junction within the stormwater system. Downstream Conduit— References the pipe downstream of the node in the storm sewer system. Flood Elevation —The maximum water elevation reached in the given pond /manhole for each referenced storm event (mean sea level). In some cases, an additional flood elevation has been given in parenthesis. This flood elevation reflects the 100 -year flood elevation of Nine Mile Creek, per the Nine Mile Creek Watershed Management Plan, May 1996. Peak Outflow Rate —The peak discharge rate (cfs) from a given ponding basin for each referenced storm event. The peak outflow rates reflect the combined discharge from the pond through the outlet structure and any overflow. NWL —The normal water level in the ponding basin (mean sea level). The normal water levels for the ponding basins were assumed to be at the outlet pipe invert or at the downstream control elevation. Flood Bounce —The fluctuation of the water level within a given pond for each referenced storm event. Volume Stored —The maximum volume (acre -ft) of water that was stored in the ponding basin during the storm event. The volume represents the live storage volume only. Table 10.4 summarizes the conveyance system data used in the model and the model results for the storm sewer system within the Southwest Ponds drainage basin. The peak flows through each conveyance system for the 10 -year and 100 -year frequency storm events are listed in the table. The values presented represent the peak flow rate through each pipe system only and does not reflect the combined total flow from an upstream node to the downstream node when overflow from a manhole /pond occurs. Barr Engineering Company 10 -2 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFTEdina SWMP FINAL DRAFT 121511REV.docx Figure 10.3 graphically represents the results of the 10 -year and 100 -year frequency hydraulic analyses. The figure depicts the Southwest Ponds drainage basin boundary, subwatershed boundaries, the modeled storm sewer network, surcharge conditions for the XP -SWMM nodes (typically manholes), and the flood prone areas identified in the modeling analyses. One of the objectives of the hydraulic analyses was to evaluate the level of service provided by the current storm sewer system. The level of service of the system was examined by determining the surcharge conditions of the manholes and catch basins within the storm sewer system during the 10 -year and 100 -year frequency storm events. An XP -SWMM node was considered surcharged if the hydraulic grade line at that node breached the ground surface (rim elevation). Surcharging is typically the result of limited downstream capacity and tailwater impacts. The XP -SWMM nodes depicted on Figure 10.3 were color coded based on the resulting surcharge conditions. The green nodes signify no surcharging occurred during the 100 -year or 10 -year frequency storm event, the yellow nodes indicate surcharging during the 100 -year frequency event, and the red nodes identify that surcharging is likely to occur during both a 100 -year and 10 -year frequency storm event. Figure 10.3 illustrates that several XP -SWMM nodes within the Southwest Ponds drainage basin are predicted to experience surcharged conditions during both the 10 -year and 100 -year frequency storm events. This indicates a probability greater than 10 percent in any year that the system will be overburdened and unable to meet the desired level of service at these locations. These manholes and catch basins are more likely to experience inundation during the smaller, more frequent storm events of various durations. Another objective of the hydraulic analysis was to evaluate the level of protection offered by the current stormwater system. Level of protection is defined as the capacity provided by a municipal drainage system (in terms of pipe capacity and overland overflow capacity) to prevent property damage and assure a reasonable degree of public safety following a rainstorm. A 100 -year frequency event is recommended as a standard for design of stormwater management basins. To evaluate the level of protection of the stormwater system within the Southwest Ponds drainage area, the 100 -year frequency flood elevations for the ponding basins and depressed areas were compared to the low elevations of structures surrounding each basin. The low elevations were initially determined using 2 -foot topographic information and aerial imagery in ArcView. Where 100 -year frequency flood levels of the ponding areas appeared to potentially threaten structures, detailed low house elevations were obtained through field surveys. The areas that were predicted to flood and threaten structures during the 100 -year frequency storm event are highlighted in Figure 10.3. Discussion and recommended implementation considerations for these areas are included in Section 10.3. 10.2.2 Water Quality Modeling Results The effectiveness of the stormwater system in removing stormwater pollutants such as phosphorus was analyzed using the P8 water quality model. The P8 model simulates the hydrology and phosphorus loads introduced from the watershed of each pond and the transport of phosphorus throughout the stormwater system. Since site - specific data on pollutant wash -off rates and sediment characteristics were not available, it was necessary to make assumptions based on national average Barr Engineering Company 10 -3 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAF71Edina SWMP FINAL DRAFT 121511REV.docx values. Due to such assumptions and lack of in -lake water quality data for model calibration, the modeling results were analyzed based on the percent of phosphorus removal that occurred and not based on actual phosphorus concentrations. Figure 10.4 depicts the results of the water quality modeling for the Southwest Ponds drainage basin. The figure shows the fraction of total phosphorus removal for each water body as well as the cumulative total phosphorus removal in the watershed. The individual water bodies are colored various shades of blue, indicating the percent of the total annual mass of phosphorus entering the water body that is removed (through settling). It is important to note that the percent of phosphorus removal is based on total phosphorus, including phosphorus in the soluble form. Therefore, the removal rates in downstream ponds will likely decrease due to the large soluble fraction of incoming phosphorus that was unsettleable in upstream ponds. The watersheds are depicted in various shades of gray, indicating the cumulative total phosphorus removal achieved. The cumulative percent removal represents the percent of the total annual mass of phosphorus entering the watershed that is removed in the pond and all upstream ponds. Ponds that had an average annual total phosphorus removal rate of 60 percent or greater, under average climatic conditions, were considered to be performing well. For those ponds with total phosphorus removal below 60 percent, the permanent pool storage volume was analyzed to determine if additional capacity is necessary. Based on recommendations from the MPCA publication Protecting Water Quality in Urban Areas, March 2000, the permanent pool for detention ponds should be equal to or greater than the runoff from a 2.0 -inch rainfall, in addition to the sediment storage for at least 25 years of sediment accumulation. For ponds with less than 60 percent total phosphorus removal, the recommended storage volume was calculated for each pond within the drainage basin and compared to the existing permanent pool storage volume. 10.3 Implementation Considerations The XP -SWMM hydrologic and hydraulic modeling analyses and P8 water quality analysis helped to identify locations throughout the watershed where improvements to the City's stormwater management system may be warranted. The following sections discuss potential mitigation alternatives that were identified as part of the 2003 modeling analyses. As opportunities to address the identified flooding issues and water quality improvements arise, such as street reconstruction projects or public facilities improvements, the City will use a comprehensive approach to stormwater management. The comprehensive approach will include consideration of infiltration or volume retention practices to address flooding and /or water quality improvements, reduction of impervious surfaces, increased storm sewer capacity where necessary to alleviate flooding, construction and /or expansion of water quality basins, and implementation of other stormwater BMPs to reduce pollutant loading to downstream waterbodies. Barr Engineering Company 10 -4 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 10.3.1 Flood Protection Projects The 2003 hydrologic and hydraulic modeling analysis identified several locations within the Southwest Ponds drainage basin where the 100 -year level of protection is not provided by the current stormwater system. The problem areas identified in 2003 are discussed below. As part of the 2003 modeling analysis, potential corrective measures were identified for the problem areas for purposes of developing planning -level cost estimates. These preliminary corrective measures are also discussed below. As the City evaluates the flooding issues and potential system modifications in these areas, consideration will be given to other potential system modifications, including implementation of stormwater infiltration or volume retention practices, where soils are conducive. 10.3.1.1 7411 Coventry Way (SWP 14) A small stormwater pond is located in the backyard of 7411 Coventry Way. The small stormwater pond outlets to a larger pond located directly east, across Delaney Boulevard (SWP_5) through a 15 -inch storm sewer system. During extreme storm events, such as the 100 -year frequency event, the flood elevation of the larger pond east of Delaney Boulevard increases and flow reverses in the 15 -inch system connecting the two ponds, equalizing the ponds. The 100 -year frequency flood elevation for both ponds (SWP_14 and SWP_5) is 833.6 MSL. Based on the 2 -foot topographic data, this flood elevation would affect the structure at 7411 Coventry Way. To prevent flooding at 7411 Coventry Way, it is recommended that a flapgate be installed at the outlet of the small pond to prevent backflow from the larger pond. With installation of a flapgate, the 100 -year frequency flood elevation of the small pond is 830.6 MSL. 10.3.1.2 7317 Cahill Road (SWP 46) A low depression area exists along Cahill Road just north of the Cahill and Dewey Hill Road intersection and extends eastward into the parking lot of 7317 Cahill Road. During intense rainfall events, such as the 100 -year frequency storm, this low area becomes inundated. The 100 -year frequency flood elevation in this area is 833.8 MSL. Based on the 2 -foot topographic data, this flood elevation will impact the structure at 7317 Cahill Road. However, because the flood elevations of the two stormwater ponds in Lewis Park north of Dewey Hill Road (SWP_35 and SWP_34) and the stormwater pond on the south side of Dewey Hill Road (SWP_5) are nearly as high, options to reduce the flooding of the road and parking lot of 7317 Cahill Road are limited. It is recommended that options to lower the flood elevation of this area be further investigated as road improvement projects are planned in the area in the future. 10.3.1.3 7709 Stonewood Court (NM494_4) A stormwater pond is located northeast of the Stonewood Court and Gleason Road intersection. The basin is drained by a 12 -inch storm sewer pipe with a negative slope that acts as an inlet and an outlet, depending upon the water level in the pond. The water level of the pond is controlled by the pipe invert downstream of the outlet on the west side of Gleason Road at Elevation 828.1 MSL. If the water level in the pond is below 828.1 MSL, the storm sewer system that collects stormwater Barr Engineering Company 10 -5 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx from Tanglewood Court and Gleason Road discharges to the pond. If the water elevation is higher than 828.1 MSL, discharge from the stormwater pond will combine with stormwater from the Tanglewood Court and Gleason Road system and will continue flowing southward towards the South Fork of Nine Mile Creek. During the 100 -year frequency storm event, the flood elevation of this stormwater pond reaches 832.5 MSL. Based on a field survey, this flood elevation will impact the structure at 7723 Stonewood Court (low house elevation of 831.97 MSL). To protect this structure from the 100 -year flood elevation, it is recommended that the capacity of the downstream storm sewer system along Stonewood Court be increased. Based on modeling results, increasing the size of pipes 1011p and 1012p from 12 -inch diameter to 24 -inch diameter will reduce the 100 -year flood elevation of the stormwater pond to 831.81 MSL, slightly below the low house elevation. 10.3.2 Construction /Upgrade of Water Quality Basins The 2003 P8 modeling analysis indicated that the annual removal of total phosphorus from several ponds in the Southwest Ponds drainage area was predicted to be below the desired 60 percent removal rate, under average year conditions. For those ponds with total phosphorus removal below 60 percent, the permanent pool storage volume was analyzed to determine if additional capacity is necessary. All of the basins were found to have sufficient dead storage volume, based on the MPCA recommended permanent pool storage volume for detention basins. As a result, no specific recommendations for water quality basin upgrades in the Southwest Ponds drainage basin are being made at this time. Construction of new or expansion of existing water quality basins is one method to increase the pollutant removal achieved prior to stormwater reaching downstream waterbodies. Many additional techniques are available to reduce pollutant loading, including impervious surface reduction or disconnection, implementation of infiltration or volume retention BMPs, installation of underground stormwater treatment structures and sump manholes and other good housekeeping practices such as street sweeping. As opportunities arise, the City will consider all of these options to reduce the volume and improve the quality of stormwater runoff. Barr Engineering Company 10 -6 P: \Mpls\23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511 REV 2.docx M#, 6 LL Q %I 0 0 a LL m SWP_27 SWP_26 SWP_4 Ank SWP_26 SWP_2.2 p- fir 70th St MUM) � f M-W CLl(� \ @W—N L CO QnPi '� U @W0 s " ✓�Pi '�10 �rp� �a1p _ __s MA EBW / Bloomington ��O e ` �,^: I VI O "y v � • ll��RPUiis�1 �,, • IUBA City of Edina Boundary Roads /Highways Creek /Stream Lake /Wetland C3 Southwest Ponds Drainage Basin Subwatershed Imagery Source: Aerials Express, 2008 0 Feet 600 0 600 Meters 200 0 200 Figure 10.1 SOUTHWEST PONDS DRAINAGE BASIN Comprehensive Water Resource Management Plan City of Edina, Minnesota d` 01 v i C v v Y ?> F 0 a t P v# + �Ii /e Cre 70th St w 9. 7 hest Pbnds ;y Hill Rd r.' � � I AV Nine Mile 1 -494 Bloomington M U .w tl y.�.W I k _i AdOW44 oe. • ,•4�URP(JR -aT�,, • IUBA (� City of Edina Boundary Roads /Highways Creek /Stream Lake /Wetland C3 Southwest Ponds Drainage Basin C3 Major Watershed (; Subwatershed Imagery Source: Aerials Express, 2008 0 Feet 1,200 0 Meters 400 0 Figure 10.2 SOUTHWEST PONDS MAJOR WATERSHEDS Comprehensive Water Resource Management Plan City of Edina, Minnesota KERRY 11b'J _49 002 1661 S'NP o2 0 MP� m O HYDE PARK CIR mi Q cr_ J z 2 Q Q MA Z Q J PN.�R�M C.� q= tW,.M KEMRICH Op-A L6� N • i Q 'Ja36 O O D 4090 U L L r� 49f�1 >-0 WIN W � W-j �J .19z�3 C O N 2 WA O co LU V BONNIE BRAE DRS) 860 ti U s.ta z- G, ti i TANGLEWOOD Figure 10.3 SOUTHWEST PONDS HYDRAULIC MODEL RESULTS Comprehensive Water Resource Management Plan City of Edina, Minnesota In City of Edina Boundary Potential Flooding During Roads /Highways 100 -Year Frequency Event Creek/Stream Pipes o Manhole Lake /Wetland Manhole Surcharge During C3Southwest Ponds ° 100 -Year Frequency Event Drainage Basin g Manhole Surcharged During Subwatershed ° 10 -Year Frequency Event Feet 200 0 200 N Meters 60 0 60 120 yL'tiO4, 1943 W WN 0 Q o � o i z F- Q W J LL a MRD �•� 9a SHANNON 993 J Q� OO O '03 -HYDE PARK 1289 iL424 IfTA ^P M IV H Emu AMU Y Q � m �9 . LONG MIT49 E Z Z O Z AV-M. O� IMDRIM 0 �I } U) W z Q U) G� S'NP-19 SIA'P_61 99EQ 1298 SAP Q z Q J Bloomington 0 Q Q MUG z W O U S'A'P_4 (, )9M 13 8 @W.X w W an M, 2 U O J tW,.M KEMRICH Op-A N • i Q z L O D 4090 L Q U O z z Q U) -HYDE PARK 1289 iL424 IfTA ^P M IV H Emu AMU Y Q � m �9 . LONG MIT49 E Z Z O Z AV-M. O� IMDRIM 0 �I } U) W z Q U) G� S'NP-19 SIA'P_61 99EQ 1298 SAP Q z Q J Bloomington 0 Q Q MUG z W O U S'A'P_4 (, )9M 13 8 @W.X w W an M, 2 U O J oot 4� cn 0, 41 � '4 ",. w J y e rn i rA n " w n a `r 0 0 0 LL t SWP_47 i SWP_33 r SWP_57 t .. V(--,r� Bloomington Imagery Source: Aerials Express, 2008 w91N�1r )y o Percent TP Removal in Water Body* This number represents the percent of the total annual mass of phosphorus entering the water body that is removed. 0 - 25% (Poor /No Removal) 25 - 40% (Moderate Removal) _ 40 - 60% (Good Removal) _ 60 - 100% (Excellent Removal) Cumulative TP Removal in Watershed* This number represents the percent of the total annual mass of phosphorus entering the watershed and upstream watersheds that is removed in the pond and all upstream ponds. - 25 - 40% (Moderate Removal) 40 - 60% (Good Removal) 60 - 100% (Excellent Removal) *Data based on results of P8 modeling. Flow Direction O Feet 600 0 600 Meters 200 0 200 Figure 10.4 SOUTHWEST PONDS WATER QUALITY MODELING RESULTS Comprehensive Water Resource Management Plan City of Edina, Minnesota Table 10.2 Watershed Modeling Results for Subwatersheds in the Southwest Ponds Drainage Basin (Revised 12/2006) Watershed Information 100 -Year Storm Results 24-Hour Event 10 -Year Storm Results 1/2 -Hour Event Watershed ID Total Area (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) 494 .1 9.5 ' .. 19 42.4 2.60 22.6 0.54. 494_2 5.4 18.. 23.7 4.39 11.1 6.25 NM494 3 7.1 13 28.8 1.77 11.4 0.31 NM494 4 5.3 30 24.3. .. 1 1.70 16.6 0.39 494 5 12.9 20 53.7 3.63' 27.2 0.74 NM494_6 7.7 22 35.2 2.22 .. 21.0 0.49 NM494 7 2.1 20 9.6 0.59 5.6 0.13 SWP 1 4.2 44 20.0 1.61 16.6 0.40 SWP 10 4.5 34 20.0 1.34 12.5 0.27 SWP 11 2.6 30 10.6 0.70 5:6 0.12 SWP 12 2.0 27 9.1 0.54 6.0 0.11 SWP 13 1.3 13 6.3 0.38 5.0 0.10 SWP 14 2.7 21 12.7 0.87 8.5 0.21 SWP _15 0.7 19 2.5 0.21 1.2 0.04 SWP 16 3.9 30 16.9 1.14 9.8 0.23 SWP 17 2.8 30 7.3 0.77 3.0 0.12 SWP 18 3.3 20 15.1 0.92 9.5 0.21 SWP-19 6.4 20 29.6 1.80 18.3 0.41' SWP _2 13.3 48 62.8 5.08 50.7 1.25 SWP _20 3.6 20 16.2 1.02 9.7 0.23 SWP _21 2.9 16 13.6 0.84 10.2 0.21 SWP 22 6.3 20 27.0 1.75 13.9 0.36 SWP _23 3.3 20 15.3 0.92 10.4 0.22- AT 24 3.9 20 14.5 1.06 6.8 0.20 SWP 25 2.9 20 13.1 0.82 7.4 0.18 SWP _26 3.1 20 13.5 0.86 7.2 0.18 SWP 27 8.2 4 32.4 1.93 10.4 0.33 SWP_ 8.9 8 38.1 2.15 14.6 0.39 _28 SWP 29 4.6 44 21.6 1.58 17.4 0.37 SWP 3 29.1 26 121.8 8.45 66.6 1.70 SWP-30. 2.5 34 10.7 0.78 .6.4 0.17 SWP _31 11.0 50 .51.0. 4.21 37.8 `1:02 SWP _32 23.6 71 108.3 9.51 72.8 2.23 SWP _33 2.3 30 10.3 0.73 6.9 0.17 SWP 34 16.7 18 75.2 5.65 44.0 1.31 SW-35 11.3 21 48.4 3.89 27.0 0:88 SWP 36 7.7 20 :. 35.9 2.21 23.7 0.52. SWP _37 2.3 22 10.5 0.87 7.3 0.20 SWP _38 43 19 21.4 1.32 12.5 0.29 SWP 39 1209 20 58.0 3.63 32.5 0.78 SWP _4 13.0 38 60.4 4.75 46.3 1.16 SWP 40 2.6 35 12.3 0.82 9.5 0.19 SWP 41 2.5 65 11.9 0.95 13.1 0023 SWP 42 4.3 46 18.8 1040 1101 0.28 SWP _43 3.5 59 16.1 1.28 10.4 0.28 SWP 44 2.4 74 11.2 1.03 7.8 0.25 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\NineMILe_SWMM_hydraulic_ output_ 2006UPDATE _final_NWL_verification.xls SWP Runoff Results Update Table 10.2 Watershed Modeling Results for Subwatersheds in the Southwest Ponds Drainage Basin (Revised 12/2006) Watershed Information 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Watershed ID Total Area (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) SWP_45 1 1.4 78 6.3 0.61 4.8 1 0.15 SWP_46 11.6 63 49.1 4.52 26.9 1.03 SWP_47 21.5 22 76.2 6.35 36.5 1.24 SWP_48 0.8 15 3.7 0.20 2.5 0.05 SWP_49 3.7 20 17.2 1.04 10.7 0.24 SWP_5 6.5 54 31.3 2.56 37.8 0.68 SWP_50 8.4 20 36.5 2.41 19.6 0.51 SAT 51 6.9 20 29.0 1.90 14.7 0.38 SWP_52 8.2 20 36.9 2.30 20.4 0.49 SWP_53 13.5 20 55.3 3.86 27.6 0.79 SWP_54 12.3 20 55.9 3.48 32.5 0.76 SWP_55 3.5 20 15.7 0.98 8.7 0.21 SWP_56 7.5 20 33.7 2.30 19.6 0.52 SWP_57 1.7 30 7.8 0.48 4.8 0.09 SAT 58 2.0 30 9.4 0.64 6.8 0.15 SWP_59 12.3 37 52.6 4.07 30.7 0.87 SWP_6 5.1 20 19.2 1.29 8.5 0.20 SWP_60 9.8 29 32.0 2.91 14.7 0.54 SWP_61 5.3 20 23.4 1.39 11.8 0.26 SWP_62 1.7 20 7.8 0.47 5.8 0.11 SWP_63 6.9 10 27.0 1.75 10.0 0.32 SWP_64 2.1 70 10.3 0.95 10.8 0.24 SWP_66 4.6 20 18.2 1.36 9.1 0.28 SWP_7 1.7 27 7.6 0.50 5.1 0.11 SWP_8 2.6 29 12.2 0.82 10.0 0.20 SWP 9 1 2.2 20 10.6 0.69 9.0 0.18 PAMpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\NineMlLe_SWMM_ hydraulic_ output_ 2006UPDATE _6nal_NWL_verification.xls SWP Runoff Results Update Table 10.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in the Southwest Ponds Drainage Basin (Revised 12/2006) Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft) Type of Storage' NWL (ft) Flood Bounce (ft) Flood Elevation (ft) NWL (ft) Flood Bounce (ft) 1171 920 938.4 935.13 1172 921 932.4 926.61 1173 922 928.3 925.27 1174 923 923.8 923.36 1175 924 923.7 922.86 1176 925 922.6 921.62 1177 926 917.2 917.22 1178 927 899.0 897.16 1180 934 884.4 883.99 1182 930 886.4 886.24 1183 931 890.0 889.86 1184 932 894.5 894.35 1185 933 896.9 896.78 1186 935 881.1 878.53 1187 936 871.4 868.23 1188 937 854.7 854.40 1190 939 847.7 845.67 1191 940 845.7 street 843.73 1192 941 843.6 841.87 1193 942 841.0 839.72 1197 945 842.4 842.42 1198 946 846.4 846.36 1205 952 835.0 832.69 1207 953 834.4 832.11 1208 955 833.8 831.53 1210 956 833.8 831.37 1211 957 833.8 831.31 1212 959 833.8 831.28 1215 960 833.8 831.24 1216 961 833.8 831.22 1219 963 835.8 834.71 1267 1000 844.9 842.78 1270 1002 842.7 840.53 1271 1003 842.7 840.40 1276 1006 844.5 839.55 1277 1007 845.4 street 840.33 1283 1012p 834.6 834.52 1285 1014 831.7 827.60 1286 1015 831.6 826.50 1288 outfall 821.3 820.51 1289 1017p 836.2 836.24 1290 1018p 840.9 835.66 1291 1019P 840.9 836.15 1292 1020p 841.3 838.33 1295 1023 840.7 838.32 1296 1024 840.4 836.24 1299 1026 838.4 838.31 1306 1619 834.2 833.65 1310 1033 833.6 829.77 1318 1039 830.2 829.01 132 1028 835.4 833.35 1322 1041 833.4 829.73 1326 1044 829.9 825.65 1327 1045 825.7 825.41 1328 1046 825.5 825.23 1330 1048p 822.3 821.60 1331 1049p 822.3 818.29 1332 1050p 822.2 814.65 1333 1051P 817.8 813.26 1334 1052p 815.5 812.01 1335 outfall 815.3 810.30 1344 1057 833.8 831.23 1350 1062 834.4 834.17 1354 1066 831.7 830.70 1356 1065 830.8 828.84 1660 1367 901.6 900.50 1661 1368 920.0 919.57 PAMpls@3MN\27\23271072 Puna Water Resources Mgmt Plan Update \WorkFles\QAQC Model for Pond\NimMILe_ _SWMM hydraulic_ output_ 2006UPDATE _ftnal_NWL_vcrilication.sls SWP_I00Y_NodeResuns_UpdaudI Table 10.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds/Nodes in the Southwest Ponds Drainage Basin (Revised 12/2006) Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft) Type of Storage' NWL (ft) Flood Bounce (ft) Flood Elevation (ft) NWL (ft) Flood Bounce (ft) 1662 1369 938.3 935.32 1663 1370 945.5 944.42 1665 1613 925.1 1 924.99 1667 1372 929.7 927.97 1676 1380 838.0 836.56 1678 1381 833.8 831.25 1857 1506 850.7 848.46 1859 1508 845.4 840.53 1860 1509 847.0 841.81 1866 1512 845.9 843.60 1894 1529 825.8 825.42 1895 1530 828.3 827.16 2424 1966p 836.5 836.41 2425 1967p 836.9 836.86 2426 1968p 837.4 837.13 2492 2023 833.8 ark 826.3 7.4 830.94 832.6 4.2 2494 2025 942.2 ditch 937.4 4.8 937.38 833.3 3.8 2497 2030 834.5 833.06 2498 2029 834.1 832.08 2499 2027 833.8 831.47 NM494_1 1016 824.7 822.31 NM494_2 1008p 840.9 834.04 NM494_3 I%gp 837.8 837.54 NM494_4 1009P 832.5 pond 828.2 4.4 829.56 818.8 15 NM494_5 1013p 832.6 831.95 NM494_6 lollp 835.6 835.36 NM494 7 1021p 841.8 b d 838.0 3.8 840.01 828.2 1.4 SWI?j 1044 830.0 pond 827.0 3.0 827.39 826.0 6.0 SW-10 1067 832.1 pond 830.1 2.0 830.96 827.2 8.2 SWP_I1 1061 838.8 ditch 835.0 3.8 837.21 838.0 2.0 SWP_12 1064 830.4 828.77 SWP_13 1043 830.5 829.11 SWP_14 1032 833.6 pond 828.5 5.1 829.77 835.0 2.2 SWP_15 1034 833.6 829.77 SWP_16 1037 835.5 835.20 SWP_17 1055 833.6 829.78 SWP_18 1507 853.0 852.79 SWP_19 1029 847.4 847.20 SWP3 2022 830.0 pond 828.0 2.0 829.01 1 827.8 2.0 SWP30 1505 840.9 street 839.72 SWP_21 1053 833.6 street 829.77 SWP32 1511 845.9 street 843.57 SWP_23 1513 851.7 851.68 SWP34 1001 843.0 b d 838.0 5.0 840.91 827.1 2.7 SWP_25 1004 842.6 840.20 SWP36 999 843.7 street 840.40 SWP37 1510 847.1 843.12 SWP_28 1005 844.4 839.46 SWP_29 1047 825.3 825.18 SWP_3 1028 839.5 pond 836.5 3.0 837.33 841.5 1.6 SWP_30 1531 829.2 829.09 SWP_31 landlocked 828.5 pond 827.1 1.4 827.45 817.6 7.6 SWP 32 landlocked 837.5 ditch 833.5 4.0 837.11 836.5 0.8 SWP_33 landlocked 839.8 depression 836.4 3.4 838.25 824.3 4.8 SWP_34 2046p 833.6 pond 828.0 5.8 831.22 827.1 0.4 SWP 35 1054 833.8 pond 828.0 5.8 831.22 833.5 3.6 SWP_36 1379 839.6 839.06 SWP_37 landlocked 836.6 pond 835.4 1.2 835.96 828.0 3.3 SWP_38 948 835.5 835.25 SWP_39 947 857.3 857.19 SWP_4 1040 830.4 pond 828.6 1.9 829.15 835.4 0.6 SWP_40 landlocked 835.7 pond 828.1 7.6 829.25 829.7 5.6 SWP_41 1383 838.8 834.98 SWP_42 1620 838.5 833.75 SWP_43 1059 837.2 832.84 SWP_44 1058 836.4 832.30 SWP 45 1382 833.8 831.34 P:\IApls\27 MN\27\23271072 Edina Wets Raoun:es Mgmt Plan Update \WorlLF1cs\QAQC Model for PondWimMn.c_SWMM hydraulic output 2006UPDATE- finat_NWL vairimtion.xls SWP_100Y_NodeRaulla- Updated 9 Table 10.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in the Southwest Ponds Drainage Basin Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft) Type of Storage' NWL (ft) Flood Bounce (f0 Flood Elevation (ft). - NWL (ft) Flood Bounce(ft)II SWP_46 3239p 833.8 street/park lot 839.63 843.0 832.80 SWP_59 1038 SWP_47 950 835.9 pond 832.0 3.9 ' 833.59 830.3 2.6 SWP_48 1056 833.8 street 831.22 SWP_49 1371 958.4 - 956.04 SWP 5 1054 833.6 pond, 828.0 5.6 829.77 828.3 4.6 SWP_50 1366 898.9 898.81 SWP_51 9380 85U6 849.35 SWP 52 1373 944.8 935.25 SWP 53 1377 851.6: street 848.87' SWP_54 928.: 887.6 887.42 SWP_55 1376 942.4 street 936.94. SWp 56 929 .1884 -8 - 884:51 SWP_57 3299p 836.8 pond 835.4 1.4. 836.04 927.0 8.2 SWP_58 landlocked 840.8 depression 838.2 2.6 839.63 843.0 5.8 SWP_59 1038 830.7 wetland 828.7 2.0 829.42 880.5 6.9 P'.\Mpls @3MNt27\23271072 Edina Water Resoumm Mgmt Plan Updatc\ WorkFilmNQAQC Model for Pmd\NimMILe_SWMM_hydraulic_ output_2006UPDATE_rmaLNWL _ veririmtionlis SWP_IOOY_NodeRCulu_Updarcd Table 10.4 Conduit Modeling Results for Subwatersheds In the Southwest Ponds Drainage Basin (Revised 1212006). Conduit m Upstream Node Downstream Node Conduit Shape Conduit Dimensions (ft) Roughness Coefficient Upstream Invert Elevation (ft) Downstream Invert Elevation (ft) Conduit Length (ft) Slope 100Y Peak Flow through Conduit (c(s) IUY Peak Flow through Conduit (cfs) IOW 1267 SWP 3 Circular 2 0.024 839.55 835.90 203 1.80 21.2 18.0 1001 SWP_24 1270 Circular 1.5 0.013 838.04 837.35 138 0.50 7.6 6.6 1002 1270 1271 Circular 1.5 0.013 837.35 837.15 39 0.51 7.6 6.6 1003 1271 SWP25 Circular 1.5 0.013 837.15 836.58 113 0.50 7.6 6.6 1004 SWP_25 SWP_3 Circular 1.5 0.013 836.58 835.75 166 0.50 15.0 11.3 1005 SWP_28 SWP_3 Circular 2.25 0.013 836.64 836.00 140 0.46 48.7 23.9 1006 1276 SWP_28 Circular 2.25 0.013 836.78 836.64 35 0.40 18.9 10.8 1007 1277 1276 Circular 2 0.013 838.50 836.98 380 0.40 18.9 10.7 1 008P NM494_2 NM494 4 Circular 1.5 0.013 833.17 827.00 143 4.33 23.8 13.9 1009P NM494_4 NM494_6 Circular 1 0.013 825.69 827.17 170 -0.87 -6.4 -6.9 101 1p NM494_6 1283 Circular 1 0.013 827.17 828.15 38 -2.58 1 5.6 5.6 1012p 1283 NM494_5 Circular 1 0.013 827.75 826.40 239 0.57 5.5 5.7 1013p NM494_5 1285 Circular 2 0.013 826.00 825.45 70 0.79 37.8 37.5 1014 1285 1286 Circular 2.75 0.013 824.95 823.20 215 0.81 38.7 37.8 1015 1286 NM494_1 Circular 2.75 0.013 823.20 821.50 232 0.73 80.7 49.0 1016 NM494_1 1288 Circular 4 0.024 818.80 818.00 59 1.36 121.4 69.1 1017p 1289 NM494_6 Circular 1.25 0.013 831.68 829.00 154 1.74 4.6 5.5 1018p, 1290 NM494_2 Circular 1.5 0.013 835.00 833.17 175 1.05 4.8 3.4 1019P 1291 1290 Circular 1.25 0.013 835.41 835.00 38 1 1.08 4.4 3.5 1020p 1 1292 1291 Circular 1 0.013 837.30 835.41 200 0.95 4.2 3.5 1021p NM494_7 1292 Circular 1 0.013 838.00 837.30 140 0.50 4.2 3.5 1022 SWP 6 1295 Circular 1 0.013 837.90 836.10 177 1.02 5.5 5.4 1023 1295 1296 Circular 1 0.013 836.10 835.35 50 1.49 7.7 5.4 1024 1296 SWP_61 Circular 1.25 0.013 835.35 834.65 45 1.56 10.9 5.4 1025 SWP_61 SWP_2 Circular 1.5 0.013 834.40 826.50 240 3.29 20.5 17.1 1026 1299 SWP_8 Circular 1 1 0.013 833.64 831.95 135 1.25 -2.8 -1.9 1027 SWP 8 SWP_31 Circular 1 0.013 831.85 822.50 170 1 5.50 9.4 1 9.3 1028 132 SWP_4 Circular 1 0.013 831.47 828.17 122 2.71 6.7 4.8 1029 SWP_19 SWP_4 Circular 1.5 0.013 836.09 830.15 220 2.70 25.2 25.0 1032 SWP 14 1310 Circular 1.25 0.024 828.51 828.30 27 0.78 -4.0 1.6 1033 1310 SWP_15 Circular 1.25 0.024 828.30 828.05 28 0.89 -4.0 1.6 1034 SWP_15 SWP_5 Circular 1.25 1 0.024 828.05 827.50 62 0.89 -3.9 2.2 1037 SWP_I6 SWP_59 Circular 1 0.013 829.48 828.40 27 4.00 10.9 8.8 1038 SWP_59 1318 Circular 2 0.013 828.65 827.91 74 1.00 13.4 4.1 1039 1318 SWP_2 Circular 2.5 0.024 827.62 826.53 97 1 1.12 13.4 4.8 1040 SWP_4 SWP3 Circular 2.5 0.013 828.57 826.62 80 2.44 15.2 7.4 1041 1322 SWP2 Circular 1.5 0.024 824.63 824.26 115 0.32 -5.6 -4.6 1042 SWP_7 SWP_13 Circular 1.5 0.024 824.26 823.14 255 0.44 5.0 -2.4 1043 SWP_I3 SWP_2 Circular 1.5 0.024 818.33 818.23 51 0.20 8.3 5.7 1044 1326 1327 Circular 1.25 0.013 823.00 821.87 79 1.44 14.8 6.6 1045 1327 1328 Circular 1.25 0.013 821.87 820.30 124 1.27 8.9 6.9 1046 1328 SWP_29 Circular 1.25 0.013 820.30 819.64 55 1.20 11.2 7.0 1047 SWP_29 1330 Circular 1.5 0.013 817.60 816.62 183 0.54 14.5 14.5 1048p 1330 1331 Circular 1.5 0.013 816.62 815.62 187 0.53 13.9 13.5 1049p 1 1331 1332 Circular 1.5 0.013 815.62 814.62 98 1.02 13.9 13.6 1050p 1332 1333 Circular 1 2 0.013 813.12 811.72 291 0.48 27.9 13.7 1051p 1333 1334 Circular 2 0.013 811.72 810.95 161 0.48 27.8 13.8 1052P 1334 1335 Circular 3 0.024 810.95 809.28 70 2.39 27.8 13.8 1054 SWP_5 SWP_35 Arch 18" eq 0.024 826.87 826.85 120 0. 1 -8.2 -6.9 1055 SWP_17 SWP_5 Circular 1.25 0.013 827.76 827.44 29 1.10 7.3 3.0 1057 1344 SWP_35 Circular 3.5 0.013 827.50 827.00 28 1.79 67.8 59.7 1058 SWP 44 1344 Circular 3 0.013 829.09 827.50 357 0.45 53.3 39.5 PAMplA23 MM27%23271072 Editu Wets Raoutcrs Mpu Pl. Upd.AW.*FdestQAQC Model for PondWiacNR. _SWhAL hydraulic_ mtpuL2W6UPDATE_GaaLNWL _vcriricatim.xls MW _CooduirtaWu Updue Table 10.4 Conduit Modeling Results for Subwatersheds In the Southwest Ponds Drainage Basin (Revised 1212006). Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimensions* (ft) Roughness Coefficient Upstream Invert Elevation (ft) Downstream Invert Elevation (ft) Conduit Length (ft) Slope IOOY Peak Flow through Conduit (c fs) I OY Peak Flow through Conduit Ws) 1059 SWP-43 SWP_44 Circular 3 0.013 830.25 829.19 236 0.45 42.6 31.7 1061 SWP II 1350 Circular 1 0.013 835.00 834.14 215 0.40 4.5 3.3 1062 1350 SWP-10 Circular 1 0.013 833.70 829.70 93 4.30 4.5 3.3 1064 SWP_12 SWP_1 Circular " 2 0.024 827.64 826.49 115 1.00 14.8 5.9 1065 1356 SWP_l2 Circular 1.5 0.024 828.14 827.64 28 1.79 8.6 2.8 1066 1354 1356 Circular 1.5 0.013 830.14 828.14 250 0.80 8.6 2.8 1067 SWP_10 1354 Circular 1.5 0.013 828.10 830.20 18 -11.67 8.6 2.8 1366 SWP_50 1185 Circular 1.5 0.013 893.30 891.49 97 1.87 22.5 24.0 1367 1660 SWP_50 Circular 1.5 0.013 896.48 893.30 112 2.85 15.4 12.5 1368 1661 1660 Circular 1.25 0.013 919.00 896.48 232 9.72 17.2 11.7 1369 1662 1661 Circular 1.25 0.013 933.48 919.00 160 9.04 17.3 10.8 1370 1663 1662 Circular 1.25 0.013 943.71 933.48 146 7.00 17.1 10.6 1371 SWP_49 1663 Circular 1.25 0.013 953.06 943.71 272 3.44 14.6 10.6 1372 1667 1665 Circular 1.75 1 0.013 919.71 918.15 178 0.88 24.6 20.2 1373 SWP 52 1667 Circular 1.5 0.013 927.02 919.96 181 3.90 29.9 20.3 1376 SWP_55 1171 Circular 1.5 0.013 936.04 933.77 148 1.53 15.6 8.7 1377 SWP-53 1190 Circular 1.75 0.013 843.04 842.71 41 0.82 29.6 25.3 1379 SWP_36 1676 Circular 4.5 0.013 835.00 834.46 150 0.36 165.6 145.9 1380 1676 SWP_35 Circular 4.5 0.024 834.46 824.12 110 9.40 165.3 144.7 1381 1678 1344 Circular 2.5 0.013 827.61 827.50 8 1.38 17.7 20.2 1382 SWP 45 1678 Circular 2 0.013 828.15 827.61 117 0.46 10.9 11.8 1383 SWP-41 SWP_42 Circular 2.5 0.013 833.80 831.87 386 0.50 14.4 13.1 1505 SWP 20 1306 Circular I 1 0.013 834.92 832.52 130 1.85 7.8 7.4 1506 1857 SWP-19 Circular 1.5 0.013 837.84 836.29 172 0.90 15.1 9.3 1507 SWP 18 1857 Circular 1.25 0.013 841.23 838.05 218 1.46 9.2 9.2 1508 1859 1277 Circular 1.75 0.013 839.06 838.60 28 1.64 17.1 10.4 1509 1860 1859 Circular 1.75 0.013 840.70 839.06 186 0.88 18.3 10.5 1510 SWP-27 1860 Circular 1.75 0.013 841.53 840.70 208 0.40 14.2 10.4 1511 SWP_22 1267 Circular 2 0.013 840.23 839.55 25 2.72 211 19.2 1512 1866 SWP-22 Circular 1.5 0.013 840.50 840.23 38 0.71 10.9 9.0 1513 SWP-23 1866 Circular 1 0.013 848.04 840.50 310 2.43 5.9 5.9 1529 1894 SWP--�9 Circular 1.25 0.013 818.40 817.80 91 0.66 4.1 3.5 1530 1895 1894 Circular 1 0.013 818.95 818.30 242 0.27 3.8 3.6 1531 SWP_30 1895 Circular 1 0.013 824.30 822.30 54 3.72 4.7 5.5 1566 SWP-60 1219 Special 1.52 0.013 832.30 832.21 47 1 0.19 12.6 13.5 1613 1665 1175 1 Circular 1.75 0.013 917.93 916.85 117 0.92 21.9 20.9 1619 1306 SWP-4 Circular 1.25 0.013 832.52 828.53 243 1.64 7.8 7.4 1620 SWP_42 SWP_43 Circular 2.5 0.013 831.77 830.65 284 0.39 28.8 23.5 1966p 2424 1289 Circular 1.25 0.013 831.96 831.68 50 0.56 4.6 1 5.4 1967p 1 2425 2424 Circular 1.25 1 0.013 832.63 831.96 120 0.56 4.6 5.4 1968p 2426 2425 Circular 1.25 0.013 833.33 832.63 125 0.56 4.6 6.0 1969p NM494_3 2426 Circular 1.25 0.013 833.89 833.33 100 0.56 4.6 6.5 2023 2492 1216 Circular 1 0.024 826.34 826.00 125 0.27 -2.6 -1.7 2024p SWP_66 SWP_51 Circular 1.5 0.013 843.51 843.00 127 0.40 16.2 8.5 2025 2494 SWP 52 Circular 1 0.013 937.38 937.00 38 1.00 7.3 0.0 2027 2499 SWP_45 Circular 1.75 0.013 828.60 828.35 38 0.66 6.6 7.4 2028 SWP 64 2497 Circular 1 0.013 831.50 829.91 33 4.82 6.7 7.9 2029 2498 2499 Circular 1.5 1 0.013 829.32 829.01 71 0.44 6.6 7.9 2030 1 2497 2498 Circular 1.25 0.013 829.70 829.32 71 0.53 6.7 7.9 2046 SWP--35 SWP_34 Circular I.5 0.013 824.52 827.93 109 -3.13 -5.7 4.9 3239 SWP 46 1678 Circular 1.5 0.013 828.25 827.60 196 0.33 8.6 9.5 3299 SWP-57 SWP_44 Circular 1 0.01 836.00 830.80 150 3.47 2.6 0.0 PAMplsl23 MNI27123271072 Edina Wata Resour<a Mgt Plan Upda ckWwkFda\QAQC Model for PonMineMILc -$WMM -hydmulic_wlput-2006UPDATF finat_NWL_vaifimLion.xls SWP_Conduit]toul� Upd- Table 10.4 Conduit Modeling Results for Subwatersheds in the Southwest Ponds Drainage Basin (Revised 12/2006). Conduit m Upstream Node Downstream Node Conduit Shape Conduit Dimensions (ft) Roughness Coefficient Upstream Invert Elevation Elevation Downstream Inver Elevation (ft) Conduit Length (0) Slope 100Y Peak Flow through Conduit (cfs) l0Y Peak Flow through Conduit (cfs) 1053 SWP -21 SWP_5 Circular 1.5 0.024 827.09 826.85 24 1.00 13.6 10.2 2022 SWP-2 SWP/ Circular 2 0.024 828.00 827.00 36 2.78 11.6 4.5 920 1171 1172 Circular 1.5 0.013 933.77 931.50 148 1.53 15.6 8.6 921 1172 1173 Circular 1.25 0.013 924.95 920.66 56 7.66 15.5 8.6 922 1173 1174 Circular 1.25 0.013 920.66 917.63 101 3.00 13.2 8.6 923 1174 1175 Circular 1.5 0.013 917.63 917.36 26 1.04 8.5 8.6 924 1175 1176 Circular 2 0.013 916.39 915.87 55 0.95 33.2 28.1 925 1176 1177 Circular 2 0.013 915.87 912.84 316 0.96 35.5 28.1 926 1177 1178 Circular 1.75 0.013 912.84 896.03 286 5.88 36.6 29.6 927 1178 SWP54 Circular 1.75 0.013 896.03 880.54 276 5.60 31.6 24.9 928 SWP 54 1180 Circular 2 1 0.013 880.54 878.54 67 3.01 43.0 39.9 929 SWP_56 1180 Circular 2.5 0.013 878.00 876.80 60 2.00 33.7 39.8 930 1182 SWP_56 Circular 1.75 0.013 881.21 878.00 117 2.76 22.6 26.3 931 1183 1182 Circular 1.75 0.013 884.73 881.21 149 2.36 22.6 24.2 932 1184 1 1183 Circular 1.75 0.013 889.11 884.73 219 2.00 22.1 23.8 933 1185 1184 Circular 1.75 0.013 891.49 889.11 74 3.24 26.1 26.1 934 1180 1186 Circular 2.5 0.013 876.80 874.12 144 1.86 86.5 86.5 935 1186 1187 Circular 2.25 0.013 874.12 863.96 106 9.56 99.7 89.5 936 1187 1188 Circular 2.25 1 0.013 863.96 847.78 172 9.43 87.3 78.6 937 1188 SWP SI Circular 2.5 0.013 847.78 843.50 210 2.04 62.2 61.9 938p SWP 51 1190 Circular 3.5 0.013 838.32 837.14 346 0.34 105.7 93.4 939 1190 1191 Circular 4 0.013 837.14 836.68 211 0.22 133.6 117.7 940 1191 1192 Circular 4 0.013 836.68 835.90 253 0.31 126.1 112.0 941 1192 1 1193 Circular 4 0.013 835.90 835.21 312 0.22 126.1 112.0 942 1193 SWP_36 Circular 4 0.013 835.21 834.99 96 0.23 137.7 112.2 945 1197 SWP_36 Circular 1.75 0.013 837.17 836.50 168 0.40 19.5 19.5 946 1198 1197 Circular 1.5 0.013 840.48 837.42 70 4.40 18.7 18.6 947 SWP_39 1198 Circular 1.5 0.013 852.04 840.48 195 5.93 24.0 23.9 948 SWP_38 SWP_34 Circular 1.25 0.013 829.67 829.52 15 1.00 15.6 15.3 950 SWP_47 1205 Circular 1.25 0.013 831.98 830.58 277 0.51 3.8 3.9 952 1205 1207 Circular 1.25 0.013 830.58 829.82 170 0.45 3.7 3.6 953 1207 1 1208 Circular 1.25 1 0.013 829.82 828.12 211 0.81 3.7 3.6 954 SWP_63 1208 Circular 1 0.013 828.75 828.12 50 1.26 -2.3 4.3 955 1208 1210 Circular 1.5 0.013 828.12 827.65 118 0.40 4.1 5.4 956 1210 1211 Circular 1.75 0.013 827.65 827.09 140 0.40 4.0 5.4 957 1211 1212 Circular 2.25 0.024 827.09 826.54 1 71 0.78 4.0 5.4 959 1212 1215 Circular 2 0.013 826.54 826.34 89 0.23 4.0 5.4 960 1215 1216 Circular 2 0.013 826.34 825.85 89 0.55 -13.2 5.4 961 1216 SWP_34 Circular 3 0.024 825.85 826.02 210 -0.08 -14.5 -8.5 963 1219 SWP_47 Arch 24" 0.013 832.21 831.78 213 0.20 12.6 13.5 999 SWF26 SWP 3 Circular 1.5 0.024 839.05 836.00 164 1.86 1 10.7 1 7.1 PAMplA23 MN't27t23271072 Ediw Wuer R-- Mgw Plan UpdatelWorkFdestQAQC Model for Pmd4NineMn iCWMM.hydraulic_omput2006UPDATF GnaLNWf�veri0catim.xls SWP_ConduitRmuJw Updete T.H. 169 North 11.0 T.H. 169 North 11.1 General Description of Drainage Area Figure 11.1 depicts the T.H. 169 North drainage area and the individual subwatersheds within this area. The T.H. 169 North drainage area is located in the northwest corner of Edina. The drainage area encompasses approximately 140 acres that ultimately drain to the T.H. 169 drainage system. 11.1.1 Drainage Patterns The stormwater system within this drainage area is comprised of storm sewers, ditches, overland flow paths, and ponding basins. Stormwater from this drainage area ultimately combines with the T.H. 169 storm sewer system at several locations along T.H. 169 between the intersection of Malibu Drive and T.H. 169 and the Edina city limits. The drainage area has been delineated into 23 subwatersheds. Table 1 1.1 describes the naming convention for subwatersheds within the drainage area. Land use within the drainage area includes low- density residential, open area, Van Valkenburg Park, and a small commercial area. Table 11.1 Major Watershed within the T.H. 169 North Drainage Area Major Watershed Subwatershed Naming Convention # of Subwatersheds Drainage Area (acres) T.H. 169 North 169N—## 23 140 11.2Stormwater System Analysis and Results 11.2.1 Hydrologic /Hydraulic Modeling Results The 10 -year and 100 -year frequency flood analyses were performed for the T.H. 169 North drainage area. The 10 -year analysis was based on a'' /2 -hour storm of 1.65 inches of rain. The 100 -year analysis was based on a 24 -hour storm event of 6 inches of rain. Table 11.2 presents the watershed information and the results for the 10 -year and 100 -year frequency hydrologic analyses for the T.H. 169 North drainage area. The results of the 10 -year and 100 -year frequency hydraulic analysis for the T.H. 169 North drainage area are summarized in Table 11.3 and Table 11.4. The column headings in Table 11.3 are defined as follows: Node / Subwatershed ID —XP -SWMM node identification label. Each XP -SWMM node represents a manhole, catchbasin, pond, or other junction within the stormwater system. Downstream Conduit — References the pipe downstream of the node in the storm sewer system. Barr Engineering Company 11 -1 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.doex Flood Elevation —The maximum water elevation reached in the given pond /manhole for each referenced storm event (mean sea level). In some cases, an additional flood elevation has been given in parenthesis. This flood elevation reflects the 100 -year flood elevation of Nine Mile Creek, per the Nine Mile Creek Watershed Management Plan, May 1996. Peak Outflow Rate —The peak discharge rate (cfs) from a given ponding basin for each referenced storm event. The peak outflow rates reflect the combined discharge from the pond through the outlet structure and any overflow. NWL —The normal water level in the ponding basin (mean sea level). The normal water levels for the ponding basins were assumed to be at the outlet pipe invert or at the downstream control elevation. Flood Bounce —The fluctuation of the water level within a given pond for each referenced storm event. Volume Stored —The maximum volume (acre -ft) of water that was stored in the ponding basin during the storm event. The volume represents the live storage volume only. Table 11.4 summarizes the conveyance system data used in the model and the model results for the storm sewer system within the T.H. 169 North drainage area. The peak flows through each conveyance system for the 10 -year and 100 -year frequency storm events are listed in the table. The values presented represent the peak flow rate through each pipe system only and does not reflect the combined total flow from an upstream node to the downstream node when overflow from a manhole /pond occurs. Figure 11.2 graphically represents the results of the 10 -year and 100 -year frequency hydraulic analyses. The figure depicts the T.H. 169 North drainage area boundary, subwatershed boundaries, the modeled storm sewer network, and surcharge conditions for the XP -SWMM nodes (typically manholes). One of the objectives of the hydraulic analyses was to evaluate the level of service provided by the current storm sewer system. The level of service of the system was examined by determining the surcharge conditions of the manholes and catch basins within the storm sewer system during the 10 -year and 100 -year frequency storm events. An XP -SWMM node was considered surcharged if the hydraulic grade line at that node breached the ground surface (rim elevation). Surcharging is typically the result of limited downstream capacity and tailwater impacts. The XP -SWMM nodes depicted on Figure 11.2 were color coded based on the resulting surcharge conditions. The green nodes signify no surcharging occurred during the 100 -year or 10 -year frequency storm event, the yellow nodes indicate surcharging during the 100 -year frequency event, and the red nodes identify that surcharging is likely to occur during both a 100 -year and 10 -year frequency storm event. Figure 11.2 illustrates that several XP -SWMM nodes within the T.H. 169 North drainage area are predicted to experience surcharged conditions during both the 10 -year and 100 -year frequency storm Barr Engineering Company 11 -2 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx events. This indicates a probability greater than 10 percent in any year that the system will be overburdened and unable to meet the desired level of service at these locations. These manholes and catch basins are more likely to experience inundation during the smaller, more frequent storm events of various durations. Another objective of the hydraulic analysis was to evaluate the level of protection offered by the current stormwater system. Level of protection is defined as the capacity provided by a municipal drainage system (in terms of pipe capacity and overland overflow capacity) to prevent property damage and assure a reasonable degree of public safety following a rainstorm. A 100 -year frequency event is recommended as a standard for design of stormwater management basins. To evaluate the level of protection of the stormwater system within the T.H. 169 North drainage area, the 100 -year frequency flood elevations for the ponding basins and depressed areas were compared to the low elevations of structures surrounding each basin. Based on the analysis, the current system in the T.H. 169 North drainage area is providing a 100 -year level of protection. Therefore, no storm sewer or pond upgrades are being recommended at this time. 11.2.2 Water Quality Modeling Results The effectiveness of the stormwater system in removing stormwater pollutants such as phosphorus was analyzed using the P8 water quality model. The P8 model simulates the hydrology and phosphorus loads introduced from the watershed of each pond and the transport of phosphorus throughout the stormwater system. Since site - specific data on pollutant wash -off rates and sediment characteristics were not available, it was necessary to make assumptions based on national average values. Due to such assumptions and lack of in -lake water quality data for model calibration, the modeling results were analyzed based on the percent of phosphorus removal that occurred and not based on actual phosphorus concentrations. Figure 11.3 depicts the results of the water quality modeling for the T.H. 169 North drainage area. The figure shows the fraction of total phosphorus removal for each water body as well as the cumulative total phosphorus removal in the watershed. The individual water bodies are colored various shades of blue, indicating the percent of the total annual mass of phosphorus entering the water body that is removed (through settling). It is important to note that the percent of phosphorus removal is based on total phosphorus, including phosphorus in the soluble form. Therefore, the removal rates in downstream ponds will likely decrease due to the large soluble fraction of incoming phosphorus that was unsettleable in upstream ponds. The watersheds are depicted in various shades of gray, indicating the cumulative total phosphorus removal achieved. The cumulative percent removal represents the percent of the total annual mass of phosphorus entering the watershed that is removed in the pond and all upstream ponds. Ponds that had an average annual total phosphorus removal rate of 60 percent or greater, under average climatic conditions, were considered to be performing well. For those ponds with total phosphorus removal below 60 percent, the permanent pool storage volume was analyzed to determine if additional capacity is necessary. Based on recommendations from the MPCA publication Barr Engineering Company 11-3 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFnEdina SWMP FINAL DRAFT 12151IREV.docx Protecting Water Quality in Urban Areas, March 2000, the permanent pool for detention ponds should be equal to or greater than the runoff from a 2.0 -inch rainfall, in addition to the sediment storage for at least 25 years of sediment accumulation. For ponds with less than 60 percent total phosphorus removal, the recommended storage volume was calculated for each pond within the drainage basin and compared to the existing permanent pool storage volume. 11.3 Implementation Considerations The XP -SWMM hydrologic and hydraulic modeling analyses and P8 water quality analysis helped to identify locations throughout the watershed where improvements to the City's stormwater management system may be warranted. The following sections discuss potential mitigation alternatives that were identified as part of the 2003 modeling analyses. As opportunities to address the identified flooding issues and water quality improvements arise, such as street reconstruction projects or public facilities improvements, the City will use a comprehensive approach to stormwater management. The comprehensive approach will include consideration of infiltration or volume retention practices to address flooding and /or water quality improvements, reduction of impervious surfaces, increased storm sewer capacity where necessary to alleviate flooding, construction and /or expansion of water quality basins, and implementation of other stormwater BMPs to reduce pollutant loading to downstream waterbodies. 11.3.1 Flood Protection Projects The 2003 hydrologic and hydraulic modeling analysis identified several locations within the T.H. 169 North drainage basin where the 100 -year level of protection is not provided by the current stormwater system. The problem areas identified in 2003 are discussed below. As part of the 2003 modeling analysis, potential corrective measures were identified for the problem areas for purposes of developing planning -level cost estimates. These preliminary corrective measures are also discussed below. As the City evaluates the flooding issues and potential system modifications in these areas, consideration will be given to other potential system modifications, including implementation of stormwater infiltration or volume retention practices, where soils are conducive. 11.3.2 Construction /Upgrade of Water Quality Basins The 2003 P8 modeling analysis indicated that the predicted annual removal of total phosphorus from Pond 169N_16 in the T.H. 169 North drainage area was below the desired 60 percent removal rate, under average year conditions. The permanent pool storage volume was analyzed to determine if additional capacity is necessary. The basin was found to have sufficient dead storage volume, based on the MPCA recommended permanent pool storage volume for detention basins for the removal of particulate phosphorus. As a result, no specific recommendations for water quality basin upgrades in the T.H. 169 North drainage area are being made at this time. Barr Engineering Company 11 -4 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx Construction of new or expansion of existing water quality basins is one method to increase the pollutant removal achieved prior to stormwater reaching downstream waterbodies. Many additional techniques are available to reduce pollutant loading, including impervious surface reduction or disconnection, implementation of infiltration or volume retention BMPs, installation of underground stormwater treatment structures and sump manholes and other good housekeeping practices such as street sweeping. As opportunities arise, the City will consider all of these options to reduce the volume and improve the quality of stormwater runoff. Barr Engineering Company 11-5 P; \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 152011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 9 J = ova 6 u n 0 a 7 _U a Y Y Y NI W U ai LL id r� 0 0 t m Q69N 22llIllIlll§UU Hopkins 4 r. mss' a F i , - N 0 • ,��URF'URPT�v • lees City of Edina Boundary Roads /Highways Creek /Stream Lake /Wetland C3 T.H. 169 North Drainage Basin (�3 Subwatershed Imagery Source: Aerials Express, 2008 O Feet 600 0 600 Meters 200 0 200 Figure 11.1 T.H. 169 NORTH DRAINAGE BASIN Comprehensive Water Resource Management Plan City of Edina, Minnesota EON, =16N 9M a N N O C 0 0 LL t= Hopkins 169N_9 169 _11 I M DEARBORN CT I ° " MORE LA — _ ir:"�1� I�1i • f 'b�BEL L Z u'k3s a. s' N . Q z m mr E 1 29 1 28 169N .3 1429 169N_1' LINCOLN AftA k4l) ow e Cn N k O 173 H tl City of Edina Boundary Roads /Highways Lake /Wetland C3 T.H. 169 North Drainage Basin Subwatershed Major Watershed Pipes 0 Manhole Manhole Surcharge During • 100 -Year Frequency Event Manhole Surcharged During 10 -Year Frequency Event Imagery Source: Aerials Express, 2008 O Feet 400 0 400 Meters 150 0 150 Figure 11.2 T.H. 169 NORTH HYDRAULIC MODEL RESULTS Comprehensive Water Resource Management Plan City of Edina, Minnesota Table 11.2 Watershed Modeling Results for Subwatersheds in the T.H. 169 -North Drainage Area (Revised 12/2006). Watershed Information 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Watershed'ID Total Area " . (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume. Runoff (ac -ft) ' Peak Runoff Rate (cfs) Total Volume kunoff (ac -ft) 169N_I 5.5 21 23.5 1`.58 12.5 0.33 169N 2 1.0 20 4.9 0.29 .3.9 0.07 169N_3 2.0 20 9.0 --0.56 5:1 0.12 169N_4 ,9.4 20 35.6 2.67 16.9 0.52 169N_5. 1'.7. 20 7.9 0.47 5:9 0.11 169N 6 1.0 14 4.5 0.26 3.6 0.00 169N 7 3.6 24 15.7 1.13 9.2 0.25 169N 8 2.1 20 9.7 0.58 6.9 0.14 169N_9.' 8.5 12 29.3 2.15 11.1 0.36 ;169N_10 6.7 19 29.5 1.85 15.6 0.39' 169N 11 8.5 20 33.6 2.35 16.1 0.45. 169N 12 12.0 13 50.3 3.16 21.5 0:62 169N 13 12.4 9 46.4 3.07 16.1 0:53 169N14 3.3 20 15.3 0.93 9.4 0.21 169N 15 8.2 0 33.2 1.87 10.9 0.32 169N_16 2.4 15 10.7 0.63 5.8 0.14 169N_17 19.5 2 66.1 4.36 19.0 0.70 169N18 4.9 41 23.1 =' 1.80 18.5 0.44 169N19 4.2 3 18.5 0.99 7.7 0.19 169N 20 9.0 16 35.8 2.42 15.9 0.46 169N21 3.2 207. 11.1 0.86 5.1 0.16 169N22 5.3 63 25.4 2.16 24.4 0.55 169N_23 6.0 0 25.3 1.47 9.8 0.29 PAMpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\NineMILe_SWMM hydraulic_ output_ 2006UPDATE _final_NWL_verification.xis 169N Runoff Results Updated Table 11.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in the T.H. 169 -North Drainage Area (Revised 1212006) Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft) Type of Storage' NWL (ft) Flood Bounce (ft) Flood Elevation (ft) NWL (ft) Flood Bounce (ft) 94 outlet to TH 169 system 914.5 912.5 106 outlet to TH 169 system 912.7 912.2 108 outlet to TH 169 system 909.3 908.8 1395 1102 939.9 938.0 1399 1104 939.3 b d 934.4 4.9 938.0 934.4 3.6 1400 1106 937.7 937.4 1401 1107 937.4 937.1 1402 1108 937.0 935.1 1404 1110 925.4 923.9 1406 1112 924.1 920.9 1408 1114 923.4 918.8 1409 1115 924.3 918.5 1411 outlet to TH 169 system 918.5 915.9 1413 1118 932.8 932.4 1416 1121 928.2 927.9 1427 1131 902.7 898.8 1428 1132 908.7 904.9 1429 1133 921.8 917.9 1431 95 915.1 913.6 1435 1137 924.2 913.0 1436 1138 905.3 901.3 1437 1139 901.6 897.4 1439 1141 893.9 891.0 1440 1142 893.8 890.3 1441 1143 905.0 902.1 1443 outlet to TH 169 system 877.3 876.4 2486 1322 913.7 910.8 2487 1323 913.7 910.7 169N_1 107 914.3 913.6 169K2 1103 953.0 949.1 169N_3 1113 923.0 919.1 169N_4 1119 932.5 932.2 169N_5 2021 918.0 917.1 169N_6 1154 972.2 971.2 169N7 120 918.0 914.4 169N8 1101 943.7 942.5 169N 9 1111 922.4 921.8 169N_10 1109 925.9 924.9 169N_I1 1116 9215 917.5 169N_12 1130 935.2 932.6 169N_13 1134 916.0 1 915.7 169N_14 1105 939.2 938.9 169N15 landlocked 932.5 depression 925.5 7.0 928.7 925.5 3.2 169N16 1136 923.8 pond 914.4 9.4 918.9 914.4 4.5 169N17 1135 926.7 922.4 169N18 1144 899.5 898.9 169N 19 1140 910.2 907.1 1691S 20 1117 935.0 934.8 169N_21 1120 930.6 930.2 169N 22 69 910.96 910.2 169N 23 1321 913.67 de -ssion 910.9 2.8 911.7 1 910.9 0.8 PAMpls\23 MN\27\23271072 Edina Water Resource Mgmt Plan Update \Workpitm \QAQC Modcl for PmMimMns_SWMM_hydrmlic output 2006UPDATE -final NWL_verifimlion.sls 169N_100y_NodeRaults UPDATED Table 11.4 Conduit Modeling Results for Subwatersheds In the T.H. 169 -North DrainageArea (Revised 12/2006) Conduit ID Upstream Node - Downstream Node Conduit Shape Conduit Dimensions (f) Roughness Coecient ffi Upstream Invert Elevation Downstream Inver Elevation Conduit Length A Slope IOOY Peak Flow through Conduit (c(s) 10Y Peak Flow through Conduit (cfs) 69 169N_22 108 Circular 2.0 0.013 904.16 903.93 31 0.7 38.4 34.2 95 1431 94 Circular 2.0 0.013 908.17 908.06 43 0.3 34.8 34.7 107 169N1 106 Circular 1.0 0.013 909.31 909.27 .19 0.2 6.9 6.1 120 169N7 109 Circular 2.0 0.013 909.28 907.17 118 1.8 38.5 28.9 1101 169N8 1395 Circular 1.25 0.013 94L86 936.25 123 4:6 9.7 6.9 1102 1395 1399 Circular 1.5 0.013 936.25 935.80 45 1.0 9.7 6.9 1103 169N2 169N_14 Circular 1.0 0.024 944.57 934.04 280 3.8 4.5 3.8 1105 169N14 1400 Circular lA 0.024 934.04 933.08 299 0.3 2.4 2.4 1106 1400 1401 Circular 1.0 0.013 933.08 932.50 161 0.4 2.4 2.3 1111 169N9 1406 Circular - 2.0 0.014 919.01 918.26 188 0.4 18.1 18.8 1112 1406 a 169N3 Circular 2.0 0.013 918.26 916.56 335 0.5 17.0 17.0. 1113 169N3 1408 Circular 3.0 0.013 916.06 914.81 324.7 0.4 22.7 21.9 1114 1408 1409 Circular - 3.0 0.013 914.80 913.28 331.1. 0.5 29.3 24.1 1115 1409 169N_II Circular 3.0 0.013 913.27 911.99. 339.6, 0.4 41.1 37.5 1116 169N-l1 1411 Circular. 3.0 0.013 912.05 910.51 290.2 0.5 62.9 49.3 1135 169N_17 169N_16. Circular . 2.0 0.013 920.83 918.50 94 2.5 41.2 21.0 1136 169N16 1435 Circular 1.0 0.013 919.50 917.10 65 3.7 6.8 0.0 1137 1435 1436::.- _ Circular 1.0 1 0.013 914.00 911.26 70 3.9 7.8 0.0 1138 1436 1437 Circular 1.0 0.013 911.26 906.11 .220 2.3 7.5 0.0 1140 169N19 1439 Circular 1.5 0.013 905.89 905.40 63 0.8 18.0 7.7 1141 1439 1440 Circular 1.75 0.013 905.40 899.92 218 2.5 1 23.2 7.7 1143 1441 169N_18 Circular 2.0 0.013 899.40 898.83 10 5.7 27.1 8.0 1154 169N6 1462 Circular 1.0 0.013 970.20 969.34 59.8 1.4 4.5 3.6 1104 1399 169N_14 Circular 1.0 0.024 934.40 934.04 30 1.2 4.1 -5.6 - 1107 1401 1402 Circular 1.0 0.013 932.23 931.91 66 .0.5 6.6 6.3 1108 1402 169N_10 Circular 1.0 0.013 931.91 920.04 315 3.8 7.5 6.4 1109 169N10 1404 Circular 1.75 0.013 920.04 919.58 60 0.8 26.1 20.5 1110 1404 169N9 Circular 1.75 0.013 919.58 919.01 161 0.4 21.2 16.9 1117 169N20 1413 Circular 1.5 0.013 928.60 926.10 331.3 ' 0.8 10.9 10.4 1118 1413 169N_4 Circular 1.75 0.013 926.10 925.30 136.5 0.6 10.7 14.1 1119 169N_4 169N21 - Circular 1.75 0.013 925.30 924.20 197. ' 0.6 23.9 24.4 1120 169N_21 1416 Circular 2.25 0.013 924.20 921.54 333 0.8 26.6 27.8 1121 1416 169N_5 Circular 0.013 921.54 911.00 270 3.9 22.2 22.6 1130 169N_12 1427 Circular 1.75 0.013 927.64 924.34 330 1.0 24.3 21.6 1131 1427 1428 'Circular 1.75 0.013 924.34 918.40 151 -. 3.9 27.2 21.2 1132 1428 1429 - Circular 2.0 0.024 917.99 914.13 189 2.0 30.1 21.2 1133 1429 169N_13 Circular 2.0 0.013 914.13 908.72 266 2.0 32.1 19.5 1134 169N13 1431 Circular 2.0 0.013 908.82 908.26 71 0.8 33.7 33.8 1139 1437 169N =19 Circular 1.0 0.013 906.11 905.89 27 0.8 7.0 -0.2 1142 1440 1441 Circular 1.75 0.024 899.67 898.95 IU 7.2' 16.8 8.0 1144 1442 169N_18 Circular 2.0 0.013 898.83 898.09. 153 0.5 37.0 '25.3 1321 16911_23 2486 Circular 2.0 0.013 910.87 908.70 6 36.2 21.8 9.9 1322 2486 2487 Circular 2.0 0.013 907.71 907.53 28 0.6 21.9 10.0 1323 2487 169N22 Circular, 2.0 0.013 907.51 904.29 68 4.7 31.0 14.2 2021 169N_5 1413 ' Circular 1.5 0.013 911.00 909.28 45.2 3:91 .27.9 28.8 P:%MpbV3 MM27U3271U72 FAim Ware Resaurca Mgua Plan UpdudWorkFdstQAQC Modd for PondWinc%M &- SWNU&hydnuGc mtpw-2006UPDA7'E-GoeLNWl�vcificaiim.xls 169N_ConduitRmulu UPDATED Northeast Minnehaha Creek 12.0 Northeast Minnehaha Creek 12.1 General Description of Drainage Area Figure 12.1 depicts the Northeast Minnehaha Creek drainage area and the individual subwatersheds within this area. The Northeast Minnehaha Creek drainage basin is located in the northeast corner of Edina. This watershed contains only a limited number of ponds and no lakes. 12.1.1 Drainage Patterns The stormwater system within this drainage area is comprised of storm sewers, ponding basins, wetlands, drainage ditches, and overland flow paths. The Northeast Minnehaha Creek basin has been divided into several major watersheds based on the drainage patterns. These major watersheds are depicted in Figure 12.2. Each major watershed has been further delineated into numerous subwatersheds. The naming convention for each subwatershed is based on the major watershed it is located within. Table 12.1 lists each major watershed and the associated subwatershed naming convention. Table 12.1 Major Watersheds within the Northeast Minnehaha Creek Drainage Basin Major Watershed Subwatershed Naming Convention # of Subwatersheds Drainage Area (acres) Morningside MS—## 58 228 Minnehaha Creek North MHN ## 89 450 Edina Country Club ECC_## 15 117 12.1.1.1 Morningside The Morningside watershed is located in the northeast corner of Edina, primarily north of West 44`h Street. This watershed is primarily single family residential and includes Weber Park. The Edina trunk storm sewer system through this area connects to the incoming St. Louis Park system just southeast of the Susan Lindgren Elementary School (Natchez Avenue and 41" Street). From this junction the system runs easterly to the east side of Weber Park, where an inlet /outlet to the Weber Park pond allows stormwater to be discharged into the basin until the water level in the pond reaches an elevation at which the head differential between the pond and the trunk storm sewer system results in a discharge from the Pond. From the Weber Park Pond, the system drains north to St. Louis Park and then east to connect with the Minneapolis system, where it eventually drains to Lake Calhoun. 12.1.1.2 Minnehaha Creek North The Minnehaha Creek North watershed lies primarily east of Minnehaha Creek, west of France Avenue, north of West 54`h Avenue and south of West 44th Avenue. There are only two wetlands within this watershed and no ponds, all other areas discharge directly to Minnehaha Creek. The land use is single family residential for the majority of the watershed, with some commercial land use Barr Engineering Company 12 -1 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx adjacent to France Avenue. There is very little open space in this watershed except for areas directly adjacent to Minnehaha Creek. 12.1.1.3 Edina Country Club The Edina Country Club watershed is a small, 117 -acre watershed that encompasses the Edina Country Club golf course and areas east of the Country Club to Minnehaha Creek. The watershed area outside of the golf course is low density residential, contains no ponds or wetlands, and all areas discharge directly to Minnehaha Creek. There are no known pipes connecting the ponds of the Edina Country Club to the adjacent storm sewer network along Wooddale Avenue. 12.2Stormwater System Analysis and Results 12.2.1 Hydrologic /Hydraulic Modeling Results The 5 -year, 10 -year, and 100 -year event frequency flood analyses were performed for the Northeast Minnehaha Creek drainage basin. For the Minnehaha Creek North and the Edina Country Club drainage areas, the storm sewers were evaluated using a 10 -year and a 100 -year storm event. The 10 -year analysis was based on a 1/2-hour storm of 1.65 inches of rain and the 100 -year analysis was based on a 24 -hour storm event of 6 inches of rain. The storm sewers in the Morningside drainage basin were evaluated using the 1/2-hour, 5 -year storm of 1.5 inches and the 100 -year, 24 -hour storm of 6 inches. Table 12.2 presents the watershed information and the results for the 5 -year, 10 -year, and 100 -year hydrologic analyses for the Northeast Minnehaha Creek basin. The results of the 5 -year, 10 -year, and the 100 -year hydraulic analysis for the Northeast Minnehaha Creek drainage basin are summarized in Table 12.3 and Table 12.4. The column headings in Table 12.3 are defined as follows: Node /Subwatershed ID — XP -SWMM node identification label. Each XP -SWMM node represents a manhole, catchbasin, pond, or other junction within the stormwater system. Downstream Conduit — References the pipe downstream of the node in the storm sewer system. Flood Elevation —The maximum water elevation reached in the given pond/manhole for each referenced storm event (mean sea level). In some cases, an additional flood elevation has been given in parenthesis. This flood elevation reflects the 100 -year flood elevation of Minnehaha Creek, as shown in the National Flood Insurance Program Flood Insurance Study for the City of Edina, May 1979. Peak Outflow Rate —The peak discharge rate (cfs) from a given ponding basin for each referenced storm event. The peak outflow rates reflect the combined discharge from the pond through the outlet structure and any overflow. Barr Engineering Company 12 -2 P: \Mpls \23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV 2.docx NWL —The normal water level in the ponding basin (mean sea level). The normal water levels for the ponding basins were assumed to be at the outlet pipe invert or at the downstream control elevation. Flood Bounce —The fluctuation of the water level within a given pond for each referenced storm event. Volume Stored —The maximum volume (acre -ft) of water that was stored in the ponding basin during the storm event. The volume represents the live storage volume only. 'fable 12.4 summarizes the conveyance system data used in the model and the model results for the storm sewer system within the Northeast Minnehaha Creek drainage basin. The peak flow through each conveyance system for the 5 -year (Morningside only), 10 -year, and the 100 -year storm event is listed in the table. The values presented represent the peak flow rate through each pipe system only and does not reflect the combined total flow from an upstream node to the downstream node when overflow from a manhole /pond occurs. Figure 12.3 graphically represents the results of the 5 -year, 10 -year, and the 100 -year frequency hydraulic analyses. The figure depicts the Northeast Minnehaha Creek drainage basin boundary, subwatershed boundaries, the modeled storm sewer network, surcharge conditions for the XP- SWMM nodes (typically manholes), and the flood prone areas identified in the modeling analyses. One of the objectives of the hydraulic analyses was to evaluate the level of service provided by the current storm sewer system. The level of service of the system was examined by determining the surcharge conditions of the manholes and catch basins within the storm sewer system during the 5 -year, 10 -year and 100 -year storm events. An XP -SWMM node was considered surcharged if the hydraulic grade line at that node breached the ground surface (rim elevation). Surcharging is typically the result of limited downstream capacity and tailwater impacts. The XP -SWMM nodes depicted on Figure 12.3 were color coded based on the resulting surcharge conditions. The green nodes signify no surcharging occurred during the 100 -year, 10 -year, or 5 -year frequency storm event, the yellow nodes indicate surcharging during the 100 -year event, the red nodes identify that surcharging is likely to occur during both a 100 -year and 10 -year frequency storm event, and the blue nodes indicate surcharging during the 100 -year and the 5 -year frequency storm event (Morningside only). Figure 12.3 illustrates that several XP -SWMM nodes within the Northeast Minnehaha Creek drainage basin are predicted to experience surcharged conditions during the 5 -year, 10 -year and 100 -year frequency storm events. This indicates a probability greater than 5 -10 percent in any year that the system will be overburdened and unable to meet the desired level of service at these locations. These manholes and catch basins are more likely to experience inundation during the smaller, more frequent storm events of various durations. Another objective of the hydraulic analysis was to evaluate the level of protection offered by the current stormwater system. Level of protection is defined as the capacity provided by a municipal drainage system (in terms of pipe capacity and overland overflow capacity) to prevent property Barr Engineering Company 12 -3 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx damage and assure a reasonable degree of public safety following a rainstorm. A 100 -year frequency event is recommended as a standard for design of stormwater management basins. To evaluate the level of protection of the stormwater system within the Northeast Minnehaha Creek drainage area, the 100 -year frequency flood elevations for the ponding basins and depressed areas were compared to the low elevations of structures surrounding each basin. The low elevations were initially determined using 2 -foot topographic information and aerial imagery in ArcView. Where 100 -year frequency flood levels of the ponding areas appeared to potentially threaten structures, detailed low house elevations were obtained through field surveys. The areas that were predicted to flood and threaten structures during the 100 -year storm event are highlighted in Figure 12.3. Discussion and recommended implementation considerations for these areas are included in Section 12.3. 12.2.2 Water Quality Modeling Results The effectiveness of the stormwater system in removing stormwater pollutants such as phosphorus was analyzed using the P8 water quality model. The P8 model simulates the hydrology and phosphorus loads introduced from the watershed of each pond and the transport of phosphorus throughout the stormwater system. Since site - specific data on pollutant wash -off rates and sediment characteristics were not available, it was necessary to make assumptions based on national average values. Due to such assumptions and lack of in -lake water quality data for model calibration, the modeling results were analyzed based on the percent of phosphorus removal that occurred and not based on actual phosphorus concentrations. Figure 12.4 depicts the results of the water quality modeling for the Northeast Minnehaha Creek drainage basin. The figure shows the fraction of total phosphorus removal for each water body as well as the cumulative total phosphorus removal in the watershed. The individual water bodies are colored various shades of blue, indicating the percent of the total annual mass of phosphorus entering the water body that is removed (through settling). It is important to note that the percent of phosphorus removal is based on total phosphorus, including phosphorus in the soluble form. Therefore, the removal rates in downstream ponds will likely decrease due to the large soluble fraction of incoming phosphorus that was unsettleable in upstream ponds. The watersheds are depicted in various shades of gray, indicating the cumulative total phosphorus removal achieved. The cumulative percent removal represents the percent of the total annual mass of phosphorus entering the watershed that is removed in the pond and all upstream ponds. Ponds that had an average annual total phosphorus removal rate of 60 percent or greater, under average climatic conditions, were considered to be performing well. For those ponds with total phosphorus removal below 60 percent, the permanent pool storage volume was analyzed to determine if additional capacity is necessary. Based on recommendations from the MPCA publication Protecting Water Quality in Urban Areas, March 2000, the permanent pool for detention ponds should be equal to or greater than the runoff from a 2.0 -inch rainfall, in addition to the sediment storage for at least 25 years of sediment accumulation. For ponds with less than 60 percent total phosphorus removal, the recommended storage volume was calculated for each pond within the drainage basin and compared to the existing permanent pool storage volume. Barr Engineering Company 12 -4 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT1Edina SWMP FINAL DRAFT 121511REV.docx 12.3 Implementation Considerations The.XP -SWMM hydrologic and hydraulic modeling analyses and P8 water quality analysis helped to identify locations throughoutthe watershed where improvements to the City's stormwater management system may be warranted. The following sections discuss potential mitigation alternatives that were identified as part of the 2003 modeling analyses. As opportunities to address the identified flooding issues and water quality improvements arise, such as street reconstruction projects, or public facilities improvements, the City will use a comprehensive approach to stormwater management. The comprehensive approach will include consideration of infiltration or, volume retention practices to address flooding: and /or water quality improvements, reduction of impervious surfaces, increased storm sewer capacity where necessary to alleviate flooding, construction_ and /or expansion of water quality basins, and implementation of other stormwater BMPs to reduce pollutant loading to downstream waterbodies. . 12.3.1 Flood Protection Projects The 2003 hydrologic and hydraulic modeling analysis identified several locations within the Northeast Minnehaha Creek drainage basin where the 100 -year level of protection is not provided by the current stormwater system. The problem areas identified in 2003 are discussed below. = As part of the 2003 modeling analysis, potential corrective measures were identified for the problem areas for purposes of developing planning -level cost estimates. These preliminary corrective, measures are also discussed below. As the City evaluates the flooding issues and potential system - modifications in -these areas, consideration. will be given to other potential system modifications, including implementation of stormwater infiltration or volume retention practices, where.soils.are conducive. 12.3.1.1 4000 West 42nd Street and 4100, 4104, and 4108 France Avenue (MS_ . A large portion of the Morningside watershed discharges to a pond located on the east side of Weber Park (Weber Park Pond). This pond was designed to provide protection for a 50 -year storm. The City's 2004 Comprehensive Water Resources Management Plan identified the potential for flooding of properties adjacent to the pond, which was confirmed during a significant rainfall event that occurred in 2005. In 2006, the City completed a Feasibility Analysis to assess the flooding problem and evaluate options to minimize the flooding potential. Results of the 2006 analysis indicate that the predicted high water elevations in the Weber Park Pond for a 50 -year and 100 -year frequency flood; event, based on existing conditions, are 868.6 ft MSL and 869.0 ft MS.L, respectively. Afield survey completed at the time indicates that the low entry elevations of four homes adjacent to the pond are aV- or below the predicted 100 -year high water elevation, including 4000 West 42 "d Street, 4100 France Avenue, 4104 France Avenue, and 4108 France Avenue. Based on the feasibility study completed, it was determined that the options to alleviate the flooding potential for the homes adjacent to the Weber Park pond are limited due to constraints in the downstream storm sewer system. Adding additional storage volume to the Weber Park pond would Barr Engineering Company 12 -5 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAF-REdina SWMP FINAL DRAFT 121511REV.docx reduce the 100 -year flood elevation of the pond to approximately 868.5 ft MSL. However, this flood elevation is still at or above the low entry elevation of three of the homes adjacent to the pond. An additional downstream capacity of 80 cfs would be required to alleviate the flooding at all adjacent properties under existing pond conditions, which is an expensive option. Should the City of Minneapolis update their storm sewer system in this area in the future, Edina will consider working with the City of Minneapolis to incorporate upgrades sufficient to provide additional capacity for the Morningside area drainage. The most cost effective option to upgrade to a 100 -year level of protection for the homes currently below the 100 -year flood level (4100, 4104, and 4108 France Avenue) would be to floodproof the affected homes and installation of a pumping station to drain stormwater runoff from the backyard area of the affected properties during significant storm events. 12.3.1.2 4308 France Avenue (MS_17) The low area in the backyard of 4308 France Avenue is inundated to an elevation of 902.5 MSL during the 100 -year frequency storm. The results of a field survey indicate that this water level will potentially impact the house located at 4308 France Avenue. To protect the structure at 4308 France Avenue, it is recommended that in this depression area a catch basin be located and connected to the storm sewer system at the intersection of Scott Terrace and West 42 "d Street. 12.3.1.3 4300, 4214, and 4212 Branson Street (MS 3) A depression in the backyard of 4300, 4214, and 4212 Branson Street is inundated to an elevation of 900.6 MSL during the 100 -year frequency storm event. At this elevation structures will be affected at 4300, 4214 and 4212 Branson Street. A 15 -inch storm sewer originating at Branson Street flows north and connects to the pipe system on Morningside Street. It is recommended that a catch basin be placed in the backyard depression area and pipe 955 upgraded to 24 -inch diameter. This will reduce the 100 -year frequency storm elevation to 899.5 MSL and protect the structures at 4300, 4214, and 4212 Branson Street. 12.3.1.4 4140 and 4150 West 44t" Street (MS_7) A depression in the backyard of 4140 and 4150 West 44th Street is inundated to 900.6 MSL during the 100 -year frequency storm as a result of runoff from its tributary watershed area. In addition, the storm sewer system on West 44`h Street surcharges during the 100 -year frequency storm and as a result, water flows from West 44`h Street and into the backyard depression area. The addition of a catch basin to the backyard of 4140 and 4150 West 44`h Street with a connection to the pipe system on West 44`h Street was evaluated, but this alternative would require that the entire pipe system along West 44`h Street and Morningside Avenue be upgraded. It is recommended that the storage capacity of this backyard area be increased by 1.4 acre -feet to an elevation of 899.3 MSL to protect the structure at 4140 and 4150 West 44`h Street. This additional storage capacity can be achieved by lowering the depth of the backyard depression area by approximately 2 feet. Barr Engineering Company 12 -6 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 12.3.1.5 Arden Avenue (MHN_14) Storm sewer improvements made in 2000 on Bridge Street, Sunny Side Road, and Arden Avenue were designed to reduce the potential for flooding at the low area on Arden Avenue just south of Bridge Street. The high water elevation of the 100 -year frequency storm was 884.6 MSL, indicating that during a 100 -year storm event the storm sewer improvements would protect.the houses on Arden Avenue with the exception of the low house at 4611 Arden Avenue. 12.3.2 Construction /Upgrade of Water Quality Basins The NO P8 modeling analysis indicated that the predicted annual removals of total phosphorus: from the ponds and wetlands in the Northeast Minnehaha Creek drainage area are greater,than the 60 percent removal rate, under average .year conditions. As a result, no specific recommendations are given for the construction or upgrade of water quality basins in this watershed. Many techniques are available to reduce pollutant loading from stormwater runoff, including impervious surface reduction or disconnection, implementation of infiltration or volume retention BMPs, installation of underground stormwater treatment structures and sump manholes and other good housekeeping practices such as street sweeping. As opportunities - arise, the City will.consider all of these options to reduce the volume and further improve the quality of stormwater runoff from this drainage area: i Barr Engineering Company 12 -7 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx M_ MS-3a St. Louis Park CRA QXM ORA MEW LOMA n 0 c c u I C 0 a LL N V 0 0 0 LL t M MVWP 90-% ' MGU F loo � � l�9 MHN�e l N_5I 5 r\ MHN_61 A, Uj O 1W City of Edina Boundary Roads /Highways Lake /Wetland Creek /Stream Minnehaha Creek - Northeast C3 Drainage Basin Subwatershed Imagery Source: Aerials Express, 2008 0 Feet 1.000 0 1,000 MOM Meters 300 0 300 Figure 12.1 NORTHEAST MINNEHAHA CREEK DRAINAGE BASIN Comprehensive Water Resource Management Plan City of Edina, Minnesota a 0 1 In St. Louis Park W I -u Minneapolis inhaaNrth R. Sk ina Co ntry Club 11Y. t re !i Q j g o e • 13 URA1�`� • 188A City of Edina Boundary Roads /Highways Creek /Stream Lake /Wetland Minnehaha Creek - Northeast C3 Drainage Basin (3 Major Watershed j Subwatershed Imagery Source: Aerials Express. 2008 Q Feet 1.000 0 1.000 Meters 300 0 300 Figure 12.2 NORTHEAST MINNEHAHA CREEK MAJOR WATERSHEDS Comprehensive Water Resource Management Plan City of Edina, Minnesota w r w Ljj W Y 8 � O r h1H -2129 MH- 430 �B- 311 ''MH -2152 FE- 148 MH -214 FE -2146 CB -2431 CAB 22 �3�! 6�2" 3 FE -231+2 GSB -2'Y45 • FE 2330 / O MHN_36 IMHN_38 • u GB -2460 C•B- 61 MHN_35 GB- FE- 144 � FE -1900 C•B -1899 EDINB ' MHN 85 OOK LA 48TH ST W c CB -22 2 FE- 243 MH- 428 h1HN 79 CB -2427 max MILLPOND • • • • • 1N Uj Figure 12.3 NORTHEAST MINNEHAHA CREEK HYDRAULIC MODEL RESULTS Comprehensive Water Resource Management Plan City of Edina, Minnesota City of Edina Boundary Roads /Highways Creek/Stream Lake/Wetland Minnehaha Creek - Northeast Drainage Basin C3 Subwatershed Feet 300 0 300 Meters 100 0 100 viva MHN_47 a 4 MEN Geri QD � QO Q� man RD C ., uvacr t cr° w a 0 D WOODHILL 9 v T a O to -o 9 z pQ z z �4, ai pP HILLTOP LA Q Potential Flooding During 100 -Year Frequency Event ' Pipes Manhole Manhole Surcharge During 100 -Year Frequency Event Manhole Surcharged During 10 -Year Frequency Event ECC_] ME E ECC 4 It •C ROM A1NN_46 C_B_ 31_3 MHN_2.1 ruG4 G :1 •}4 BRIDGE 8T w q m p O z �D j m i A� WWRI\GO U0 �P d `aJP `il Ord N >Z EGC_5' EDINA COUNTRY CLU E�i CCU ECC_2 777 ECCWE ECC_'5 G\-V6 RD IMR K G v O Y� m 9G m &% II ME—% MS_36 l 'i auf A w low Q 45TH ST W w 2 O c Cx0 c cCI3�C$3• SUNNYSIDE v TOWNES CIR 19 G� PO EMS 2�N Y 7/l 1 0 O TM `BRIDGE ST BRIDGE LA ON G L e40TH ST W J MMM j .. A w Q > > w w L94 w lc�'• J ¢ c w X i �r 0 ¢ c w ¢ 0 0 Q 3 m } w w z ' O Q ly w a J CL Z O Z Z Y O rL J \J 0 •ou .41ST ST W <o:r% C3 , i l •0 i p I MIA Li :0 I1 V'V -A cn w P MA Q w tY LL' I�1P� C • 0 :A42ND ST W Wnw6/�i kill' M,• I a49TH uj C G�91/ C3 w . o Q >O d r ¢ ° wLi2 I GI_71t Li3 49 112 ST W O w w W D Q Q Yd O^ Q Z �I, w a H Emu z G 9p — C7 O i Map_. ✓. vy u• 0 50TH ST W 00 G �i w U d J MMA _ , MO NfNGSIDEARD V) E d O w a ELIO U) d _ O •• z WOODDDAAL�E3 LA o �' s C��i1(�}' J(• d O ST •`• BRANSON 'i auf A w low Q 45TH ST W w 2 O c Cx0 c cCI3�C$3• SUNNYSIDE v TOWNES CIR 19 G� PO EMS 2�N Y 7/l 1 0 O TM `BRIDGE ST BRIDGE LA G w Q > > w L94 J ¢ w X 0 ¢ 0 0 U m O Q O 0 Li :0 P tY ST W a49TH G�91/ C3 COUNTRY CLUB RD I GI_71t Li3 49 112 ST W d a Emu z G 9p Map_. ✓. vy u• 0 50TH ST W 00 G �i w U d J MMA _ , E d O _ •• WOODDDAAL�E3 LA �' s C��i1(�}' J(• ST •`• w 51ST ST W T X" Lu Emu * �. BRt10EAVE a mmus w w'm FA d J O Z z w Q • Z d P Y OODDALE w a� OMEN ' . �_r a fl o c� \ G7Zfl QiGO .� • S T W � C:3 W_52nd o p p. CD o �Q' u C 0 Z =fir Muff w w 0 O O O O� Pi ` m y i I • ti. c u a f A. St. Louis Park reek a --4 r _3 try U" Minneapolis �. MHN_66 MHN 11 Imagery Sourc - ials Exprels 2008 4,91i A.lrl. 0 Percent TP Removal in Water Body* This number represents the percent of the total annual mass of phosphorus entering the water body that is removed. 0 - 25% (Poor /No Removal) 25 - 40% (Moderate Removal) 40 - 60% (Good Removal) _ 60 - 100% (Excellent Removal) Cumulative TP Removal in Watershed* This number represents the percent of the total annual mass of phosphorus entering the watershed and upstream watersheds that is removed in the pond and all upstream ponds. 25 - 40% (Moderate Removal) 40 - 60% (Good Removal) 60 - 100% (Excellent Removal) 'Data based on results of P8 modeling. Area Draining Directly to Minnehaha Creek Flow Direction O Feet 1,000 0 1,000 Meters 300 0 300 Figure 12.4 NORTHEAST MINNEHAHA CREEK WATER QUALITY MODELING RESULTS Comprehensive Water Resource Management Plan City of Edina, Minnesota Table 12.2 Watershed Modeling Results for Subwatersheds in the Minnehaha North East Drainage Area (Revised 12/2006) Watershed Information I00 -Year Storm Results 5 -Year Storm Results 10 -Year Storm Results 24 -Hour Event 12 -Hour Event 12 -Hour Event Watershed ID ,Total Area (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume Runoff (ac- ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac- ft) Peak Runoff Rate -°(cfs) Total Volume Runoff (ac -ft) -; MS-1 0.5 17. 2.3 0.22 1.2 0.04 MS -10 3.2 44 15.0 1.08 12.3 0.24` S_II 0.2 80 1.0 0.10 3.1 0.02 S_13 4.2 20 9.1 1.08 3.3 0.14 MS _14 1.4 10 6.0 1 0.34 3.1 0.07 S_15 1.2 20 5.5 0.34 2.8 0.07 S_16 3.6 :* 20 11.1', 0.97 4.3 0.14 S_17 2.2 20 - 9.7 0.61 4.1 0.12 S_18 3.0 17 11.0 0.80 -4.2 0.13 S_19 -3.2 20 12.0 0.88 4.8 0.14 S2 10.0 20 32.8 2.70 117 0.41 S20 -5.4 17 23.2 1.48 9.5 0.26 MS_21 5:0 20 16.1 1.38 6.3 0.21 MS -22 4.8 20 19.9 1.33 8.4 0.23 S_23 1:4 10 4.8 0.56 1.7 0.10 S_24 ` 2.0 20 9.6 0.84 6.5 0.18 MS -25, 1.0 17 4.1 0.40 1.9 0.08 S_26. 4.3 24 19.8 1.82 12.0 0.39 MS -27 4.0 20 15.6 1.11 6.4 0.19 528, 1.7 20 7.9 0.51 5.5 0.12 MS -29 4.0 20 14.2 1.23 5.8 0.22 S' 3 3.3 , 20 12.9 1.02 5.5 .0:19 S30 5.9 17 16.9 1.51 7.5 0.19 MS-3 1. 6.0 5 19.2 2.30 5.5 0.37 MS -32 3.6 20 12.9 1.28 5.3 0.23 S_33 5.4, 20 20.3 1.58 8.3 0.28 MS -34 3.4 20 11.4 0.93 4.4 0.14 MS -35 3t8 20 6.9 0.95 2.4 0.11 MS -36 1.8 20 3.3 0.45 1.2 0.05 MS -37 2.2 20 9.2 0.60 4.0 0.11 MS -38 1.5 14 '6.4 0.47 2.9 0.10 MS -39 14.2 0 46.4 4.84 9.9 0.78 MS -4 3.7 20 17.3 1.32 10.3 019 S_40 12.0 32 42.7 3.62 18.5 0.62 MS 41 0.9 16 3.5 0.36 1.5 0.07 MS -42 4.4 20 15.0 1.20. 5.9 0.19 S' 43 '. 5.2 20 21.6 1.44 9.2 0.25 S='44. 1.1 18 5.2 0.45 3.2 0.10 MS -45 2.1 20 9.8 0.62 5.9 0.14 S,46 35.7 23 97.8 9.89 8.4 1.63 S_47. 4.3; 20 10.1 1.12 3.7 0.15 S_48 10.2 ... 20 23.2 2.64 8.4 0.34 S 49' 5.2 ' 17 22.6 1.45 9.5 0.26 S-5 3.3 20 13.5 0.90 6.8 0.15 MS '50 33 20 13.7 0.93 5.7 0.16 S51 7:6 20 22.8 2.04 8.7 0.30 S_52 4.5 20 19.1 1.25 8.3 0.22 MS J3 1.0 20 4.7 0.29 2.3 0.06 MS -54 10.1 0 21.5 2.57 13.3 0.54 S_55 6.7 10 8.9 1.99 3.9 0.26 5 -56 0.8 . 20 3.4 0.24 1.0. 0.03 MS 57 1.8 20 8.2 0.50 2.8 0.07 S_58 2.8 20 12.8 0.81 3.5 0.10 MS -59 1.8 20 7.6 0.51 3.2 0.09 MS -6 4.2 18 12.0 1.09 4.5 0.15 S 7 4.8 20 18.0 1.33 8.8 0.21 MS_8 3.8 20 15.8 1.06 6.7 0.18 S_9 2.5 20 11.6 0.71 5.8 0.14 HN '1 10.6 27 43.6 3.25 - - 27.5 0.75 HN_10 1.3 20 1 0.35 2.6 0.07 HN I1 6.7 18 26.6 2.09 14.4 0.47 HN 12 2.2 20 9.5 0.75 6.5 0.18 HN 13 7.3 20 20.7 1.92 9.9 0.32 P:\Mpts\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WmkFiles\QAQC Model for Pmd\NEMHC_SWMM_ hydraulic _mtput_UPDA7E_NWI-_veatcation.xls Table 12.2 Watershed Modeling Results for Subwatersheds in the Minnehaha North East Drainage Area (Revised 12/2006) Watershed Information 100 -Year Storm Results 5 -Year Storm Results 10 -Year Storm Results 24 -Hour Event 1/2 -Hour Event 1/2 -Hour Event Watershed ID Total Area (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume Runoff (ac- ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac- ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) HN_14 5.5 20 18.4 1.47 9.4 0.27 HN_15 6.1 20 21.1 1.65 9.9 0.32 HN 16 8.3 20 21.3 2.15 19.4 0.51 HN_17 9.9 20 27.5 2.84 13.1 0.47 HN_18 2.6 0 6.3 1.00 3.8 0.15 HN_19 7.1 20 29.5 2.14 17.5 0.51 HN 2 1.4 20 5.9 0.41 3.3 0.09 HN_20 8.8 20 23.9 2.88 11.0 0.43 HN 21 5.4 20 22.5 1.80 1 8.7 0.32 HN_22 5.7 20 20.7 2.35 11.0 0.41 HN_23 9.9 20 40.9 3.65 15.2 0.59 HN_24 5.6 20 20.4 1.85 10.7 0.37 HN_25 1.8 20 7.6 0.49 4.5 0.11 HN_26 2.3 20 10.3 0.65 7.9 0.16 HN 27 0.6 20 2.4 0.23 1.7 0.05 HN 28 0.5 2 1.9 0.20 0.9 0.04 HN_29 7.4 20 31.7 2.03 19.7 0.48 HN 3 3.6 23 14.8 0.99 8.9 0.22 HN 30 4.7 20 14.2 1.24 6.9 0.22 MHN 31 7.8 20 30.7 2.13 16.4 0.45 HN 32 9.6 20 37.6 2.88 20.4 0.63 HN_33 5.2 20 21.8 1.42 12.8 0.33 MHN-34 4.4 20 18.3 1.21 10.5 0.27 HN_35 1.3 20 5.7 0.36 3.8 0.09 HN_36 3.5 23 13.2 0.96 7.3 0.20 MHN-37 0.6 34 2.7 0.19 3.3 0.05 MHN-38 2.0 48 8.5 0.68 6.5 0.17 HN 39 5.3 51 21.2 1.84 13.0 0.41 HN 4 3.4 20 7.8 0.86 3.6 0.13 HN_40 14.8 18 40.8 3.79 18.9 0.61 MI-IN-Al 2.4 20 10.3 0.65 7.1 0.16 42 6.1 20 17.0 1.59 8.1 0.26 MIK-43 6.0 20 17.7 1.59 8.5 0.27 MHN-44 10.7 20 21.8 2.68 9.8 0.36 HN_46 3.0 20 13.5 0.91 11.4 0.25 MHN-47 1.1 20 4.6 0.30 2.7 0.07 MHN-48 1.4 21 6.1 0.40 3.8 0.09 MIN-49 1.4 20 5.9 0.37 4.9 0.10 MHN-5 7.7 20 30.2 2.08 16.2 0.45 MEN-50 8.4 20 22.2 2.18 10.5 0.35 HN31 2.4 20 1 10.4 0.66 5.8 0.15 MI-N-52 1.8 20 8.0 0.59 6.6 0.16 HN 53 3.7 20 11.7 0.98 5.7 0.18 HN_54 1.3 20 4.5 0.33 2.2 0.06 HN_55 2.7 20 9.1 0.73 4.5 0.14 MM-56 2.1 37 9.3 0.66 9.3 0.17 HN_57 1.5 79 6.7 0.64 4.9 0.15 MI-11458 5.3 74 23.5 2.13 20.0 0.51 HN 59 1.3 80 5.9 0.56 5.7 0.14 HN 6 3.9 20 12.9 1.05 6.3 0.19 HN_W 2.2 20 5.4 0.67 2.5 0.10 HN_6l 3.9 45 16.8 1.33 12.3 0.32 HN_62 6.7 55 30.2 2.51 18.3 0.58 HN_63 2.8 80 12.4 1.21 9.8 0.29 HN 64 4.6 20 13.1 1.20 6.2 0.20 HN_65 14.0 4 50.4 3.56 17.8 0.68 HN 66 12.7 26 50.9 4.06 31.0 0.92 HN_67 2.1 2 4.8 0.45 1.1 0.05 HN_68 0.8 20 3.7 0.23 2.7 0.06 HN_69 21.9 20 86.2 6.11 46.4 1.33 HN 70 3.7 20 11.5 0.99 5.5 0.17 M-71 6.5 21 11.2 1.71 14.2 0.41 HN 72 8.8 29 30.2 2.38 16.0 1 0.43 PAMpls\23 MN\27\23271072 Edina Water Resources Mgnat Plan Updatc \WorkFilcs \QAQC Model for PmdWFMHC_SWMM hydraulic mtput_UPDATE_NWL_verif'ic tion.xls q.. Table 12.2 Watershed Modeling Results for Subwatersheds in the Minnehaha North East Drainage Area (Revised 12/2006) Watershed Information 100-Year Storm Results 5 -Year Storm Results 10 -Year Storm Results 24 -Hour Event 1/2 -Hour Event 1/2 -Hour Event Watershed ID Total Area (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume Runoff (ac- ft) Peak Runoff Rate (as) Total Volume Runoff (ac- ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) HN_73 2.1 75 8.8 -0.85 5.7 0.19 HN 74 15.8 20 47.0 4143 20.5 0.72 HN_75 2.1 29 8.9 0.61 6.6 0.15. HN_76 2.1 80 9.2 0.87 8.0 0.21 HN_77 2.3 80 8.9 0.97 4.5 0.18 HN 78 10.1 26 39.7 2.90 23.3 0.63 HN_79 3.3 23 14.7 0.95 11.3 0.24 HN_8 ' 2.3 :' 19 10.3 0.64 9.5 0.17 HN_80 8:9 24 33.4 2.50 14.4 0.45 HN_81 2.0 48 8.4 0.68 6.4 i_0.16 HN_82 3.3 58 14.0 1.15 - -9.9 0.26 MHN 83 5.2 2 13.0 1.12 3.2 0.14 HN 84 4.6, 58 19.7 1.66 13.4 037. HN_85 .2.0 21 8.5 0.54 6.2 0.14 HN 86. 1.7 20 6.7 0.46 3.5 0.10 HN_87 4.2 20 18.2 1.17 11.6 0.28 HN 88 3.5 20 14.9 0.96 ..8.9 0.22 HN_89 7.7 21 26.8 2.08 13.5 0.40 HN 9 15.0 12 54.8 4.66 24.2 0.92 HN W 2.5 1 25 9.7 0.72 5.6 0.15 HN_91 0.8 20 3.3 0.22 2.0 0.05 CC_l 5.3 7 20.9 1.28 7.69 0.25 CC-10 2.8 9 12.2 0.76 3.00 0.12 CC_l1 3.8 13 15.5 0.96 3.49 0.12 CC_12 1.7 20 7.6 0.50 5.49 0.13 CC_13 1.8 20 8.2 0.74 7.01 0.18 CC_14 3.4 10 14.8 0.85 2.93 0.10 _ CC 15 4.7 2 15.0 1.05 4.19 0.16 `F CC-2 4.0 19 13.6 1-.06 6.59 0.20 CC 31 8.4 11 30.2 2.08 11.49 0.39 CC 4 8.7 9 29.7 2.33 10.75 0.43 CC-5 17.8 3 29.4 .3.71 7.35 0.34 C6 6 8.1 7 29.3 1.91 9.80 0.35 CC 7 31.5 2 73.2 7.92 19.46 0.95 CC-8 4.6 2 17.1 1.03 5.50 0.19 CC 9 10.1 5 35.5 2.53 11.68 0.46 PAMpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pmd\NEMHC_SWMM -hydmuac_ output _UPDATE_NWL_vcritication.xls Table 12.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in Minnehaha Creek North East Drainage Area (Revised 12/2006) Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 5 and 10 -Year Storm Results 1/2-Hour Event Flood Elevation (ft)3 Type of Storage" NWL (ft) Flood Bounce (ft) 5 -Year Flood Elevation (ft) 10 -Year Flood Elevation (ft) NWL (ft) Flood Bounce (ft) 1608 935 871.2 866.8 1610 916 906.7 901.8 1611 920 902.3 900.3 1612 928 899.4 898.9 1617 929 1 896.2 895.6 1618 930 872.4 867.2 1619 931 870.9 867.1 1620 932 870.8 867.0 1621 933 870.4 1 866.6 1624 936 870.7 866.6 1626 939 869.0 864.9 1628 941 1 869.0 864.6 1629 970 869.0 864.6 1633 944 869.1 866.0 1634 945 869.0 865.8 1636 947 879.7 879.6 1637 948 876.7 876.0 1638 949 874.8 874.8 1640 962 874.6 871.3 1642 954 901.2 899.9 1645 956 899.0 895.6 1648 1975 894.9 892.2 1649 959 878.4 874.6 1651 961 874.9 872.7 1653 966 870.6 866.3 1654 964 872.8 868.2 1656 1889 870.9 866.4 1659 969 872.1 1 869.7 1661 outfall 868.3 864.3 1663 973 868.7 865.7 1669 978 889.0 - 884.3 1671 980 886.6 881.0 1681 987 884.9 880.4 1682 988 884.1 879.6 1684 990 882.6 1 878.2 1685 991 881.5 877.3 1687 1001 877.7 874.9 1689 1002 877.7 875.7 1691 995 878.4 877.8 1692 996 877.0 876.8 1693 997 876.8 876.7 1694 998 877.3 1 876.4 1695 999 877.8 876.3 1697 1003 877.7 875.3 1702 1098 876.9 875.7 1704 1100 876.0 873.9 1705 1899 875.5 872.7 1714 1109 868.6 (867) 867.5 1715 outfall 864.6 864.3 1718 1112 878.9 880.7 1721 1114 883.9 882.7 1722 1116 886.1 884.7 1728 1123 893.1 ST 888.0 1729 1125 893.0 1 1 887.5 1731 1126 892.4 ST 887.1 1732 1128 891.9 886.8 1736 1131 887.3 (889) 884.3 P.\Mpls\23 MN\27\73271072 Edina Water Resources Mgmt Plan Update \WorkFles \QAQC Model for PondWEMHC_SWMM_hydmulic_ output _UPDATE_NWL_verification.zls Table 12.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in Minnehaha Creek North East Drainage Area (Revised 12/2006) Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 5 and 10 -Year Storm Results 1/2-Hour Event Flood Elevation (ft), Type of Storage NWL (ft) Flood Bounce (ft) 5 -Year Flood Elevation (ft) 10 -Year Flood Elevation (ft) NWL (ft) Flood Bounce (ft) 1737 outfall 855.1 887.6 1739 outfall 887.7 887.9 1741 1135 894.4 ST 892.6 1745 outfall 884.5 884.3 1747 outfall 883.3 882.7 1749 outfall 883.7 883.7 1870 1246 893.3 887.3 1872 1248 884.8 884.6 1900 outfall 883.8 883.7 2144 outfall 886.5 886.4 2146 outfall 885.8 885.8 2148 outfall 885.9 885.8 2151 1707 900 (890) 895.8 2152 1710 891.5 891.3 2154 1709 898.0 895.1 2235 1774 875.8 871.8 2237 1777 866.9 866.9 2239 outfall 864.4 864.4 2246 outfall 883.5 883.4 2251 outfall 869.4 869.4 2253 outfall 867.0 866.8 2255 outfall 863.6 863.5 2285 outfall 869.4 (878) 869.4 2287 outfall 870.2 870.0 2289 outfall 871.3 871.3 2293 1813 885.4 884.9 2295 outfall 884.1 883.9 2298 outfall 870.8 (878) 870.5 2300 outfall 870.4 870.3 2312 outfall 886.2 886.1 2330 outfall 870.4 - 870.4 2378 1886 906.0 905.0 - 2380 1888 898.2 898.0 2384 1892 869.0 864.6 - 2385 1895 873.7 - 874.2 2386 outfall 868.7 868.8 2387 1897 870.7 (872) 870.8 2389 1905 875.5 ST 872.2 2390 1900a 875.1 871.9 2394 1902 874.9 871.7 2397 1908 879.0 876.3 2398 1909 877.7 875.6 2400 1911 884.4 883.5 2401 1912 883.2 882.1 2402 1913 1 881.4 880.0 2403 1914 880.8 879.6 2404 1915 880.1 879.1 2406 1917 886.8 886.6 2408 outfall 883.5 883.5 2412 1922 877.0 875.9 2413 1 outfal1 883.7 883.6 2430 1936 898.2 898.1 2431 1937 894.9 894.8 PAMpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for PondWEMHC SWMM hydraulic_ output _UPDATE_NWL_verification.xis Table 12.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in Minnehaha Creek North East Drainage Area (Revised 12/2006) Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 5 and 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft)' Type of Storage° NWL (ft) Flood Bounce (ft) 5 -Year Flood Elevation (ft) 10 -Year Flood Elevation (ft) NWL (ft) Flood Bounce (ft) 2432 1938 893.9 - 893.8 2459 1976 894.0 886.1 ECC t landlocked 899.0 BYD 896.2 2.8 - 897.8 896.2 1.6 ECC 10 1249 879.4 879.1 ECC- 11 1247 886.8 885.5 ECC-12 1789 870.9 (868) 870.8 ECC- 13 1787 870.8 (872) 870.5 ECC_l4 1245 935.1 890.6 ECC- 15 1816 876.8 876.7 ECC-2 landlocked 901.4 P 899.5 1.9 900.2 899.5 0.7 ECC -3 landlocked 900.9 P 898.8 2.1 899.3 898.8 0.5 ECC _4 landlocked 904.4 P 899.9 4.5 900.8 899.9 0.9 ECC-5 landlocked 890.8 P 887.0 3.8 889.5 887.0 2.5 ECC-6 landlocked 912.8 P 910.4 2.4 911.1 910.4 0.7 ECC-7 landlocked 884.8 BYD 881.7 3.1 883.0 881.7 1.3 ECC-8 landlocked 887.6 BYD 884.6 3.0 885.9 884.6 1.3 ECC 9 landlocked 906.6 P 904.1 2.5 906.3 904.1 2.2 MS 1 1829 871.8 867.1 - MS_10 outfall 897.8 DDP 885.7 12.1 892.0 885.7 6.3 MS_11 976 897.5 1 892.0 MS-13 965 871.3 866.9 MS-14 landlocked 903.3 BYD 900.9 2.4 902.0 900.9 1.1 MS-15 landlocked 871.9 BYD 867.5 4.4 869.2 867.5 1.7 MS-16 937 869.0 865.5 MS-17 landlocked 902.5 BYD 899.8 2.7 900.9 899.8 1.1 MS 18 967 869.3 865.1 MS-19 946 880.6 880.5 MS 2 960 876.0 ST 873.5 MS-20 landlocked 875.8 BYD 871.5 4.3 873.4 871.5 1.9 MS_21 950 875.1 874.9 MS _22 landlocked 872.3 BYD 869.8 2.5 870.9 869.8 1.1 MS-23 landlocked 870.6 ST 870.2 MS 24 landlocked 871.8 BYD 867.5 4.3 869.4 867.5 1.9 MS-25 1830 871.8 866.3 1 5.5 867.3 866.3 1.0 MS-26 outfall 871.8 P 865.0 6.8 867.1 865.0 2.1 MS_27 1827 872.8 867.3 MS _28 1925 870.7 BYD 863.5 7.2 867.1 863.5 3.6 MS-29 934 869.8 866.3 MS -3 landlocked 900.6 BYD 897.7 2.9 899.0 897.7 1.3 MS 30 1785 872.3 ST 869.6 MS-31 - 869.0 ST 867.2 MS 32 1786 871.9 BYD 862.4 9.5 868.8 862.4 6.4 MS-33 972 869.0 866.5 MS-34 927 901.8 899.7 MS _35 924 903.2 901.4 MS 36 926 906.9 902.1 MS-37 912 906.8 1 903.3 MS 38 1839 869.0 860.0 9.0 864.6 860.0 4.6 MS 39 - 869.0 BYD 864.5 4.5 864.7 864.5 0.2 MS-4 1887 906.4 904.6 MS 40 outfall 869.0 P 861.5 7.5 864.6 861.5 3.1 MS 41 1828 871.8 864.9 6.9 867.1 864.9 2.2 MS 42 L163 871.8 868.2 MS 43 951 904.4 1 903.5 MS 44 1831 871.8 865.6 6.2 867.4 865.6 1.8 MS _45 963 1 872.6 869.0 MS 46 909 1 873.6 BYD 863.5 10.1 870.9 863.5 7.4 P:WplsX23 MNUA23271072 Edina Water Resources Mgmt Plan Update %WorkRks %QAQC Model for PondWEMHC_SWMM_hydraulic_ output_UPDATE_NWL _ verification.xls Table 12.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in Minnehaha Creek North East Drainage Area (Revised 12/20061 Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 5 and 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft)' Type of Storage° NWL (ft) Hood Bounce (ft) 5 -Year Flood Elevation (ft) 10 -Year Flood Elevation (ft) NWL (ft) Flood Bounce (ft) MS 47 957 898.3 895.0 MS-48 955 900.5 ST 8983 , MS 49 1940 869.0 864.6 MS-5 953 905.0 903.5 MS-50 ' 938 869.4 BYD 860.9 8.5 866.3 860.9 . 5.3 MS 51 968 875.7 872.1 MS' 52 943 869.2 BYD 863.0 6.2 866.5 863.0 3.5 MS-53 1942 .871.5 BYD 866.6 4.8 867.3 866.6 0.7 MS 54 landlocked 869.0 BYD 864.1 4.9 864.9 864.1 0.8 MS _55 1890 869.0 864.6 MS-56 landlocked 903.6 BYD 900.5 3.1 901.9 900.5 1.4 MS-57 landlocked 903.6 BYD 900.9 2.7 902.1 900.9 1.2 MS-'58 landlocked 872.0 BYD 869.5 2.5 871.0 869.5 1.5 MS 59 landlocked 910.9 BYD 909.6 L3 910.0 - 909.6 0.4 MS 6 1885 905.1 905.0 - MS 7 landlocked 900.6 BYD 897.7 2.9 898.8 897.7- 1.1 MS-8 952 901.9 ST 900.0 MS-9 1943 874.5 BYD 868.9 5.6 869.7 868.9 0.8 MHN 1 outfall 873.4 P 867.0 6.4 - 869.1 867.0 2.1 MM-10 1896 873.3 (872) 873.6 ,MHN _11 landlocked 871.7 P 870.2 1.5 870.6 870.2 0.3 MHN_12 landlocked 880.5 BYD 878.6 1.9 880.1 878.6 1.5 MHN 13' 1117 885.9 885.7 MHN-14- , 1115 884.6 ST 883.2 MHN-15, 1113 888.9 ST 882.1 MM-16 1894 887.4 ST 880.0 MM-17 11111 889.6 ST 887.6 MHN 18 landlocked 898.3 BYD 897.3 1.0 898.3 897.3. 1.0 MHN-19 1129 890.5 886.4 MHN-2 1099 876.9 ST 875.7 MHN_20. 1124 895.5 893.2 MM 21 1127 894.9 893.8 MHN 22 1134 894.5 ST 893.1 MHN-23 1133 894.4 893.5 MHN 24 ' 1136 893.8 ST 891.5 MHN-25 1782 895.3 (889) 894.0 MHN-26 1132 899.4 (889) 899.3 MHN-27 1809 872.3 (872) ' 872.2 MHN 28 1808 872.4 (878) 872.3 MHN 29 outfall to ditch 906.3. 906.2 MHN -3 1903 877.0 873.8 MM-30 1916 888.4 ST 8873 MHN-31 1918 886.4 (889) 886.3 MHN-32 1781 898.0 897.9 MHN_33 1138 893.6 (889) 1 1 888.5 MHN-34 1139 891.4 (889) ST 891.3 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \Woks \QAQC Model for Pond\NEMHC_SWMM_hydmulic_out put_ wDATE_NWI-_verification.zls Table 12.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in Minnehaha Creek North East Drainage Area (Revised 12/2006) Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 5 and 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft)' Type of Storage° NWL (ft) Flood Bounce (ft) 5 -Year Flood Elevation (ft) 10 -Year Flood Elevation (ft) NWL (ft) Flood Bounce (ft) MHN 35 1702p 891.1 ST 889.9 MHN 36 1824 889.3 889.2 MHN-38 1939 888.7 (891) 888.6 MHN-39 1935 901.7 901.6 MHN -4 1962 880.2 ST 874.5 MHN-40 977 891.1 886.1 MHN 41 landlocked 892.1 BYD 889.4 2.7 890.8 889.4 1.4 MHN 42 1776 866.8 (867) 866.7 MHN _43 1121 893.0 889.6 MHN 44 1122 893.2 889.0 MHN-46 1825 (2) 894.9 894.8 MHN-47 1705p 904.6 900.2 MHN 48 1706 899.9 898.6 MHN _49 landlocked 885.2 BYD 882.5 2.7 883.7 882.5 1.2 MFIN_5 1775 872.7 871.2 MHN-50 1118 889.5 886.3 MHN-51 1137 891.3 (889) 888.6 MHN-52 1130 888.4 885.8 MHN 53 1919 884.3 883.5 MHN 54 1920 884.3 - 882.9 MHN 55 1901 878.7 878.6 MHN 56 1907 879.6 876.7 MHN 57 989 883.4 879.0 MHN 58 985 886.4 882.0 MHN 59 1910 885.9 885.4 MM-6 1106 883.5 882.1 MHN-60 1814 885.4 (889) 884.9 MHN 61 landlocked 887.9 BYD 876.1 11.8 877.5 876.1 1.4 MM-62 1097 876.9 ST 876.0 MFQV_63 1898 876.2 - 872.7 MHN 64 979 889.1 - 883.0 MHN 65 landlocked 875.4 BYD 868.8 6.6 - 871.8 868.8 3.0 MHN- 66 outfall 873.3 p 869.4 3.9 - 870.3 869.4 0.9 MHN 67 outfall to ditch 889.2 - 889.1 MHN-68 981 874.1 - 872.7 MHN _69 1923 889.3 (889) ST 887.6 MHN7 1105 884.3 ST - 882.9 MHN 71 1924 875.0 - 876.8 MHN 72 1104 885.7 - 883.2 MHN _73 986 885.8 - 881.3 MHN-74 983 879.1 - 879.0 MHN 75 1704p 890.4 - 890.1 MHN 76 993 877.8 - 876.2 MHN-77 994 879.9 - 878.9 MHN 78 1780 895.2 ST - 892.8 MHN 79 1934 890.5 BYD 887.7 2.8 - 889.6 887.7 1.9 MHN-8 outfall to ditch 889.3 - 889.2 MHN 80 1823 891.5 (890) - 889.6 MHN 81 1708 899.7 - 896.4 MHN-82 1 992 880.5 - 876.6 MHN-83 outfall to ditch 896.2 896.1 MHN 84 1772 877.8 ST 875.2 PAMpts\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update\WorkRles \QAQC Model for Pond\NEMHC_ SWMM _hydraulic_output_UPDATE_NWL wrification.xts Table 12.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in Minnehaha Creek North East Drainage Area (Revised 12/20061 Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 5 and 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft)' Type of Storage° NWL (ft) Flood Bounce (ft) 5 -Year Flood Elevation (ft) 10 -Year Flood Elevation (ft) NWL (ft) Flood Bounce (ft) MHN_85 1271 886.6 (889) 885.9 MHN_86 1788 880.7 (889) 871.1 MHN_87 landlocked 878.0 BYD 874.2 3.8 876.0 1 874.2 1.8 MHN_88 landlocked 874.2 BYD 871.7 2.5 874.1 871.7 2.4 MHN 89 1904 877.1 871.9 MHN 9 1810 880.8 880.4 MHN_90 1921 877.2 ST 876.3 MHN 91 landlocked 884.6 BYD 882.4 2.2 - 882.7 882.4 0.3 N 134 911 871.8 867.6 A N135 L176 871.6 867.0 t-� 1 Conduit modeled as an orifice for the 100 -Year Storm Event 2 Conduit modeled as an orifice fo the 100 -Year and the 10 -Year Storrs Event 7 Flood elevations in parenthesis indicate a 100 -year flood elevation based on the 100 -year flood elevation of Minnehaha Creek, according to the Federal Emergency Management Agency Flood Insurance Study for the City of Edina ST= Street, BYD--Back Yard Depression, P =Pond P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for PondWEMHC_SWMM_hydmulc_ output _UPDATE_NWL_verification.xls Table 12.4 Conduit Modeling Results for Subwatersheds In the North East Minnehaha Creek Drainage Areas (Revised 1212006) Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimensions • (ft) Roughness Coefficient Upstream Invert Elevation fl) Downstream laver Elevation (fl) Conduit Length (fl) Slope IOOY Peak flow Through Conduit (cfs) SY Peak flow through Conduit (cfs) JOY Peak flow though Conduit (cfs) 909 MS-46 MS 30 Circular 4.5 0.013 863.52 863.00 347 0.15 148.2 111.5 911 N134 N135 Circular 4 0.013 861.95 861.57 253 0.15 56.2 63.9 912 MS-37 1610 Circular 1.25 0.013 902.00 901.01 327 0.30 6.7 3.8 916 1610 1611 Circular 1.5 0.013 900.80 899.48 337 0.39 11.9 4.9 920 1611 1612 Circular 2 0.013 899.11 898.09 324 0.32 18.7 7.2 924 MS-35 1611 Circular 1.25 0.013 900.50 900.40 30 0.33 6.9 2.4 926 MS-36 1610 Circular 1.25 0.013 901.50 901.40 21 0.48 3.7 1.2 927 MS-34 1612 Circular 1.25 0.013 898.29 898.29 30 0.00 11.4 4.5 928 1612 1617 Circular 2 0.013 898.09 894.98 74 4.20 30.1 11.3 929 1617 1618 Circular 1.5 0.013 894.98 869.50 280 9.10 30.1 11.3 930 1618 1619 Circular 2.25 0.013 863.96 863.19 134 0.58 30.1 11.6 931 1619 1620 Circular 2.25 0.013 863.19 862.87 35 0.91 19.7 11.9 932 1620 1621 Circular 2.25 0.013 863.02 862.43 280 0.21 20.2 12.1 933 1621 MS-29 Circular 2.25 0.013 862.43 861.63 108 0.74 22.9 12.1 934 MS_29 N147 Circular 3.5 0.013 861.00 860.74 186 0.14 58.4 52.9 935 1608 1624 Circular 3.5 0.013 861.50 861.31 128 0.15 54.7 47.1 936 1674 MS-29 Circular 3.5 0.013 861.31 861.00 199 0.16 54.8 49.2 937 MS-16 1626 Circular 1.75 0.013 862.72 862.62 104 0.10 8.1 11.1 938 MS-50 1626 Circular 1.25 0.013 860.92 860.43 175 0.28 5.6 5.4 - 939 1626 1628 Circular 2 0.013 860.43 860.28 175 0.09 13.5 16.0 940 N147 2384 Circular 3.5 0.013 860.74 860.03 471 0.15 58.9 56.0 941 1628 MS 49 Circular 4 0.013 860.28 859.66 126 0.49 80.5 66.4 943 MS_52 1633 Circular 1.75 0.013 863.00 862.87 134 0.10 6.0 9.2 944 1633 1634 Circular 1.75 0.013 862.87 862.76 108 0.10 6.0 9.2 945 1634 MS-16 Circular 1.75 0.013 862.76 862.72 108 0.04 5.9 9.3 946 MS-19 1636 Circular 1 0.013 877.10 876.10 43 2.33 4.4 4.4 947 1636 1637 Circular 1 0.013 876.10 874.14 307 0.64 4.4 4.2 948 1637 1638 Circular 1 0.013 874.14 872.52 273 0.59 3.0 2.6 949 1638 MS-21 Circular 1 0.013 871.30 871.00 41 0.74 2.5 3.0 950 MS_21 1640 Circular 1 0.013 869.94 861.40 455 1.88 4.7 5.6 951 MS-43 MS_5 Circular 3.5 0.013 901.53 898.75 622 0.45 10.2 9.0 952 MS-8 1642 Circular 2.25 0.013 898.10 898.09 368 0.00 13.2 5.9 953 MS-5 1642 Circular 1 0.013 898.75 898.09 48 1.38 9.9 8.6 954 1642 1645 Circular 2.25 0.013 898.09 897.35 342 0.22 21.2 13.1 955 MS 48 1645 Circular 1.25 0.015 894.90 892.66 401 0.56 6.9 5.3 956 1645 MS-47 Circular 2.25 0.013 892.35 892.42 59 -0.12 24.1 17.5 957 MS_47 1648 Circular 2.25 0.013 892.42 891.45 235 0.41 33.2 20.9 959 1649 MS-2 Circular 2.5 0.013 871.90 869.40 416 0.60 32.7 21.4 960 MS_2 1651 Circular 3 0.013 869.25 868.14 347 0.32 36.1 32.3 961 1651 1640 Circular 2.25 0.013 868.14 861.60 49 13.35 25.9 30.2 962 1640 MS_45 Circular 2.5 0.013 861.26 861.02 225 0.11 37.0 37.3 963 MS-45 1653 Circular 2.5 0.013 861.02 860.78 215 0.11 40.3 40.6 964 1654 MS-13 Circular 1.25 0.013 867.38 866.00 106.5 1.30 8.7 5.8 965 MS-13 1656 Circular 2.5 0.013 866.00 864.30 167 1.02 18.9 11.1 966 1653 MS-18 Circular 3.5 0.013 860.78 860.60 440 0.04 56.8 49.1 967 MS-18 1628 Circular 3.5 0.013 860.60 860.28 438 0.07 67.4 52.2 968 MS-51 1659 Circular 1.25 0.013 871.30 869.50 48 3.75 17.7 8.8 969 1659 MS 52 Circular 1.25 0.013 864.89 863.00 185 1.02 10.7 8.7 970 1629 MS-40 Circular 3.5 0.013 861.50 858.50 190.5 1.58 52.8 50.6 972 MS-.13 1663 Circular 2.08 0.024 862.88 861.48 250 0.56 9.4 8.5 973 1663 1661 Circular 2 0.024 861.48 860.00 364 0.41 9.3 8.1 976 MS_II MS-10 Circular 1.25 0.013 891.00 886.00 285 1.75 -2.2 2.3 977 MHN-40 1669 Circular 2 0.013 885.20 882.85 58 4.09 40.8 18.9 978 1669 WIN-64 Circular 2 0.013 882.65 881.56 35 3.16 32.6 18.9 979 MHN 64 1671 Circular 2 0.013 881.56 880.11 29 5.00 48.8 25.1 980 1671 MHN_68 Circular 2 0.013 880.11 868.98 180 6.20 48.8 25.8 981 MHN_68 MHN_I Circular 2 0.013 868.98 868.69 48 0.60 35.2 27.7 P.Wplxt23 MN1 232X072 Pdim WN Ite- Mam[Plaa UpJ&eAWaWLJ=%QAQC Modd for PmdWEA41C_SWMM bydmulir mrpuk-UPDAIE NWL ve iL Lkmxb Table 12.4 Conduit Modeling Results for Subwalersheds In the North East Minnehahs Creek Drainage Areas (Revised 1212006) Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimensions• ft) Roughness CoeRtcicnt Upstream Invert Elevation ft) Downstream Invert Elevation (ft) Conduit length (ft) Slope IOOY Peak Flow Though Conduit (cfs) SY Peak flow through Conduit (cfs ) IOY Peak Mow through Conduit cfs) 983 MHN_74 MHN_71 Circular 1 0.013 874.64 871.78 309 0.93 5.0 5.0 985 MHN_58 MHN_73 Circular 2.25 0.013 878.70 875.40 158 2.10 21.2 - 19.6 986 MHN_73 1681 Circular 2.25 0.013 875.40 875.45 16 -0.32 282 - 252 987 1681 1682 Circular 2.5 0.013 875.45 874.70 159.9 0.47 28.1 25.1 988 1682 MHN_57 Circular 2.5 0.013 874.70 874.10 134 0.45 28.1 25.2 989 MHN_57 1684 Circular 2.5 0.013 874.10 873.78 97 0.33 33.8 30.1 990 1684 1685 Circular 2.5 0.013 873.78 873.18 148 0.40 33.7 30.1 991 1685 MHN_82 Circular 2.5 0.013 873.18 872.74 124 0.36 33.7 30.1 992 MHN_82 1687 Circular 2.5 0.013 872.74 872.08 165 0.40 46.3 39.8 993 MHN_76 1689 Circular 2 0.013 869.49 869.01 57 0.84 16.4 17.0 994 MHN 77 1691 Circular 1.5 0.013 873.85 872.27 87 1.82 10.8 9.6 995 1691 1692 Circular 1.5 0.013 872.27 871.21 127 0.84 10.8 9.4 996 1692 1693 Circular 2 0.013 871.21 870.87 40 0.85 10.8 9.2 997 1693 1694 Circular 2 0.013 870.87 870.39 57 0.84 13.1 9.7 998 1694 1695 Circular 2 0.013 870.39 869.70 107 0.64 13.1 10.4 999 1695 MHN_76 Circular 2 0.013 869.70 869.49 107 0.20 143 12.0 1001 1687 MHN_3 Circular 4 0.013 866.14 866.14 433 0.00 66.5 72.1 1002 1689 1697 Circular 2 0.013 869.01 868.93 8 1.00 16.6 17.1 1003 1697 MHN_84 Circular 3.5 0.013 866.85 866.79 32 0.19 21.6 21.6 1097 MHN_62 1702 Circular 1.5 0.013 872.02 871.90 230 0.05 6.4 4.2 1098 1702 Ml-[N_2 Circular 1.5 0.013 871.90 871.85 22 0.91 6.7 - 4.5 1099 MHN_2 1704 Circular 1.5 0.013 871.85 871.01 280 0.30 9.5 5.3 1100 1704 1705 Circular 1.5 0.013 871.01 870.30 237 0.30 9.5 5.3 1104 MHN_72 M104_7 Circular 2 0.013 875.82 875.13 69 1.01 30.2 15.9 1105 MHN_7 MHN 6 Circular 2 0.013 875.13 874.58 56 0.98 24.8 - 20.5 1106 MHN_6 MHN_10 Circular 2 0.013 874.58 870.39 500 0.84 29.8 28.0 1109 1714 1715 Circular 4.5 0.024 862.48 861.48 200 0.50 113.3 92.8 1111t MHN_17 1718 Circvlarl 1.25 1 0.013 880.20 872.60 460 1.65 3.2 9.0 1112 1718 N235 Circular 2.5 0.015 872.48 871.45 225 0.46 27.3 26.6 1113 MHN_15 1718 Circular 2.25 0.015 873.84 872.58 338 0.37 24.1 23.1 1114 1721 N245 Circular 2.25 0.015 875.88 873.80 398 0.52 20.9 21.1 1115 MHN_14 1721 Circular 2.25 0.013 876.08 875.88 128 0.16 21.0 21.1 1116 1722 MHN_14 Circular 1.75 0.013 879.15 876.08 231 1.33 7.8 - 17.1 1117 MHN_13 1722 Circular 1 0.013 881.72 880.40 60 2.20 3.1 9.0 1118 MHN 50 1722 Circular 1.75 0.013 882.96 881.72 311 0.40 5.0 10.5 1121 MHN 43 MHN 44 Circular 2 0.013 888.07 887.69 304 0.13 12.7 8.5 1122 MHN_44 1728 Circular 3 0.013 887.69 886.83 147 0.59 28.2 18.2 1123 1728 1729 Circular 3 0.013 886.83 885.45 186 0.74 28.3 18.2 1124 MHN_20 1729 Circular 1.25 0.013 889.70 889.49 43 0.49 15.3 11.0 1125 1729 1731 Circular 3.5 0.013 885.45 884.80 176 0.37 51.3 28.7 1126 1731 1732 Circular 3.5 0.013 884.80 884.12 165 0.41 51.5 28.4 1127 MHN_21 1732 Circular 1.25 0.013 891.38 891.27 35 0.31 11.4 8.7 1128 1732 MHN_19 Circular 3.5 0.013 884.12 882.18 342 0.57 62.6 36.7 1129 MFW_19 MHN_52 Circular 4 0.013 882.18 882.10 356 0.02 97.9 51.1 1130 MHN_52 1736 Circular 4 0.013 882.10 882.04 133 0.05 105.9 56.0 1131 1736 1737 Circular 4 0.013 882.04 882.00 95 0.04 105.9 56.0 1132 MHN_26 1739 Circular 1.25 0.015 898.50 886.92 190 6.01) 10.3 7.9 1133 MHN 23 1741 Circular 1.5 0.013 888.82 887.31 253 0.60 13.1 15.1 1134 MHN_22 1741 Circular 1.25 0.015 888.60 887.31 280 0.46 6.9 9.6 1135 1741 MHN_24 Circular 1.75 0.015 887.31 885.62 343 0.49 12.4 10.9 1136 MHN_24 MHN_51 Circular 1.75 0.015 885.62 883.48 342 0.63 15.7 13.1 1137 MHN_51 1745 Circular 2 0.024 883.48 882.86 190 0.33 21.7 16.0 1138 MHN_33 1747 Circular 1.5 0.015 887.40 881.80 142 3.94 21.8 12.8 1139 MHN_34 1749 Circular 1.25 0.02 885.75 882.60 195 1.62 8.3 8.2 1245 ECC 14 1870 Circular 1 0.013 887.94 886.40 334 0.46 14.7 3.1 1246 1870 ECClI _ Circular 1 0.013 886.40 880.20 323 1.92 5.2 2.9 1247 ECC l l 1872 Circular 1 0.013 880.20 876.61 289 1.24 4.9 6.1 PAMphU3 M4\27123271072 Ed- W- R- Mgm Nan UpdetAWukFil.\QAQC Modd fQ PmdINFM1IC SNTUtyyd aWic wtput_UPDATEI4WI_•v if -om.sh Table 12.4 Conduit Modeling Results for Subwatersheds In the North East Minnehaha Creek Drainage Areas (Revised 12/2006) Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimensioas• Hi Roughness CoefScient Upstream Inver Elevation N Downstream Invert Elevation (ft) Conduit Length (0) Slope 100Y Peak Flow Through Conduit (cfs) SY Peak Flow through Conduit (cfs ) IOY Peak Flow through Conduit cfs ( ) 1248 1872 ECC 10 Circular 1 0.013 876.61 873.10 289 1.21 5.0 - 5.0 1249 ECC_10 ECC_I5 Circular 1 0.013 873.10 871.00 122 1.72 6.9 6.0 1271 MHN 85 1900 Circular 1.25 0.013 884.95 882.95 86 2.33 8.5 6.2 1706 MHN_48 2151 Circular 1 0.013 895.80 895.10 67 1.04 7.1 6.4 1707 2151 2152 Circular 1 0.013 894.90 890.11 123 3.89 8.8 6.4 1708 MHN_81 2154 Circular 1 0.013 894.70 894.30 20 2.00 8.4 6.4 1709 2154 2152 Circular 1 0.013 894.20 890.11 80 5.11 8.4 6.4 1710 2152 MEN-75 Circular 3 0.013 890.11 889.14 215 0.45 17.2 12.9 1772 MHN_94 1687 Circular 3.5 0.013 866.79 866.14 320 0.20 41.5 33.5 1774 2235 MHN S Circular 2 0.013 869.10 865.21 283 1.37 23.9 - 11.4 1775 MHN S 2237 Circular 2 0.013 865.21 862.89 363 0.64 28.0 24.0 1776 MM-42 2237 Circular 1 0.01 863.37 862.48 84 1.06 4.8 - 4.7 1777 2237 2239 Circular 2 0.013 86148 862.76 145 -0.19 22.0 21.7 1780 MHN_78 MHN_79 Circular 1.5 0.01 891.48 888.00 228.71 1.52 18.3 - 14.5 1781 MHN }2 MHN_25 Circular 1.5 0.013 891.99 888.94 374 0.82 13.1 - 13.1 1782 MHN 25 2246 Circular 1.5 0.013 890.04 882.47 75 10.09 26.2 23.6 1785 MS-30 MS-32 Circular 4.5 0.013 863.00 862.42 194 0.30 112.2 109.6 1786 MS-32 MS-42 Circular 4.5 0.013 862.42 862.00 136 0.31 106.8 114.0 1787 ECC_13 2251 Circular 1.25 0.013 868.66 868.32 34 1.00 8.2 7.0 1788 MHN_96 2253 Circular 1 0.024 867.18 866.00 118 1.00 6.6 3.5 1789 ECC_12 2255 Circular 1.25 0.01 870.17 863.00 220 3.26 7.6 5.5 1808 MFW28 2285 Circular 1 0.024 872.03 869.01 26 11.62 1.9 0.9 1809 MHN 27 2287 Circular 1 0.024 871.79 859.70 26 8.04 2.4 - 1.7 1810 MHN_9 2289 Circular 1.25 0.013 871.88 870.00 242 0.78 13.1 - 12.8 1813 2293 MHN_60 Circular 1 0.013 884.85 884.29 42 1.33 0.1 - 0.0 1814 MM-60 2295 Circular 1.25 0.013 884.29 883.48 36 2.25 5.4 - 2.5 1816 ECC_15 2298 Circular 1.25 0.013 871.00 869.50 38 3.95 17.0 10.3 1823 MHN_80 2312 Circular 1.6 0.024 886.04 884.64 41 3.41 20.4 - 16.8 1824 MHN_76 2146 Circular 1 0.024 886.55 884.83 12 14.33 5.9 5.8 1827 MS-27 1608 Circular 1.25 0.013 866.50 861.50 13 38.46 15.0 7.4 1828 MS-41 MS 26 Circular 1 0.024 864.90 864.50 30 1.33 4.8 1.5 1829 MS-1 MS-26 Circular 1 0.024 865.97 865.27 70 1.00 2.3 1.2 1830 MS-25 MS-26 Circular 1 0.024 866.30 865.60 70 1.00 3.4 1.9 1831 MS 44 MS-26 Circular 1.5 0.024 865.59 865.50 22 0.41 9.1 6.6 1839 MS-38 1661 Circular 2.5 0.013 859.99 859.67 617 0.05 17.9 17.9 1885 MS-6 2378 Circular 1.25 0.013 901.50 900.30 405 0.30 5.1 3.9 1886 2378 MS_4 Circular 1.5 0.013 900.12 898.92 427 0.28 5.2 4.0 1887 MS-4 2380 Circular 1.5 0.013 898.92 897.49 377 0.38 14.2 12.2 1888 2380 MS-10 Circular 1.5 0.013 897.49 885.72 50 23.54 14.2 14.0 1889 1656 1653 Circular 2.5 0.013 864.30 864.00 32 0.94 18.9 11.5 1890 MS-55 MS_40 Circular 2 0.013 858.50 858.00 200 0.25 11.5 II.S 1892 2384 MS-38 Circular 3.5 0.013 860.03 859.99 27 0.15 37.4 25.8 1893 2384 1629 Circular 3.5 0.014 860.03 861.50 36 -4.08 52.8 50.7 1894 MW-16 2385 Circular 2.5 0.015 871.50 868.94 468 0.53 31.9 36.3 1895 2385 MHN_IO Circular 2.5 0.015 868.94 868.94 15 0.00 32.4 36.3 1896 MHN_10 2387 Circular 3 0.013 868.81 866.78 176 1.15 63.5 65.5 1897 2387 2386 Circular 3 0.013 866.78 866.40 37 1.03 63.5 65.5 1898 MHN_63 2389 Circular 2.25 0.013 868.50 866.90 377 0.42 12.4 10.6 1899 1705 2390 Circular 1.5 0.013 870.30 869.78 173 0.30 9.6 5.4 1901 MHN 55 2394 Circular 1.5 0.014 869.57 865.77 8.5 44.71 13.1 9.5 1902 2394 1714 Circular 4 0.013 865.77 862.48 823 0.40 113.3 92.8 1903 MHN_3 2389 Circular 4 0.013 866.14 866.10 424 0.01 76.1 79.5 1904 MHN_89 2235 Circular 2 0.013 870.25 869.10 245 0.00 16.4 8.9 1905 2389 2394 Circular 4 0.013 866.10 865.77 23 1.43 93.1 84.6 1906 MHN_89 2394 Circular 1.5 0.013 870.25 865.77 13 34.46 16.4 12.2 1907 MHN 56 2397 Circular 1.5 0.013 874.43 872.94 100 1.49 9.1 9.2 1908 2397 2398 Circular 1.5 0.013 872.94 870.64 230 1.00 9.2 10.4 P.Udplst27 &DIUM3271072 Ed- Water R-- M®w PIm Uptate\WarkF,1m %QAQC Modd fm PmdWFMHC -SVIMUydnulie wipuLUPDA7F NWL-ve iliotiw.W Table 12.4 Conduit Modeling Results for Subwatersheds In the North East Minnehaha Creek Drainage Areas (Revised 12/2006) -• - Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimensions• - fl) Roughness Coefficient Upstream Invert Elevation 0) -- Downstream Invert Elevation (fl) - Conduit Length -(fl) Slope 100Y Peak Flow Through Conduit _(cfs) - SY Peak flow through Conduit (cfs ) IOY Peak flow through Condui[(cfs) 1909 2398 1697 Circular ' - 1.5 0.013 870.64 866.85 `• 84; - 4.51 -x.8.0 8.6 1910 MHN_59 2400 Circular 1 0.013 880.60 878.97 94,!, 1.73 - 7 5.1 5.7 1911 2400 2501 Circular 1 0.013 - 878.77', 878.58 71 0.27 5.0 5.6 1912 2401 2402 Circular 1 0.013 877.38 _ 876.90 87 0.55 • _ 5.0 5.6 1913 2402 2403 Circular - 1.25 0.01 "- 876.90 '874.05 108 2.64 5.9 5.6 1914 2403 2404 Circular 1.25 0.01 874.05 875.74 90 - -1.88 - 5.2 5.6 1915 2404 MHN_77 Circular 1.5 0.013 875.74 873.85 71 2.66 5.2 5.6 1916 MHN 30 2406 Circular 1.25 0.01 884.22 883.74 102 - 0.47 10.3 6.9 1917 2406 MHN_31 Circular 1.25 0.01 883.74 883.55 - 29- 0.66 8.4 6.9 1918 MHN_31 2408 Circular 1.5 0.01 883.55 882.67 13 7.04 14.1 13.9 1919 MHN_53 MHN 6 Circular 1 0.013 876.79 876.05 37 2.00 6.5 5.7 1920 MHN34 MHN_7 Circular 1 0.013 -.. 876.25 875.51 37 2.00 7.3 5.6 1921 MHN30 2412 Circular 1.5 0.013 873.12 872.40 - 240 0.30 5.6 4.4 1922 2412 1702 Circular 1.5 0.013 872.40 871.90 90 0.56. 5.5 4.3 1923 - MHN_09 2413 Circular 2 0.015 - :882.41 881.77 180 0.36 - 34.3 29.0 1924 MHN21 MHN_66 Circular 1.25 0.013 870.60. 869.40 78 1.54- 15.2 13.3 1925 MS-28 1624 Circular 1 0.013 863.50 863.10 100 0.40 2.9 4.2 1934. MHN29 2428 Circular 1.75 0.013 887.71 886.68 57.9 - L43 28.4 22.4 1935 MHN 39 2430 Circular 1.25 0.013 894.37 893.65 150 0.48 9.4 9.4 1936 2430 2431 - Circular 1.25 0.013 892.95 891.98 122 0.80 9.2 - -' 9.3 1937 2431 -2432 Circular 1.25 0.013 891.98 891.87 40 0.28 9.0 9.0 1938 2432 - MHN_38 Circular 1.25 0.013 891.87 884.65 222 3.25 9.0 9.0 1939 MHN_38 ' 2330 Circular 1.25 0.013 884.65 883.95 "120 0.58 9.5. 9.5 1940 MS_49 MS-40 Circular 4 0.013 859.66 858.63 127 0.81 103.1 74.2 1942 - MS_53 MS-13 - Circular 1.25 0.013 866.61 866.00 134.5• 0.45 - -- 4.5 2.3 1943 MS-9 1654 Circular 1.25 0.013 868.86 867.38 - 113.8 1.30 8.8 5.8 1962 MHN_4 2235 Circular 1 0.01 874.02 869.10 175 2.81 7.7 4.3 1975 1648- 2459 Circular 2.25 0.013 891.45 885.14 81 7.79 77.0 20.9 1976 2459 -' 1649 Circular 1.5 0.013 - 885.14 871.90 170 7.79 '32.7 22.0 1702 MHN 35 2144 _ Circular 1 0.023 887.00 885.70 - 159 0.82 3.2 2.7 1704 MHN_75 - 2148 Circular 3 0.013 889.14 885.03 88 - 4.67 - 26.0 19.1 1705 MHN_47 - �M1414_48 Circular 1 0.013 - 898.40 895.80 289 '0.90 4.6 2.7 1900a 2390 MHN_55 Circular 1.5 0.014 869.78 869.57 19.5 1.08 10.2 5.9 L163 MS-42 N134 Circular 4.5 0.013 '862.00 861.95 40.6 0.12 115.7 118.4 - L164 N135 1608 Circular 3.5 0.013 861.57: 861.50 40 0.18 54.4: 41.7 575 N174 '- N146 Circular 3.5 0.013 .861.95 860.25 40 4.25 62.7 54.5 - LI76 N135 - N145 Circular 3.5 0.013 .. 861.57." 860.25 .. 30 4.40 -- 54.8•:. 41.1' .. Conduit modeled as an orifice for the 100 -year storm event P.UfphU3MM27\23271072 Edina Waux Res -Mgmt Plea Update \WakFLla\QAQC M adel for PmdWII.1HC_SWMM_byd..Ii. ampu.- UPDA7EIJWL_�crili.,ioo.xb - i Southeast Minnehaha Creek 13.0 Southeast Minnehaha Creek 13.1 General Description of Drainage Area Figure 13.1 depicts the Southeast Minnehaha Creek drainage area and the individual subwatersheds within this area. The Southeast Minnehaha Creek drainage basin is located in east - central Edina and contains several ponds, Lake Harvey, Lake Pamela, and Melody Lake. 13.1.1 Drainage Patterns The stormwater system within this drainage area is comprised of storm sewers, ponding basins, wetlands, drainage ditches, and overland flow paths. The Southeast Minnehaha Creek basin has been divided into several major watersheds based on the drainage patterns. These major watersheds are depicted in Figure 13.2. Each major watershed has been further delineated into numerous subwatersheds. The naming convention for each subwatershed is based on the major watershed it is located within. Table 13.1 lists each major watershed and the associated subwatershed naming convention. Table 13.1 Major Watersheds within the Southeast Minnehaha Creek Drainage Basin Major Watershed Subwatershed Naming Convention # of Subwatersheds Drainage Area (acres) Lake Pamela LP ## 28 274 Minnehaha Creek South MHS ## 86 508 Melody Lake ML—## 1 15 1 178 13.1.1.1 Lake Pamela The Lake Pamela watershed is located in the east central portion of Edina. The entire 272 -acre watershed drains to Lake Pamela and then north to Minnehaha Creek. The land use of this watershed is primarily low density residential with Pamela Park surrounding Lake Pamela. Four stormwater management basins in this watershed, two on the south end of Lake Pamela and two on the north end of the lake recently have been constructed for water quality treatment of stormwater. The two ponds on the north end of the lake also receive runoff from about half of the Southeast Minnehaha Creek watershed (described below). This runoff is routed through the ponds, over a weir and then to the north bay of Lake Pamela, and finally, to Minnehaha Creek. These ponds were designed to treat runoff from the Minnehaha Creek South watershed before discharge to Minnehaha Creek. Lake Pamela has been excavated to increase the dead storage volume within the lake for water quality treatment. 13.1.1.2 Minnehaha Creek South The Minnehaha Creek South watershed extends from areas just south of the Edina Country Club at Lake Harvey, west to T.H. 100 and south to West 54`h Street. The land use is predominantly low Barr Engineering Company 13 -1 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx density residential with some scattered areas of institutional land use. There are no ponds east of Minnehaha Creek and only a few wet and dry detention ponds on the western half of this watershed. However, most of the western half of the watershed is routed through ponds and through the northern bay of Lake Pamela before discharge to Minnehaha Creek. Areas directly east and west of Minnehaha Creek are drained by short storm sewer systems or directly by overland flow. There is a stormwater control weir in a manhole that is located just east of the intersection of West 58'h Street and Concord Avenue. This weir is designed to prevent flooding of the backyard area of the house at 5801 Concord Avenue. Also part of this system is a flap gate on a pipe leading from the backyard area of 5801 Concord Avenue. This pipe connects into the downstream end of the weir - manhole and the flap gate stops water from backing into this pipe. The weir, located at node 1849, forces water to back into a pipe that discharges into a ball field located along Concord Avenue. This entire system is designed to store water in the ball park and slowly release it back into the storm sewer system over time so that the house at 5801 Concord Avenue is not flooded during the 100 -year frequency storm event. 13.1.1.3 Melody Lake This 178 -acre watershed contains low density residential, institutional, and T.H. 100. The outlet from Melody Lake is a pumped outlet to the T.H.100 drainage system. This system flows north and ultimately discharges to Minnehaha Creek. The T.H. 100 storm sewer system was not modeled as part of this study. 13.2Stormwater System Analysis and Results 13.2.1 Hydrologic /Hydraulic Modeling Results The 10 -year and 100 -year frequency flood analyses were performed for the Southeast Minnehaha Creek drainage basin. The 10 -year analysis was based on a'' /s -hour storm of 1.65 inches of rain and the 100 -year analysis was based on a 24 -hour storm event of 6 inches of rain. Table 13.2 presents the watershed information and the results for the 10 -year and 100 -year hydrologic analyses for the Southeast Minnehaha Creek basin. The results of the 10 -year and the 100 -year hydraulic analysis for the Southeast Minnehaha Creek drainage basin are summarized in Table 13.3 and Table 13.4. The column headings in Table 13.3 are defined as follows: Node /Subwatershed ID—XP -SWMM node identification label. Each XP -SWMM node represents a manhole, catchbasin, pond, or other junction within the stormwater system. Downstream Conduit — References the pipe downstream of the node in the storm sewer system. Flood Elevation —The maximum water elevation reached in the given pond/manhole for each referenced storm event (mean sea level). In some cases, an additional flood elevation has been Barr Engineering Company 13 -2 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx given in parenthesis. This flood elevation reflects the 100 -year flood elevation of Minnehaha Creek, as shown in the National Flood Insurance Program Flood Insurance Study for the City of Edina, May 1979. Peak Outflow Rate —The peak discharge rate (cfs) from a given ponding basin for each referenced storm event. The peak outflow rates reflect the combined discharge from the pond through the outlet structure and any overflow. NWL —The normal water level in the ponding basin (mean sea level). The normal water levels for the ponding basins were assumed to be at the outlet pipe invert or at the downstream control elevation. Flood Bounce —The fluctuation of the water level within a given pond for each referenced storm event. Volume Stored —The maximum volume (acre -ft) of water that was stored in the ponding basin during the storm event. The volume represents the live storage volume only. Table 13.4 summarizes the conveyance system data used in the model and the model results for the storm sewer system within the Southeast Minnehaha Creek drainage basin. The peak flow through each conveyance system for the 10 -year and the 100 -year frequency storm event is listed in the table. The values presented represent the peak flow rate through each pipe system only and does not reflect the combined total flow from an upstream node to the downstream node when overflow from a manhole /pond occurs. Figure 13.3 graphically represents the results of the 10 -year and the 100 -year frequency hydraulic analyses. The figure depicts the Southeast Minnehaha Creek drainage basin boundary, subwatershed boundaries, the modeled storm sewer network, surcharge conditions for the XP -SWMM nodes (typically manholes), and the flood prone areas identified in the modeling analyses. One of the objectives of the hydraulic analyses was to evaluate the level of service provided by the current storm sewer system. The level of service of the system was examined by determining the surcharge conditions of the manholes and catch basins within the storm sewer system during the 10 -year and 100 -year frequency storm events. An XP -SWMM node was considered surcharged if the hydraulic grade line at that node breached the ground surface (rim elevation). Surcharging is typically the result of limited downstream capacity and tailwater impacts. The XP -SWMM nodes depicted on Figure 13.3 were color coded based on the resulting surcharge conditions. The green nodes signify no surcharging occurred during the 100 -year or 10 -year storm event, the yellow nodes indicate surcharging during the 100 -year frequency event, the red nodes identify that surcharging is likely to occur during both a 100 -year and 10 -year frequency storm event. Figure 13.3 illustrates that several XP -SWMM nodes within the Southeast Minnehaha Creek drainage basin are predicted to experience surcharged conditions during both the 10 -year and 100 -year frequency storm events. This indicates a probability greater than 10 percent in any year that the system will be overburdened and Barr Engineering Company 13 -3 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAMEdina SWMP FINAL DRAFT 121511REV.docx unable to meet the desired level of service at these locations. These manholes and catch basins are more likely to experience inundation during the smaller, more frequent storm events of various durations. Another objective of the hydraulic analysis was to evaluate the level of protection offered by the current stormwater system. Level of protection is defined as the capacity provided by a municipal drainage system (in terms of pipe capacity and overland overflow capacity) to prevent property damage and assure a reasonable degree of public safety following a rainstorm. A 100 -year frequency event is recommended as a standard for design of stormwater management basins. To evaluate the level of protection of the stormwater system within the Southeast Minnehaha Creek drainage area, the 100 -year frequency flood elevations for the ponding basins and depressed areas were compared to the low elevations of structures surrounding each basin. The low elevations were initially determined using 2 -foot topographic information and aerial imagery in ArcView. Where 100 -year flood levels of the ponding areas appeared to potentially threaten structures, detailed low house elevations were obtained through field surveys. The areas that were predicted to flood and threaten structures during the 100 -year frequency storm event are highlighted in Figure 13.3. Discussion and recommended implementation considerations for these areas are included in Section 13.3. 13.2.2 Water Quality Modeling Results The effectiveness of the stormwater system in removing stormwater pollutants such as phosphorus was analyzed using the P8 water quality model. The P8 model simulates the hydrology and phosphorus loads introduced from the watershed of each pond and the transport of phosphorus throughout the stormwater system. Since site - specific data on pollutant wash -off rates and sediment characteristics were not available, it was necessary to make assumptions based on national average values. Due to such assumptions and lack of in -lake water quality data for model calibration, the modeling results were analyzed based on the percent of phosphorus removal that occurred and not based on actual phosphorus concentrations. Figure 13.4 depicts the results of the water quality modeling for the Southeast Minnehaha Creek drainage basin. The figure shows the fraction of total phosphorus removal for each water body as well as the cumulative total phosphorus removal in the watershed. The individual water bodies are colored various shades of blue, indicating the percent of the total annual mass of phosphorus entering the water body that is removed (through settling). It is important to note that the percent of phosphorus removal is based on total phosphorus, including phosphorus in the soluble form. Therefore, the removal rates in downstream ponds will likely decrease due to the large soluble fraction of incoming phosphorus that was unsettleable in upstream ponds. The watersheds are depicted in various shades of gray, indicating the cumulative total phosphorus removal achieved. The cumulative percent removal represents the percent of the total annual mass of phosphorus entering the watershed that is removed in the pond and all upstream ponds. Ponds that had an average annual total phosphorus removal rate of 60 percent or greater, under average climatic conditions, were considered to be performing well. For those ponds with total Barr Engineering Company 13 -4 P:\Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx phosphorus removal below 60 percent, the permanent pool storage volume was analyzed to determine if additional capacity is necessary. Based on recommendations from the MPCA publication Protecting Water Quality in Urban Areas, March 2000, the permanent pool for detention ponds should be equal to or greater than the runoff from a 2.0 -inch rainfall, in addition to the sediment storage for at least 25 years of sediment accumulation. For ponds with less than 60 percent total phosphorus removal, the recommended storage volume was calculated for each pond within the drainage basin and compared to the existing permanent pool storage volume. 13.3 Implementation Considerations The XP -SWMM hydrologic and hydraulic modeling analyses and P8 water quality analysis helped to identify locations throughout the watershed where improvements to the City's stormwater management system may be warranted. The following sections discuss potential mitigation alternatives that were identified as part of the 2003 modeling analyses. As opportunities to address the identified flooding issues and water quality improvements arise, such as street reconstruction projects or public facilities improvements, the City will use a comprehensive approach to stormwater management. The comprehensive approach will include consideration of infiltration or volume retention practices to address flooding and /or water quality improvements, reduction of impervious surfaces, increased storm sewer capacity where necessary to alleviate flooding, construction and /or expansion of water quality basins, and implementation of other stormwater BMPs to reduce pollutant loading to downstream waterbodies. 13.3.1 Flood Protection Projects The 2003 hydrologic and hydraulic modeling analysis identified several locations within the Southeast Minnehaha Creek drainage basin where the 100 -year level of protection is not provided by the current stormwater system. The problem areas identified in 2003 are discussed below. As part of the 2003 modeling analysis, potential corrective measures were identified for the problem areas for purposes of developing planning -level cost estimates. These preliminary corrective measures are also discussed below. As the City evaluates the flooding issues and potential system modifications in these areas, consideration will be given to other potential system modifications, including implementation of stormwater infiltration or volume retention practices, where soils are conducive. 13.3.1.1 6213 Ewing Avenue (LP 15) A depression area on the street adjacent to 6213 Ewing Avenue collects water from a 3.8 -acre watershed. The 100 -year frequency flood elevation of 884.3 MSL will potentially impact the structure at 6213 Ewing Avenue. It is recommended that the diameters of pipes 1696 and 1695 be increased to 18-inches to provide a I00 -year level of protection. Barr Engineering Company 13 -5 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAF'REdina SWMP FINAL DRAFT 121511REV.docx 13.3.1.2 3600 West Fuller Street (MHS_4) The 100 -year frequency flood elevation for the backyard depression area directly behind 3600 West Fuller Street is 875.4 MSL. A field survey indicates this elevation is above the low entry (872.6 MSL) at 3600 West Fuller Street. It is recommended that a catch basin be placed in the backyard depression and connected to a new storm sewer system installed east along Fuller Street and south along Beard Avenue to Minnehaha Creek. An existing bituminous drainage channel between Beard Avenue and Minnehaha Creek at this location appears to be a potential access point to Minnehaha Creek for the new pipe. The addition of a pipe system and catch basins extending from Fuller Street to Beard Avenue and then to Minnehaha Creek would provide the additional benefit of handling the significant street flows that occur on Fuller Street and Beard Avenue. 13.3.1.3 5605, 5609, 5613, 5617, 5621, 5625, and 5629 South Beard Avenue (MH4_79) Water in the alley between Abbott and Beard Avenue and south of West 56th Street rises to an elevation of 880.1 MSL during the 100 -year frequency storm and affects the garages in this alley. This is the result of water flowing from West 56th Street to the alley and the limited flow in the pipe leading from the alley to the storm sewer system located on Beard Avenue. Currently the storm sewer system on Beard Avenue does not provide a 10 -year level of service and is significantly undersized for the 100 -year storm. At the intersection of Beard and West 56th Street, street flow on Beard Avenue reaches a peak of 97 cfs during the 100 -year storm while the pipe carries only a peak flow of only 4.7 cfs. The street flow then flows on Beard Avenue to Minnehaha Creek. The following pipe sizes are recommended to protect the structures in the alley during a 100 -year storm: Pipe 1851p ..................... 12 to 24 -inch Pipe 1852p .....................12 to 24 -inch Pipe 1156 ....................... 12 to 24 -inch Pipe 1159 ....................... 27 to 36 -inch Pipe 1158 ....................... 27 to 36 -inch Pipe 1152 .......................33 to 36 -inch Pipe 1153 .......................15 to 36 -inch An additional catch basin is also required at the low point in the alley. To collect runoff along West 56th Street before it enters the alley, an additional catch basin is recommended on the south side of West 56th Street, east of the alley entrance. These recommendations are not designed to reduce the large street flows that are present on Beard Avenue during the 100 -year storm. Further pipe size increases of the entire system and the addition of catch basins would be required to significantly reduce the flow of water along Beard Avenue. Barr Engineering Company 13 -6 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 13.3.1.4 5837, 5833, 5829, 5825 South Chowen Avenue (LP 24) A backyard depression area directly behind 5829 South Chowen Avenue is inundated to an elevation of 884.6 MSL during the 100 -year frequency storm and affects the structures at 5837 5833, 5829, and 5825 South Chowen Avenue. It is recommended that a catch basin be placed in the backyard depression area and connected with a 12 -inch RCP to the storm sewer node LP-27 located at the intersection of South Chowen Avenue and West 601h Street. 13.3.1.5 Chowen Avenue and West 60th Street (LP 27) A 100 -year frequency flood elevation of 883.9 MSL has been calculated at the intersection of Chowen Avenue and West 601h Street. Although the model shows that there is the potential for significant flooding in this intersection, a thorough survey of the storm sewers and structures in this area needs to be completed to verify their size, invert elevations, and low point of entry. 13.3.1.6 5912, 5916, 5920, 5924, 5928 Ashcroft Avenue and 5925 Concord Avenue (MHS_51) Water in the backyard depression area of subwatershed MHS_51 will rise to 882.9 MSL during the 100 -year frequency storm event. This flood elevation will inundate several of the houses adjacent to the depression. Water frequently ponds in this backyard depression area and either a pumped or gravity outlet from this area with a 3 cfs capacity is required to provide a level of protection. 13.3.1.7 5840 and 5836 Ashcroft Avenue (MHS_89) The houses at 5840 and 5836 Ashcroft Avenue are located in a shallow depression area that fills with water from a small 0.7 -- directly adjacent watershed. The calculated 100 -year frequency flood elevation of 884 MSL will inundate the structures at 5840 and 5836 Ashcroft Avenue. It is recommended that a catch basin be placed at this depression and connected to the adjacent storm sewer system on Concord Avenue (node MHS_58). This outflow capacity will reduce the flood elevation to 883 MSL and provide the required level of protection for these structures. 13.3.1.8 5609 and 5605 Dalrymple Road (MHS_24) and 5610 and 5612 St. Andrews Avenue (MHS_66) The calculated 100 -year frequency flood elevation for the depression on Dalrymple Road is 895.3 MSL. This flood elevation is above the lowest entry way for both 5609 (low entry at 893.4 MSL) and 5605 (low entry at 893.25) Dalrymple Road. A field survey of the area indicates that a surface outflow existed between Dalrymple Road and the backyard area of subwatershed MHS_66 but has been filled. It is recommended that either this outflow be reestablished or pipes 1784 and 1240 be upgraded to 24 -inch diameter pipes. The backyard depression area of MHS_66 is inundated to 894.8 MSL during the 100 -year frequency flood. This elevation is above the elevation (894.46 MSL) of a back yard entry to 5610 Andrews Avenue, the basement windowsill (891.44 MSL) at 5612 Andrews Avenue, and the basement windowsill (893.53 MSL) at 5608 Andrews Avenue. It is recommended that a surface outflow be established between the backyard depression area and St. Andrews Avenue or pipes 1784 and 1240 be upgraded to 24 -inch diameter pipes. Barr Engineering Company 13 -7 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx 13.3.1.9 5701 Dale Avenue (ML_12) A depression on Dale Avenue, directly adjacent to 5701 Dale Avenue, is inundated to an elevation of 935.8 MSL during the 100 -year frequency storm event. According to a field survey, the low entry way at 5701 Dale Avenue is at an elevation of 935.5 MSL, indicating that the storm sewer system on Dale Avenue does not provide a level of protection for the structure at 5701 Dale Avenue during the 100 -year frequency storm event. It is recommended that the diameter of pipes 1 and 1826 be increased to 24 inches to protect the structure at 5701 Dale Avenue from flooding. 13.3.1.10 5213 and 5217 Richwood Drive (ML _7) A wetland area behind 5213 and 5217 Richwood Drive receives runoff from a 3 -acre watershed. This wetland receives water from backyard areas, rooftops, and a small section of Windsor Avenue. During the 100 -year frequency storm event the water level in this wetland rises to 928.6 MSL. This water level is above the elevation of the low entry for 5213 and 5217 Richwood Drive. It is recommended that the storage capacity of this wetland area be surveyed and the flooding potential be further evaluated. 13.3.2 Construction /Upgrade of Water Quality Basins When considered individually, the ponds MHS_13, LP_5, and LP_ 13, and the two bays of Lake Pamela, LP_14 and LP _26 are removing less that 60 percent of the total phosphorus in storm water inflows. Because water from a watershed greater than 500 acres in size is routed through the ponds and the two bays of Lake Pamela before being discharged to Minnehaha Creek, the cumulative phosphorus removal by the ponds should be considered. In addition, ponds MHS_13, LP 5, and LP_13 were recently constructed and were designed to function as a treatment train and not individually. On a cumulative basis, the ponds and Lake Pamela are removing 63 percent of the total phosphorus load from this entire watershed and it is not necessary to upgrade these ponds. Because over 60 percent of the total phosphorus in storm water runoff is being removed by all other ponds and wetlands in the Southeast Minnehaha Creek watershed, no recommendations are given for the construction or upgrade of water quality basins in this watershed. Many techniques are available to reduce pollutant loading from stormwater runoff, including impervious surface reduction or disconnection, implementation of infiltration or volume retention BMPs, installation of underground stormwater treatment structures and sump manholes and other good housekeeping practices such as street sweeping. As opportunities arise, the City will consider all of these options to reduce the volume and further improve the quality of stormwater runoff from this drainage area. 13.3.3 Stream Improvement Projects 13.3.3.1 Minnehaha Creek Reach 14 Stream Restoration The MCWD Comprehensive Water Resources Management Plan identified a potential capital improvement project in Edina to implement a stream restoration project on Reach 14 of Minnehaha Barr Engineering Company 13 -8 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx Creek. This reach extends from France Avenue to 54th Avenue West. This project would include streambank stabilization, in- stream habitat enhancement, and buffer enhancement. Barr Engineering Company 13 -9 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx L c LL t C a c Y ter � 1 +�° � rll t p.. �/ �,:.: � fi, �•. �� M �ffi r� 1 M _3 M ML_13 100 MHS_3 MHS_ MHS_ • MHS_43 MHS_88 MHI Hanep MHS_t MHS_25 Lake MHS_2 � MH$_8 IMHS_48 ,fffM� /B MHS_26 ML_15 MHS_59 ML_14 �S 0 MHS_7 1 MHS_17r IMHS_5 LP_69 Minneapolis 1 MFST_68 I ,� `MH' MHLS_67 M'HST23 MHS.7�� MHS_4 MHS_60 MHS_7 MHS_6 MHS_45 MHS_5 MHS_ MHS_11 innehaha Creek MHS_5 MHS_ MHS_39 MHS_37 MHS_1 MHS�38 MHS_33'MHS � � MHS_ MHS_1 �� � MHS_79 MHS_41 1• a64H$Z� � innehaha Creek HS• 1 MHS_40 1�� MHS_32 MHS_7 I� MHS_81 �� MHS_62 LP_2 �- LP_3 LP_7 LP 1 LP_25 MHS_52 MHS 50 ILP_24 LP_4 LP_14 P_ L LP_8 LP_27 , Lake $amela � &P-9 � LP_1 LP_22 9P_M F M'y Y � t ;hfiel 1 ow e N o Was City of Edina Boundary Roads /Highways Lake /Wetland Creek /Stream Minnehaha Creek - Southeast C3 Drainage Basin M Subwatershed Imagery Source: Aerials Express, 2008 "Ard Feet 1,000 0 1,000 Meters 300 0 300 Figure 13.1 SOUTHEAST MINNEHAHA CREEK DRAINAGE BASIN Comprehensive Water Resource Management Plan City of Edina, Minnesota a , wit IM, VY tl 7 WV n r 4* W 54 `rte r V� 1 Melody Lake inne a a Creek outh 120110S.M `Calker' Minneapolis W 58th - a s• LL J. Lk� �, Lake Pa ela t 1_ '+ rr z r e+i w ". ice... ° a# .: . -. i c h f i e I rte t . effigy t -:r.+err 4^ �,. . , O • •l�UFiPUR�1Y,, • City of Edina Boundary Roads /Highways Creek /Stream Lake /Wetland Minnehaha Creek - Southeast C3 Drainage Basin W Major Watershed Subwatershed Imagery Source: Aerials Express, 2008 WJ u Feet 1,000 0 1,000 Meters 300 0 300 Figure 13.2 SOUTHEAST MINNEHAHA CREEK MAJOR WATERSHEDS Comprehensive Water Resource Management Plan City of Edina, Minnesota Y Figure 13.3 SOUTHEAST MINNEHAHA CREEK HYDRAULIC MODEL RESULTS Comprehensive Water Resource Management Plan City of Edina, Minnesota City of Edina Boundary Roads /Highways Creek /Stream Lake /Wetland Minnehaha Creek - Southeast Drainage Basin Subwatershed Feet X11 1 300 611 Meters 100 0 100 200 Potential Flooding During 100 -Year Frequency Event Pipes o Manhole Manhole Surcharge During ° 100 -Year Frequency Event Manhole Surcharged During ° 10 -Year Frequency Event u / NJ. 54TH ST ryry�� r W1n�bQ O Eno _ _ _. • Ste: i�•y� /J m • 0 w FULLER ST W K ir)OORE3T Mau < n w • a aw w mw i o >TH Si N Tryi_ U � nntn [�sY.Y.f •d' 55TH ST `.. x W U � UunPa(Iw w a mw Z m ---J - W�� O p IfLMM Mal • 55TH S Wti > tC + I CIR i I Z .0 H ��wu • F ��'J pO II G�03'�C` w� 'i y6 C�t3°- 9Ei� 0 9G`�i' I twm v WOODLAN�:; Ki;4= IM:PIASl1l•IVL�iII• -�+il ,J.._. _ Q REST U w w ? w p w W MRM p o 0 T OUT I' D � O • w tl U Z W w 4 G 1 M44mkm m L�P�'1 :,,-* 3 apd@ 1, Llr I w < I D X \ w U I 2 i 0 st 00 O0. 00 .- an CCiilIILSGCU w z 3 w �� 00 00 JJJ 7� &2ND ST N. w a U Q y W x a w a MHS_33 I MHS_n5n6H 17`I MHS_79 Iu MHS 3 — 67TH ST W �•J O Z w L,,W,U 5.- s w � Q W Z < 0 p O 4 U m �. IPCl/VIiC?JU'"v - 601H S�/IN @091 .-,@ �8 h1H- 011 LP_23 &P-0 62ND ST W y N Q ,... -TH i tit E a 5. .; Y IF F a M s ■ f 7 C 'm I e S 22 J, -4 r MHS_19 a a T.Z:13] p. L tt _ �. r. Creek Minneapolis Imagery Source: Ae ,hfielc l ss, 2008 1 o e , r o Percent TP Removal in Water Body* This number represents the percent of the total annual mass of phosphorus entering the water body that is removed. 25 - 40% (Moderate Removal) - 40 - 60% (Good Removal) - 60 - 100% (Excellent Removal) Cumulative TP Removal in Watershed* This number represents the percent of the total annual mass of phosphorus entering the watershed and upstream watersheds that is removed in the pond and all upstream ponds. _ 0 - 25% (Poor /No Removal) i 25 - 40% (Moderate Removal) 40 - 60% (Good Removal) 60 - 100% (Excellent Removal) *Data based on results of P8 modeling. Area Draining Directly to Minnehaha Creek Flow Direction 0 Feet 1,000 0 1,000 Meters 300 0 300 Figure 13.4 SOUTHEAST MINNEHAHA CREEK WATER QUALITY MODELING RESULTS Comprehensive Water Resource Management Plan City of Edina, Minnesota Table 13.2 Watershed Modeling Results for Subwatersheds in the Minnehaha Creek South East Drainage Area Watershed Information 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Watershed ID Total Area (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) LP A . 6.5 10 16.0 1.52 6.0 0.24 LP-2 7.1 8 29.7 1.80 14:6 0.42 LP 3' 3.2 20 13.8 0.89 '8.4 0.21 'LP-4 2.2 21 _ 9.4 0.60 6.1 0:15 LP 5`, : 2.8 10 11.3 6.70. 4.9 0.15 LP-6 26.9 27 73.3 7.51 35.9 1.44 LP ,'7 5.8 20 20:9 1:56. 10.5 0.32 LP 8 9.4 20 36:9' 2.55 19.7 0.55 LP 9 6.7 20 25.6 1.82 13.5 0.39 LP_ 10 5.8 20 21.2 1.57 10.8 0.32 LP 11 10.0 20 31.3 2.65 15.2 0.51 LP 12 3.6 10 15.8 1.41 11.1 0.34 LP_13 10.5 10 34.6 2.55 9.4 0.38 LP 14 26.6 26 100.5 9.84 56.7 2.34 L15 _ 15 3.8 20 15.8 1.06 _6.3 0.21 LP 16 6.3 20 24.1 1.71 8.6 0.31 LP 17 16.3 13 55.6 4.09 23.5 0.78 LP_ 18 3.9 20 16.3 1.07 9.3 0.24 LP 19 13.7 20 49.8 3.70 21.8 0.71 LP 20 13.8 20 50A 3.73 16.0 0.62 LP 21 3.7 20 14.1 1.01 7.3 0.21 LP 22 9.6 10 .34.9 2.39 13.4 0.47 LP 23 6.0 20 21.0 1.85 10.7 0.42 LP 24 3.0 0 12.4 0.89 8.7 0.26 LP-25 4.0 5 16.4 1.24 8.0 0.30 LP-26 41.3 24 136.0 14.94 70.0 3.40 LP .27 19.7 20 56.0 6.00 26.5 1.24 LP-28 1.6 20. 5.0 0.43 2.4 0.08 NMS-1 2.5 20- 5.6 0.78 '2.5 0.15 MHS_2.. 1.6 20 5:2 0.42 5.9 0.11 MHS 3 1.5 19 6.4 0.43 4.1 0.11 MHS _4, L5 20 6.0 0.42' 3.3 0.09 MHS 5 6.5 24 27.5 1.84 11:0 0.36 MHS _6 2.5 22 10.2 0.68 .4:2 0.13 MHS-7 65 20 17:5,;, 1.70 16.2 0.41 MHS _8 5.5 20 24.6 1:74 19.9 0.46 MHS 9 3.7 20 14.7 LIT 8.3 0.28 MHS 10 3.7 20 16.5 1.49 12.5 0.37 MHS-l1 8.3 20 34.8 2.27 20.5 0.52 MHS-12 8.4 20 28.3 2.39 14.1 0.51 MHS 13 8.1 20 26.0: 2.16 12.7 0.42 MHS-14 2.2 20 9.0' 0.59 4.0 0.12 MHS-15 4.7 20 20.8 1.31 10.6 0.29 MHS_ 16 1.9 .20 8:1 0.51 5.5 0.13 MHS 17 11.0 20 33.7 2.91 17.3 0.57 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\SEMHC_S W MM_hydraulic_output_noUPDATE_N W L_ verification.xls Table 13.2 Watershed Modeling Results for Subwatersheds in the Minnehaha Creek South East Drainage Area Watershed Information 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Watershed ID Total Area (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) MHS 18 1.9 5 6.9 0.58 4.1 0.15 MHS-19 3.2 31 13.6 0.95 10.3 0.23 MHS 20 10.9 20 31.8 2.88 15.3 0.53 MHS 21 6.7 20 12.5 1.64 5.5 0.26 MHS 22 22.3 40 77.9 7.56 40.1 1.76 MHS 23 4.7 40 20.6 1.53 17.7 0.39 MHS 24 7.0 20 23.5 1.89 11.7 0.38 MHS _25 6.1 20 19.1 1.63 9.3 0.31 NMS-26 10.7 20 29.8 3.42 13.9 0.72 MHS-27 5.1 20 15.9 1.35 7.7 0.26 MHS 28 3.5 20 12.9 0.95 6.5 0.20 MHS-29 1.6 20 6.0 0.44 3.1 0.09 MHS 30 1.4 20 5.7 0.39 3.1 0.09 MHS 31 3.6 20 14.3 0.97 7.8 0.22 MHS-32 13.4 18 42.3 3.60 20.2 0.71 MHS 33 2.8 20 7.7 0.74 3.7 0.13 NMS-34 4.9 20 18.2 1.32 9.3 0.28 MHS 35 8.2 5 27.6 1.87 8.5 0.33 MHS-36 1.9 20 7.2 0.57 3.8 0.13 MHS 37 0.8 7 2.2 0.21 0.7 0.04 MHS_38 3.12 20 13.0 0.94 7.6 0.23 MHS-39 7.86 20 30.2 2.33 16.2 0.54 MHS 40 3.8 20 17.1 1.58 15.7 0.39 MHS 41 3.2 46 14.8 1.42 18.4 0.37 MHS 42 1.7 5 5.7 0.51 3.3 0.13 MHS 43 4.3 20 13.6 1.16 12.7 0.26 MHS-44 2.2 20 7.9 0.60 4.0 0.13 NMS-45 37.3 20 68.8 9.17 30.3 1.45 MHS 46 5.6 20 10.2 1.36 3.1 0.26 NMS-47 10.4 20 32.1 2.76 13.5 0.55 MHS 48 20.2 20 40.9 5.11 13.5 0.98 NMS 49 1.3 19 5.7 0.36 4.4 0.09 MHS 50 21.5 20 61.8 5.76 29.8 1.08 NMS 51 2.2 0 9.7 0.64 7.7 0.19 MHS-52 13.4 20 28.6 3.39 13.0 0.56 MHS 53 13.9 17 33.2 3.56 13.5 0.58 NMS 55 1.4 20 5.4 0.39 2.8 0.08 MHS 56 6.0 20 17.4 1.61 8.4 0.31 MHS-57 23.1 20 48.2 5.89 21.9 0.98 MHS 58 3.3 20 11.6 0.97 5.9 0.21 MHS-59 11.3 20 32.9 3.21 15.8 0.65 NMS-60 3.8 20 16.7 1.06 8.4 0.23 NMS-61 9.4 20 20.4 2.42 9.2 0.41 MHS 62 10.0 20 19.5 2.48 8.7 0.40 MHS 63 12.3 26 33.4 3.43 18.7 0.69 PAMpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\ SEMHC _SWMM_hydraulic_output_noUPDATE NWL verification.xls Table 13.2 Watershed Modeling Results for Subwatersheds in the Minnehaha Creek South "East Drainage Area Watershed Information 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Watershed ID Total Area (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) Peak Runoff Rate (cfs)" . Total Volume Runoff (ac -ft) MHS 64 6.7 19 26.0 1.84 10.4 0.35 MHS 65 . 7.4 20 28.5 2:01 10.0 0.36 MHS_66 2.5 0 8 -.2 0.60 4.5: 0.16 MHS -67 4.6 20 18.8 1.28 10.6 0.29 MHS, 3.9 .20 7.4 0.96 8:5 0.23 MHS 69 1.1 20 4.9 0.31 1.9 0:06 MHS _ 70 3.4 '20 13':1 0.92 4.4 0.16 MHS 71 3.5 19 8.2 0.91 6.7 0.21 MHS 72 3.6 13 14.6 0.95 18 0.16 MHS_73 2.4 7 9.8 0.61 4.1 0.13 MHS 74 1.4 20 6.4 0.48 • 6.3 0.13 MHS__75 2.0 0 6.2 0.43 3.7 0:11 MHS 76 2.5 20 10.5 0.69 6.0 0.16 MHS 77 3.1 20 9.5 0.81 6.6 0.13 MHS 79 2.1 20 8.5 0.68 43 0.17 MHS 80 3.5 20 14.4 0.96 8.0 0.21 MHS-81 5.0 13 16.4 0.87 7.5 0.25 MHS 82 2.0 20 6.9 0.56 3.4 0.11 MHS 83 4.3 20 16.6 1.19 11.6 0.40 MHS_ _84 2.4 20 7.3 0.67 4.2 MHS 86 2.1 20 8.1 0.70 3.9 0.14 MHS-87 2.6 20 10.1 0.71 5.6 0.16 MHS-88 1.8 10 7.9 0.47 4.6 0.11 MHS 89 0.7 20 3.1 0.14 2.1 0.05 ML_ ' 1 6.1 19 21.5 1.68 10.4 0.34 ML 10 4.0 21 17:9 1.13 12.2 0.28 ML 11 4.9 20, 16.3 1.33 7.8 0.26 ML 12 9.5 20 30.1 2.54 14.4 0.49. , ML 13 42.5 36 87.0 12.42: 35.6 2.4L ML ' 14. 5.0 22 14.6 1.35 2.3 0.12 -ML- 15 2.0 20 8.4 0.55 4.7 0.12 ML 2 7.2 20 30.8 1.97 17.9 0.46 ML 3 26.5 20 86.2 7.11 41.4 1.37 ML 4' 19.4 18 56.7 5.07 26.2 0.92 ML 5 5.8 20 22.7 1.58 11.7 0.34 ML _6 4.5 20 17.4 1.22 8.9 0.26 ML _7 3.0 17 11.6 0.81 5.6 0.17 ML -8 27.7 42 124.5 9.39 55.0 1.60 ML 9 9.5 19 33.8 2.53 16.2 0.51 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\SEM HC_S W MM_hydrauli c_output_noUPDATE_NW L_verificati on.xls Table 13.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in the Minnehaha Creek South East Drainage Area Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft)3 Type of Storage NWL (ft) Flood Bounce (ft) Node Name Flood Elevation (151) NWL (ft) Flood Bounce (ft) 1602 outfall 856.9 1602 856.9 1754 1846P 864.9 1754 864.8 1758 outfall 858.7 1758 858.7 1760 outfall 858.7 1760 858.3 1762 outfall 864.9 1 1 1762 864.8 1764 outfall 851.0 1764 850.7 1766 1151 863.0 1766 862.8 1767 1805 851.1 1767 850.7 1769 1153 875.3 1769 875.1 1770 outfall 854.3 1770 854.4 1771 outfall 870.7 1771 871.1 1775 1157 881.0 1775 880.7 1776 1158 878.6 1776 878.1 1778 outfall 853.9 1778 853.6 1780 1163 882.3 1780 881.9 1784 1168 870.4 1784 870.3 1786 1170 870.2 1786 870.0 1788 outfall 856.3 1788 856.3 1791 outfall 862.8 1791 862.6 1793 1174 863.9 1793 863.7 1794 1175 862.4 1794 862.0 1796 1177 859.7 1796 859.1 1798 outfall 856.0 1798 855.8 1802 1181 (861) ST 1802 861.3 1806 outfall 857.4 1806 857.3 1804 outfall 857.3 1804 857.2 1808 1185 894.1 1808 893.9 1809 1186 894.0 1809 893.9 1810 1187 893.7 1810 893.5 1811 1188 892.6 1811 892.5 1812 1189 891.8 1812 891.7 1813 1190 891.3 1813 891.1 1814 1191 889.6 1814 889.5 1815 1192 888.8 1 1815 888.6 1820 1196 890.3 1820 889.6 1822 1198 886.4 ST 1822 886.1 1823 1954 886.4 1823 885.8 1824 1845P 885.4 ST 1824 884.2 1826 1201 887.7 1826 886.8 1828 1203 886.7 1828 886.7 1830 1206 881.1 1 1830 876.5 1833 1209 877.4 1833 873.9 1834 1217 876.6 1834 871.6 1835 1211 880.2 1835 875.6 1836 1212 877.4 1836 872.6 1838 1213 865.2 1 1838 863.9 1839 outfall/weir 858.2 1 1839 857.4 1840 1214 870.3 1840 867.4 1844 1220 878.9 1844 873.5 1845 1221 879.1 1845 873.6 1846 1222 879.3 1846 873.7 1848 1224 879.6 1848 873.9 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\SEMHC_SWMM_hydmulic_out put _noUPDATE_NWL_verification.xls Table 13.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in the Minnehaha Creek South East Drainage Area Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft), Type of Storage NWL (ft) Flood Bounce (ft) . Node Name Flood Elevation (ft) NWL (ft) Flood Bounce (ft); 1849 1225 879.9 1849, 878:8: 1854 1231 882.8 1854 882.6 1856 1232 883.1 1856 882.0 1858 1234 882.2 1858i 880.9` 1859 1235 .881.9 1859 879.7 1860 1236 883.5 1860 880.1 1861 1237 885.5 1861 882.0 1863 1239 89114 ST 1863 880.3 1865 1241 891.6 1865 880.6 "1868 1244 893.0 1868 882.9 1904 outfall 843.5 1 1904 843.5 1993 1803 858.6 1993 857.7 2000 outfall 860.5 2000 860.5 2003 1590 866.2 2003 862.7 2005 1592 866.4 2005 863.5 2007 1595 876.4 2007 876.4 2008 1596 878.6 2008 878.0 2009 1597 880.8 2009 879.7 2011 1599 885.0 1 2011 8823 2012 1600 885.3 2012 882.8 2111 1673 866.7 2111 866.6 2112 1675 863.8 2112 863.6; ' 2114 1677 862.7 2114 862.0 2116 1678 862.0 2116 861.3 2118 1679 860.9 2119 860.3 2119 1681 859.1 2119 858.9 2123 1804 859.0 2123 ---;857.4 2125 1684 860.1 2125 858.5 2127 1686 860.4 2127 858.9 2130 1689 865.5 2130 862.9 2131 1690 865.7 2131 863.2 2132 1691 869.7 2132 869.7 .2134 1693 868.9 2134 865:5 2136 1695 879.3 2136 875:8' 2240 1779 (863) 2240 860.6`. 2241 outfall 859.1 2241 MA 2247 -, outfall 869.6 2247 869.5. 2257 outfall 864.4 2257 864.4, 2259 outfall 881.0 2259 881'.0 2261 outfall 878.3 2261 878.1. 2263 outfall 867.6 2263 866.9 2265 outfall 869.9' 2265 869.9 2281 outfall 850.7 2281 850.3 2335 outfall 872.1 2335 872.1 2336 1778P 864.3 2336 864.2 2338 1848P 879.9 2338 876.4 2340 1850 880.8 ST 2340 878.3 2342 1852P 880.1 2342 878.8 2425 1933 890.6 2425 890.1 LP_1 1674 882.2 LP _1 881.3 LP _2 1682 859.9 ST LP-2 858.9 LP _3 1680 860.9 LP-3 860.2 PAMpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\ SEMHC_ SWMM_ hydmulic_ output _noUPDATE_NWL_veritication.xls is }s Table 13.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in the Minnehaha Creek South East Drainage Area Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft)3 Type of Storage° NWL (ft) Flood Bounce (ft) Node Name Flood Elevation (ft) NWL (ft) Flood Bounce (ft) LP _4 1676 865.6 LP _4 864.1 LP_5 1582 880.7 LP _5 877.9 LP _6 1672 869.4 LP-6 869.3 LP-7 1685 864.9 ST LP-7 863.3 L.P_8 1692 881.4 ST LP _8 878.5 LP-9 1688 865.0 ST LP-9 862.1 LP- 10 1687 863.4 LP_ 10 860.6 LP-1 1 1593 875.0 ST LP-1 1 874.8 LP 12 1931 861.0 ST LP 12 860.9 LP 13 1601 885.3 ST LP 13 884.1 LP-14 1841 (861) P 855.0 3.2 LP-14 857.3 856.4 0.9 LP 15 1696 884.3 ST LP 15 879.0 LP 16 1694 879.2 LP 16 875.6 LP 17 1588 862.5 LP 17 862.2 L.P 18 1591 866.5 LP- 18 864.5 LP -19 1589 865.0 LP 19 861.2 LP 20 1617 892.3 LP 20 892.1 LP 21 landlocked 862.6 BYD 858.6 4.0 LP 21 860.5 858.6 1.9 LP 22 1584 863.3 LP-2 2 858.5 LP 23 1598 883.1 LP-23 881.4 LP 24 landlocked 884.6 BYD 882.8 1.8 LP_24 883.9 882.8 1.1 LP 25 outfall1weir 858.2 P 856.5 1.7 LP 25 857.4 856.5 0.9 LP 26 between bays (861) P 855.0 LP 26 857.6 856.5 1.1 LP 27 1602 883.9 ST LP 27 882.2 LP_28 landlocked 885.5 BYD 884.0 1.5 LP 28 885.3 884.0 1.3 MHS_1 1172 (859) MHS_1 866.1 MHS_2 1840P 870.6 MHS_2 870.6 MHS_3 1148 (854) MHS_3 868.4 MHS_4 landlocked 875.4 BYD 872.4 3.0 MHS_4 873.7 872.4 1.3 MHS_5 1147 882.5 MHS_5 881.1 MHS_6 1833P 891.4 ST MHS_6 889.8 MHS_7 1146 (863) ST MHS_7 867.5 MHS_8 907 858.4 MHS_8 858.1 MHS_9 1178 859.2 MHS_9 858.6 1804 outfall 857.3 1804 857.2 MHS_10 1183 862.1 MHS_10 860.1 MHS_11 1176 862.3 MHS_11 861.2 MHS_12 1179 863.2 MHS_12 862.4 MHS_13 1215 871.3 MHS_13 871.0 MHS_14 landlocked 882.9 BYD 880.7 2.2 MHS_14 882.0 880.7 1.3 MHS_15 1216 876.1 MHS_15 871.2 MHS_16 landlocked 879.7 BYD 877.1 2.6 MHS_16 878.7 877.1 1.6 MHS_17 1219 882.3 ST MHS_17 873.4 MHS_18 1195 891.1 BYD 888.5 2.6 MHS_18 891.2 888.5 2.7 MHS_19 1200 886.9 P 885.0 1.9 MHS_19 885.7 885.0 0.7 MHS_20 1242 892.8 MHS_20 881.0 MHS_21 1184 897.1 MHS_21 895.8 MHS_22 1243 894.3 P 893.5 0.8 MHS_22 893.8 893.5 0.3 MHS_23 1143 894.9 MHS_23 894.9 MHS_24 1784P 895.3 ST MHS_24 894.3 MHS_25 ditch 896.9 MHS_25 896.9 MHS 26 1226 880.1 MHS 26 878.9 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update\WorkFiles \QAQC Model for Pond\SEMHC_SWMM_hydraulic_ output _noUPDATE_NWL_verification.xls Table 13.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in the Minnehaha Creek South East Drainage Area Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft)3 Type of Storage NWL (ft) Flood Bounce (ft) Node Name Flood Elevation (ft) .1 WL (ft) Flood Bounce (ft) MHS_27 landlocked 898.2 BYD 896.4 1.8 MHS-27 898.1 896.4 1.7 MHS .,28 overland path.. 904.2 MHS-28 904.1 MHS 29 landlocked 897.0 BYD 895.0 2.0 MHS-29 896.1 895.0. 1.1 MHS 30 1229 891.0' MHS 30 883.0 MHS-31 1150 (854.5) MHS_31 875.6, MHS 32' 1162 881.6 MHS 32 881.4 MHS_33 " 716P (857) MHS. 33 873.1 MHS 34, " ,overland pa [h; 888.1- MHS =34 888:1 MHS 35 landlocked-, ' 898.8 BYD 895.1 3.7 MHS 35 896.2 895.1 1.1 MHS-36 1169 (861') MHS-36. 864.9 MHS 37 1783P (859) MHS-37 872.0 MHS 38. creek NA MHS 38 NA MHS-39: creek NA MHS_39 NA MHS 40 1182 (861) 861.6 MHS-41 1180 859.9 P 857.0 2.9 -MHS-40 MHS-41 857.9, 857.0 0.9 MHS-42 1870 876.7 BYD 874.7 2.0 MHS_42 875.0 874.7 0.3 MHS 43 1194 895.1 MHS-43 895.0 MHS-44 1193 885.2 MHS-" 884.0 MHS 45 1173 872.7 MHS_45 872.5 MHS-46 1208 879.0 MHS-46 875.0 MHS 47 1953P 882.0 MHS 47 879.6 MHS-48 1238 889.6 MHS-48 879.9 MHS 49 1790.: (869) MHS--:49 875.3 MHS-50 1164 884.7 MHS-50 884.4 MHS-51 landlocked 882.9 BYD 880.2 2.7 MHS-51 8810 880.2 1.8 MHS-52 1167 876.2 MHS-52 876.0 MHS-53 1223 882.2 ST MHS-53 873.9 MHS_55 2 1152 (856) MHS-55 879.1 MHS 56' 1159 880.6 MHS-56 880.2 MHS 57 1230 884.5 MHS-57 883.8 MHS 58 _ 1233' 882.9 MHS-58 881.6 " MHS-59 1228' 880.1 BYD 867.7 12.5 MHS 59 879.0 867.7 - 11.3 MHS, 1273.: (854.5) MHS-60 " 862.5 MHS 61 1205. 885.0 MHS _61 -" 881.6 MHS 62 1165 884.9 ST MHS-62 879.8 " M14S_63 ditch 862.5 MHS_63 862.4 MHS 64 1149 863.8 MHS-64 854.1 MHS 65 1218 883.9 1 MHS-65 872.7 MHS-66 1240 894.8 BYD 886.1 8.7 MHS-66 893.1' 886.1 7.0 MHS 67 1794P (867) MHS-67 877.2 MHS-68 overland "path 896.6 ST MHS-68 896.6 M14S_69 1793P (867) MHS 69 873.3 MHS 70 1792 (867) MHS-70 887.9 MHS-71 1791 P (867) MHS_71 886.9 MHS 72 1815P 877.0 MHS-72 876.8 MHS_73 1844P 879.2 MHS-73 876.8 MHS 74 1166 872.3 BYD 867.3 5.1 MHS-74 872.0 867.3 4.8 MHS-75 1849 881.6 BYD 877.4 4.2 MHS-75 880.0 877.4 2.7 MHS 76 1847P 880.5 BYD 874.9 5.6 MHS-76 877.4 874.9, 2.5 MHS 77 overland path 882.5 ST MHS 77 882.4 MHS 79 1851P 880.1 ST MHS 79 879.1 MHS 80 1932 895.6 ST MHS 80 892.1 PAMpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFles \QAQC Model for Pond\.SEMHC_ SWMM_ hydraulic_ output _noUPDATE_NWL_veriftcation.xls u'F �E a i Table 13.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in the Minnehaha Creek South East Drainage Area Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft)3 Type of Storage NWL (ft) Flood Bounce (ft) Node Name Flood Elevation (ft) NWL (ft) Flood Bounce (ft) MHS_81 1944 (861) P 856.0 2.2 MHS_81 857.4 856.0 1.4 MHS_82 1197 890.2 ST MHS_82 889.4 MHS_83 1955 886.3 ST MHS_83 885.4 MHS_84 1202 888.2 MHS_84 887.2 MHS_86 1204 881.9 MHS_86 878.2 MHS_87 1207 880.3 ST MHS_87 875.9 MHS_88 1961 895.6 1 BYD 891.4 4.2 MHS_88 895.1 891.4 3.7 MHS_89 landlocked 884.0 BYD 881.6 2.4 MHS_89 883.3 881.6 1.7 102 2 919.9 102 915.7 103 3 913.1 103 910.0 104 1949 909.7 104 908.4 109 8 897.4 109 897.4 110 9 895.1 110 895.1 112 11 900.5 112 898.2 113 12 895.8 113 889.7 118 17 903.0 118 900.0 119 outfall 885.0 119 885.0 2374 1882 911.6 2374 911.6 2375 1883 910.3 2375 910.3 2376 1884 907.1 2376 907.0 2444 1950 908.1 1 2444 907.6 ML -I 6 896.3 ML_1 896.1 ML_10 1965 916.0 BYD 912.6 3.3 ML-10 915.0 912.6 2.4 ML_l l 1 935.9 ML'_ 11 934.4 ML 12 1826 935.8 ST ML-12 934.7 ML 13 908 897.8 ST ML_13 897.8 ML-14 1820 912.8 ST ML-14 910.6 ML 15 1821 912.9 ST ML-15 912.5 ML _2 5 907.0 ML-2 906.9 ML-3 15 902.5 ST MI -3 897.2 ML _4 10 916.5 MI-4 912.1 ML _5 7 907.7 MI-5 907.0 ML _6 16 916.2 ST MI -6 912.4 ML _7 landlocked 928.6 BYD 924.3 4.3 ML _7 926.5 924.3 2.2 ML _8 1966 (force main) 891.8 P 887.4 4.4 ML 8 888.4 887.4 1.0 M L 9 1881 1 ML 9 913.6 1 Catch basin inflows limited to 24 cfs 2 Catch basin inflows limited to 15 cfs ' Flood elevations in parenthesis indicate a 100 -year flood elevation based on the 100 -year flood elevation of Minnehaha Creek, according to the Federal Emergency Management Agency Flood Insurance Study for the City of Edina ST= Street, BYD =Back Yazd Depression, P--Pond PAMpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorILFiles \QAQC Model for Pond\SEMHC SWMM _hydraulic_output_noUPDATE_NW L_verification.xls Table 13.4 Conduit Modeling Results for Subwatersheds In the Minnehaha Creek South Easit Drainage Areas Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimensions* (ft) Roughness Coefficient Upstream Invert p Elevation (ft) Downstream Invert Elevation (ft) Conduit Length (fQ Slope IOOY Peak Flow Through Conduit (cfs) IOY Peak Flow Through Conduit (cfs) 907 MHS_8 1602 Circular 1.25 0.013 856.3 856 150 0.20 5.3 4.6 1143 MHS_23 1754 Circular 1.25 O.0224 887.1 863.6 340 6.91. 10.5 10.5 1146 MHS 7 1758 Circular 1.25 0.013 860.5 857.5 390 0.77 9.9 9.6 1147 MHS_5 1760 Circular 1 0.010 880.67 857.8 261 8.76 14.7 5.8 1148 MHS_3 1762 Circular 1.5 0.024 867.87 864.29 39 9.18 6.4 4.1 1149 MHS 64 1764 Circular 1.5 0.013 851 849.49 285 0.53 20.9 10.4 1150 MHS_31 1766 Circular 1.5 0.013 874.75 872.15 30 8.67 14.3 7.8 1151 1766 1767 Circular 1.5 0.013 862.3 854.76 49 15.39 143 7.8 1152 MHS_55(2) 1769 Circular 2.75 0.013 871.43 869.74 98 1.73 34.0 32.9 1153 1769 1770 Circular 1.25 0.013 864.19 853.14 75 14.73 26.8 26.7 1154 1769 1771 Circular 1 0.013 864:19 870.23 26 -23.23 8.9 8.7 1157 1775 MHS_56 Circular 1 0.013 874.68 873.55 303 0.37 4.7 4.7 1158 1776 MHS_55 (2) Circular 2.25 0.013 872.66 871.43 168 0.73 26.3 26.2 1159111 MHS_56 1776 Circular 2.25 0.013 873.55 872.66 101 0.88 26.6 26.6 1160 MHS 56 MHS 33 Circular.. 1.25 0.013 876 874.32 145 1.16 12.1 12.0 1161 MHS 33 1778 Circular 1.25 0.013 871.87 852.65 280 6.86 16.6 15.1 1162 MHS_32 1775 Circular 1 0.013 875.4 874.68 327 0.22 . 3.5 4.3 1163 1780 MHS_32 Circular 2 0.013 876.6 875.4 323 0.37 9.9 10.1 1164 MHS_50 1780 Circular 2 0.013 877.6 876.6 325 0.31 18.6 18.8 1165 MHS_62 MHS 74 Circular 1 0.013 878.92 867.25 152 7.68 10.6 8.5 1166 MHS 74 1784 Circular 1 0.013 867.25 866 150 0.83 4.3 4.8 1167 MHS 52 1784 Circular 1.25 0.013 869.2 866 302 1.06 1 8.9 8.9 1168 1784 1786 Circular 1.25 0.013 866 865.3 218 -L -0.32 6.6 6.7 1169 MHS_36 1788 Circular 1 0.013 863.8 855.43 175 4.78 8.4 8.4 1170 1786 MHS_1 Circular 1.25 0.013 865.3 863.5 235 0.77 7.3 8.3 1172 MHS_I 1791 Circular 1.25 0.013 863.5 861.8 42 4.05 12:8 10.3 1173 MHS_45 1793 Circular 1.5 0.013 866.32 858.3 272 2.95 21.4 212 1174 1793 1794 Circular 1.5 0.013 858.3 856.12 47 4.64. 26.7 24.5 1175 1794 MHS_ll Circular 2.75 0.013 856.12 856 16 0.75 38.8 31.3 1176 MHS-I1 1796 Circular 2.75 0.013 856 853.9 234 0.90 53.2 46.2 1177 1796 MHS 9 Circular 3 0.013 853.9 853.6 62 0.48 46.4 43.9 1178 MHS9 1798. Circular 3.5 0.024 853.6 853.6 169 0.00 57.8 50.5 1179 MHS_12 MHS 41 Circular 1.5 0.024 857.34 851.5 134 4.36 10.0 10.6 1180 MHS_41 1802 Circular 1.25 0.024 857 856.86 142 0.10 -6.0 -4.5 1181 1802 MHS 40 Circular 1.25 0.013 856.86 856.72 36 0.39 8.1 -5.9 1182 MHS_40 MH1804 Circular 1.5 0.024 856.72 856.02 125 0.56 11.4 9.7 1183 MHS 10 1806 Circular 1.5 0.013 856.6 856 145 0.41 16.5 12.5 1184 MHS_21 1808 Circular 1.25 0.013 891.85 888.7 271 1.16 7.0 5.5 1185 1808 1809 Circular 1.25 O.Ol3 888.7 888.4 22 1.36 5.3 4.4 1186 1809 1810 Circular 1.25 0.013 888.4 888.2 39 0.51 8.1 9.2 1187 1810 1811 Circular 1.25 0.013 888.2 886.9 162- 0.80 8.0 9.0 1188 1811 1812 Circular 1.25 0.013 886.9 886.05 94 0.90 8.2 9.1 1189 1812 1813 Circular 1.25 0.013 886.05 885.45 62 0.97 8.2 9.2 1190 1813 1814 Circular 1.25 0.013 885.45 884 123 1.18 8.4 9.5 1191 1814 1815 Circular 1.25 0.013 884 883.05 57 1.67 8.7 10.0 1192 1815 MHS_61 Circular 1.25 0.013 883.05 878.4 303 1.53 8.7 10.4 ' 1193 MHS_44 MHS_61 Circular 2 0.013 878.8 877 315 0.57 13.3 7.7 1193 MHS_44 MHS_61 Circular 2 0.013 878.8 877 315 0.57 13.2 7.7 1194 MHS 43 1809 Circular I 1 0.010 890.63 888.4 - 407 0.55 4.7 5.4 P.\Mpb\23 MM270271072 Edina Water Resourm Mgmt Plan Update \WorkFdw\QAQC Model fm Poad\SEMHC_SWMMJtydmulic mtpuLwUPDATE_NWI vaiiticatim.xls Table 13.4 Conduit Modeling Results for Subwatersheds in the Minnehaha Creek South Fast Drainage Areas Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimensions. (ft) Roughncss Coefficient Upstream Invert Elevation (ft) Downstream Invert Elevation (ft) Conduit Length (ft) Slope IOOY Pcak Flow Through Conduit (cfs) IOY Peak Flow Through Conduit (cfs) 1195 MHS_18 1820 Circular 0.75 0.020 888.5 887.4 130 0.85 1.9 2.4 1196 1820 MHS_82 Circular 1 0.024 887.4 887.1 29 1.03 1.9 2.4 1196 1820 MHS_82 Circular 1 0.024 887.4 887.1 29 1.03 3.1 2.4 1197 MHS_82 1822 Circular 1.25 0.024 884.2 882.5 167 1.02 5.3 5.0 1198 1822 1823 Circular 1.25 0.013 882.5 882.2 34 0.88 5.1 4.9 1200 MHS_19 1826 Circular 0.75 0.010 884.54 882.97 142 1.11 -2.4 -1.9 1201 1826 MHS_84 Circular 1 0.024 882.97 882.34 28 2.29 -2.4 -2.0 1202 MHS_94 1828 Circular 1 0.013 882.34 880.95 128 1.09 3.8 2.9 1203 1828 MHS 44 Circular 1 0.024 880.95 880.7 350 0.07 2.1 1.7 1204 MHS_86 1830 Circular 2 0.013 873.35 871.54 206 0.88 19.5 18.9 1205 MHS_61 1830 Circular 2 0.013 877 875.24 327 0.54 28.7 25.0 1206 1830 MHS 87 Circular 2 1 0.013 875.3 874.6 1 140 0.50 20.4 8.7 1207 MHS_87 MHS 46 Circular 2 0.013 874.6 873.3 248 0.52 17.3 12.5 1208 MHS_46 1833 Circular 2 0.013 873.3 872.3 116 0.86 29.0 19.1 1209 1833 1834 Circular 2.5 0.013 872.3 870.86 131 1.10 28.7 19.0 1210 1830 1835 Circular 2.5 0.013 871.5 870.8 71 1.04 40.3 40.5 1211 1835 1836 Circular 2.5 0.013 870.8 867.1 467 0.80 39.1 38.8 1212 1836 MHS 15 Circular 2.5 0.013 867.1 865.9 131 0.88 39.0 38.9 1213 1838 1839 Circular 4 0.013 860 857.1 298 0.97 127.9 107.3 1214 1840 1838 Circular 4 0.013 861.45 860 547 0.27 127.9 107.8 1215 MHS_13 1840 Circular 1 0.013 867.2 867.05 50 0.30 6.8 6.9 1216 MHS_15 1840 Circular 4 0.013 862.6 861.45 605 0.19 124.1 101.1 1217 1834 MHS_15 Circular 4 0.013 862.91 862.79 28 0.43 83.9 62.7 1218 MHS_65 1834 Circular 3.5 0.013 864.25 862.91 333 0.40 68.0 46.5 1219 MHS_17 MHS_65 Circular 3.5 0.013 864.9 864.25 328 0.20 67.6 42.5 1220 1844 MHS_17 Circular 3.5 0.013 864.45 864.9 108 -0.42 1 58.5 34.8 1221 1845 1844 Circular 3.5 0.013 865.5 864.45 220 0.48 58.5 34.7 1222 1846 1845 Circular 3.5 0.013 865.7 865.5 172 0.12 58.5 33.8 1223 MHS_53 1846 Circular 3.5 0.013 865.8 865.7 162 0.06 58.5 33.0 1224 1848 MHS_53 Circular 3.5 0.013 865.5 865.8 160 -0.19 50.5 28.1 1225 1849 1848 Circular 3.5 0.013 865.4 865.5 16 -0.63 48.7 27.9 1226 MHS 26 1849 Circular 3.5 0.013 866.25 865.4 153 0.56 48.6 24.7 1228 MHS 59 MHS -26 Circular 3.5 0.013 867.65 867.45 27 0.74 -79.6 -32.9 1229 MHS_30 1854 Circular 1.25 0.013 881.75 879 288 0.95 4.0 3.9 1230 MHS_57 1856 Circular 1.25 0.013 879.23 878.46 230 0.34 6.1 6.7 1231 1854 MHS_58 Circular 1.25 0.013 879 878.1 225 0.40 2.9 4.5 1232 1856 MHS 58 Circular 1.25 0.013 878.46 877.87 147 0.40 5.8 6.1 1233 MHS_58 1858 Circular 1.25 0.013 877.87 877.1 188 0.41 6.2 6.9 1234 1858 1859 Circular 1.25 0.013 877.1 875.82 211 0.61 6.4 6.6 1235 1859 MHS 59 Circular 1.25 0.013 875.82 873 219 1.29 8.3 6.2 1236 1860 MHS26 Circular 3 0.013 867.8 866.25 340 0.46 65.9 29.5 1237 1861 1860 Circular 3 0.013 871.25 867.8 120 2.88 76.8 29.2 1238 MHS_48 1861 Circular 3 0.013 874.3 871.25 279 1.09 76.9 29.3 1239 1863 MHS_48 Circular 3 0.013 875.6 874.3 362 0.36 51.0 18.9 1240 MHS_66 1865 Circular 1 0.013 886.07 884.4 164 1.02 8.0 7.1 1241 1865 1863 Circular 3 0.013 878 875.6 394 0.61 38.3 25.1 1242 MHS 20 1865 Circular 3 0.013 879.8 878 360 0.50 38.1 15.2 1243 MHS_22 1868 Circular 2 0.013 893.5 888.4 220 2.32 12.8 1.3 1244 1868 M HS_20 Circular 2 0.013 882.5 882.1 50 0.80 18.9 1.3 1273 MHS 60 1904 Circular 1 0.074 859.34 842.65 97 17.24 8.4 8.4 P:\Mpb\23 MM A23271072 Fdim Water Resources Mgmt Plan Updaze \WorkFd.%QAQC Model for Pood'SEMHC_SWMMJgMtaulic mtput_mUPDAT _NWL_vcifimion.xls Table 13.4 Conduit Modeling Results for Subwatersheds in the Minnehaha Creek South East Drainage Areas Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimensions (ft) Roughness Coefficient Upstream Invert Elevation (ft) Downstream Invert Elevation (ft) Conduit Lcngth (ft) Slope IOOY Peak Flow Through Conduit (cfs) 1 OY Peak Flow Through Conduit (cfs) 1582 LP_5 LP-12 Circular 1 0.013 877.6 855.8 245 8.90 10.1 4.9 1584 LP 22 1993 Circular 2 0.013 855.71 855.42 288 0.10 27.3 13.4 1588 LP_ 17 2000 Circular 1.5 0.013 859.03 857.64 68 2.04 16.2 15.4 1589 LP_19 LP_26 Circular 3.5 0.013 858.7 857.33 185 0.74 121.9 77.4 1589 LP-19 LP-26 Circular 3.5 0.013 858.7 857.33 185 0.74 150.2 75.8 1590 2003 LP_19 Circular 1.5 0.013 860.0 858.7 62 2.05 20.1 21.6 1591 LP- 18 2003 Circular 1.5 0.013 860.87 859.97 179 0.50 13.6 21.6 1592 2005 1?-- 19 Circular 3.5 0.013 862.2 858.7 285 1.23 55.9 34.9 1593 LP_11 2005 Circular 2 0.013 866.39 862.2 333 1.65 37.1 32.7 1595 2007 LP_lI Circular 2 0.013 866.5 866.39 175 0.06 25.4 23.6 1596 2008 2007 Circular 2 0.013 866.83 866.5 165 0.20 25.4 22.8 1597 2009 2008 Circular 2 0.013 867.15 866.83 162 0.20 25.4 22.8 1598 LP-23 2009 Circular 2 0.013 867.72 867.15 173 0.33 25.4 22.8 1599 2011 LP_23 Circular 1.5 0.013 871.76 870.9 165 0.52 10.3 6.8 1600 2012 2011 Circular 1.5 0.013 872.59 871.76 110 0.75 9.4 6.8 1601 LP-13 2012 Circular 1.5 0.013 874.14 872.59 290 0.53 7.9 8.0 1602 LP-27 LP-23 Circular 2 0.013 869.64 867.72 427 0.45 22.2 20.3 1617 LP-20 LP-27 Circular 1.5 0.013 880.0 875.0 660 0.75 14.0 13.3 1672 LP_6 2111 Circular 2 0.013 863.03 861.64 267 0.52 23.2 24.6 1673 2111 2112 Circular 2 0.013 861.6 859.6 250 0.80 23.2 23.3 1674 LP_I 2112 Circular I 0.013 880.9 859.6 145 14.65 11.9 6.3 1675 2112 2114 Circular 2 0.013 859.64 857.35 248 0.92 22.4 22.4 1676 LP-4 2114 Circular 1 0.013 860.4 857.4 72 4.28 7.8 6.1 1677 2114 2116 Circular 2.5 0.013 857.9 856.7 215 0.52 25.8 23.7 1678 2116 LP_3 Circular 2.5 0.013 856.7 855.6 220 0.53 25.8 23.7 1679 2118 LP-3 Circular 1 0.013 858.0 855.6 60 4.07 -0.2 -1.5 1680 LP_3 2119 Circular 2.5 0.013 857.52 856.55 174 0.56 36.9 32.1 1681 2119 LP-25 Circular 2.5 0.013 856.55 856.1 120 0.38 36.8 32.6 1682 LP_2 LP_25 Circular 1.5 0.013 855.98 855.2 194 0.40 Ill 11.6 1684 2125 2123 Circular 1.5 0.010 856.9 855.9 170 0.58 11.3 10.4 1685 LP-7 2125 Circular 1.25 0.013 859 856.88 165 1.28 11.4 10.5 1686 2127 2123 Circular 2.5 0.010 856.4 855.9 100 0.50 40.4 30.7 1687 LP 10 2127 Circular 2.25 0.013 857.6 856.4 148 0.80 40.4 30.7 1688 1P_9 LP-10 Circular 2 0.013 858.0 857.6 102 0.42 25.8 20.1 1689 2130 LP_9 Circular 1.5 0.013 861.3 858.0 158 2.08 9.2 6.8 1690 2131 2130 Circular 1.5 0.013 862.0 861.3 29 2.31 7.1 6.7 1691 2132 2131 Circular 1 0.013 865.0 862.0 195 1.55 6.5 6.5 1692 LP-8 2132 Circular 1 0.013 875.1 865.0 138 7.32 10.3 8.8 1693 2134 LP-18 Circular 1.25 0.013 863.11 860.87 243 0.92 9.2 13.6 1694 LP 16 2134 Circular 1.25 0.013 874.74 863.11 293 3.97 12.2 13.9 1695 2136 LP_16 Circular 1.25 0.013 874.88 874.74 43 0.33 7.9 5.3 1696 LP 15 2136 Circular 1.25 0.013 878.2 874.9 401 0.84 7.9 5.3 1778P 2336 2240 Circular 2.5 0.013 863.6 859.3 140 3.07 11.7 10.5 1779 2240 2241 Circular 2.5 0.013 859.3 858 327 0.40 11.6 10.5 1783P MHS_37 2247 Circular 1.5 0.013 871.8 869.3 44 5.68 2.2 0.7 1784P MHS_24 MHS 66 Circular 1 0.013 887 886.07 162 0.58 5.7 5.3 1790 MHS_49 2257 Circular 1 0.013 865.7 863.4 234 1.00 9.6 7.4 1791P MHS 71 2259 Circular 1.25 0.013 886.24 880.46 57 10.14 8.2 6.7 1792 MHS 70 2261 Circular 1 0.024 887.2 877.5 93 10.48 6.3 4.7 1793P MHS_69 2263 Circular 1 0.013 872.97 866.61 92 6.95 10.3 1.9 P:\APM21 MN127tU3271072 Fdim Water Rcvattrcea Mgtnt Plan Update \WorkPila\QAQC Modd far Pond\SEMHC SWMM- tydtaulic_output noUPDATE_NWL_verificatiun.xls Table 13.4 Conduit Modeling Results for Subwatersheds In the Minnehaha Creek South East Drainage Areas Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimensions• (0) Roughness Coefficient Upstream Invert P Elevation (ft) Downstream invert Elevation (ft) Conduit Length (ft) Slope IOOY Peak Flow Through Conduit (cfs) IOY Peak Flow Through Conduit (cfs) 1794P MHS_67 2265 Circular 1 0.013 872.02 868.86 86 3.67 10.7 10.5 1803 1993 LP76 Circular 2.5 0.013 855.42 854.9 50 1.04 27.3 13.4 1804 2123 LP-14 Circular 3 0.013 854.4 853.4 80 1.21 50.9 41.1 1805 1767 2281 Circular 2.5 0.024 849.8 849.4 16 2.31 14.3 7.8 1815P MHS22 MHS_73 Circular 1 0.013 874.27 873.24 321 0.32 -3.0 2.1 1833P MHS_6 MHS_23 Circular 1.25 0.013 888.3 887.1 169 0.71 -9.4 -8.7 1840P MHS_2 1786 Circular 1.25 0.013 869.1 865.3 25 15.20 5.2 5.9 1841 LP 14 2334 Circular 2.5 0.013 855.0 853.5 150 1.00 53.8 44.9 1844P MHS 73 2335 Circular 1 0.013 873.24 871.19 329 0.62 5.4 4.4 1845P 1824 MHS_44 Circular 1.25 0.013 879.2 878.8 24 1.67 9.9 6.0 1846P 1754 2336 Circular 2.5 0.013 863.6 863.6 36 0.00 11.7 10.5 1847P MHS_76 2338 Circular 1.25 0.010 874.92 874.6 200 0.16 7.1 5.9 1848P 2338 MHS_46 Circular 1.25 0.013 874.6 873.9 181 0.39 7.1 5.9 1849 MHS 75 2340 Circular 1 0.010 877.35 875.85 181 0.83 4.2 5.9 1850 2340 MHS_86 Circular 1.25 0.013 874.25 873.85 27 1.48 13.2 6.4 1851P MHS79 2342 Circular 1 0.013 876.15 875 215 0.53 4.0 3.5 1852P 2342 MHS_56 Circular 1 0.013 875 873.39 151 1.07 4.0 3.5 1870 MHS_42 1848 Circular 1.25 0.013 874.7 874.2 62 0.81 6.4 8.6 1931 LP_12 LP-26 Circular 1 0.010 855.1 855.0 1 350 0.00 1 4.1 5.8 1932 MHS 80 2425 Circular 1 0.015 889.2 888.0 309 0.39 4.0 3.8 1933 2425 MHS_49 Circular 1 0.015 888 886 231 0.87 4.0 3.7 1944 MHS 81 LP_25 Circular 5 0.013 852.62 852.23 167 0.23 59.9 54.8 1953P MHS 47 MHS 86 Circular 2 0.013 875 873.37 430 0.38 18.3 14.0 1954 1823 MHS_83 Circular 1.25 0.013 882.2 881.1 106 1.04 5.1 4.9 1955 MHS_83 1824 Circular 1.25 0.013 881.1 879.2 182 1.04 9.5 6.1 1961 MHS 88 MHS 43 Circular 1 0.010 891.4 890.4 145 0.69 3.3 4.1 1 ML-II 102 Circular 1.250 0.013 929.1 914.95 329.00 4.3 14 7.7 10 ML-4 112 Circular 1.500 0.013 910 892.84 220.00 7.8 28 26.0 11 112 113 Circular 1.500 0.013 892.84 887 75.00 7.8 28 26.0 12 113 ML ,8 Circular 2.000 0.013 887 885.9 55.00 2.0 48 26.0 15 ML-3 ML -8 Circular 2.000 0.013 896 885 131.00 8.4 57 41.3 16 ML-6 118 Circular 1.000 0.013 895.7 895 220.00 0.3 10 9.6 17 118 ML-8 Circular 1.000 0.024 895 885 55.00 18.2 9 8.5 1966 (force main) MLS 119 Circular 1.000 0.02 907.59 911.36 NA NA 4 4.0 1820 MI-14 ML 13 Circular 1.250 0.013 910 909.24 86.00 0.9 9 2.3 1821 ML 15 ML-13 Circular 1.000 0.013 908.44 907.76 332.00 0.7 4 3.7 1826 ML 12 Midi Circular 1.250 0.013 929.5 927.83 328.00 0.5 8 6.2 1881 ML-9 2374 Circular 1.250 0.013 907.48 905.08 80.00 3.0 9 9.4 1882 2374 2375 Circular 1.250 0.013 905.08 903.86 76.00 1.6 7 8.2 1883 2375 2376 Circular 1.250 0.013 903.86 900.42 215.00 1.6 7 7.4 1884 2376 ML _5 Circular 1.250 0.013 900.42 899.67 27.00 2.8 8 8.2 1949 104 2444 Circular 1.250 0.013 905 901.6 60.00 5.7 12 8.9 1950 2444 ML-2 Circular 1.250 0.013 901.6 900.2 42.00 3.3 12 9.1 1965 ML-10 ML-13 Circular 1.000 0.013 912.64 911.59 101.00 1.0 6 5.0 2 102 103 Circular 1.250 0.013 914.95 907.62 235.00 3.1 12 8.0 3 103 104 Circular 1.250 0.013 907.62 905 90.00 2.9 12 8.5 5 ML-2 ML_l Circuhv 1.250 0.013 900.2 890 170.00 6.0 16 16.6 6 ML_1 ML_8 Circular 1.500 0.013 888 887.2 80.00 1.0 25 24.0 7 ML _5 109 Circular 1.250 0.013 899.67 889.71 293.00 3.4 12 11.9 8 109 110 Circular 1.250 0.013 889.71 888.86 85.00 1 1.0 9 9.5 PAMpM23 MN\27\23271072 Edina Weser Resoutua Mgt Nan Update \Wort Fdes\QAQC Model for PmMEMHC_SWMMJrydraulic_output uoUPDATE_NWL verifiwtion.xls Table 13.4 Conduit Modeling Results for Subwatersheds In the Mlnnehaha Creek South East ,Drainage Areas . t Catch basin inflows at node MHS 56 Limited to 24 cfs 'Catch basin inflows at node MHS_55 limited to 15 cfs P:\Mpb\23 MN\27\23271072 Edina Water Resources Mgmt Plain Update \WwkFiles \QAQC Model for PonMEMHC_SWMMJtydreulic output_noUPDATE_NWL_ve ification.xls Conduit Dimensions' Roughness Upstream Invert P Downstream Invert - .Conduit Length IOOY Peak Flow Through I OY Peak Flow Conduit ID Upstream Node Downstream Node Conduit Shape (ft) Coefficient Elevation Elevation (ft) - Slope Conduit (cfs) Through Conduit (ft) (ft) (cfs) 9 110 Mhl Circular `' 1.250 0.013 888.86 888 86.00 1.0 -6 7.5 908 MIL 13 ML_8 Circular 3.500 0.013 886.56 886 48.00 1.2 105 46.5 t Catch basin inflows at node MHS 56 Limited to 24 cfs 'Catch basin inflows at node MHS_55 limited to 15 cfs P:\Mpb\23 MN\27\23271072 Edina Water Resources Mgmt Plain Update \WwkFiles \QAQC Model for PonMEMHC_SWMMJtydreulic output_noUPDATE_NWL_ve ification.xls Northwest Minnehaha Creek 14.0 -Northwest Minnehaha Creek 14.1 General Description of ;Drainage Area Figure 14 :1 depicts the Northwest Minnehaha Creek drainage basin and the individual subwatersheds within this area. The Northwest Minnehaha' ,Creek drainage basin is located in the far northwest corner of Edina, east of the T.H. 169 North drainage area. This watershed is the smallest of the Minnehaha Creek watersheds and extends from T.H. 100 to areas west of the Interlachen Golf Course. 14.1.1 Drainage Patterns The stormwater system within this drainage area is comprised of storm sewers, .ponding basins, -wetlands, drainage ditches, and overland flow paths. The Northwest Minnehaha Creek basin has been divided into several major watersheds based on the drainage patterns. These major watersheds are depicted in Figure 14.2. Each major watershed has been further delineated into numerous sub watersheds. The naming convention for each subwatershed is based on the major watershed it is located within. Table 14.1 lists each major watershed and the associated subwatershed naming convention. . Table 14.1 Major. Watersheds within the Northwest. Minnehaha Creek Drainage Basin Major Watershed Subwatershed Naming Convention .# of Subwatersheds Drainage Area (acres) T.H. 100 H 100 ## 15 104 Hopkins HO ## 22 94 Interlachen El —#i 37 345 14.1.1.1 T.H. 100 The land use of this watershed is.primarily commercial and most of the runoff drains to a trunk stormsewer system along T.H. 100 that. flows north to Minnehaha Creek. The storm sewer system analyzed in this watershed runs along Vernon Avenue, goes east to Eden Avenue and them to the. T.H. 100';storm sewer system., The T.H. 100 storm sewer system was not analyzed as part of this study., The pipe system and ;ponds within the Grandview Square development were also incorporated in the hydraulic and water quality models. 14.1.1.2 Hopkins The Hopkins watershed is "located just -south of the City of Hopkins and west of the Interlachen Country Club. This is a small. watershed and consists of 94 acres of total land area. All of the water in this watershed is routed north by a lift station to a Hopkins storm sewer system. The land use is primarily low density residential with several ponds and wetlands. Sarr`Engineering Company 44 -1 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT-12151 IREV.docx h. 14.1.1.3 Interlachen The Interlachen watershed consists of the Interlachen Country Club and residential areas adjacent to the golf course. There are several ponds and wetlands that provide storage and treatment for runoff in this watershed. There are few storm sewer pipes and water conveyed by the storm sewer system drains north to Minnehaha Creek. Modeling of the storm sewer system includes proposed pipes connecting the ponds within the Interlachen Country Club. These pipes are shown on Figure 14.3. 14.2Stormwater System Analysis and Results 14.2.1 Hydrologic /Hydraulic Modeling Results The 10 -year and 100 -year frequency event flood analyses were performed for the Northwest Minnehaha Creek drainage basin. For the Northwest Minnehaha Creek watersheds, the storm sewers were evaluated using a 10 -year and a 100 -year frequency storm event. The 10 -year analysis was based on a'' /z -hour storm of 1.65 inches of rain and the 100 -year analysis was based on a 24 -hour storm event of 6 inches of rain. The storm sewers in Table 14.2 present the watershed information and the results for the 10 -year and 100 -year hydrologic analyses for the Northwest Minnehaha Creek basin. The results of the 10 -year and the 100 -year hydraulic analysis for the Northwest Minnehaha Creek drainage basin are summarized in Table 14.3 and Table 14.4. The column headings in Table 14.3 are defined as follows: Node /Subwatershed ID—XP -SWMM node identification label. Each XP -SWMM node represents a manhole, catchbasin, pond, or other junction within the stormwater system. Downstream Conduit — References the pipe downstream of the node in the storm sewer system. Flood Elevation —The maximum water elevation reached in the given pond /manhole for each referenced storm event (mean sea level). In some cases, an additional flood elevation has been given in parenthesis. This flood elevation reflects the 100 -year flood elevation of Minnehaha Creek, as shown in the National Flood Insurance Program Flood Insurance Study for the City of Edina, May 1979. Peak Outflow Rate —The peak discharge rate (cfs) from a given ponding basin for each referenced storm event. The peak outflow rates reflect the combined discharge from the pond through the outlet structure and any overflow. NWL —The normal water level in the ponding basin (mean sea level). The normal water levels for the ponding basins were assumed to be at the outlet pipe invert or at the downstream control elevation. Barr Engineering Company 14 -2 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 'Flood Bounce —The fluctuation of the water level within a given pond for each referenced storm event. Volume Stored —The maximum volume,(acre -ft) of water that was stored in the ponding basin during the storm event. The volume represents the live storage volume only. 'fable 14.4 summarizes the conveyance system data used in the model and the model results for the storm sewer system within the Northwest Minnehaha Creek drainage basin. The peak flow through each conveyance system for the 10 -year, and the 100 -year frequency storm event is listed in the :. table. The values presented represent the peak flow rate through each pipe system only and does not reflect the combined total flow from an upstream node to the downstream node when overflow from a manhole /pond occurs. Figure 14.3 graphically represents the results of the 10 -year and the 100 -year frequency hydraulic analyses. The figure depicts the Northwest Minnehaha Creek drainage basin boundary, subwatershed boundaries, the modeled storm sewer network, surcharge conditions for the XP -SWMM nodes (typically manholes), and the flood prone areas identified in the modeling analyses. One of the objectives of the hydraulic analyses was to evaluate the level of service provided by the current storm sewer system. The level of service of the system was examined by determining the surcharge conditions of the manholes and catch basins within the storm sewer system during the . 10 -year and 100 -year frequency storm events. An XP -SWMM node was considered surcharged if the 'hydraulic grade line at that node breached the ground surface (rim elevation). Surcharging is typically-the result of limited downstream• capacity and tailwater impacts. The XP -SWMM nodes depicted on Figure 14.3 were -color coded based on the resulting surcharge conditions. The green nodes signify no surcharging occurred during the 100 -year or 10 -year frequency storm event, the yellow nodes indicate surcharging during the 100 -year frequency event, and the red nodes identify that surcharging is likely to occur during both a 100 -year and 10 -year frequency storm event. Figure 14.3 illustrates that several XP -SWMM nodes within the Northwest Minnehaha Creek drainage basin are predicted to experience surcharged conditions during both the 10 -year and 100 7year frequency storm events. This indicates a probability greater than 10 percent in any year I hat the system will be overburdened and unable to meet the desired level of service at'these ,locations. These manholes and catch basins are more likely,to experience inundation during the .smaller, more frequent storm events of various durations. Another objective of the hydraulic analysis was to evaluate the level of protection offered by the current stormwater system. Level of protection is defined as the capacity provided by a municipal drainage` system (in terms of pipe capacity and overland overflow capacity) to prevent property damage and assure a reasonable degree of public safety following a rainstorm. A 100 -year event is recommended as a standard for design of stormwater management basins. To evaluate the level of protection of:the stormwater system within the Northwest Minnehaha Creek drainage area, the 100 -year frequency flood elevations for the ponding basins and depressed areas were compared to the low elevations of structures surrounding each basin. The low elevations were initially determined Barr Engineering Company 14 -3 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL 'DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx using 2 -foot topographic information and aerial imagery in ArcView. Where 100 -year frequency flood levels of the ponding areas appeared to potentially threaten structures, detailed low house elevations were obtained through field surveys. 14.2.2 Water Quality Modeling Results The effectiveness of the stormwater system in removing stormwater pollutants such as phosphorus was analyzed using the P8 water quality model. The P8 model simulates the hydrology and phosphorus loads introduced from the watershed of each pond and the transport of phosphorus throughout the stormwater system. Since site - specific data on pollutant wash -off rates and sediment characteristics were not available, it was necessary to make assumptions based on national average values. Due to such assumptions and lack of in -lake water quality data for model calibration, the modeling results were analyzed based on the percent of phosphorus removal that occurred and not based on actual phosphorus concentrations. Figure 14.4 depicts the results of the water quality modeling for the Northwest Minnehaha Creek drainage basin. The figure shows the fraction of total phosphorus removal for each water body as well as the cumulative total phosphorus removal in the watershed. The individual water bodies are colored various shades of blue, indicating the percent of the total annual mass of phosphorus entering the water body that is removed (through settling). It is important to note that the percent of phosphorus removal is based on total phosphorus, including phosphorus in the soluble form. Therefore, the removal rates in downstream ponds will likely decrease due to the large soluble fraction of incoming phosphorus that was unsettleable in upstream ponds. The watersheds are depicted in various shades of gray, indicating the cumulative total phosphorus removal achieved. The cumulative percent removal represents the percent of the total annual mass of phosphorus entering the watershed that is removed in the pond and all upstream ponds. 14.3 Implementation Considerations The XP -SWMM hydrologic and hydraulic modeling analyses and P8 water quality analysis helped to identify locations throughout the watershed where improvements to the City's stormwater management system may be warranted. The following sections discuss potential mitigation alternatives that were identified as part of the 2003 modeling analyses. As opportunities to address the identified flooding issues and water quality improvements arise, such as street reconstruction projects or public facilities improvements, the City will use a comprehensive approach to stormwater management. The comprehensive approach will include consideration of infiltration or volume retention practices to address flooding and /or water quality improvements, reduction of impervious surfaces, increased storm sewer capacity where necessary to alleviate flooding, construction and /or expansion of water quality basins, and implementation of other stormwater BMPs to reduce pollutant loading to downstream waterbodies. Barr Engineering Company 14 -4 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 14.3.1 Flood Protection Projects The 2003 hydrologic and hydraulic modeling analysis identified several locations within the Northwest Minnehaha Creek drainage basin where the 100 -year level of protection is not provided by the current stormwater system. The problem areas identified in 2003 are discussed below. As part of the 2003 modeling analysis, potential corrective measures were identified for the problem areas for purposes of developing planning -level cost estimates. These preliminary corrective measures are also discussed below. As the City evaluates the flooding issues and potential system modifications in these areas, consideration will be given to other potential system modifications, including implementation of stormwater infiltration or volume retention practices, where soils are conducive. 14.3.1.1 Interlachen Landlocked Area The MCWD Plan identified a landlocked area located west of T.H. 100 and north of Vernon Avenue. This area, which encompasses subwatersheds EI_11, EI_12, EI_24, EI_13, and EI_19, currently drains to a wetland complex (EI_19) just south of Meadowbrook Golf Course. Two -foot topographic information for the area indicates that the natural overflow elevation between the landlocked wetland complex and the Meadowbrook Golf Course is approximately 885 feet M.S.L. Based on the FEMA Flood Insurance Study for Hennepin County (FEMA, 2004), the 100 -year flood level of Minnehaha Creek as it flows through the golf course is 892 feet M.S.L. The maximum flood elevation that the City will allow in the wetland area (EI_19) is 888 feet M.S.L. To prevent the backflow of water from the Meadowbrook Golf Course to the wetland complex (EI_19), it is recommended that an embankment be constructed/raised between the wetland and the golf course to an elevation of at least 892 feet M.S.L. Upon raising the embankment, a pumped outlet will be required to keep the flood elevation below 888 feet M.S.L. The City should establish a management plan to address necessary pumping scenarios. Previous analyses for the area indicate a 1 cfs pumped outlet would be sufficient. 14.3.2 Construction /Upgrade of Water Quality Basins Several ponds in this watershed are removing less than 60 percent of the average annual phosphorus load from storm water inflows. The light blue ponds in Figure 14.4 are achieving less than 60 percent total phosphorus removal. However, the cumulative phosphorus removal was greater than 60 percent for all the subwatersheds. Additional analysis was performed to identify those ponds that were functioning properly and those ponds that were functioning poorly. In the P8 model, phosphorus particles are grouped into several fractions. The unsettleable, or dissolved fraction, is called P0. From the mass balance output of the P8 model, the percent total phosphorus removal for the other settleable phosphorus fractions was evaluated for the apparently non - performing ponds to determine if the ponds were removing greater than 60 percent of the settleable phosphorus fractions. From this analysis it was determined that these ponds were removing greater than 60 percent of the Barr Engineering Company 14 -5 P: \Mpls \23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAF'nEdina SWMP FINAL DRAFT 121511REV 2.docx W d U LZ i a N 0 N 0 0 LL m MMA �Jk�N Hopkins St. Louis Park I I f i C� o dE VA.. MU E 0 mX XX W � WU @L% MN MU [ XS ° ° In As rya raa 1 XX 4� Alp f XX �� \_7 rrmm� �� - 14LW _ . ► A- # .� •,gyp`,. _ .i� ..r', 1!" ,,� •. �� ' - ' � _ t . �, ' 5 R , }r EI_15 FEI L49 001 H1 _5 H1 0_1 li COC II 11 11 Q H1ooT_s = H100_10 *fpr tai¢ •,, ��' , & #Y. `� R � np 3 � � .,.may' -, a..nM4°. ., „ ,„ � y • t�- � .r '. yam, �, $ y,t _ � . r '' •. � • Y.h'o*s t ta`�'� '�' w.s••%''"� .�� I M •e * • � � r - �'�� - .r,.._ . �`y li r zs' aT '*����ril: ,ti, ' r •.+ . .v. 1 -cif w .+' iE` ,�' a. a + �" .r r a r * y F , H "1 "OOT9 1 o�_1•s �v �y • ,1��UkPUR���`l • Was C City of Edina Boundary Roads /Highways Lake /Wetland Creek /Stream Minnehaha Creek - Northwest Drainage Basin MSubwatershed Imagery Source: Aerials Express, 2008 0 Feet 1,000 0 1,000 Meters 300 0 Figure 14.1 300 NORTHWEST MINNEHAHA CREEK DRAINAGE BASIN Comprehensive Water Resource Management Plan City of Edina, Minnesota N E L 3 Hopkins yl O L � � L t O y � K r D T U N O n a� a °w c d U m a a r E E 0 m { t Le d me F,1 d. ,►. # ii , p St. Louis Park leek �zN 4V M►r' 7l�'.+R� �: ,s�J psi- 4- �.j :�}s S n•9! fa I �Alfl F..T,. x # Ile ^y. �M1 p -+ i �;• <� *,d's) i y •,F # } ! s ore • f ��UFiPUR -a�Y�l • 1�8H City of Edina Boundary Roads /Highways Creek /Stream Lake /Wetland Minnehaha Creek - Northwest C3 Drainage Basin (�3 Major Watershed Subwatershed Imagery Source: Aerials Express. 2008 0 1,000 300 Feet 0 Z Meters 0 Figure 14.2 1,000 300 NORTHWEST MINNEHAHA CREEK MAJOR WATERSHEDS Comprehensive Water Resource Management Plan City of Edina, Minnesota *.444�rj leek �zN 4V M►r' 7l�'.+R� �: ,s�J psi- 4- �.j :�}s S n•9! fa I �Alfl F..T,. x # Ile ^y. �M1 p -+ i �;• <� *,d's) i y •,F # } ! s ore • f ��UFiPUR -a�Y�l • 1�8H City of Edina Boundary Roads /Highways Creek /Stream Lake /Wetland Minnehaha Creek - Northwest C3 Drainage Basin (�3 Major Watershed Subwatershed Imagery Source: Aerials Express. 2008 0 1,000 300 Feet 0 Z Meters 0 Figure 14.2 1,000 300 NORTHWEST MINNEHAHA CREEK MAJOR WATERSHEDS Comprehensive Water Resource Management Plan City of Edina, Minnesota "Jio .a lw. EI_35 9E 3 max tw1 rl� I�wo��.f �1 st 1 p, s ry� a B[L MORF- LA /�tVrt�t.t�t� • � �r�j •f • !'N" . 0 0 ° U4 IGYali1 u� 9M I 1 0 `, I !n a 0 1 • w . y / / ALONEY AVE MAWNF o t-igure 14.3 NORTHWEST MINNEHAHA CREEK HYDRAULIC MODEL RESULTS Comprehensive Water Resource Management Plan City of Edina, Minnesota City of Edina Boundary i Roads /Highways Creek /Stream Lake /Wetland Minnehaha Creek - C3Northwest Drainage Basin C3 Subwatershed Feet 400 0 400 Meters 150 0 150 i, Pipes o Manhole Manhole Surcharge During ° 100 -Year Frequency Event Manhole Surcharged During ° 10 -Year Frequency Event 4 u f��II ��pp IYlln� •fI��II ��R`�ro� _ 3 a�FRk� { f�1 alik-Awl 4affa* "; --, -2- _ E ZEt� o ff 2 G� m m F EI_13 `I_24 0 EI_' 9 EI_ C•B -2232 FE- 233 EI "2 AA IM 4,4 e icit 1888 3 s Hopkins r S St. Louis Park EI_25 EI125 2, El 6 r EI_13 El 19 EI_1 EI_30 El 32 1PLE14 1-2'01!PMW _PM EI_29 EI_31 Ef_21 , 0. EA .a x ' A . . e , s �` M AP j. t= A* j16 �'. -. fir` ; ,,fie ,r ' � (�i-- � `- 44 r ,�� �'=°�� • ^ .;1 a� '`+r�,,s... r*' �9'�' "`, r' ar � K #`,.�1 r a .% .�� a + tt i� JAW li e 4, 7. ifs f f,. Souke: Aerials E ZQO$ oek vt Percent TP Removal in Water Body* This number represents the percent of the total annual mass of phosphorus entering the water body that is removed. 0 - 25% (Poor /No Removal) ® 25 - 40% (Moderate Removal) _ 40 - 60% (Good Removal) _ 60 - 100% (Excellent Removal) Cumulative TP Removal in Watershed* This number represents the percent of the total annual mass of phosphorus entering the watershed and upstream watersheds that is removed in the pond and all upstream ponds. - 25 - 40% (Moderate Removal) 40 - 60% (Good Removal) 60 - 100% (Excellent Removal) *Data based on results of P8 modeling. Area Draining Directly to Minnehaha Creek Flow Direction u Feet 1,000 0 1,000 Meters 300 0 300 Figure 14.4 NORTHWEST MINNEHAHA CREEK WATER QUALITY MODELING RESULTS Comprehensive Water Resource Management Plan City of Edina, Minnesota Table 14.2 Watershed Modeling Results for Subwatersheds in the Minnehaha Creek North East Drainage Area Watershed Information 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Watershed ID Total Area (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) EI_ 1 10.2 41 45.8 3.66 37.8 0.97 EI_10 12.7 41 55.1 4.21 39.4 1.04 EI_ 11 1.5 20 5.7 0.41 2.9 0.09 EI_12 5.2 30 23.1 1.58 17.3 0.39 EI_13 8.1 28 36.2 2.42 27.1 0.60 El 14 11.5 19 36.9 3.05 17.4 0.58 EI_15 13.4 31 57.7 4.08 39.5 0.97 EI_16 16.1 21 47.7 4.30 22.8 0.80 EI_17 3.0 23 12.8 0.84 8.1 0.20 EI_18 10.5 19 41.2 2.86 21.0 0.61 EI_19 16.2 52 72.0 6.26 54.9 1.62 EI_2 17.0 20 72.4 5.97 43.8 1.47 EI_20 23.5 20 82.5 6.63 40.8 1.39 EI_21 4.3 30 19.2 1.47 11.7 0.35 EI_22 2.3 20 9.5 0.65 5.0 0.14 EI_23 3.7 19 14.2 1.00 7.1 0.21 EI_24 22.5 26 93.4 6.73 56.4 1.57 EI_25 10.6 13 31.3 3.58 13.2 0.70 EI_26 5.2 3 20.0 1.34 7.4 0.29 EI_27 2.7 5 10.6 0.96 5.0 0.23 El 28 5.9 32 19.0 1.33 15.6 0.42 EI_29 9.8 2 38.6 3.93 17.1 0.85 EI_3 20.6 20 49.4 7.11 21.4 1.22 EI_30 3.6 5 15.8 1.47 9.0 0.34 EI_31 6.0 22 26.9 2.53 19.9 0.62 EI_32 11.9 19 39.5 4.27 19.4 0.91 EI_33 9.0 2 29.5 2.86 9.9 0.58 EI_34 13.4 8 36.3 4.88 13.0 0.86 EI_35 5.9 20 19.5 1.94 9.7 0.42 EI_36 2.9 20 12.2 0.79 7.0 0.18 EI_37 1.5 20 6.7 0.30 4.8 0.10 EI_4 14.6 20 59.4 4.14 31.9 0.93 EI_5 7.4 20 32.3 2.04 19.7 0.48 EI_6 1.9 20 8.0 0.52 4.8 0.12 EI_7 7.8 20 27.8 2.10 13.7 0.42 EI_8 18.5 20 65.6 5.02 32.2 1.01 EI_9 3.8 20 17.2 1.07 21.5 0.30 HO_ 1 5.1 20 19.5 1.39 9.4 0.30 HO_ 10 1.6 20 5.8 0.42 2.9 0.09 HO 11 1.8 20 7.8 0.50 4.6 0.12 2 2.0 20 8.2 0.56 4.4 0.12 3 t 1.2 20 5.3 0.33 3.4 0.08 4 2.2 20 8.8 0.60 4.6 0.13 PAMpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\NWMHC_S WMM_hydraulic_output _ noUPDATE_N WL_veri fication.xls Table 14.2 Watershed Modeling Results for Subwatersheds in the Minnehaha Creek North East Drainage Area Watershed Information 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Watershed ID Total Area (ac) % Impervious Area Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) Peak Runoff Rate (cfs) Total Volume Runoff (ac -ft) HO-15 3.4 20 13.5 0.93 8.0 0.21 HO-16 2.7 44 12.2 0.92 12.2 0.24 HO-17 15.4 20 50.3 4.14 24.2 0.80 HO 18 2.0 20 7.5 0.55 3.7 0.11 HO_ 19 13.1 22 51.4 3.65 27.8 0.80 HO _2 1.1 16 4.7 0.28 2.9 0.07 HO-20 1.3 20 4.0 0.35 1.9 0.07 HO-21 0.7 20 3.1 0.19 2.6 0.05 HO_22 3.7 5 14.3 0.87 8.2 0.22 HO _3 6.5 20 16.7 1.70 7.7 0.30 HO_4 2.6 5 10.4 0.60 6.2 0.16 HO _5 8.3 20 30.0 2.26 14.7 0.46 HO-6 3.9 20 16.3 1.08 9.4 0.24 HO-7 1.5 21 6.4 0.42 3.6 0.09 HO-8 9.9 30 40.1 2.97 24.1 0.68 HO_9 3.5 20 9.5 0.92 4.4 0.16 H100_1 9.2 20 30.5 2.48 14.7 0.48 H 100_ 10 5.48 25 18.7 1.54 9.6 0.31 H100_11 0.66 21 2.7 0.18 1.5 0.04 H100_12 2.42 20 9.1 0.66 4.5 0.14 H100_13 3.93 35 10.8 1.25 5.0 0.26 H100_14 4.49 50 20.4 1.65 17.6 0.43 H100_15 6.56 68 29.6 2.67 23.1 0.71 H 100_2 3.64 30 13.1 1.08 7.1 0.23 H 100_3 12.8 41 44.4 4.14 22.3 0.92 H 100_4 9.93 46 42.3 3.40 28.1 0.82 H100_5 13.53 68 52.5 5.44 27.3 1.39 H100 6 4.22 20 17.2 1.16 9.1 0.25 H1007 21.8 23 77.4 7.18 40.1 1.65 H100 8 0.71 20 3.2 0.20 2.2 0.05 H100 9 4.66 21 16.0 1.26 7.9 0.25 PAMp1s\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \QAQC Model for Pond\N WMHC_S WMM_hydraulic_ output _noUPDATE_NWL_veriftcation.xls Table 14.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in Minnehaha Creek North East Drainage Area Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft)'- Type of Storage NWL (ft) Flood Bounce (ft) Node Name Flood Elevation (ft) NWL (ft) Flood Bounce (ft) 1906 1275 924.2 1906 924.0 1907 1276 917.4 1907 917.2 1908 1277 905.4 1908 905.2 1911 1279 906.9 1911 905.3 1912 1281 897.5 1912 896.1 1913 1282 894.1 1913 893.0 2138 1700 892.6 2138 889.0 2141 1701 889.7 2141 887.8 2142 outfall 886.8 2142 886.1 2155 1711 920.5 2155 1 920.3 2156 1952 900.5 2156 900.2 2159 1714 929.7 2159 929.5 2160 1715 930.2 2160 930.0 2161 1716 931.0 2161 930.9 2162 1717 931.2 2162 931.0 2163 1718 943.0 2163 943.0 2173 1725 918.4 2173 918.0 2174 1726 917.8 2174 917.2 2175 1728 916.5 2175 914.7 2177 1854 891.9 2177 890.4 2183 1733 920.5 2183 917.1 2186 1736 916.7 2186 914.9 2187 1737 916.5 2187 914.5 2188 1738 916.3 2188 914.3 2189 1741 915.8 2189 1 913.5 2191 1742 915.7 1 2191 913.3 2198 1748 914.6 2198 912.9 2200 outfall 919.0 2200 918.2 2203 1750 924.1 2203 919.9 2204 1751 924.1 2204 919.7 2210 1754 924.1 2210 921.0 2214 1758 931.2 2214 928.0 2215 1759 928.7 1 1 2215 926.3 2217 1761 924.8 2217 922.8 2218 1762 924.8 2218 921.4 2226 1768 888.7 2226 888.7 2227 outfall 887.4 2227 887.4 2229 outfall 886.3 2229 886.3 2344 1855 891.9 2344 890.3 2346 1857 891.3 1 2346 889.6 2347 1858 891.2 2347 888.9 2348 1859 888.9 2348 888.0 2349 1860 888.6 2349 887.9 2350 1861 888.3 2350 887.7 2351 1862 887.7 2351 1 886.9 2352 1863 887.2 2352 886.6 2353 1864 885.4 1 2353 884.7 2354 outfall 883.8 2354 883.4 2356 1866 892.5 (892) 2356 891.1 2357 1867 893.0 (892) 2357 891.9 2358 1868 893.0 2358 892.1 2421 PP6 900.5 2421 898.6 2442 1947 922.6 2442 918.4 2443 1948 921.7 2443 917.8 2445 outfall 890.5 2445 889.5 2456 PP8 897.1 2456 1 894.7 2457 PP9 1 894.0 2457 1 890.6 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFdes \QAQC Model for Pond\NWMHC_SWMM_hydraulic_out put _noUPDATE_NWL_verification.xls Table 14.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in Minnehaha Creek North East Drainage Area Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2-Hour Event Flood Elevation (ft)' Type of Storage3 NWL (ft) Flood Bounce (ft) Node Name Flood Elevation (ft) NWL (ft) Flood Bounce (ft) EI_1 1869 891.6 P 887.0 4.6 El_1 888.3 887.0 1.3 EI_10 landlocked 890.5 P 887.9 2.6 EI_10 888.5 887.9 0.6 El-11 1771 917.6 El-11 918.4 EI_12 outfall 914.8 P 912.1 2.7 EI_12 912.8 912.1 0.7 El 13 landlocked 899.3 P 888.0 11.3 El_13 896.1 888.0 8.1 EI_14 1699 893.0 (892) ST El- 14 891.2 EI_15 1278 909.9 ST El 15 909.7 904.5 5.2 EI_16 1280 903.4 EI_16 899.3 El 17 1274 928.4 El 17 927.9 EI_18 1697 893.9 Ei_18 892.2 EI_19 landlocked 882.6 P 879.0 3.6 El- 19 880.6 879.0 1.6 EI_2 1720 895.8 EI_2 895.6 EI_20 1769 888.5 (892) EI_20 888.4 El 21 landlocked 888.3 P 884.6 3.7 El 21 886.3 884.6 1.7 EI_22 drains to ditch 888.4 (892) EI_22 888.3 El 23 1698 892.8 (892) El 23 890.7 El 24 landlocked 885.4 P 883.5 1.9 EI_24 884.9 883.5 1.4 EI_25 1865 892.7 (892) 889.0 3.7 El 25 889.8 889.0 0.8 EI_26 overland flow 910.0 P 905.8 4.2 EI_26 908.0 905.8 2.2 EI_27 landlocked 905.3 P 901.8 3.5 El 27 903.8 901.8 2.0 El 28 overland flow 896.6 BYD 894.4 2.2 El 28 895.9 894.4 1.5 EI_29 PP5 902.7 898.1 4.6 EI_29 899.4 898.1 1.3 EI_3 1727 893.1 (892) 1 886.6 6.5 EI_3 892.3 886.6 5.7 EI_30 PP2 906.0 902.8 3.2 El 30 904.5 902.8 1.7 EI_31 PP7 899.3 896.3 3.0 El 31 897.0 896.3 0.7 EI_32 PP3 907.5 906.6 0.9 32 906.9 906.6 0.3 EI_33 pump 905.3 BYD 901.5 3.8 -El El 33 902.5 901.5 1.0 EI_34 landlocked 892.7 P 887.1 5.5 EI_34 889.8 887.1 2.7 El 35 landlocked 898.4 BYD 897.3 1.1 EI_35 897.9 897.3 0.6 EI_36 landlocked 953.0 BYD 949.2 3.8 EI_36 951.7 949.2 2.5 EI_37 landlocked 946.1 BYD 944.0 2.1 EI_37 1 945.3 944.0 1.3 El _4 1766 893.1 EI_4 892.9 El-5 1856 891.9 El-5 890.3 EI 6 1767 893.1 EI_6 893.0 EI_7 1719 946.5 El _7 946.4 EI_8 1713 929.5 EI_8 929.2 EI_9 1712 923.7 EI_9 923.6 HO_1 1722 918.8 P 913.2 5.6 HO-1 917.6 913.2 4.4 HO_ I0 1946 924.1 HO_ 10 919.2 HO_ll 1753 924.1 HO_ll 920.5 HQ- 12 1740 922.7 HO 12 916.7 HQ- 13 Hopkins system 919.0 HO_13 918.2 HO-14 1763 930.7 BYD 925.9 4.8 HO 14 930.6 1 925.9 4.7 HO 15 1724 919.5 ST HO_15 919.3 HO 16 1729 924.1 P 917.5 6.6 HO_16 919.7 917.5 2.2 HO_17 1755 924.5 HO_17 921.7 HO 18 1752 924.2 HO 18 919.7 HO- 19 1747 (force main) 913.2 P 908.8 4.4 HQ- 19 909.5 908.8 0.7 HO_2 1744 917.0 HO-2 915.0 HO 20 1760 928.0 ST HO 20 924.5 1-10_21 landlocked 946.1 BYD 945.0 1.1 HQ-21 946.0 945.0 1.0 HO 22 landlocked 932.7 BYD 930.1 2.6 HO 22 932.6 930.1 2.5 HO 3 1739 916.2 1 HQ _3 914.1 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles\QAQC Model for Pond\NWMHC SWMM_hydreulk:_ output _noUPDATE_NWL_verification.xls Table 14.3 Hydraulic Modeling Results for XP -SWMM Subwatersheds /Nodes in Minnehaha Creek North East Drainage Area Subwatershed or Node Downstream Conduit 100 -Year Storm Results 24 -Hour Event 10 -Year Storm Results 1/2 -Hour Event Flood Elevation (ft)' Type of Storage NWL (ft) Flood Bounce (ft) Node Name Flood Elevation (ft) NWL (ft) Flood Bounce (ft) HO-4 1843 916.9 BYD 912.9 4.0 HO-4 915.2 912.9 2.3 HO _5 1743 915.6 HO _5 915.6 HO-6 1723 922.2 HO _6 922.0 HO _7 1853 924.3 ST HO _7 922.1 HO _8 1745 915.6 P 912.0 3.6 HO _8 913.2 912.0 1.2 HO_9 1757 933.9 HO _9 929.3 1885 1258 914.3 1885 913.8 1886 1259 913.8 1886 913.3 1889 1262 951.1 1889 949.0 1891 1263 951.1 1891 948.4 1892 1264 950.7 1892 1 947.5 1893 1265 950.4 1893 947.3 1894 1266 949.9 1894 947.0 1895 1267 949.7 1895 946.8 1896 1268 949.4 1896 946.6 1897 1269 948.6 1897 946.1 1898 1270 947.4 1898 945.1 2268 outfall 906.8 2268 906.6 2271 outfall 914.4 2271 911.2 2274 outfall 916.0 2274 914.1 2276 outfall 919.0 2276 918.8 2278 outfall 911.9 2278 911.8 2362 1872 931.7 P 928.6 3.1 2362 930.1 928.6 1.5 2364 1873 928.0 2364 927.7 2365 1874 924.8 2365 924.4 2366 1875 921.9 1 2366 1 921.3 2367 1876 921.1 2367 920.7 2368 1877 920.0 2368 919.4 2370 1879 919.5 P 916.0 3.5 2370 918.1 916.0 2.1 2372 1880 918.6 2372 917.8 2455 outfall 902.8 2455 901.7 1-11001 1261 951.2 1-1100_1 950.8 H100_10 (1) 911.4 H100_10 909.7 H100_11 (1) 919.2 HI00_11 918.9 H100_12 (1) 916.3 H100_12 914.2 H100_13 (1) 908.2 H100_13 906.0 H100_14 1878 919.9 H100_14 918.6 H100_15 outfall 908.0 H100_15 907.9 *100_2 1260 951.3 H100_2 949.0 *100_3 1256 939.8 H100_3 939.6 H1004 1871 932.7 H 100_4 930.7 H 100_5 1257 916.7 H 100_5 916.2 H100_6 private sewer system 919.4 ST H100_6 916.5 H100_7 (1) 907.2 ST H100_7 904.9 H100_8 (1) 915.9 H100_8 915.9 H1009 (1) 914.9 H100_9 911.2 I Downstream conduit modeled as an orifice '- Flood elevations in parenthesis indicate a 100 -year flood elevation based on the 100 -year flood elevation of Minnehaha Creek, according to the Federal Emergency 3 ST= Street, BYD =Back Yard Depression, P =Pond PAMplsU3 MM27\23271072 Edina Water Resources Mgmt Plan Update\WorkFiles\QAQC Model for PondWWMHC_SWMM_hydraulic_output mUPDATE_NWL_verifcation.xls m o. u 3 Nr,dmmm r,4 o`.m d�1 —mm _1n noe v? as r -- CL U � O }U o r. � t•i N ynj C T M'+ N h O. N T O\ T n m d oo O O d d d m m m m m N m d t�f m 9 a ° 0 } U c 0 6 N m n vl 1n O— 0- C C C1 ^ yCt�O 1'1 m S r N d m M T N V^ N N Z Vi M 'O V d r•1 tNn emn N m C O U C c F N 10 m �O h N N vl O� 1/1 O e•f m r n vl [� h m —� 1/) en h O� .• r Hf h h VI N n m .+ 00 y `' e�f O� N n G O T en O\ O m O. OC m m �G � m � � � � et � O\ `G en N 7 N N V1 �G N N m m m � �G Vi � — �' !` •.: r C1 !V —_ — O O O � _N m m ^ _ _ m m am0 omO O, T T T D` O, m D\ 01 T D\ m a, 01 O, m O\ O 0 C O h V1 v1 VI �p V) Hf d � _ � O. O V1 r t�1 h n h d r 0 10 P m of r. N HI m y N1 m h m 1ri m m b Hl Vi Vl Vl m n N CI „�„ r h Vf d r h m CI G O 'i N � ^ _ 0; r 00 n GO w� O, of Ol a c C u M M1 M1 H1 en M1 H1 H1 f+1 e�f Nl fn !n fn d d HI M t�1 1�1 M M to r1 M Nf M M M N1 Nf M M to !•1 M M � N1 Pl to N1 M H1 to en Hf fn t•1 0 .c u E^. v� 1n vl 1n vl in '^ 1n ,� 1n v, 1n in 1n vl 1n '^ 1n ,r, m h h 1n 1n C O U 55595555 A55 55e5�_ 5�55``�5555e5555= 555��� ��hAR G U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U U O U b� 1n nom — I2en'nd d�nln_I_I moo I C�O hN rN nCI �z' O_ Q= mCI mC_I �=' mN mN aN o� gO�OOOO Z O Z N N I N W N m .i CrI Tcl;i 0 uO O Z 000 N en dln _I _I I I 1 I I�� I� Im_mmm I Imo+ 1 I I Io�Og I I^ _mmmm c � c E O u � n Table 14.4 Conduit Modeling Results for Subwatersheds in the Minnehaha Creek North East Drainage Areas Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimensions. (ft) Roughness Coefficient Upstream Invert Elevation (ft) Downstream Invert Elevation (ft) Conduit Length (ft) Slope I OOY Peak Flow Through Conduit (efs) I OY Peak Flow through Conduit (efs) 1755 HQ-17 2210 Circular 2.25 0.013 918.86 918.46 96 0.42 33.9 24.1 1757 HO -9 2214 Circular 1.5 0.013 928.32 927.01 329 0.40 9.5 4.6 1758 2214 2215 Circular 1.5 0.013 926.8 925.8 278 0.36 9.4 4.4 1759 2215 HO_20 Circular 1.5 0.013 925.8 923.75 60 3.42 9.4 4.4 1760 HO 20 2217 Circular 1.5 0.013 923.75 920.2 175 2.03 12.7 6.2 1761 2217 2218 Circular 1.5 0.013 920.2 918.46 100 1.74 11.7 10.4 1762 2218 HO_11 Circular 1.5 0.010 918.46 917.85 100 0.61 14.6 10.4 1763 HQ-14 2217 Circular 0.5 0.015 925.9 921.3 239 1.92 1.0 1.0 1766 EI_4 EI_1 Circular 1 0.013 887.62 887 176 0.35 5.7 5.5 1767 EI 6 2226 Circular 1 0.024 889.1 887.7 138 1.01 3.5 3.5 1768 2226 2227 Circular 1 0.013 887.4 886.6 85 0.94 3.5 3.5 1769 EI 20 2229 Circular 1 0.013 885.5 885.34 31 0.52 6.6 6.4 1771 EI_II EI_12 Circular 1 0.013 916.52 912.1 138 3.20 5.6 3.4 1843 HO_4 2186 Circular 1.75 0.013 912.91 912.52 110 0.35 6.7 7.3 1853 HQ-7 2203 Circular 1 0.013 919.66 919.34 158 0.20 5.1 3.6 1854 2177 2344 Circular 2 0.010 886.29 885.99 193 0.16 8.1 5.2 1855 2344 EI_5 Circular 2 0.013 885.99 885.87 152 0.08 8.1 5.2 1856 EI_5 2346 Circular 2 0.013 885.87 885.87 100 0.00 21.2 17.5 1857 2346 2347 Circular 2 0.013 885.87 885.79 91 0.09 20.1 17.8 1858 2347 2348 Circular 2 0.013 885.79 885.76 112 1 0.03 29.1 17.7 1859 2348 2349 Circular 3 0.013 885.76 885.74 98 0.02 29.1 17.2 1860 2349 2350 Circular 3 0.013 885.74 885.79 91 -0.05 29.1 17.2 1861 2350 2351 Circular 3 0.013 885.79 886 131 -0.16 29.1 17.1 1862 2351 2352 Circular 3 0.013 885 884.77 123 0.19 29.1 17.1 1863 2352 2353 Circular 3 0.013 884.77 884.77 73 0.00 29.1 17.1 1864 2353 2354 Circular 3 0.013 883 882.07 281 0.33 29.1 17.1 1865 EI_25 2356 Circular 1.5 0.010 889 886.2 39 7.18 -18.0 -11.2 1866 2356 2357 Circular 2 0.010 884.4 883.91 1 163 0.30 -18.0 -11.2 1867 2357 2358 Circular 2 0.010 883.91 883.6 225 0.14 .12.6 -11.2 1868 2358 EI_3 Circular 2 0.010 887 886.62 225 0.17 -14.2 -12.2 1869 EI_1 2177 Circular 1 0.013 887 886.29 247 0.29 -4.1 -2.2 1946 HO 10 2442 Circular 1 0.013 917.54 917.4 94 0.15 4.7 3.4 1947 2442 2443 Circular 1 0.013 917.4 917.12 54 0.52 4.7 3.4 1948 2443 2183 Circular 1 0.013 917.12 916.02 71 1.55 4.7 3.5 1952 2156 2445 Circular 2 0.013 894.58 888.52 174 3.48 52.9 42.1 PP2 EI_30 2421 Circular 1 0.013 902.8 902.5 411 0.07 2.7 1.7 PP3 I EI_32 El -.29 Circular 1.25 0.013 906.6 898.1 264 3.22 8.5 1.7 PP5 EI_29 2421 Circular 1.25 0.013 898.1 898 150 0.07 6.0 2.5 PP6 2421 EI_31 Circular 1.25 0.013 898 896.3 50 3.40 8.5 4.0 PP7 EI 31 2456 Circular 1.25 0.013 896.3 894 230 1.00 6.4 3.5 PPS 2456 2457 Circular 1.25 0.013 894 890 350 1.14 6.1 3.5 PP9 2457 EI 1 Circular 1.25 0.013 1 890 887 250 1.20 6.1 3.5 1256 H100_3 HI00_5 Circular 1 1.75 0.013 934 911.6 440 5.09 35.7 35.7 1257 HI00_5 1885 Circular 2.5 0.013 909.35 908.74 130 0.47 57.4 57.0 1258 1 1885 1886 Circular 3.58 0.013 908.74 908.43 77 0.40 64.8 61.2 1259 1886 HI00_15 Circular 3 0.013 908.3 906.9 285 0.49 64.8 61.2 1260 H100_2 1889 Circular 2 0.013 945.38 944.6 146 0.53 13.1 7.1 1261 H100_1 1889 Circular 1.25 0.013 946.18 944.6 78 2.03 11.1 11.5 1262 1889 1891 Circular 2 0.013 944.6 944.39 112 0.29 16.8 16.9 1263 1891 1892 Circular 2 0.013 944.39 944.11 99 0.28 23.0 20.7 PAMpls\23 MM27\23271072 Edina Water R-, Mgna Plan Update\WorkFilm\QAQC Model for Pon&LJVIMHC_SWKLM hydraulic outputnoUPDATE_NWL _ vedfication.xls Table 14.4 Conduit Modeling Results for Subwatersheds In the Minnehaha Creek North East Drainage Areas Conduit ID Upstream Node Downstream Node Conduit Shape Conduit Dimensions* (ft) Roughness Coefficient Upstream Invert P Elevation (ft) Downstream Invert Elevation (ft) Conduit Length (ft) Slope 100Y Peak Flow Through Conduit (cfs) IOY Peak Flow through Conduit (cfs) 1264 1892 1893 Circular 2.5 0.013 944.11 943.81 48 0.63 25.4 20.7 1265 1893 1894 Circular 2.5 0.013 943.81 943.69 124 0.10 22.7 20.6 1266 1894 1895 Circular 2.5 0.013 943.69 943.6 46 0.20 22.6 20.5 1267 1895 1896 Circular 2.5 0.013 943.6 943.31 81 0.36 22.5 20.3 1268 1896 1897 Circular 2.5 0.013 943.31 943.08 135 0.17 22.6 20.0 1269 1897 1898 Circular 2 0.013 943.08 942.5 32 1.81 22.5 19.5 1270 1898 H100_3 Circular 1.75 0.013 942.5 934 365 2.33 22.5 19.1 1871 H100_4 2362 Circular 3 0.013 928.8 927.5 186 0.70 42.3 28.3 1872 2362 2364 Circular 2 0.013 929 927.3 186 0.91 18.7 7.9 1873 2364 2365 Circular 2 0.013 927.3 923.8 24 14.58 18.7 7.9 1874 2365 2366 Circular 1.75 0.013 923.8 920.5 92 3.59 18.7 7.9 1875 2366 1 2367 Circular 2.5 0.013 920.5 920 1 55 0.92 18.7 7.9 1876 2367 2368 Circular 2.5 0.013 920 918.7 88 1.48 18.7 7.9 1877 2368 H100_14 Circular 2.5 0.013 918.7 917.4 80 1.63 18.7 7.9 1878 H100_14 2370 Circular 2.5 0.013 917.4 917 19 2.16 38.3 17.6 1879 2370 2372 Circular 2 0.013 916 917.1 25 4.49 -27.5 -10.5 1880 2372 H100_5 Circular 2 0.013 917.1 911.2 35 16.86 27.5 13.4 NA -Not Applicable P:\MplsN23 MM27U3271072 Fdim Water Resouren Mgmt Plan Update %WotkFilm\QAQC Model for PondW WMHC_SWMM_ hydraulic _mtputnoUPDATTMVL_vcifiwtion.xls Issues & Implementation Program 15.0 Issues and Implementation Program This chapter describes the significant components of the City's CWRMP implementation program, including its NPDES Phase II MS4 permit, ,specific requirements of the NMCWD and MCWD, financial considerations, ordinance implementation and official controls, and implementation priorities. The implementation program is discussed in Section 15.7, which presents summary details of the implementation program, including a project description, cost estimate, potential funding sources, and proposed years of implementation. 15.1 Water Quality /NPDES Phase II MS4 General Permit Under the federal 1987 Clean Water Act revision, discharges of pollutants into waters of the United States are prohibited without a permit under the National Pollutant Discharge Elimination System (NPDES) program. Traditionally, this program concentrated on discharges from industries and publicly owned treatment plants. In 1990, the EPA promulgated rules establishing Phase I of the NPDES Stormwater Program in an effort to reduce the water quality impact of stormwater drainage systems on receiving water bodies. Phase I of the program regulates stormwater runoff from municipal separate storm sewer systems (MS4s) generally serving populations of 100,000 or greater, construction activities disturbing five acres of land or greater, and various industrial activities. In 1999, the Phase II Rule of the NPDES Stormwater Program extended the coverage of the NPDES program to operation of "small" MS4s in urbanized areas and operation of small construction sites. Through the use of NPDES permits, these operations are required to implement programs and practices to control polluted stormwater runoff. Because the City of Edina is located in an "urbanized area ", as defined by the Bureau of the Census, it is covered under the Phase II NPDES Stormwater Program. Operators of Phase II small MS4s in Minnesota were required to apply for coverage under the Small Municipal Separate Storm Sewer Systems (MS4s) General Permit from the Minnesota Pollution Control Agency (MPCA) by March 10, 2003. This permit, which addresses how the City will regulate and improve stormwater discharges, requires MS4s to develop and implement a Storm Water Pollution Prevention Program ( SWPPP). 15.1.1 NPDES Phase II MS4 Storm Water Pollution Prevention Program The SWPPP outlines the appropriate best management practices (BMPs) for the City to control or reduce the pollutants in stormwater runoff to the maximum extent practicable (MEP). The City will accomplish this through the implementation of the BMPs outlined within its SWPPP. These BMPs will be a combination of education, maintenance, control techniques, system design and engineering methods, and other such provisions that are appropriate to meet the requirements of the NDPES Phase II permit. BMPs have been planned and implemented to address each of the six minimum control measures as outlined in the rules: 1. Public education and outreach on stormwater impacts. Barr Engineering Company 15 -1 P: \Mpls\23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511 REV 2.docx 2. Public participation /involvement. 3. Illicit discharge detection and elimination. 4. Construction site stormwater runoff control. 5. Post - construction stormwater management in new development and redevelopment. 6. Pollution prevention/good housekeeping for municipal operations. The six minimum control measures are described in further detail in subsequent sections. The SWPPP BMP implementation program is incorporated into the City's overall stormwater implementation program presented in Table 15 -3. 15.1.1.1 Public Education and Outreach Public education and outreach is a key component in a successful stormwater management program. An informed and knowledgeable community will lead to greater support and greater compliance with the City stormwater program, as the public becomes aware of the personal responsibilities expected of them as community members. As required by the MPCA MS4 General Permit, the City has developed and is implementing a public education program to distribute information and conduct outreach activities regarding the impacts of stormwater discharges on water bodies, as discussed in Section 3.8. The public education program must address each of the six control measures required by the General Permit. For each control measure, the City's education program identifies the audience involved, educational goals, activities used to reach activity goals, activity implementation plans, and available performance measures that can be used to determine success in reaching educational goals. The public education program also includes working collaboratively with the local watershed districts in distributing educational materials and promoting/supporting outreach programs. At least one public meeting is held every year prior to submittal of the SWPPP annual report. Notice of the meeting is distributed in a local newspaper and contains a reference to the SWPPP, the date, time, and location of the public information meeting; a description of the manner in which the public information meeting will be conducted; and the proper method to obtain a copy of the SWPPP. Details regarding the measurable goals, implementation schedule, and responsible parties for the public education program can be found in the City of Edina's SWPPP (Appendix A). 15.1.1.2 Public Involvement and Public Participation As required by the MPCA MS4 General Permit, the City of Edina will solicit public input on the adequacy of the SWPPP, including input from the annual public meeting addressing the annual report. Oral and written input from the public regarding the SWPPP will be sincerely considered and adjustments will be made where appropriate. The City will comply with applicable public notice Barr Engineering Company 15 -2 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFnEdina SWMP FINAL DRAFT 121511REV.docx requirements of the General Permit when implementing the provisions of the SWPPP. The City also intends to incorporate public information on SWPPP issues into the City's website. Details regarding the measurable goals, implementation schedule, and responsible parties for the public involvement and public participation requirements can be found in the City of Edina's SWPPP (Appendix A). 15.1.1.3 Illicit Discharge Detection and Elimination Identification of stormwater pollutant sources includes identification of illicit pollutant discharges and nonpoint sources throughout the city. An illicit pollutant discharge is defined as a nonpermitted point source of pollutants that is discharged to the storm sewer system at a specific location. Illicit discharges can enter a storm sewer system directly (through wastewater piping mistakenly or deliberately connected to the storm drains) or indirectly (through infiltration from cracked/leaking sanitary systems, spills collected by drain outlets, or other contaminants such as paint or oil dumped directly into a storm drain). To prevent the harmful effects of illicit discharges, a number of BMPs have been developed to implement and enforce a program to detect and eliminate illicit discharges into the municipal separate storm sewer system. The BMPs include: Based on the requirements of the NPDES Phase II MS4 General Permit, the program must include the following components: 1. An annually- updated storm sewer system map showing the location of all City -owned storm sewer pipes (24 -inch diameter or greater), outfalls, locations where discharge leaves the city, and water bodies. 2. Review of existing City ordinances relating to illicit discharges and develop /adopt an illicit discharge ordinance as necessary. 3. Expansion of the City's program to detect and reduce all forms of non - stormwater discharges and continuation of inspection for illicit discharge during the outfall and pond inspections. 4. Distribution of educational materials to residents and providing illicit discharge educational information or training to City staff at a minimum of once a year. Details regarding the measurable goals, implementation schedule, and responsible parties for the public education program can be found in the City of Edina's SWPPP (Appendix A)." 15.1.1.4 Construction Site Stormwater Runoff Control Runoff management from construction sites is crucial in the effort to minimize the amount of sediment and other pollutants entering the water bodies within the city. Phase II of the NPDES Barr Engineering Company 15 -3 P: \Mpls \23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx stormwater program requires reduction of stormwater pollutant discharges from construction activities that result in a land disturbance of greater than or equal to one acre. The policies and design standards adopted by the City to control stormwater pollutant discharges from construction sites are detailed in the Water Quality Management Standards (Section 3.2) and the Erosion and Sediment Control (Section 3.3) sections. In addition to the policies and 13MPs previously discussed, a number of BMPs have been developed and will be implemented and enforced to reduce pollutants and storm water runoff from construction activities with land disturbances equal to or greater than one acre. These 13MPs include: 1. Review of current permit stipulations /City codes relating to project specific erosion and sediment control and update as necessary. 2. Every applicant for a City permit to allow land disturbing activities must submit a project specific stormwater management plan (if applicable) and /or erosion control plan to the City. 3. Construction site operators must provide a phone number, website, and point of contact for the public to report storm water pollution issues. Staff procedures for stormwater non- compliance are defined in the SWPPP (Appendix A). 4. Construction site operators must conform to NPDES Phase II, watershed district, and City ordinances pertaining to erosion and sediment controls and waste controls. For projects less than one acre, the Rules and Regulations of the Nine Mile Creek and Minnehaha Creek watershed districts are applicable. Details regarding the measurable goals, implementation schedule, and responsible parties for the construction site stormwater runoff control requirements can be found in the City of Edina's SWPPP (Appendix A). 15.1.1.5 Post - Construction Stormwater Runoff Control The Phase II NPDES Program requires small MS4s to develop, implement and enforce a program to reduce pollutants from new development or redevelopment areas having a land disturbance of greater than or equal to one acre. The city of Edina has adopted the control policies and 13MPs discussed in the Runoff Management and Flood Control (Section 3. 1), Water Quality (Section 3.2), and the Erosion and Sediment Control (Section 3.3) sections to ensure pollutant reduction from new development and redevelopment areas. The City's policies and 13MPs are enforced through issuance of permits through the City and the Nine Mile Creek and Minnehaha Creek watershed districts. Barr Engineering Company 15 -4 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx In addition to the control measures addressed in earlier sections, a program of BMPs has been prepared to address storm water runoff from new development and redevelopment projects that disturb equal to or greater than one acre. This program insures that controls are in place that would prevent or minimize water quality impacts from development activities. These BMPs include: 1. Continuing to use existing development review policies currently in place to address water quality, erosion control, and BMPs. 2. Evaluating all structural and non - structural BMPs during the plan review process for the potential of new and /or revised BMPs. 3. Actively looking for non - structural BMP opportunities where prudent and feasible. 4. Inspecting post- construction BMPs and evaluating inspection records for determining the corrective maintenance actions (if necessary) for the long -term operation of all storm water management facilities. The City of Edina also addresses runoff problems with sound planning procedures. Land use and zoning ordinances promote improved water quality by guiding the growth and redevelopment of the community away from sensitive areas and by restricting certain types of growth to areas that can support it without compromising water quality. The City is currently in the process of updating their zoning ordinance. Details regarding the measurable goals, implementation schedule, and responsible parties for the post- construction stormwater runoff control requirements can be found in the City of Edina's SWPPP (Appendix A). 15.1.1.6 Pollution Prevention and Good Housekeeping Methods Pollution prevention and good housekeeping methods can ensure a reduction in the amount and type of pollution that is discharged into waterways from streets, parking lots, open spaces, and storage and vehicle maintenance areas. To take advantage of the benefits provided by pollution prevention practices, the Phase II Rule requires that the City develop and implement an operation and maintenance program has the ultimate goal of preventing or reducing pollutant runoff from municipal operations into the storm sewer system. The program must include employee training on incorporation of pollution prevention and good housekeeping techniques into municipal operations such as park and open space maintenance, fleet and building maintenance, new construction and land disturbances, and storm water system maintenance. To meet the requirements of the pollution prevention and good housekeeping for municipal operations, a number of BMPs have been developed. These BMPs include: 1. Annual inspection of 20% of the outfalls, sediment basins, and ponds within the City's storm sewer system. Barr Engineering Company 15 -5 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 2. Inspection and documentation of all structural pollution control devices a minimum of once per year. 3. Evaluating, annually inspecting, and modifying (if necessary) current BMPs in place on all exposed stockpiles, storage, and materials located within City -owned property. 4. Annually evaluating landscaping and lawn -care practices, which may include the use of fertilizers, pesticides, herbicides, lawn mowing, grass clipping collection, mulching and composting, and developing BMPs to reduce storm water pollution. 5. Annually reviewing practices and policies related to road salt applications. The City will consider alternative products, calibration of equipment, inspection of vehicles and staff training to reduce pollutants from road deicing activities. 6. Continuation of the current street sweeping program, identification of improvements, and implementation of changes to reduce storm water pollutants. Details regarding the measurable goals, implementation schedule, and responsible parties for the pollution prevention and good housekeeping requirements can be found in the City of Edina's SWPPP (Appendix A). 15.1.2 Nondegradation Report The City's nondegradation report was required by the MPCA to address modifications to the SWPPP for measures that may be necessary to meet the new, applicable requirements of the NPDES MS4 permit. These modifications cover discharge to wetlands and other special waters as applicable, and the nondegradation requirements for selected MS4s (30 permittees including the City of Edina), including the development of a loading assessment and nondegradation report. The Nondegradation Report Submittal to the Minnesota Pollution Control Agency for Selected MS4 Permit Requirements (Barr, 2007) is presented in the CWRMP as Appendix B. The City's loading assessment and nondegradation report assumes that future BMP implementation throughout the city would follow the most stringent standards of the two watershed management organizations. The NMCWD has adopted amended stormwater management rules (March 2008), but the MCWD is in the process of formal rule revisions. Because the MCWD is still in the process of revising their water quality treatment standards, the City assumed that the NMCWD volume retention standards ( NMCWD, 2008) would be applied throughout the city in the future. Upon approval of the MCWD revised standards (if more stringent), the City will update its development review policies, standards and procedures, as cited in the SWPPP. This approach will ensure the following: 1. Receiving water quality should be improved for lakes, wetlands and creeks in Edina. 2. Channel erosion and creek morphology changes will be minimized. Barr Engineering Company 15 -6 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 3. Further protection will be provided for the physical and biological integrity of the creek and wetland corridors 4. Controlled bounce and duration of inundation in the City's wetlands and preservation of the functions and values for each type of wetland classification. For projects that impact wetlands, and where the requirements of the Wetland Conservation Act (WCA) are not as comprehensive as the MPCA water quality standards, then the requirements of the NPDES permit require an LGU to make a determination that will also satisfy Minn. R. 7050.0186. The City of Edina will continue to defer LGU authority to the NMCWD and MCWD. The City will revise its SWPPP to show where the vulnerable wellhead protection areas are within the city and to define the measures that will reduce the threat to drinking water to the maximum extent practicable. These measures will be developed in accordance with the guidance provided by the Minnesota Department of Health's Evaluating Proposed Stormwater Infiltration Projects in Vulnerable Wellhead Protection Areas (2007), and the MPCA's Minnesota Stormwater Manual (2005) regarding potential stormwater hotspots. Prior to June 30 of each year of the five -year permit cycle, the City must hold an annual public meeting. At this meeting, the City distributes educational materials and presents an overview of the MS4 program and the City's SWPPP. The City also receives oral and written comments and considers them for inclusion into the SWPPP. Also prior to June 30, the City must submit an annual report to the MPCA. This annual report summarizes the following: • Status of Compliance with Permit Conditions. The annual report contains an assessment of the appropriateness of the BMPs and the City's progress toward achieving the identified measurable goals for each of the minimum control measures. This assessment is based on results collected and analyzed, inspection findings, and public input received during the reporting period. • Work Plan. The annual report lists the stormwater activities that are planned to be undertaken in the next reporting cycle. • Modifications to the SWPPP. The annual report identifies any changes to BMPs or measurable goals for any of the minimum control measures. • Notice of Coordinated Activities. A notice is included in the annual report for any portions of the permit for which a government entity or organization outside of the MS4 is used to fulfill any BMP contained in the SWPPP. 15.1.3 Impaired Waters and TMDL Issues The federal Clean Water Act (CWA) requires states to adopt water quality standards to protect the nation's waters. Water quality standards designate beneficial uses for each waterbody and establish Barr Engineering Company 15 -7 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx criteria that must be met within the waterbody to maintain the water quality necessary to support its designated use(s). Section 303(d) of the CWA requires each state to identify and establish priority rankings for waters that do not meet the water quality standards. The list of impaired waters, or 303(d) list, is updated by the state every two years. For impaired waterbodies, the CWA requires the development of a total maximum daily load (TMDL). A TMDL is a threshold calculation of the amount of a pollutant that a waterbody can receive and still meet water quality standards. A TMDL establishes the pollutant loading capacity within a waterbody and develops an allocation scheme amongst the various contributors, which include point sources, non -point sources and natural background, as well as a margin of safety. As a part of the allocation scheme a waste load allocation (WLA) is developed to determine allowable pollutant loadings from individual point sources (including loads from storm sewer networks), and a load allocation (LA) establishes allowable pollutant loadings from non -point sources and natural background levels in a waterbody. The city's SWPPP also requires the City to complete a review of impaired waters, including identification of the impaired waters that are likely to be impacted by the City's stormwater discharge, identification of all potential stormwater discharges to impaired waters, delineation of the watershed areas that contribute to these discharges, and evaluation of the hydrology, land use and other characteristics of the watershed areas that may impact the impaired water as a results of a stormwater discharge. Based on this review, the City must determine whether changes to the City's SWPPP are warranted to reduce the impact from the City's stormwater discharge to each impaired water of concern. The City must incorporate the changes identified in the impaired waters review into the City's SWPPP. Impaired waters located within the City of Edina, as identified by the MPCA's 2008 303(d) Impaired Waters List, include: Lake Cornelia, Lake Edina, Nine Mile Creek and Minnehaha Creek. These waterbodies are listed in Table 15.1, along with the affected MPCA designated use, the pollutant or stressor that is not meeting the MPCA water quality criteria, and the MPCA target for starting and completing the TMDL process. It is likely that TMDLs will be completed to address these impairments, and load reductions will be assigned to the City, based on the TMDL results. This Water Resources Management Plan will likely need to be amended to incorporate future TMDL requirements. The TMDL requirements will also be incorporated into the City's NPDES Phase II MS4 permit. Barr Engineering Company 15 -8 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx Table 15.1 City of Edina Waters on MPCA's 303(d) Impaired Waters List 15.1.3.1 Nine Mile Creek Nine Mile Creek is currently on the 303(d) Impaired Waters List for several aquatic life impairments, including excess chloride, fish bioassessment, and turbidity. In 2007, the MPCA and NMCWD began development of a chloride TMDL for the creek, to be completed in 2010. The City of Edina will continue to participate in the stakeholder process for the chloride TMDL. The loading allocation and implementation plan that results from the TMDL will focus on reducing road salt application, where possible, and other BMPs to reduce the amount of salt that reaches the creek. The Nine Mile Creek is also listed for a fish biota impairment. In 2009, the MPCA and NMCWD began development of a TMDL to address the biotic impairment. Stakeholder meetings have been held and the draft TMDL report is to be completed in early 2010. Barr Engineering Company 15 -9 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx Target Dates for Pollutant or Starting /Complet Reach/Waterbody Description Affected Use Stressor ing TMDL Lake Cornelia' Aquatic Nutrient /Eutrophic 2012/2016 Recreation ation Biological Indicators Lake Edina2 Aquatic Nutrient/Eutrophic 2013/2017 Recreation ation Biological Indicators Nine Mile Creek' Headwaters to Aquatic Life Fish 2005/2009 Minnesota River Bioassessments Nine Mile Creek Headwaters to Aquatic Life Chloride 2005/2009 Minnesota River Nine Mile Creek Headwaters to Aquatic Life Turbidity 2005/2009 Minnesota River Minnehaha Creeks Lake Minnetonka to Aquatic Life Fish 2007/2012 Mississippi River Bioassessments Minnehaha Creeks Lake Minnetonka to Aquatic Fecal Coliform 2007/2012 Mississippi River Recreation Minnehaha Creeks Lake Minnetonka to Aquatic Life Chloride 2007/2012 Mississippi River Minnehaha Creek Lake Minnetonka to Aquatic Life Dissolved Oxygen 2009/2012 Mississippi River t Draft 2010 303(d) list indicates a target start date of 2013 and completion date of 2018 2 Draft 2010 303(d) list indicates a target completion date of 2018 ' Draft 2010 303(d) list indicates a target completion date of 2010 4 Nine Mile Creek has been delisted for a turbidity impairment on the Draft 2010 303(d) List s Draft 2010 303(d) list indicates a target start date of 2009 6 Draft 2010 303(d) list includes a dissolved oxygen impairment for Minnehaha Creek (was not on the 2008 303(d) list. 15.1.3.1 Nine Mile Creek Nine Mile Creek is currently on the 303(d) Impaired Waters List for several aquatic life impairments, including excess chloride, fish bioassessment, and turbidity. In 2007, the MPCA and NMCWD began development of a chloride TMDL for the creek, to be completed in 2010. The City of Edina will continue to participate in the stakeholder process for the chloride TMDL. The loading allocation and implementation plan that results from the TMDL will focus on reducing road salt application, where possible, and other BMPs to reduce the amount of salt that reaches the creek. The Nine Mile Creek is also listed for a fish biota impairment. In 2009, the MPCA and NMCWD began development of a TMDL to address the biotic impairment. Stakeholder meetings have been held and the draft TMDL report is to be completed in early 2010. Barr Engineering Company 15 -9 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx In 2002, the Nine Mile Creek was listed for turbidity impairment. In 2008 -2009, the NMCWD disputed the impairment, based on evaluation of historical turbidity data collected from various reaches of the creek. The MPCA has concurred that the creek is not impaired for turbidity, and the impairment has been removed in the 2010 draft 303(d) list. 15.1.3.2 Minnehaha Creek Minnehaha Creek is currently on the 303(d) list for several impairments, including excess chloride, fecal coliform, and fish biota impairment. Lake Hiawatha, located on Minnehaha Creek downstream of the City of Edina, is also on the impaired waters list for excess nutrients and eutrophication biological indicators. The MPCA and MCWD initiated the TMDL development process in 2009 to address bacteria, nutrients and chloride in Minnehaha Creek and downstream Lake Hiawatha. The TMDL development process will also likely address the biological impairment for the creek. The City of Edina will continue to participate in the stakeholder process for the Minnehaha Creek/Lake Hiawatha TMDL. The MPCA's draft 2010 303(d) list also includes an aquatic life impairment for Minnehaha Creek due to low dissolved oxygen levels. 15.1.3.3 Lake Cornelia Lake Cornelia (North Basin) was included on the MPCA's 303(d) list in 2008 for excess nutrients and eutrophication biological indicators, with a targeted TMDL start date of 2012 and completion date of 2016. The MPCA's draft 2010 303(d) list extends the targeted TMDL start and completion dates to 2013 and 2018, respectively. In 2004 -2005, the NMCWD completed a Draft Use Attainability Analysis for Lake Cornelia, which is a scientific assessment of a water body's physical, chemical, and biological condition. The study included a water quality assessment and prescription of protective and /or remedial measures for the lake and its tributary watershed. In 2008 -2009, the NMCWD collected additional data on the lake's water quality to verify the conclusions of the draft Use Attainability Analysis and evaluate several additional remedial measures to improve lake water quality. It is anticipated that the completed UAA will be used as a starting point for the TMDL development process in the future. The City of Edina will partner with the NMCWD in evaluating potential remedial measures for the lake and its watershed and implementing recommended BMPs to improve the quality of Lake Cornelia. The City of Edina will also participate in the stakeholder process for TMDL development. 15.1.3.4 Lake Edina Lake Edina was included on the MPCA's 303(d) list in 2008 for excess nutrients and eutrophication biological indicators, with a targeted TMDL start date of 2013 and completion date of 2017. The MPCA's draft 2010 303(d) list extends the targeted TMDL completion date to 2018. For the MPCA to list a water body (besides a river or creek) on the impaired waters list, it must meet the MPCA's definition of a "lake" and there must be sufficient data to determine if the lake is Barr Engineering Company 15 -10 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx impaired (see MPCA guidance manual, 2005). The City will work with the NMCWD to assess whether Lake Edina meets the MPCA's definition of a "lake ". If it is determined that the waterbody does not meet the appropriate "lake" criteria, efforts will be made to remove this lake from the 303(d) list. 15.1.3.5 Other Downstream Waterbodies There are also impaired lakes and streams outside the city that receive stormwater from Edina and will be the subject of TMDL studies, including Lake Hiawatha (discussed in Section 15.1.3.2), the Mississippi and Minnesota Rivers, and Lake Pepin. Lake Pepin is located downstream of the city via the Mississippi River. It is on the impaired waters list for excess nutrients, and a large -scale TMDL development effort is underway by the MPCA. Once the Lake Pepin TMDL is completed, it could impact the City of Edina, since the area tributary to Lake Pepin is the entire Mississippi River and Minnesota River basins upstream of the lake. In addition to TMDLs for specific impaired waters, the MPCA has developed a statewide TMDL for mercury. Mercury in Minnesota fish comes almost entirely from atmospheric deposition, with approximately 90 percent originating outside of Minnesota (MPCA, 2004). Because the main source of mercury comes from outside the state and the atmospheric deposition of mercury is relatively uniform across the state, the TMDL for mercury is 11 kg /year for the entire state. 15.2Specific MCWD Tasks /Issues The Minnehaha Creek Watershed District (MCWD) Comprehensive Water Resources Management Plan (MCWD Plan) requires the City of Edina to address the following specific items as part of this CWRMP's implementation program. 15.2.1 Phosphorus Load Reduction The MCWD Plan has identified required annual phosphorus loading reductions for each Local Governmental Unit (LGU) within the watershed in an effort to improve downstream water quality. The MCWD Plan requires that the City reduce its annual phosphorus load by 67 pounds and that the City include "strategies and specific steps for achievement of the prescribed loading reductions, including operational, land use, and capital improvements implemented since 2000, and those planned for the future" in its local water management plan. The City of Edina has met its required phosphorus load reduction through implementation of capital improvements since 2000, including the Pamela Park Water Quality Improvement Project (annual reduction of 88 lbs), installation of underground stormwater treatment structures and sump manholes as part of recent street reconstruction efforts (annual reduction of 8 lbs), and its biannual street sweeping program (annual reduction of 80 lbs). Further phosphorus loading reductions are anticipated between 2010 and 2019 as a result of the City's impervious surface reduction efforts (estimated annual reduction of 3 lbs). These capital improvements and practices, and the associated phosphorus load reductions, are discussed in more detail in the following sections. Barr Engineering Company 15-11 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAF'REdina SWMP FINAL DRAFT 121511REV.docx In addition to these capital improvements and practices, the City will continue to seek opportunities to implement infiltration and other BMPs as part of their street improvement and repair work. Based on current projections, the City expects to undertake several road improvement projects within the portion of the City that drains to Minnehaha Creek in the next 10 years. A map of the City's 2010 -2019 anticipated local bituminous street reconstruction projects is included as Appendix C. The City will seek to partner with the MCWD to explore opportunities for incorporating water quality improvement BMPs as part of the street reconstruction projects. 15.2.1.1 Pamela Park Water Quality Improvement Project In 2001- 2002, the Pamela Park Water Quality Improvement Project was constructed to improve the water quality conditions of Pamela Lake and reduce the external phosphorus and sediment loads to the lake and to Minnehaha Creek. The capital improvement project, which was initiated by the City of Edina and completed in partnership with the MCWD, included construction of three stormwater ponds in the northern part of Pamela Park, construction of two stormwater treatment wetlands on the south side of Pamela Lake, and removal of accumulated sediment from open water areas of Pamela Lake. The three stormwater ponds in the northern part of Pamela Park were constructed in series and treat stormwater runoff from a drainage area of approximately 304 acres. The drainage area is primarily single - family residential land use, but also includes approximately 41 acres of institutional land use (Edina Community Center/Normandale Elementary, Southview Middle School, and Concord School). Prior to construction of these stormwater ponds, runoff from much of this drainage area was discharged directly to Minnehaha Creek. Runoff from the remainder of the drainage area discharged to the wetland complex located upstream of Pamela Lake, which outlets to Minnehaha Creek via a concrete weir and culvert under 58`h Street. Two stormwater treatment wetlands were constructed on the south side of Pamela Lake at the locations of two major storm sewer outfalls to the lake. These wetlands, which were constructed at the edges of the pre- existing Lake Pamela wetland, provide pretreatment of stormwater prior to its discharge into the lake. The 132 -acre drainage area to these treatment wetlands is primarily single - family residential land use. In addition to construction of the stormwater ponds, the capital improvement project also included removal of accumulated sediment in Pamela Lake. Over the years, nutrient and sediment loads flowing directly into Pamela Lake from stormwater runoff had significantly reduced the water depths within the lake. As part of the project, much of the accumulated sediment was removed from the lake to restore the lake to its `original' conditions, improving lake water quality and habitat and increasing the water quality treatment achieved through sedimentation as stormwater passes through the lake to Minnehaha Creek. A P8 water quality model was developed to assess the annual phosphorus removal achieved through construction of the stormwater ponds and treatment wetlands. The model was run for a twenty -year time period (1981- 2001). Based on the modeling results, the average annual phosphorus removal Barr Engineering Company 15 -12 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAF`nlEdina SWMP FINAL DRAFT 121511REV.docx achieved from construction of the stormwater ponds and treatment wetlands is approximately 90 pounds. In 2005, portions of the Edina Community Center and adjacent school complex were redeveloped, which triggered the MCWD's stormwater treatment requirements. In lieu of constructing an onsite stormwater treatment pond, the MCWD allowed the school district to utilize the Pamela Park stormwater treatment ponds to meet their treatment requirements. The school redevelopment results in an additional six pounds of annual phosphorus loading to the Pamela Park stormwater ponds, of which approximately two pounds is removed prior to discharge to Minnehaha Creek. The MCWD has indicated that the City's required phosphorus load reduction cannot be attained through implementation of the MCWD stormwater rules. Therefore, the portion of the average annual phosphorus removal from the Pamela Park water quality improvement project attributed to the school redevelopment (two of the 90 lbs phosphorus removed annually) is not included as part of the City's required phosphorus load reduction. This results in an average annual phosphorus removal of 88 pounds due to construction of the Pamela Park stormwater ponds and treatment wetlands. 15.2.1.2 Underground Stormwater Treatment Structures and Sump Manholes Since 2000, the City of Edina has completed several significant street reconstruction projects in the portion of the City that drains to Minnehaha Creek. As part of these projects, the City has upgraded the stormwater management system to include sump manholes and underground stormwater treatment structures, which reduce the amount of sediment and phosphorus that are discharged to downstream waterbodies. In total, fifteen sump manholes and twelve underground stormwater treatment structures have been installed since 2000 in the portion of the city that drains to Minnehaha Creek. The locations of these structures are shown in Figure 15.1. To estimate the amount of annual phosphorus removal achieved through installation of the sump manholes and underground stormwater treatment structures, the Sizing Hydrodynamic Separators and Manholes (SHSAM) model was utilized. SHSAM is a model developed by Barr Engineering in 2008 -2009 to simulate the sediment removal from hydrodynamic separators and sump manholes, based on the laboratory research conducted by the St. Anthony Falls Laboratory (SAFL), University of Minnesota. The SHSAM model uses the manufacturer - specific performance functions developed by the SAFL, in conjunction with site - specific watershed parameters, local precipitation records, and sediment characteristics to estimate sediment removal performance (Mohseni, 2009). A relationship between phosphorus and suspended solids in stormwater runoff was developed to estimate the amount of phosphorus removal annually from the sump manholes and underground stormwater treatment structures (Barr, 2009). Based on the modeling results, the fifteen sump manholes and twelve underground stormwater treatment structures result in an eight pound reduction in average annual phosphorus loading to Minnehaha Creek. 15.2.1.3 Street Sweeping The City of Edina implements a biannual street sweeping program, sweeping all streets at least twice a year (typically spring and fall), and more often on an as- needed basis. City records indicate that Barr Engineering Company 15 -13 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx approximately 2,500 cubic yards of debris were collected from the City's streets in the fall of 2008 and spring of 2009. Quantifying the phosphorus load reduction from street sweeping can be difficult, as relevant, site - specific data is often limited and the available research documents a wide range of pollutant removal effectiveness from street sweeping. Information regarding the mass of suspended sediment or phosphorus in the City's street sweepings from the fall of 2008 and spring of 2009 was not available. To quantify the mass of total suspended solids (TSS) swept, it was estimated that 5.5% of the volume of street sweepings collected was of a particle size that falls into the P8 TSS particle size class distribution, based on sample results from Eden Prairie sweepings (Eden Prairie Draft Nondegradation Assessment, 2007). Assuming a phosphorus load of 569 mg TP /kg total solids from streets in residential areas (USGS, 1999), the estimated annual city -wide phosphorus reduction from the street sweeping program is 350 lbs. Of this, the estimated portion of the phosphorus load reduction within the MCWD is approximately 80 lbs, based on the proportion of the city's total impervious area within the MCWD. 15.2.1.4 Impervious Surface Reduction In recent years, the city has strived to reduce the impervious footprint of its roadways, where feasible, as part of its street reconstruction program. Between 2005 and 2009, the city -wide net decrease in impervious surfaces as a part of road reconstruction projects was 0.95 acres. The majority of this decrease was within the portion of the city that drains to Nine Mile Creek, and therefore the resulting phosphorus load reduction to Minnehaha Creek is negligible. Based on the City's street reconstruction plan for 2010 to 2019 (Appendix C), there are ten neighborhood street reconstruction projects anticipated in the Minnehaha Creek watershed. Assuming conditions will be conducive to achieving impervious surface reductions similar to those of recent projects (2005- 2009), a decrease of 1.7 acres of impervious surface is anticipated. This translates to an annual phosphorus load reduction of approximately three lbs, based on the Simple Method for estimating phosphorus export (MPCA, 2005). 15.2.2 Landlocked Basins The MCWD Plan identified two landlocked subwatershed units: one located in the northeast portion of the city (White Oaks area), and the other located west of T.H. 100 and north of Vernon Avenue (Interlachen area). The MCWD Plan requires that the City discuss and incorporate strategies to minimize new stormwater volumes and address any flooding issues in these areas. These areas are discussed in further detail below. 15.2.2.1 White Oaks Landlocked Area The MCWD Plan identified a landlocked area located in the northeast portion of the city, generally south of Sunnyside Road and north of West 49`h Street, east of Arden Avenue and west of France Avenue. To assess the flood potential in this landlocked area, the 100 -year, 10 -day snowmelt event was simulated in XP -SWMM, assuming impervious (frozen ground) conditions. Comparison of the Barr Engineering Company 15 -14 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx modeling results with the City's 2 -foot topographic information indicates that there is potential for the 100 -year high water levels to impact structures in the following subwatersheds: MHN_1, MHN_49, MHN_12, MHN_65. To assess the potential for flooding, the City will complete a field survey to determine the low entry elevations of the potentially impacted structures and a detailed feasibility study to identify remedial measures, if necessary. 15.2.2.2 Interlachen Landlocked Area The MCWD Plan identified a landlocked area located west of T.H. 100 and north of Vernon Avenue. This area, which encompasses subwatersheds EI_11, EI_12, EI_24, EI_13, and EI_19, currently drains to a wetland complex (EI_19) just south of Meadowbrook Golf Course. Two -foot topographic information for the area indicates that the natural overflow elevation between the landlocked wetland complex and the Meadowbrook Golf Course is approximately 885 feet M.S.L. Based on the FEMA Flood Insurance Study for Hennepin County (FEMA, 2004), the 100 -year flood level of Minnehaha Creek as it flows through the golf course is 892 feet M.S.L. The maximum flood elevation that the City will allow in the wetland area (EI_19) is 888 feet M.S.L, based on review of the city's two -foot topographic data in relation to structures adjacent to the wetland. To prevent the backflow of water from the Meadowbrook Golf Course to the wetland complex (EI_19), it is recommended that an embankment be constructed /raised between the wetland and the golf course to an elevation of at least 892 feet M.S.L. Upon raising the embankment, a pumped outlet will be required to keep the flood elevation below 888 feet M.S.L. The City should establish a management plan to address necessary pumping scenarios. Previous analyses for the area indicate a 1 cfs pumped outlet would be sufficient. 15.2.3 Flooding or Modeled High Water Locations The MCWD Plan identified several locations in Edina where there are known or modeled flooding issues. These areas were evaluated and are discussed in further detail below. 15.2.3.1 Kresse Circle The area near Kresse Circle in Northeast Edina drains to a land - locked basin located directly east of Maloney Avenue and north of the Interlachen Country Club parking lot (Subwatershed HO_19). This land - locked basin has a pumped outlet; stormwater discharge is conveyed northward via a forcemain into the Hopkins system, which appears to then flow east along Excelsior Boulevard and eventually into Minnehaha Creek. There is a natural overflow on the east side of the pond at an elevation of approximately 916 feet Mean Sea Level (M.S.L.);water will flow eastward into the Interlachen Country Club golf course. The City is not aware of any flooding issues at this location. 15.2.3.2 Minnehaha Creek at West 58`h Street Based on the most current FEMA Flood Insurance Study for Hennepin County (FEMA, 2004), the 100 -year flood level of Minnehaha Creek just north of West 58th Street is approximately 861 ft M.S.L. At this elevation, the creek will overtop its banks north of West 58th Street and flow Barr Engineering Company 15 -15 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx westward. The creek overtopping will result in inundation /ponding in subwatersheds MHS_81 (stormwater pond north of West 58'h Street), LP_2 (including portions of West 58'h Street), LP_25 (stormwater ponds south of West 58'h Street), and portions of Pamela Park (including Lake Pamela and the wetland complex to the north of Lake Pamela, Subwatersheds LP-14 and LP-26). To further evaluate the flooding in this area and the potential impact to nearby properties, the City will complete a stormwater analysis and detailed feasibility, if necessary. The City will seek to partner with the MCWD to address this potential flooding problem through the sharing of hydrologic and hydraulic modeling information and requesting funding assistance. 15.2.3.3 Utility Bridge in Arden Park The MCWD Plan has identified a potential flooding issue at or near the utility bridge in Arden Park, located in Northeast Edina. The referenced bridge is a pedestrian bridge that crosses Minnehaha Creek just north of West 53rd Street. The City is not aware of any flooding problems in this area. Potential inundation of this bridge in a 100 -year precipitation event is not critical, as it would not result in property damage to nearby homes nor pose a significant risk to public safety. 15.2.4 Flow Velocity and Erosion The MCWD Plan identified three locations where the MCWD's modeling indicated existing and future high pipe peak flow velocities may require erosion control measures or energy dissipaters at inlets and outlets: Minnehaha Creek downstream of 50th Street, storm sewer discharge that enters Minnehaha Creek just north of Pamela Park, and the storm sewer outfall into the ditch that leads to Minnehaha Creek just north of Pamela Park. Per the MCWD Plan requirement, the City assessed the need for erosion control at these locations. A visual observation field inspection was performed in the fall of 2009. At the time of inspection, stream flow was nonexistent, which made for ideal inspection conditions. Observations and recommendations for each site are summarized below. 15.2.4.1 Downstream of 50th Street The City of Edina has recently completed a repair /improvement project of the 50`h Street dam structure, including installation of a cable- concrete blanket below the spillway. Beyond the cable concrete, the channel bottom is well armored. South of 50th Street, the channel butts up against a high bank on the west side of the channel. There is moderate erosion on this bank; however it is heavily forested and very steep. The erosion appears to be occurring slowly and does not warrant the installation of countermeasures at this time. Two drain tile outlets were also observed approximately 500 feet downstream of 501h Street on the west bank, near the bottom of the slope. These outlets are apparently private systems originating from the Edina Country Club. One of the lines is perched higher than the other and has a significant scour hole below it. This line may have been abandoned and replaced with the other observed line, but water was observed dripping from its end. The City of Edina encourages the MCWD to work with the Edina Country Club to verify whether this line is abandoned or not and repair the scour hole. Barr Engineering Company 15 -16 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx 15.2.4.2 Storm Sewer Discharge North of Pamela Park A 30 -inch RCP discharges to a channel leading to Minnehaha Creek immediately north of West 58`h Street. There is a moderate scour hole downstream of the culvert. The scour is approaching a fairly large cottonwood tree on the west bank, and it may be desirable to place some fieldstone riprap along this bank to prevent further undercutting. Otherwise, the channel is relatively free of erosion and appears to be quite stable. 15.2.4.3 Storm Sewer Outfall to Ditch North of Pamela Park A 48 -inch RCP storm sewer discharges to a ditch located approximately 300 feet north of West 58`h Street. The ditch flows east to Minnehaha Creek; a weir is present directly downstream of the storm sewer outlet at the head of the ditch. The ditch has a mild slope and is filled with downed timber on the downstream end. Since there was very little flow during the observation, it is not clear whether the debris presents any problem during higher flows. Only minor, site specific erosion was observed in the channel and no action is recommended. 15.2.5 Potential Capital Projects and Other Issues The MCWD Plan identified a potential capital improvement project in Edina to implement a stream restoration project on Reach 14 of Minnehaha Creek. This reach extends from France Avenue to 54`h Avenue West. This project would include streambank stabilization, in- stream habitat enhancement, and buffer enhancement. The MCWD has historically had jurisdiction and maintains responsibility over county ditches within its boundaries. County ditch #17, located in the far northeast portion of Edina (Morningside area) has been converted to local storm sewer and no longer performs its historical function and is used mainly as a local, inter - community stormwater conveyance. The MCWD is interested in transferring jurisdiction of Ditch # 17 to the City. The City is not interested in transferring the jurisdiction of County Ditch #17 at this time. However, the City will seek to partner with the MCWD to address identified flooding problems related to this storm sewer system (see Section 12.3.1.1 for additional details). 15.2.6 Housekeeping Requirements The MCWD Plan requires that the City consider changes in housekeeping (land management) practices in the CWRMP. The City of Edina implements many `housekeeping' best management practices as part of its SWPPP, and reviews these practices annually as part of their annual SWPPP reporting. No specific modifications have been made to the City's housekeeping practices as a result of this plan update. However, modifications will be made to the City's housekeeping practices on an as- needed basis, in response to requirements by the MPCA or local water quality improvement efforts. For example, the City has been adjusting winter salting practices to address future requirements of the Nine Mile Creek Chloride TMDL, including using calibrated salt application equipment to optimize salt usage. The City is also considering use of Global Positioning System (GPS) units to further reduce salt usage. Barr Engineering Company 15 -17 P: \Mpls\23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 15.3Specific NMCWD Tasks /Issues 15.3.1 Use Attainability Analyses The NMCWD has developed Use Attainability Analyses (UAAs) for Mirror, Arrowhead, Indianhead, and Cornelia lakes. A UAA is an intensive, watershed -based lake study that diagnoses water quality problems and their causes and evaluates feasible alternative improvement measures. The UAAs for each of these lakes are described in further detail in the following sections. 15.3.1.1 Mirror Lake Use Attainability Analysis In 2003 -2004, the NMCWD completed the Draft Mirror Lake Use Attainability Analysis (Barr Engineering Co., 2004) based on water quality data collected from the lake in 2001. The watershed and in -lake modeling analyses indicated that the internal release of phosphorus accounts for the largest portion of annual phosphorus loading to Mirror Lake (approximately 50 %), with watershed loading comprising approximately 45% and atmospheric deposition accounting for the remaining phosphorus loading. In the summer of 2004, the NMCWD collected additional water quality data for Mirror Lake, and the watershed and in -lake modeling analyses where re- evaluated to verify the conclusions of the draft Use Attainability Analysis. The preliminary management recommendations from these efforts included implementation of BMPs in the Mirror Lake watershed, continued monitoring of aquatic plant populations and potential aquatic plant management to control Curlyleaf pondweed, and an in- lake application of alum (aluminum sulfate) to limit the internal phosphorus loading to the lake. The City of Edina will work with the NMCWD to further evaluate and implement the recommendations of the draft UAA as deemed appropriate. 15.3.1.2 Arrowhead and Indianhead Lakes Use Attainability Analysis In 2004 -2006, the NMCWD completed the Draft Arrowhead and Indianhead Lakes Use Attainability Analysis (Barr Engineering Co., 2006). The NMCWD's proposed management strategy for these lakes is to "protect ", which means "to avoid significant degradation from point and nonpoint pollution sources and from wetland alterations, in order to maintain existing beneficial uses, aquatic and wetland habitats, and the level of water quality necessary to protect these uses in receiving waters ". The watershed and in -lake modeling analyses completed for Arrowhead Lake indicated that watershed loading is the largest source of phosphorus to the lake (approximately 75 %), with internal phosphorus loading (likely due to die -back of Curlyleaf pondweed and the release of phosphorus from lake sediment) comprising approximately 20 %, and atmospheric deposition accounting for the remaining phosphorus loading. The watershed and in -lake modeling analyses completed for Indianhead Lake indicated that watershed loading is the primary source of phosphorus to the lake; internal loading was not found to be a significant source of phosphorus to Indianhead Lake. Barr Engineering Company 15 -18 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx Preliminary management recommendations for these two lakes included continued periodic monitoring of aquatic plant populations to assess the growth of undesirable non - native species such as Eurasian watermilfoil and Curlyleaf pondweed. To reduce the internal phosphorus loading in Arrowhead Lake, Curlyleaf pondweed management was suggested. The City of Edina will work with the NMCWD to further evaluate and implement the recommendations of the draft UAA as deemed appropriate. 15.3.1.3 Lake Cornelia Use Attainability Analysis In 2004 -2006, the NMCWD completed the Draft Lake Cornelia Use Attainability Analysis (Barr Engineering Co., 2006). In 2008 -2009, the NMCWD collected additional data on the lake's water quality to verify the conclusions of the draft Use Attainability Analysis and evaluate several additional remedial measures to improve lake water quality. It is anticipated that the completed UAA will be used as a starting point for the TMDL development process in the future. The City of Edina will partner with the NMCWD in evaluating potential remedial measures for the lake and its watershed and implementing recommended BMPs to improve the quality of Lake Cornelia. The City of Edina will also participate in the stakeholder process for TMDL development. 15.3.2 Water Quality Improvement Projects In 2009 the City of Edina petitioned the NMCWD for assistance in planning, implementing, and funding various water quality improvements throughout the portion of the city in the Nine Mile Creek Watershed District. The petition includes, but is not limited to, streambed stabilization projects, off road multi - purpose trail accompanying the creek to the extent possible, creek corridor management, and improvements of lake water quality. The NMCWD passed a resolution accepting the City's petition, upon several conditions. The NMCWD engineer will be preparing a feasibility report in appropriate phases to reflect 1) streambank restoration, including streambank stabilization, removal of sediment deposits, deadfalls, and other debris, maintenance of Bredesen Park, and other measures to restore natural function, scenic values, and enhance public access, including ponds, storm sewer devices, or other improvements appropriate to achieving the NMCWD's water quality goals identified in their Water Management Plan (NMCWD Plan) or in a NMCWD Use Attainability Analysis (UAA), and 2) lake water quality improvements, through implementation of the NMCWD Use Attainability Analyses prepared for Edina, Arrowhead, Cornelia, Indianhead, and Mirror lakes, including ponds, storm sewer devices, or other improvements to the extent they are necessary to achieve the water quality goals identified in the NMCWD Plan or in a NMCWD UAA. The City of Edina will continue to work with the NMCWD in development of the above mentioned feasibility analyses and in implementation of the resulting water quality improvement projects. 15.4Financial Considerations Implementation of the proposed regulatory controls, programs and improvements that are identified in the plan will have a financial impact on the City. To establish how significant this impact will be, a review of the means and ability of the City to fund these controls, programs, and improvements is Barr Engineering Company 15 -19 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx necessary. Table 15.2 lists potential sources of revenue for implementation of the water resources management efforts outlined in this plan. Table 15.2 Potential Funding Sources for Plan Implementation Description of Funding Sources Revenue Generated 1. Revenue generated by City's Storm Water Utility $1,800,000 /yr. 2. Special assessments for local improvements made Variable depending on activities undertaken under the authority granted by Minnesota Statutes Chapter 429 3. Revenue generated by the Watershed Management Variable depending on activities undertaken Special Tax Districts provided for under Minnesota Statutes Chapter 473.882. 4. For projects being completed by or in cooperation Variable depending on activities undertaken with the Nine Mile Creek and Minnehaha Creek Watershed Districts, project funds could be obtained from watershed district levies associated with their administrative funds, construction funds, preliminary funds, repair and maintenance funds or survey and data acquisition funds, as provided for in Minnesota Statutes Chapter 103D.905. 5. Grant monies that may be secured from various Variable depending on activities undertaken local, regional, County, State, or Federal agencies. This would include MnDOT, MPCA, Metropolitan Council, the DNR, and others 6. Other Sources: These may be other sources of Variable funding for storm water activities such as tax increment financing (TIF), state aid, etc. The City will continue to explore additional revenue sources as they become available. 7. Tax abatement 15.5PIan Update and Amendment Procedure It is the intention of the City to have this Comprehensive Water Resource Management Plan reviewed and approved by the Nine Mile Creek and Minnehaha Creek Watershed Districts. Once approved, no significant changes to this plan can be made without the approval of the proposed revisions by the watershed districts within the city that are affected by the change. Significant changes to the local plan shall be made known to the following parties: • City Manager, Director of Public Works, and City Engineer • Affected Watershed District within the City Barr Engineering Company P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx 15 -20 • Metropolitan Council • City Council Following notification of the above parties, they shall have 60 days to comment on the proposed revisions. Failure to respond within 60 days constitutes approval. Upon receipt of approvals from the affected watershed districts within the city, any proposed amendments will be considered approved. Minor changes to the Plan shall be defined as changes that do not modify the goals, policies, or commitments expressly defined in this plan by the City. Adjustment to subwatershed boundaries will be considered minor changes provided that the change will have no significant impact on the rate or quality in which storm water runoff is discharged from the city boundaries. Minor changes to this plan can be made by the staff at the City without outside review. This Comprehensive Water Resources Management Plan (CWRMP) will guide the City of Edina's activities through 2020, or until superseded by adoption and approval of a subsequent CWRMP. Amendments to the CWRMP will be required within two years of the adoption of an updated watershed plan by the watershed districts, consistent with 8410.0160. 15.6Regulatory Framework and Agency Responsibilities Various units of government are involved in regulating water resource related activities including: the City of Edina, watershed management organizations, the Metropolitan Council, Hennepin County, the Minnesota Department of Natural Resources, the Minnesota Board of Water and Soil Resources, the Minnesota Pollution Control Agency, the Minnesota Department of Health, the Minnesota Environmental Quality Board, the US Corps of Engineers, and the Minnesota Department of Transportation. 15.6.1 City of Edina The City of Edina manages stormwater to protect life, property, waterbodies within the city, and receiving waters outside the city. However, the City relies heavily on the Nine Mile Creek and Minnehaha Creek watershed districts for implementation of water resource protection rules and requirements. The City defers Local Governmental Unit (LGU) authority to the NMCWD and MCWD for floodplain management and drainage alterations, wetlands management, stormwater management, erosion and sediment control, waterbody crossings and structures, shoreline and streambank improvements, and sediment removal. The City of Edina also defers Local Governmental Unit (LGU) authority for the Wetland Conservation Act to the NMCWD and MCWD. This includes requiring and verifying that all projects impacting wetlands meet the requirements of the Minnesota Wetland Conservation Act. For projects in or around wetlands that do not trigger WCA regulation or NMCWD /MCWD involvement, the City is considering incorporating wetland management requirements into their zoning code, Barr Engineering Company 15 -21 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx which is being updated in 2009 -2010. The Board of Water and Soil Resources serves as both a state administrator of the programs associated with the WCA, as well as providing technical assistance to LGUs administering the WCA. The City of Edina is required to meet the conditions of the NPDES Phase II MS4 General Permit and to implement its SWPPP. The City continues to actively engage the MPCA and others to keep its permit and implementation up -to -date with regard to technology and regulations. The City utilizes its Development Review process to address stormwater management and ensure water resource protection within the city. Engineering staff review development and redevelopment proposals to ensure that the stormwater management policies and standards detailed in Section 3.0 of this plan are met. Engineering staff also consult the City's Wellhead Protection Plan to ensure that development and redevelopment proposals are in line with the protective measures established for the City's sensitive groundwater resources. Staff from the City's planning department review development and redevelopment proposals with the guidance of the City's long -range Comprehensive Plan and Zoning Ordinance. In addition to the incorporating the policies and design standards of this CWRMP, the Edina Comprehensive Plan (City of Edina, 2009) includes policies, principals, and guidelines that integrate water resources protection and management with land use planning. Among these include the City's land use policy to "grow and develop in a sustainable manner that will protect its high quality natural environment, promote energy efficiency and conservation of natural resources" and to "maintain the current open space and wetlands acreage and seek to expand it whenever possible ". The Comprehensive Plan encourages reductions in impervious surfaces and associated stormwater runoff from redevelopment sites and parking lot design that promotes stormwater infiltration., and also encourages protection and improvement of urban forests, which provides stormwater management benefits, among others. The City's zoning ordinance is used by staff in the planning department to guide development and redevelopment within the city. The zoning ordinance establishes required setbacks from naturally occurring lakes, ponds, and streams. In some cases, the buffer requirements of the watershed districts may be more stringent, upon which the watershed district requirements supersede. The City's zoning ordinance also addresses development within the floodplain districts of the city. The City of Edina is basically fully developed; thus land alteration activities are primarily of a redevelopment nature. As the city redevelops, the City utilizes the policies of the Edina Comprehensive Plan, the zoning ordinance, and this CWRMP to encourage low- impact site design. The City also relies on implementation of the rules and regulations of the Nine Mile Creek and Minnehaha Creek watershed districts to promote low- impact site design. The City and its residents highly value the parks, open space, and natural resources throughout the city. Through their Comprehensive Plan, they have identified the preservation of natural resources and, where appropriate, restoration of natural resources to create an environment that promotes sustainable natural resources. The City plans to continue to work closely with the Nine Mile Creek Barr Engineering Company 15 -22 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAMEdina SWMP FINAL DRAFT 121511REV.docx and Minnehaha Creek watershed districts to coordinate and support future efforts to create, protect, and preserve wetland areas and restoration projects that improve shoreline stabilization, establish and maintain environmentally sound shoreline buffer zones and other water quality best practice projects (City of Edina, 2009). The City of Edina currently owns and maintains approximately 350 acres of natural resource open space areas, which includes 148 acres along the Nine Mile Creek right -of -way and 23 acres along the Minnehaha Creek right -of -way. The City is basically fully developed, and is therefore no longer actively acquiring additional property to develop as park land or open space. However, the City plans to retain all of the current publicly owned park land and consider any additional property that may be offered in the future as potential additional park property. The City will also seek to acquire additional park and open space land as more private land may become available for public acquisition. 15.6.2 Watershed Management Organizations The Metropolitan Surface Water Management Act (Chapter 509, Laws of 1982, Minnesota Statute Section 10313.201 to 10313.255 as amended) establishes requirements for watershed management organizations to prepare watershed management plans within the Twin Cities Metropolitan Area. The law requires these plans to focus on preserving and using natural water storage and retention systems to: • Improve water quality. • Prevent flooding and erosion from surface flows. • Promote groundwater recharge. • Protect and enhance fish and wildlife habitat and water recreation facilities. • Reduce, to the greatest practical extent, the public capital expenditures necessary to control excessive volumes and rate of runoff and to improve water quality. • Secure other benefits associated with proper management of surface water. Edina lies within two major drainage areas. As a result two watershed management organizations cover Edina, each with its own governing body; the Minnehaha Creek Watershed District (MCWD) and the Nine Mile Creek Watershed District (NMCWD). More information is available at: www. lea .state.mn.tts /Ig /statutes.asl2 15.6.2.1 Minnehaha Creek Watershed District The Minnehaha Creek Watershed District (MCWD) consists of 27 cities and 3 townships on the western edge of the Twin Cities area. The MCWD adopted their most recent watershed management Barr Engineering Company 15 -23 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.doex plan (Minnehaha Creek Watershed District Comprehensive Water Resources Management Plan) on July 5, 2007. The MCWD maintains a robust regulatory program that requires development and some redevelopment projects to treat and control the rate of stormwater discharge, using a variety of best management practices (BMPs). Development and water resource related projects must apply for and receive MCWD permits before work can begin. The MCWD permitting program includes rules and permitting requirements for sediment and erosion control, stormwater management (including stormwater runoff volume reductions and water quality requirements), wetlands protection, shoreline improvements, floodplain alterations, and dredging. Where lakes do not currently meet water quality goals, the MCWD uses three key strategies to achieve load reductions: 1) rules requiring removal of at least 50 percent of new phosphorus loads generated by new development on new permitted development and redevelopment; 2) management of volumes generated by that new development; and 3) a requirement for stormwater plan approval earlier in the development process. In 2003 the MCWD completed a Functional Assessment of Wetlands that assigned wetlands in the watershed to a management classification based on existing conditions. The MCWD will consider amending its wetland regulatory program to manage wetlands on the basis of that classification. The MCWD operates a Land Conservation Program that undertakes conservation activities ranging from assisting property owners in enrolling property in conservation programs to acquiring easements or fee title over high value resources. The MCWD Plan has identified Key Conservation Areas, which are priority areas in the watershed where the conservation of land will improve the characteristics of the aquatic ecosystem and the water quality locally and downstream. The MCWD's designated Key Conservation Areas within Edina generally follow Minnehaha Creek, and fall mainly on park lands and riparian wetlands adjacent to the creek. Figure 15.2 shows the portions of the MCWD's Key Conservation Areas within the city that intersect with City -owned property. The City will strive to protect and conserve the hydrologic and ecologic values of these areas and other natural areas in the city through implementation of their stormwater management goals and policies (Section 3.0) and development/re- development review process. These resources will also be protected through implementation of the MCWD's rules and permitting program. The MCWD operates a watershed -wide Strategic Education and Communications Program that provides general watershed education and outreach as well as targeted information. The program philosophy is that an informed and well- educated public and public base will better understand the benefits that water quality protection and improvement offers throughout the MCWD. More information is available at the MCWD website: www.minnehahacreek.orQ. Barr Engineering Company 15 -24 P: \Mpls \23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles\Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511 REV 2.docx 15.6.2.2 Nine Mile Creek Watershed District The NMCWD works cooperatively with other governmental bodies at the city, county and state level to maintain and enhance water quality, regulate stormwater runoff, and provide year -round recreation. The NMCWD also works with developers on any project that proposes to alter floodplains, wetlands, lakes or the creek itself. The NMCWD requires permits for these types of projects to ensure that land use changes do not negatively impact water quality and flood protection. The NMCWD's review of permits provides an opportunity for citizen input on water - related issues. The NMCWD Watershed Management Plan was adopted in March 2007. Through their plan, the NMCWD pursues projects that improve water quality. These projects, like past flood control projects, will be conducted in full cooperation with municipalities. The NMCWD permitting program includes rules and permitting requirements for sediment and erosion control, stormwater management (including stormwater runoff volume reductions), wetlands management, floodplain management, and water quality. The NMCWD's permitting program is independent of permits that may be required by other governmental agencies. If a permit is required by the Minnesota Department of Natural Resources (DNR) for a project, the NMCWD reviews and provides comments to the DNR regarding the project. General Permitting authority has been given to the NMCWD by the DNR for projects related to shore protection, docks, road crossings and maintenance at storm sewer intakes and outfalls. The formal review by the NMCWD typically is held at a regular Board of Managers meeting within one month from the approval of the project by the city council. NMCWD meetings are open to the public. At the meeting, Managers receive comments from the permit applicant and the general public regarding the project. After review of the application and all comments, the Board of Managers votes to approve, approve with modification, or deny the application on behalf of the NMCWD. If the project is approved by the NMCWD, correspondence is prepared summarizing the conditions of the NMCWD's approval. This correspondence and approved permit is usually sent to the permit applicant within two weeks of the Board of Managers' meeting date. More information, including the NMCWD's most current rules and design criteria, are available at the NMCWD's website: http: / /www.ninemilecreek.org/ 15.6.3 The Metropolitan Council The Metropolitan Council provides regional planning and wastewater services (collection and treatment) for the seven county metropolitan area. The Metropolitan Council provides review and comment on watershed management plans, local water management plans, and local comprehensive (land use) plans; conducts lake monitoring (including the Citizen Assisted Monitoring Program); and conducts river and stream monitoring. Questions concerning the Metropolitan Council's role in water resource management should be directed to the Metropolitan Council, 390 North Robert Street, St. Paul, MN 55101 (651- 602 - 1000). Barr Engineering Company 15 -25 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx More information is available at the Met Council website: www.metrocotlncil.orm 15.6.4 Hennepin County Hennepin County plays a role in groundwater protection and management, through implementation of its Ground Water Plan (1994). The county administers a well sealing cost share grant program and works with the cities in the county to implement the county's groundwater plan. More information is available at the County website: www.co.hennepin.mn.us 15.6.5 Minnesota Department of Natural Resources The Mn DNR Division of Waters (Waters) manages water resources through a variety of programs in its Water Management Section, Surface Water and Hydrographics Section, and Ground Water and Climatology Section. Mn DNR Waters administers the public waters work permit program, the water appropriation permit program, and the dam safety permit program. Mn DNR Fisheries administers the aquatic plant management control permit program and other fishery related permits. In addition to permit programs, the Mn DNR oversees the floodplain management program, the public waters inventory program, the shoreland management program, the flood damage reduction grant program, the wild and scenic rivers program, various surface and groundwater monitoring programs, and the climatology program. The Mn DNR is involved in enforcement of the Wetland Conservation Act (WCA) and is responsible for identifying, protecting, and managing calcareous fens. The Mn DNR's public waters work permit program (Minnesota Statutes 103G) requires a Mn DNR public waters permit for work below the Mn DNR designated Ordinary High Water Level (OHWL) that will alter or diminish the course, current, or cross - section of any public waters or public waters wetlands, including lakes, wetlands and streams. For lakes and wetlands, the Mn DNR's jurisdiction extends to designated U.S. Fish and Wildlife Service Circular #39 Types 3, 4, and 5 wetlands which are 10 acres or more in size in unincorporated areas, or 2.5 acres or more in size in incorporated areas. The program prohibits most filling of public waters and public waters wetlands for the purpose of creating upland areas. The public waters work permit program was amended in 2000 to reclassify public waters and to make the administrative program more consistent with the WCA administrative program. Under certain conditions, work can be performed below the OHWL without a public waters work permit. Examples include docks, watercraft lifts, beach sand blankets, ice ridge removal /grading, riprap, and shoreline restoration. The Mn DNR regulates groundwater usage rate and volume as part of its charge to conserve and use the waters of the state. For example, suppliers of domestic water to more than 25 people or applicants proposing a use that exceeds 10,000 gallons per day or 1,000,000 gallons per year must obtain a water appropriation permit from the DNR. Appropriation permits from the DNR are not required for domestic uses serving less than 25 persons for general residential purposes. The DNR is Barr Engineering Company 15 -26 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx also responsible for mapping sensitive groundwater areas, conducting groundwater investigations, addressing well interference problems, and maintaining the observation well network. The Mn DNR's shoreland management program provides statewide standards for shoreland protection that local governments must adopt into their own land use controls. The City of Edina does not have a specific ordinance for shoreland protection, but instead has included the current Mn DNR shoreland management standards as part of its zoning ordinance. More information is available at the Mn DNR website: www.dnr.state.mn.us 15.6.6 Minnesota Board of Water and Soil Resources BWSR oversees the state's watershed management organizations (joint powers, county and watershed district organizations), oversees the state's Soil and Water Conservation Districts, and administers the rules for the WCA and metropolitan area watershed management. More information is available at the BWSR website: www.bwsr.state.mn.us 15.6.7 Minnesota Pollution Control Agency (MPCA) The MPCA administers the State Discharge System/National Pollutant Discharge Elimination System ( NPDES) Permit program (point source discharges of wastewater), the NPDES General Stormwater Permit for Construction Activity, the NPDES General Industrial Stormwater Permit program, the NPDES Phase I and Phase II Storm Water Permit program, and the individual sewage treatment system regulations (7080 Rules). The MPCA also reports the state's "impaired waters" to the U.S. Environmental Protection Agency. Spills should be reported directly to the MPCA. The Minnesota Pollution Control Agency (MPCA) administers and enforces laws relating to pollution of the state's waters, including groundwater. The MPCA monitors ambient groundwater quality, and administers septic system design and maintenance standards. The Tanks and Spills Section of the MPCA regulates the use, registration and site cleanup of underground and above ground storage tanks. The MPCA is responsible for administering the programs regulating construction and reconstruction of individual sewage treatment systems (ISTS). The MPCA requires an inspection program for ISTS that meets MPCA standards. Minnesota Rules 7080 govern administration and enforcement of new and existing ISTS. Hennepin County's Ordinance 19 also sets standards for ISTS and adopts by reference Minnesota Rules 7080. The MPCA no longer administers Section 401 of the Clean Water Act - Water Quality Certification program, which is primarily administered by the COE (see Section 15.6.1 lbelow). However, formal applications for 401 certification must still be sent to the MPCA. More information is available at the MPCA website: www.pca.state.mn.us Barr Engineering Company 15 -27 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAF71Edina SWMP FINAL DRAFT 121511REV.docx 15.6.8 Minnesota Department of Health The MDH is the official state agency responsible for addressing all environmental health matters, including groundwater protection. The MDH administers the Well Management Program, the Wellhead Protection Program, and the Safe Drinking Water Act rules. The MDH also issues fish consumption advisories. The MDH is responsible for preventing pollution of water supplies to ensure safe drinking water sources and limit public exposure to contaminants. Through implementation of the federal Safe Drinking Water Act, the MDH conducts the Public Water Supply Program, which allows the MDH to monitor ground water quality and train water supply system operators. The 1996 amendments to the federal Safe Drinking Water Act require the MDH to prepare source water assessments for all of Minnesota's public water systems and to make these assessments available to public. Through its Well Management Program, the MDH administers and enforces the Minnesota Water Well Code, which regulates activities such as well abandonment and installation of new wells. The MDH also administers the Wellhead Protection Program, which is aimed at preventing contaminants from entering the recharge zones of public water supply wells. In 1997, the Wellhead Protection Program rules (Minnesota Rules 4720.5100 to 4720.5590) went into effect. These rules require all public water suppliers that obtain their water from wells to prepare, enact, and enforce wellhead protection plans. The MDH prepared a prioritized ranking of all such suppliers in Minnesota. Regardless of the ranking, Rules 4720 require all public water suppliers to initiate wellhead protection measures for the inner wellhead management zone prior to June 1, 2003. If a city drills a new well and connects it to the distribution system, the city must begin development of a wellhead protection plan. Wellhead protection plans include: delineation of groundwater "capture" areas (wellhead protection areas), delineation of drinking water supply management areas (DWSMA), assessment of the water supply's susceptibility to contamination from activities on the land surface, and management programs, such as identification and sealing of abandoned wells, and education/public awareness programs. As part of its role in wellhead protection, the MDH developed the guidance document Evaluating Proposed Stormwater Infiltration Projects in Vulnerable Wellhead Protection Areas (MDH, 2007). See the Minnesota Department of Health website (http: / /www. health. state .mn.us /divs /eh /water /index.htmI ) for more information about these programs. 15.6.9 Minnesota Environmental Quality Board (EQB) The EQB administers the state's environmental review program, including Environmental Assessment Worksheets (EAW) and Environmental Impact Statements (EIS). More information is available at the EQB website: www.egb.state.mn.us Barr Engineering Company 15 -28 P: \Mpls \23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles\Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 15.6.10 Minnesota Department of Transportation (Mn /DOT) When NPDES Phase II became effective in 2003, Mn /DOT was required to apply for a NPDES permit to discharge stormwater from its right -of -way. As part of the NPDES Permit, Mn /DOT Metro District was required to develop and implement a Stormwater Pollution Prevention Program (SWPPP) to reduce the discharge of pollutants from our storm sewer system to the maximum extent practicable. Within the Metro District there are 114 local government MS4s that are designated for the NPDES permit coverage under the Phase II stormwater program. It is the primary goal of Mn /DOT Metro to develop, and implement, its Phase II program consistent with these MS4s to ensure a uniform regulatory environment for the public. Any work done on, or affecting, Mn/DOT property must be approved by Mn/DOT. More information is available at the Mn/DOT website: http: / /www.dot.state.mn.us/ 15.6.11 U.S. Army Corps of Engineers (COE) The COE administers the Section 10 of the Rivers and Harbors Act permit program, and the Section 404 permit program. Section 404 Authorizations. The Federal Clean Water Act requires that anyone who wants to discharge dredged or fill material into U.S. waters including wetlands must first obtain a Section 404 permit from the U.S. Army Corps of Engineers. Examples of activities that require a Section 404 permit include: construction of boat ramps, placement of riprap for erosion protection, placing fill in a wetland, building a wetland, construction of dams or dikes, stream channelization, and stream diversion. When Section 404 permit applications are submitted to the Corps of Engineers, the applications are typically posted for the U.S. Fish and Wildlife Service, the U.S. Forest Service, the U.S. EPA, and other federal agencies to review and provide comments on the application. The Corps of Engineers evaluates permit requests for the potential impact to various functions and values of the wetland. Section 401 Water Quality Certifications. A Section 401 water quality certification may be granted if an applicant demonstrates that a proposed activity "will not violate Minnesota's water quality standards or result in adverse long -term or short-term impacts on water quality." Greater protection is given to a category of waters designated as Outstanding Resource Value Waters. The waters in this category have received this designation because of their exceptional value. These include such groups as scientific and natural areas, wild, scenic and recreational river segments and calcareous fens. More information is available at the COE website: www.usace.army.nlil Barr Engineering Company P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \Work Files \Report \December 15 2011 FINAL DRAFnEdina SWMP FINAL DRAFT 121511REV.docx 15 -29 15.7 Implementation Priorities This CWRMP serves as a master plan for the City's water resources management and storm drainage system. The City will work with residents to implement structural (capital) improvements and non- structural programs to address existing water resource problems within the city and to prevent future problems from occurring. The implementation program identifies and prioritizes the programs and improvements, and provides cost estimates for budgeting purposes. Table 15.3 presents the City's water resource - related implementation program for 2010 -2019, which includes the City's non- structural (administration) programs and structural (capital) improvement program. Table 15.4 identifies numerous stormwater improvement projects that have been identified throughout the city based on the hydrologic and hydraulic analyses completed as part of the City's 2004 Comprehensive Water Resource Management Plan or more recent analyses. Table 15.4 also identifies several potential pond upgrade projects to improve the effectiveness of the current stormwater system in removing stormwater pollutants such as phosphorus. These flood protection and water quality improvement projects have been prioritized (see Table 15.4). The City has identified funding in their Capital Improvement Program (CIP) for such projects (see Table 15.3). The City will review the potential projects in Table 15.4 when developing their annual capital improvement program. However, stormwater management improvements will not be limited to what is included in Table 15.4 and prioritization of studies and /or implementation projects will be dependent upon additional factors such as the City's street reconstruction schedule (see Appendix C) and the timeline of other roadway and utility improvement projects. As the City designs and implements stormwater improvement projects, including those identified in Table 15.4, the City will consider ways to incorporate volume reduction or retention practices. Barr Engineering Company 15 -30 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx i, I Minnetonka Eden Prairie a e 0 0 t I I_._o___—_ ®___ a t St. Louis Park I I Hopkins y Y A m bfad Lake rrowhead bake ® I r ter �) Q L Interlachen Blvd--' 41 0 .fl! 5 r Lake Pamela Lake. Cornelia ,7 d a u i�f C A LL I Bloomington Minneapolis Richfield O e o Wes +� Storm Sewer Sump Manhole Underground Stormwater Treatment Structure Roads /Highways Creek /Stream Lake /Pond City of Edina Boundary W Feet 3,000 0 3,000 Meters 1,000 0 1,000 Figure 15.1 UNDERGROUND STORMWATER TREATMENT STRUCTURES AND SUMP MANHOLES Comprehensive Water Resource Management Plan City of Edina, Minnesota �I I� 1 I vl I 1 I I I I I Minneton Eden Pr Bloomington Minneapolis Richfield o • RPUfu����l • joss Q Feet 3,000 0 3,000 Meters 1,000 0 Figure 15.2 1.000 MINNEHAHA CREEK WATERSHED DISTRICT KEY CONSERVATION AREAS Comprehensive Water Resource Management Plan City of Edina, Minnesota City of Edina Boundary ® MCWD Key Conservation Area located on City Property Creek /Stream f Lake /Pond C3 Watershed District Boundary Roads /Highways Q Feet 3,000 0 3,000 Meters 1,000 0 Figure 15.2 1.000 MINNEHAHA CREEK WATERSHED DISTRICT KEY CONSERVATION AREAS Comprehensive Water Resource Management Plan City of Edina, Minnesota Table 15.3 Water Resources Implementation Program Project Name / Cost Proposed Funding Location Description Proposed Improvement Estimate' ($) Year Source Plan Amendments This Water Resources Management Plan may need to be amended periodically. This plan will be amended as required. As Required As Required SW Utility This Water Resources Management Plan will expire in 2019 and need to be This Plan will be updated to maintain Plan Update /Revision updated /revised to be consistent with WMO compliance with state and federal rules and 100,000 2018 -2020 SW Utility plans and policies and state and federal WMO policies. rules. City -wide education and Implement the City's Education Program Maintain the education program to educate resident involvement including educational and outreach tasks residents about the Plan and about various 10,000 /yr Ongoing SW Utility program called out in the City's SWPPP water related issues. Illicit discharge detection Continue implementation of the SWPPP Inventory, mapping, inspection, and elimination Illicit discharge detection and elimination enforcement and education. City Staff Ongoing SW Utility tasks Develop Interactive GIS Development of a web -based mapping Water resources information will be more water resources web system for sharing water resource easily accessible to interested public via the 11,000 2009 -2010 SW Utility mapping tool information with the interested public City's website. Maintenance of Interactive Annual updates and maintenance activities Web mapping tool will have continued GIS water resources web for interactive GIS web mapping tool, as functionality and reflect most up -to -date 3,000 Ongoing SW Utility mapping tool needed. information available. Illicit discharge ordinance Review existing City ordinances and City ordinances consistent with illicit develop /adopt an illicit discharge ordinance, discharge requirements of NPDES Phase II City Staff Ongoing SW Utility review as necessary. MS4 General Permit Construction site Maintain construction site stormwater runoff Plan review, inspection, enforcement and City Staff Ongoing SW Utility stormwater runoff control control program and SWPPP tasks education Post construction stormwater management Maintain the post construction stormwater management and SWPPP tasks Design standards and review, education City Staff Ongoing SW Utility BMPs— Housekeeping, Maintain the City's Pollution prevention — Street sweeping, structure clean-out, City Street Sweeping, & Storm Good housekeeping practices and related facility operations and maintenance and City Staff Ongoing SW Utility Drainage System SWPPP tasks including Street sweeping and training, inspections and recording with Maintenance system maintenance. concentration of efforts in target areas. Storm Drainage System Continue inventorying storm sewers, Complete inventory. Tie inventory into the City Staff Ongoing SW Utility Inventory manholes, catch basins, etc. City's GIS and CityWorks system. Barr Engineering Company P: \Mpls \23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT \Edina_SWMP_FINAL_DRAFT_121511 REV. docx 15 -31 Project Name I Cost Proposed Funding Location Description Proposed Improvement Estimate' ($) Years Source Updates to Hydrologic and Annual updates to City's stormwater Hydraulic Modeling management system modeling to reflect Current, up -to -date modeling results. 10,000 /year infrastructure improvements Impaired Waters Tracking Monitor impaired waters list and respond The City will remain fully informed and and Review with review and implementation as needed responsive to impaired waters issues. City Staff Ongoing SW Utility per the S WPPP. Nondegradation Report Determine pollutant load reduction Follow -up City -wide loading assessment necessary for nondegradation of water 5,000 TBD SW Utility bodies Annual S WPPP update and Make any needed updates to the City's Involve residents in water resource issue meeting SWPPP and hold an annual public meeting development and implementation tasks. City Staff Ongoing SW Utility to receive public input. BMPs - Sedimentation Pond Sedimentation ponds require frequent Develop and implement a program to 2,800,000 / Maintenance cleaning and maintenance. inspect, clean and maintain sedimentation 10 years Ongoing SW Utility and water quality ponds and lakes. Miscellaneous Drainage Improvements Miscellaneous Drainage Improvements Miscellaneous Drainage Improvements 23,000,000/ 10 years Ongoing SW Utility Infiltration and Inflow Reduce the amount of infiltration and inflow Reduce the amount of infiltration and 200,000 /year Ongoing SW Utility reduction to the sanitary sewer system inflow to the sanitary sewer system Participation in Nine Mile Participate in stakeholder process for Nine City Staff 2009 -2010 SW Utility Creek Chloride TMDL Mile Creek Chloride TMDL Implementation of Nine Implement the requirements of the Nine To be determined TBD 2010 -2020 SW Utility/ NMCWD/ Mile Creek Chloride TMDL Mile Creek Chloride TMDL Grant Funding Participation in Minnehaha Participate in stakeholder process for Creek/Lake Hiawatha Minnehaha Creek/Lake Hiawatha TMDL City Staff 2009 -2012 SW Utility TMDL Development development Implementation of Implement the requirements of the SW Utility/ Minnehaha Creek/Lake Minnehaha Creek/Lake Hiawatha TMDL To be determined TBD 2012 -2020 MCWD/ Hiawatha TMDL loading allocation and implementation plan. Grant Funding Participation in the Partner with the NMCWD to evaluate NMCWD Lake Cornelia Use Attainability Analysis potential remedial measures for improving City Staff 2009 -2010 SW Utility (UAA) development the water quality of Lake Cornelia. Barr Engineering Company P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT \Edina_SWMP_FINAL_DRAFT_12151 IREV.docx 15 -32 Project Name / Cost Proposed Funding Location Description Proposed Improvement Estimate' ($) Year Source Participation in Lake Participate in stakeholder process for Lake Cornelia TMDL Cornelia TMDL City Staff 2013 -2018 SW Utility Development Implementation of recommendations from the Partner with the NMCWD to implement the SW Utility/ NMCWD Lake Cornelia recommended remedial measures to improve To be determined TBD 2010 -2020 NMCWD/ UAA and Lake Cornelia the water quality of Lake Cornelia Grant Funding TMDL Participation in Lake Edina Participate in stakeholder process for Lake City Staff 2013 -2018 SW Utility TMDL Development Edina TMDL Implementation of Lake Implement the requirements of the Lake SW Utility/ Edina TMDL Edina TMDL loading allocation and To be determined TBD 2018 -2020 NMCWD/ implementation plan. Grant Funding Implementation of Partner with the NMCWD to implement SW Utility/ recommendations from the recommended remedial measures to improve To be determined TBD NMCWD/ Draft NMCWD Mirror Lake the water ualit of Mirror Lake q y Grant Funding UAA Implementation of Partner with the NMCWD to implement SW Utility/ recommendations from the recommended remedial measures to improve To be determined TBD NMCWD/ Draft NMCWD Arrowhead the water quality of Arrowhead and and Indianhead Lakes UAA Indianhea Lakes Grant Funding Minnehaha Creek Reach 14 Stream Improvement Project Streambank stabilization, in- stream habitat MCWD Stream Restoration enhancement, and buffer enhancement. Zoning Ordinance Revise zoning ordinance to include wetland Revisions management and shoreland restriction City Staff 2009 -2010 SW Utility aspects. Develop and implement stormwater Stormwater Management management ordinance reflecting the City Staff 2010 -2012 SW Utility Ordinance Development policiesand design standards detailed in the CWRMP. 1 TBD — To be determined Barr Engineering Company 15 -33 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina —SWMP— FINAL— DRAFT_12151 I REV.docx Table 15.4 Potential Implementation Activities (including Capital Improvements) Project Name /Location Description Proposed Improvement Priority' Nine Mile Creek -North Subwatershed ML 19 (505, 509, 513 Tyler Ct) Flooding problem Upgrade to larger pipe. C -40 Suwatershed HL-2 (Hawkes Drive) Flooding problem Construction of overflow swale between homes C -41 Subwatershed HL-18 (5711 & 5717 Grove St) Flooding problem Upgrade to larger pipes C -22 Subwatershed HL 25 (5516 & 5520 Dundee Rd) Flooding problem Perform detailed field survey. Additional pumping capacity may be required at lift station. E -3 Subwatershed MD_22 (6009 Leslie Ln) Flooding problem Upgrade to larger pipes. C -39 Subwatershed MD_28 (5316 Schaeffer Rd) Flooding problem Maintain road overflow and positive overflow swale. C -18 Subwatersheds NMN_90, NMN_23 (Fountain Woods Apartments) Flooding problem Privately owned drainage system. Notify owners of flood potential. E -2 Pond MD_3 (Bredesen Park, east of parking area) Water Quality Improvement Excavate to remove accumulated sediment. C -12 Pond MD_15 (Sun Road) Water Quality Improvement Provide additional 0.3 acre -feet of dead storage volume. C -10 Pond NMN_24 (Between Waterford Ct and Habitat Ct) Water Quality Improvement Increase pond depth. C -7 Pond NMN_27 (Northeast of T.H. 62 & T.H. 169) Water Quality Improvement Provide additional 1.4 acre -feet of dead storage volume. C -8 Pond NMN_49 (West of 5521 Malibu Drive) Water Quality Improvement Provide additional 0.2 acre -feet of dead storage volume. C -1 1 Nine Mile Creek- Central Manhole 457 (6005 & 6009 Crescent Dr) Flooding problem Construction of a positive overflow channel. C -38 Subwatershed IP_4 (Cherokee Trail & Gleason backyard depression area) Flooding problem Work with homeowners to evaluate construction of a low level outlet from landlocked depression. C -37 Subwatershed NMC_80 (5339 West 64th St) Flooding problem Upgrade to larger pipes at Ridgeview Dr and Valley Ln. C -36 Subwatersheds NMC_86, NMC_120 (Valley View Rd & Hillside Rd) Flooding problem Upgrade to larger pipe. C -35 Subwatersheds NMC_71, NMC_103 (West 66th St & Naomi Dr) Flooding problem Provide additional outlet capacity from backyard depression area through gravity outlet system (1) or pumped outlet (2). C -44 Subwatershed NMC_106 (6712, 6716, 6720 Ridgeview Dr) Flooding problem Installation of a gravity storm sewer system at backyard depression. C -34 Barr Engineering Company 15 -34 P: \Mpls \23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT \Edina_SWMP_FINAL_DRAFT_12151 IREV.docx Subwatershed NMC_107 (6808, 6812, 6816, 6820 Flooding problem Installation of a gravity storm sewer system at backyard C -33 Ridgeview Dr) depression. Lake Cornelia /Lake Edina /Adam's HiU Subwatersheds NC_62, NC_3 (Swimming Pool Pond/ North Flooding problem Upgrade pipe and outlet structure. C -31 Lake Cornelia) Subwatershed NC_11 (6312, 6316, 6321, 6329 Tingdale Flooding problem No recommendation at this time. Further analysis E -9 Ave) required. Subwatersheds NC_40, NC_26 (St. Johns /Ashcroft & West Flooding problem Installation of additional pipe to drain T.H. 62 median C -21 64th St) ditch and prevent upstream flooding. Subwatersheds NC_86, NC_97, NC_99 (Barrie Rd & Flooding problem No recommendation at this time. Reevaluation of T.H. 62 E -10 Heritage Dr) system will be required. Subwatershed NC_88 (York Ave & West 64th St) Flooding problem Increase pump capacity. Adjust pump on /off elevations. E -1 Subwatershed NC-132 (T.H. 62 at France Ave) Flooding problem No recommendation at this time. Reevaluation of T.H. 62 E -14 system will be required. Subwatershed NC-135 (Parnell Ave & Valley View Rd) Flooding problem No recommendation at this time. Further analysis E -13 required. Subwatersheds LE_53, LE_7, LE_10 (Hibiscus Ave) Flooding problem Construct positive overflow swale. C -31 Pond LE-38 (West of Lake Edina) Water Quality Improvement Provide additional 1.4 acre -feet of dead storage volume C -9 within MnDOT right -of -way Nine Mile Creek- South Subwatershed CL-51 (7001 & 7025 France Ave) Flooding problem No recommendation at this time. E -11 Pond SP_1 (Border Basin - West of Minnesota Dr & West 77th St) Water Quality Improvement Provide additional 21.5 acre -feet of dead storage volume. C -2 Subwatershed NMS_1 (Southwest quadrant of the T.H. 100 Water Quality Improvement Construct water quality basin. C -1 & West 77th St interchange) Ponds NMS_72, NMS_74 (Fred Richards Golf Course) Water Quality Improvement Increase pond depths. C -6 Pond NMS_76 (Fred Richards Golf Course) Water Quality Improvement Provide additional 2.5 acre -feet of dead storage volume. C -4 Pond NMS_104 (Fred Richards Golf Course) Water Quality Improvement Provide additional 0.2 acre -feet of dead storage volume. C -5 Nine Mile South Fork Barr Engineering Company P: \Mpls\23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP_FINAL_DRAFT_12151 IREV.docx 15 -35 Subwatershed AH_31 (6309 Post Lane) Flooding problem Construction of two control structures to restrict flow C -42 through the existing storm sewer system. Subwatershed NMSB_62 (Braemar Golf Course) Flooding problem No recommendation at this time. Further analysis E -12 required. Subwatershed NMSB_70 (7009 & 7013 Sally Ln Backyard Flooding problem Perform detailed field survey. Positive overflow swale E -7 Depression Area) may be necessary. Subwatersheds NMSB_83, NMSB_84 (Paiute Pass & Sally Flooding problem Perform detailed field survey. Positive overflow swale E -8 Ln) from backyard depression may be necessary. Ponds NMSB_3, NMSB_2 (Braemar Golf Course) Water Quality Improvement Provide additional 1.2 acre -feet of dead storage volume. C -13 Pond NMSB_7 (Braemar Golf Course) Water Quality Improvement Increase pond depth. C -15 Pond NMSB_12 (Braemar Golf Course) Water Quality Improvement Regular maintenance. C -3 Pond NMSB_85 (Braemar Golf Course) Water Quality Improvement Provide additional 1.2 acre -feet of dead storage volume. C -16 Pond NMSB_86 (Braemar Golf Course) Water Quality Improvement Provide additional 0.15 acre -feet of dead storage volume. C -14 Southwest Ponds Subwatershed SWP_14 (7411 Coventry Way) Flooding problem Installation of flapgate. C -17 Subwatershed S WP_46 (7317 Cahill Road) Flooding problem No recommendation at this time. Further analysis E -6 required. Subwatershed NM494_4 (7709 Stonewood Court) Flooding problem Upgrade to larger pipes. C -43 Northeast Minnehaha Creek White Oaks Landlocked Area Flooding Analysis and Complete stormwater analysis to determine potential Feasibility Study (if necessary) Flooding problem flooding impacts of 100 -year snowmelt event to structures E -16 surrounding the landlocked areas Subwatershed MS (4300, 4214, & 4212 Branson St) Flooding problem Install catchbasin in backyard depression and upgrade to C -24 _3 larger pipe. Subwatershed MS (4140 & 4150 West 44th St) Flooding problem Provide additional storage capacity in backyard C -25 _7 depression. Subwatershed MS 17 (4308 France Ave) Flooding problem Work with homeowners to evaluate installation of gravity C -23 system to drain backyard depression area. Subwatershed MS 40 (4000 West 42nd St and 4100, 4104, Flooding problem Implement recommendations of the 2006 Weber Park C -45 & 4108 France Ave) Pond Feasibility Study Barr Engineering Company 15 -36 P: \Mpls\23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT \Edina_SWMP_FINAL_DRAFT_12151 IREV.docx Southeast Minnehaha Creek Complete stormwater analysis to determine potential Flooding problem Complete stormwater analysis to determine potential Flooding impacts of Minnehaha Creek overtopping just north flooding impacts of Minnehaha Creek overtopping just E -15 of West 58'h Street. north of West 58`h Street. Subwatershed LP-15 (6213 Ewing Ave) Flooding problem Upgrade to larger pipes. C -26 Subwatershed LP_24 (5837, 5833, 5829, & 5825 South Flooding problem Installation of a catchbasin in backyard depression area. C -27 Chowen Ave) Subwatershed LP 27 ( Chowen Ave & West 60th St) Flooding problem Perform detailed survey /verification of storm sewer to E -4 verify pipe sizes, inverts, and low point of entry. Subwatershed MHS_4 (3600 West Fuller St) Flooding problem Installation of a catchbasin in backyard depression and C -19 storm sewer along Beard Ave. Subwatersheds MHS_24, MHS_66 (5609, 5605 Dalrymple Flooding problem Construct surface overflow swale (1) or upgrade to larger C -29 Rd & 5610, 5612 St. Andrews Ave) pipes (2). Subwatershed MHS_79 (5605, 5609, 5613, 5617, 5621, Flooding problem Upgrade to larger pipes. Install catchbasin in alley. C -20 5625, & 5629 Beard Ave) Subwatershed MHS_89 (5840 & 5836 Ashcroft Ave) Flooding problem Work with homeowners to evaluate installation of catch C -28 basin from backyard depression. Subwatershed ML (5213 & 5217 Richwood Ave) Flooding problem Perform detailed field survey of wetland storage. Further E -5 _7 analysis required. Subwatershed ML-12 (5701 Dale Avenue) Flooding problem Upgrade to larger pipes. C -30 Northwest Minnehaha Creek Construct/raise embankment between landlocked wetland Interlachen Landlocked Area Flooding problem and Meadowbrook Golf Course. Develop management C -46 plan for pumped outlet. C indicates a construction project, E indicates that an engineering study is required Barr Engineering Company 15 -37 P: \Mpls\23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT \Edina_SWMP_FINAL_DRAFT_12151 IREV.docx Wetlands 16.0 Wetlands The wetlands in the City of Edina are an important community asset. These resources supply aesthetic and recreational benefits, in addition to providing wildlife habitat and refuge. To protect the wetlands in the City of Edina, a goal of no net loss of wetland functions and values has been adopted. To provide a basis for wetland protection efforts, a planning -level inventory and field assessment of all the wetlands within the City was completed in 1999. The wetland inventory identified wetland location, approximate size, type, wetland classification, dominant wetland vegetation, function, and value. In 2003, the Minnehaha Creek Watershed District developed a Functional Assessment of Wetlands (FAW) to provide a comprehensive inventory and assessment of existing wetland functions within the district. The City adopts the Minnehaha Creek Watershed District FAW for portions of the city within the Minnehaha Creek Watershed. Figure 16.1 depicts the wetlands that were identified and assessed as part of these two wetland inventories, which are discussed in further detail in subsequent sections. Note that the wetlands identified within the Minnehaha Creek Watershed District are based on the 2003 FAW, and the remainder are based on the City's 1999 planning -level inventory. 16.1 City of Edina Wetlands Inventory- 1999 In order to compile detailed wetland data and assess the functions for hundreds of wetlands based on a short field visit to each wetland, a wetland assessment methodology was needed to allow for rapid assessment of wetlands while maximizing the integrity and value of the data. The most common wetland assessment methodology used in Minnesota has been the Minnesota Routine Assessment Method for Evaluating Wetland Functions commonly referred to as " MNRAM." A modified version of MNRAM 2.0 was used for the wetland inventory in the City of Edina, which was completed in 1999. A copy of the modified version of MNRAM 2.0 is included in Appendix D. Copies of the modified MNRAM field data sheets for each wetland have been compiled into a Wetlands Field Investigation document. The results of the wetlands inventory and assessment are provided in a geographic information system (GIS) wetlands inventory database, included as Appendix E. 16.1.1 Delineation During the summer of 1999, a wetland inventory was conducted within the City of Edina. The inventory consisted of field inspecting each wetland in the city and mapping the approximate wetland boundary in general accordance with the routine determination method as specified in the U.S. Army Corps of Engineers Wetlands Delineation Manual, 1987. Existing wetland maps (MDNR Protected Waters and Wetlands maps and National Wetland Inventory (NWI) maps), Soil Conservation Service (SCS) soil survey maps, and aerial photographs were used as baseline information to assist in the identification of wetland areas. Barr Engineering Company 16 -1 P: \Mpls \23 MN \27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles\Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511 REV 2.docx Additionally, USFWS Cowardin and Circular 39 classifications were assigned to each wetland during field inspections. 16.1.2 Dominant Vegetation The dominant vegetation within each wetland was characterized during the field inspection process using the modified version of MNRAM 2.0. For each wetland, the percent of the site occupied by the various vegetation communities for each stratum (open water, floating leafed community, emergent community, herbaceous community, shrub community, and tree community) were recorded, along with the dominant species present for each stratum. Where invasive and exotic species were encountered, the species and the percent areal coverage were also recorded. In addition, the plant community types and quality level were noted for each wetland. 16.1.3 Wetland Functional Assessment The modified version of MNRAM 2.0 used for the wetland inventory in the City of Edina included a list of questions for a number of assessment categories. Those questions all measure some unique characteristic of the wetland. Each wetland functional rating was determined loosely based on the user guidance provided for each function in MNRAM 2.0. The modified version of MNRAM 2.0 assesses the wetland functions and values described below. 16.1.3.1 Hydrology A wetland's hydrologic regime or hydroperiod is the seasonal pattern of the wetland water level which is like a hydrologic signature of each wetland type. It defines the rise and fall of a wetland's surface and subsurface water. The constancy of the seasonal patterns from year to year ensures a reasonable stability for the wetland (Mitsch and Gosselink, 2000). The ability of the wetland to maintain a hydrologic regime characteristic of the wetland type is dependent upon wetland soil and vegetation characteristics, land use within the wetland, land use within the upland watershed contributing to the wetland, and wetland inlet /outlet configuration. Maintenance of the hydrologic regime is important for maintaining a characteristic vegetative community, and is closely associated with other functions including flood attenuation, water quality and groundwater interaction. The hydrology of each wetland was rated subjectively based on the extent of hydrologic alteration. This evaluation focused primarily on the presence or absence of directed storm water, outlets, and ditching along with upland watershed characteristics. 16.1.3.2 Vegetative Diversity The vegetative diversity rating is based primarily on the diversity of vegetation within the wetland in comparison to an undisturbed condition for that wetland type. The vegetative diversity value of each wetland was assessed and rated based loosely on the ratings in MNRAM 2.0 with additional emphasis placed on invasive species and multiple communities and vegetative strata. The results of this assessment are included in the GIS wetlands inventory database. An exceptional rating typically reflects one of the following conditions: (1) highly diverse wetlands with virtually no non- native species, (2) rare or critically impaired wetland communities in the watershed, or (3) the presence or Barr Engineering Company 16 -2 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx previous siting of.rare, threatened, or endangered plant species. A high rating indicates the presence of diverse, native wetland species and a lack of non - native or invasive species. Wetlands that rate low are primarily dominated by non - native and /or invasive species. 16.1.3.3 Wildlife Habitat The ability of a wetland to support various wildlife, species is difficult to determine due to the specific requirements of the many potential wildlife species that utilize wetlands. This function determines the value of a wetland for wildlife in a more general sense, and not based on any specific species. The characteristics evaluated to determine the wildlife habitat function include: surrounding land use conditions, the interspersion of wetlands in the area, barriers to wildlife movement, rare. wetland types, special habitats, and the presence of rare or listed species. 16.1.3:4, Fishery Habitat The ability, 'f the wetland to support fisheries is determined based on the hydrologic connectivity to a. native game fishery. Wetlands without a direct hydrologic connection to a waterbody supporting fish are determined to not provide this function. Wetlands rated high are lacustrine or riverine and - provide spawning /nursery habitat, or refuge for native game fish. Wetlands rated medium may ; support native minnow populations but not native gamefish. Low quality wetlands include those with an intermittent hydrologic connection to a waterbody with a native fishery. 16.1.3.5 Flood / Stormwater Attenuation A wetland's ability to provide flood storage and /or flood wave attenuation is dependent on many_ characteri "stics "of the. wetland and contributing watershed. Characteristics of the subwatershed that affect the wetlands ability to provide flood storage and attenuation include: soil types, land use and resulting stormwater runoff volume, sediment delivery from the subwatershed, and the abundance of wetlands and waterbodies in the subwatershed. Parameters used to assess the ability of the wetlands to provide flood`storage and /or flood wave attenuation included: flood/stormwater management levels; presence and connectivity of channels; and most importantly outlet configuration. 16.1.3.6 Water Quality Protection This assessment rates the wetland's ability and opportunity to improve water,. quality. The level of functioning is.determined based on runoff,characteristics,.wetland configuration, vegetation, sedimentation processes, and nutrient cycling. Runoff characteristics that are-evaluated include: land use in the upstream watershed, the stormwater delivery system to the wetland,;sediment delivery . . characteristics, and the extent, condition, and width of upland buffer. The ability of the wetland to remove sediment from stormwater is determined by wetland configuration, emergent vegetation, and overland flow characteristics., Indicators that a wetland has been affected by nutrient loading include the presence of monotypic vegetation and /or algal blooms. 16.1.3.7 Shoreline Protection Shoreline protection is typically evaluated only`for those wetlands adjacent to lakes, streams, or deepwater habitats. The function is rated based on the wetlands opportunity and ability to protect the Barr Engineering Company 16-3 P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \Work Files \Report \December 15 2011 FINAL DRAFnEdina SWMP FINAL DRAFT 121511REV.docx shoreline; i.e., wetlands located in areas frequently experiencing large waves and high currents have the best opportunity to protect the shore. In addition, shore areas with sandy soils and little vegetation or shallow- rooted vegetation will benefit the most from shoreline wetlands. The wetland width, vegetative cover, and resistance of the vegetation to erosive forces determine the wetland's ability to protect the shoreline. This function is rated based on the potential for bank erosion due to wave action and characteristics of the bank along with the wetland vegetation characteristics. 16.1.3.8 Aesthetics /Recreation /Education and Science The aesthetics /recreation/education and science function and value of a wetland could be evaluated based on the wetland's visibility, accessibility, evidence of recreational uses, evidence of human influences (e.g. noise and air pollution) and any known educational or cultural purposes. Accessibility of the wetland is key to its aesthetic or educational appreciation. While dependent on accessibility, a wetland's functional level could be evaluated by the view it provides observers. Distinct contrast between the wetland and surrounding upland may increase its perceived importance. Also, diversity of wetland types or vegetation communities may increase its functional level as compared to monotypic open water or vegetation. This wetland value was rated using best professional judgment based primarily on observable recreational uses and potential educational benefits. 16.1.4 Wetland Sensitivity to Stormwater Input Stormwater runoff carries soil particles, nutrients, and contaminants which can change the ecological balance of the receiving water body. Changes in the volume or rate of stormwater entering or discharging from the water body can also change the ecological balance. Change in the ecological balance of a wetland often results in changes in the water quality, changes in animal and fish habitat, replacement of native vegetation with invasive and tolerant plant species, and/or other impacts to the wetland's functions and values. The state guidance document (State of Minnesota, Storm Water Advisory Group, June 1997) developed a classification for determining the susceptibility of wetlands to degradation by stormwater input. This classification relates wetland type to a rating of susceptibility as shown in Table 16.1. Wetlands such as bogs and fens can be easily degraded by changes in the stormwater inflows and are designated as highly susceptible. On the other hand, floodplain forests can tolerate relatively significant changes in the chemical and physical characteristics of stormwater inflow without degradation and are therefore slightly susceptible. Commonly observed shallow marshes and wet meadows dominated by cattail and reed canary grass (respectively) have a moderate susceptibility to stormwater fluctuations. Field notes recorded during the wetland delineations were used to determine the wetland susceptibility classification for each wetland. The susceptibility of each wetland to degradation by stormwater input was assessed and categorized as high, moderate, or least susceptible. Table 16.2 lists management recommendations for wetlands within each sensitivity classification. The sensitivity rating of each wetland is included in the GIS wetland inventory data tables. Barr Engineering Company 16 -4 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx Table 16.1 Susceptibility of Wetlands to Degradation by Stormwater Impacts 1 Special consideration must be given to avoid altering these wetland types. Inundation must be avoided. Water chemistry changes due to alteration by stormwater impacts can also cause adverse impacts. Note: All scientific and natural areas and pristine wetland should be considered in this category regardless of wetland type. 2 a., b., c. Can tolerate inundation from 6 inches to 12 inches for short periods of time. May be completely dry in drought or late summer conditions. d. Can tolerate +12 inches inundation, but adversely impacted by sediment and /or nutrient loading and prolonged high water levels. e. Some exceptions. 3 a. Can tolerate annual inundation of 1 to 6 feet or more, possibly more than once /year. b. Fresh meadows which are dominated by reed canary grass. c. Shallow marshes dominated by reed canary grass, cattail, giant reed or purple loosestrife. 4 These wetlands are usually so degraded that input of urban stormwater may not have adverse impacts. Notes: Appendix A (of the "source" of this table) contains a more complete description of wetland characteristics under each category. Pristine wetlands are those that show little disturbance from human activity. Source: "Storm Water and Wetlands: Planning and Evaluation Guidelines for Addressing Potential Impacts of Urban Storm Water and Snow Melt Runoff on Wetlands," State of Minnesota. Storm Water Advisory Group, June 1997. Barr Engineering Company 16 -5 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx Moderately Slightly Highly Susceptible Susceptible Wetland Susceptible Least Susceptible Wetland Types:' Types :2 Wetland Types:' Wetland Types:° Sedge Meadows Shrub- carrsa Floodplain Forests' Gravel Pits Open Bogs Alder Thicketsb Fresh (Wet) Cultivated Hydric Meadows° Soils Coniferous Bogs Fresh (Wet) Shallow Marshes` Dredged Meadows" a Material /Fill Material Disposal Sites Calcarcous Fens Shallow Marshesd' a Deep Marshese Low Prairies Deep Marshesd. e Lowland Hardwood Swamps Seasonally Flooded Basins 1 Special consideration must be given to avoid altering these wetland types. Inundation must be avoided. Water chemistry changes due to alteration by stormwater impacts can also cause adverse impacts. Note: All scientific and natural areas and pristine wetland should be considered in this category regardless of wetland type. 2 a., b., c. Can tolerate inundation from 6 inches to 12 inches for short periods of time. May be completely dry in drought or late summer conditions. d. Can tolerate +12 inches inundation, but adversely impacted by sediment and /or nutrient loading and prolonged high water levels. e. Some exceptions. 3 a. Can tolerate annual inundation of 1 to 6 feet or more, possibly more than once /year. b. Fresh meadows which are dominated by reed canary grass. c. Shallow marshes dominated by reed canary grass, cattail, giant reed or purple loosestrife. 4 These wetlands are usually so degraded that input of urban stormwater may not have adverse impacts. Notes: Appendix A (of the "source" of this table) contains a more complete description of wetland characteristics under each category. Pristine wetlands are those that show little disturbance from human activity. Source: "Storm Water and Wetlands: Planning and Evaluation Guidelines for Addressing Potential Impacts of Urban Storm Water and Snow Melt Runoff on Wetlands," State of Minnesota. Storm Water Advisory Group, June 1997. Barr Engineering Company 16 -5 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx Table 16.2 Management Recommendations for Each Wetland Sensitivity Classification High Moderate Least Special consideration must be These wetlands can tolerate These wetlands are usually so given to avoid altering these only moderate alterations in degraded that input of urban wetland types. Inundation must hydrology. They have very stormwater may not have adverse be avoided. Water chemistry due good wildlife habitat value and impacts. to alteration by stormwater a relatively diverse plant impacts can also cause adverse community. They will tolerate impacts. an additional 6 inches of inundation, but will be adversely impacted by sediment and /or nutrient loading and prolonged high water levels. Maintain the existing Storm Maintain the existing Storm No limit for Storm Water Water Bounce or degree of Water Bounce or degree of Bounce or degree of water level water level fluctuation. water level fluctuation. Limit fluctuation. the maximum addition of water to 6 inches. Maintain the existing Discharge Maintain the existing Discharge Maintain or decrease the existing Rate. Rate. Discharge Rate. For 1 & 2 -year storm events, For 1 & 2 -year storm events, For 1 & 2 -year storm events, maintain existing inundation maintain existing inundation maintain existing inundation periods. periods. Limit maximum periods. Limit maximum inundation to one additional inundation to an additional 7 days. day. For 10 -year storm events and For 10 -year storm events and For 10 -year storm events and greater, maintain existing greater, maintain existing greater, maintain existing inundation periods. inundation periods. Limit inundation periods. Limit maximum inundation to an maximum inundation to an additional 7 days. additional 21 days. Do not change the outlet control Do not change the outlet control May raise outlet control elevation. elevation. elevation up to 4 feet above existing outlet elevation. For landlocked wetlands, keep For landlocked wetlands, keep For landlocked wetlands, keep the the Run -out control elevations the Run -out control elevations Run -out control elevations above above the delineated wetland above the delineated wetland the delineated wetland edge. edge. edge. Recommendation: If not already Recommendation: These Recommendation: These wetlands implemented, a preservation wetlands have good potential to could be altered to improve program should be initiated. restore native plant stormwater storage and to improve Active protection from invasive communities. It is well worth water quality and not severely plant species should begin. the effort to control invasive impact the wetland quality. Purple Loosestrife, reed canary species (especially purple grass, and hybrid cattail should loosestrife) in these wetlands. be eradicated from these wetlands. Barr Engineering Company P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx 16 -6 16.2MCWD Functional Assessment of Wetlands — 2003 In 2001 -2003, the MCWD undertook a Functional Assessment of Wetlands (FAW) within the entire Minnehaha Creek Watershed District, which covers the northeast portion of the City of Edina. This assessment included the evaluation of the majority of wetlands within the MCWD including the verification the presence of a wetland, the mapping of the approximate wetland boundary, and assessment of wetland functions. The following sections discuss the FAW in more detail. 16.2.1 Delineation and Inventory The 2003 wetland assessment evaluated the wetlands identified in the Hennepin Conservation District Comprehensive Wetland Inventory (HCWI) that were greater than one - quarter acre in size. Most of the wetlands greater than approximately one - quarter acre in size were inventoried and field evaluated, to determine if the area was actually a wetland. The inventory identified wetland vegetation, type, location and boundaries, size, groundwater interaction, function, restoration potential, as well as the presence of buffers, invasive or nuisance vegetation, and rare /unique features. Wetland functions were evaluated using a variant of the Minnesota Routine Assessment Method (MnRAM) (DNR, 1998). Restoration potential was estimated based on wetland size, property ownership, and ease of restoration. Additionally, USFWS Cowardin and Circular 39 classifications were assigned to each wetland during field inspections. Wetlands identified on the HCWI that are smaller than one - quarter acre in size were originally identified using historic aerial photos, infrared photos, soil types, NWI and PWI data, and Hennepin County Mosquito Control maps but were not field verified or assessed as part of the 2003 MCWD FAW. These wetlands have been included in the City's updated wetland inventory for the portion of the city within the Minnehaha Creek Watershed District, but may not have complete information available. 16.2.2 Critical Wetland Resources Wetlands in the MCWD were evaluated for designation as critical resources based on several features defined in the Minnesota Statutes. These critical wetland resources are classified by the MCWD into the Preserve management classification. Criteria for designating wetlands as critical resources are as follows: • Outstanding Resource Value Waters (Minn. Rules 7050.0180) • Designated Scientific and Natural Areas (Minn. Rules 86A.05) • Wetlands with known occurrences of threatened or endangered species (Minn. Stat. 84.0895) • State Wildlife Management Areas (Minn. Stat. 86A.05) Barr Engineering Company 16 -7 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx • State Aquatic Management Areas (Minn. Stat. 86A.05) • Calcareous Fens (Minn. Rules 8420.1010 through 8420.1060) • High priority areas for wetland preservation, enhancement, restoration, and establishment (Minn. Rules 8420.0350, subpart 2) • Designated historic or archaeological sites 16.2.3 Wetland Susceptibility to Stormwater The state guidance document Stormwater and Wetlands: Planning and Evaluation Guidelines for Addressing Potential Impacts of Urban Stormwater and Snow -Melt Runoff on Wetlands (State of Minnesota, Storm Water Advisory Group, June 1997) developed a methodology for determining the susceptibility of wetlands to degradation by stormwater input. This methodology relates wetland type to a level of susceptibility as shown in Table 16.1. The MCWD used this methodology to identify those wetlands susceptible to degradation by stormwater. 16.2.4 Wetland Management Classification Based on the results of the field evaluation and its resource significance and susceptibility to stormwater input, each wetland within the MCWD was assigned to one of four categories: Preserve, Manage 1, Manage 2, or Manage 3. Preserve wetland are the highest quality wetlands or have been identified as important wetland resources. The MCWD management classification of each wetland is included in the GIS wetland inventory data tables. 16.3Circular 39 Wetland Classification The Wetlands of the United States was published in 1959 by the U.S. Fish and Wildlife Service and is commonly referred to as "Circular 39" (Shaw and Fredine, 1959). The Circular 39 Wetland Classification System was the first method that the U.S. Fish and Wildlife Service used to classify wetland basins in the U.S. It is composed of 20 wetland types of which 7 are found in the City of Edina. A general description of each wetland type is provided below. As part of the City of Edina's 1999 wetland inventory and the 2003 MCWD FAW, Circular 39 classifications were assigned to each wetland during field inspections. Figure 16.2 shows the wetlands classification within the City. The Circular 39 classification for each wetland within the City is included in the GIS wetlands inventory database. 16.3.1.1 Type 1: Seasonally Flooded Basin, Floodplain Forest Soil is covered with water or is waterlogged during variable seasonal periods but usually is well- drained during much of the growing season. This type is found both in upland depressions and in overflow bottomlands. In uplands, basins or flats may be filled with water during periods of heavy rain or melting snow. Barr Engineering Company 16 -8 P:\Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx Vegetation varies greatly according to season and duration of flooding: from bottomland hardwoods to; herbaceous plants. Where the water has receded early in the growing season, smartweeds, wild millet, fall panicum, redroot cyperus, and weeds (i.e., marsh.elder; ragweed, and cockleburs) are likely to occur. Shallow basins that are submerged only very temporarily usually develop little or no wetland. vegetation. 16.3.1.2 Type 2: Wet Meadow, Fresh Wet Meadow, Wet to Wet -Mesic Prairie, Sedge Meadow, and Calcareous Fen Soil is usually without standing water .during most of the growing season but is waterlogged within at least a few inches of the surface. Meadows may fill shallow basins, sloughs, or.farmland sags, or these,meadows may border shallow marshes on the.,landward.side. Vegetation ircludes.grasses, sedges, rushes, and various broad - leaved .plants. -In the North,; representative plants are Carex, rushes, redtop; reedgrasses, manna. grasses; prairie cordgrass,;and mints. Other wetland plant community types include low prairies, sedge meadows, and calcareous .fens. 16.3.1.3 Type 3: Shallow Marsh Soil is usually waterlogged early during the growing season and may often be covered with as much as 6`inches.or more of water. These- marshes may nearly fill shallow lake basins or sloughs, or may border deep marshes on the landward side. These are common as seep areas on irrigated lands. Vegetation includes grasses, bulrushes, spikerushes, and various other marsh plants such as cattails, arrowhead, pickerelweed, and- smartweeds. Common representatives in the North are reed, whitetop, rice.cutgrass, Carex, and giant burreed. 16.3.1.4 Type 4: Deep Marsh Soil °is usually covered with 6 inches to 3 feet or more of water during the growing season. These deep `marshes may completely fill shallow lake basins; potholes, limestone sinks and sloughs, or they may border open water iri'such depressions. Vegetation includes cattails, reeds, bulrushes, spikerushes and wild rice. In open areas, pondweeds, naiads, coontail, watermilfoils, waterweeds, duckweed, water lilies, or spatterdocks may occur. 16.3.1.5 Type 5: Shallow Open Water Shallow ponds and reservoirs are included in this type. Water is usually less than 10- feet:deep and is fririg& by a border of emergent vegetation similar to open areas of Type 4. Vegetation:(mainly at water depths less than 6 feet) includes pondweeds, naiads, wild celery, coontail, watermilfoils, muskgrass, waterlilies, and spatterdocks. 16.3.1.6 Type 6: Shrub Swamp; Shrub Carr, Alder Thicket The soil is usually waterlogged during the growing season and is often covered with as much as 6 inches of water. Shrub swamps occur mostly along sluggish streams and occasionally on flood plains. Vegetation includes alders, willows, buttonbush, dogwoods and swamp - privet. Barr Engineering Company 16 -9 P:\Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 16.3.1.7 Type 7: Wooded Swamps; Hardwood Swamp, Coniferous Swamp The soil is waterlogged at least to within a few inches of the surface during the growing season and is often covered with as much as I foot of water. Wooded swamps occur mostly along sluggish streams, on old riverine oxbows, on floodplains, on flat uplands, and in very shallow lake basins. Forest vegetation includes tamarack, arborvitae (cedar), black spruce, balsam fir, red maple, and black ash. Northern evergreen swamps usually have a thick ground covering of mosses. Deciduous swamps frequently support beds of duckweeds, smartweeds, and other herbs. 16.4Cowardin Wetland Classification The Classification of Wetlands and Deepwater Habitats of the United States was published by the U.S. Fish and Wildlife Service in 1979 (Cowardin et al., 1979). This wetland classification methodology was used to classify wetlands in the development of the National Wetlands Inventory maps beginning in the late 1970s and early 1980s. The structure of the classification is hierarchical progressing from Systems and Subsystems, at the most general levels, to Classes, Subclasses, and Dominance Types at the most specific levels. A general description of the hierarchical structure is provided below. As part of the City of Edina's 1999 wetland inventory and the 2003 MCWD FAW, Cowardin wetland classifications were assigned to each wetland during field inspections. The Cowardin classification for each wetland within the City is included in the GIS wetlands inventory database. 16.4.1.1 System The term System refers to a complex of wetlands and deepwater habitats that share the influence of similar hydrologic, geomorphologic, chemical, or biological factors. The primary systems found in Edina are Palustrine, Lacustrine, and Riverine while Marine and Estuarine Systems are not found in the City. L: Lacustrine (lakes and deep ponds) - Lacustrine Systems include wetlands and deepwater habitats with all of the following three characteristics: • Situated in a topographic depression or a dammed river channel; • Lacking trees, shrubs, persistent emergents, emergent mosses or lichens with greater than 30 percent areal coverage; • Total area exceeds 8 hectares (20 acres). • Basins or catchments less than 8 hectares in size are included if they have at least one of the following characteristics: • A wave- formed or bedrock feature forms all or part of the shoreline boundary; or • The catchment has, at low water, a depth greater than 2 meters (6.6 feet) in the deepest part of the basin. Barr Engineering Company P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 121511REV.docx 16 -10 P: Palustrine (shallow ponds, marshes, swamps and sloughs) - Palustrine Systems include all nontidal wetlands dominated by trees, shrubs, persistent emergents, emergent mosses or lichens. R: Riverine (rivers, creeks and streams) - Riverine Systems are contained in natural or artificial channels periodically or continuously containing flowing water. Upland islands or Palustrine wetlands may occur in the channel, but they are not part of the Riverine System. 16.4.1.2 Subsystem The term Subsystem refers to a further subdivision of Systems into more specific categories. The Palustrine System has no subsystems associated with it while Lacustrine Systems have two Subsystems and Riverine Systems have four, of which only one applies in the City of Edina. Each Subsystem is unique for the System to which it applies. L1: Limnetic - Extends outward from Littoral boundary and includes deepwater habitats within the Lacustrine System. L2: Littoral - Extends from shoreward boundary to 2 meters (6 feet) below annual low water or to the maximum extent of non - persistent emergents, if these grow at greater than 2 meters. R2: Lower Perennial 16.4.1.3 Class, Subclass The wetland Class is the highest taxonomic unit below the Subsystem level. The Class code describes the general appearance of the habitat in terms of either the dominant life form of the vegetation or the physiography and composition of the substrate. Life forms (e.g. trees, shrubs, emergents) are used to define classes because they are easily recognizable, do not change distribution rapidly, and have traditionally been used to classify wetlands. Finer differences in life forms are recognized at the Subclass level. Mixed classes are used as sparingly as possible, under two main conditions: (1) The wetland contains two or more distinct cover types each encompassing at least 30 percent areal coverage of the highest life form, but is too small in size to allow separate delineation of each cover type; and (2) The wetland contains 2 or more classes or subclasses each comprising at least 30 percent areal coverage so evenly interspersed that separate delineation is not possible at the scale used for classification. Mixed subclasses are also allowed and follow the same rules for mixed classes (Cowardin et al., 1979). AB: Aquatic Bed — Includes wetlands and deepwater habitats dominated by plants that grow principally on or below the surface of the water for most of the growing season in most years. Subclasses include: AB = Algal, AB2 = Aquatic Moss, AB3 = Rooted Vascular, AB4 = Floating Vascular, A135 = Unknown Submergent, and A136 = Unknown Surface. Barr Engineering Company P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAF'nEdina SWMP FINAL DRAFT 121511REV.docx 16 -11 EM: Emergent— Characterized by erect, rooted, herbaceous hydrophytes, excluding mosses and lichens. This vegetation is present for most of the growing season in most years. Subclasses include: EMI = Persistent (plants that normally remain standing at least until the beginning of the next growing season), and EM2 = Nonpersistent (plants which fall to the surface of the substrate or below the surface of the water at the end of the growing season). FO: Forested —Woody vegetation greater than 6 meters (20 feet) tall. Subclass determination is based on: which type represents more than 50 percent of the areal canopy coverage during the leaf -on period. Subclasses include: FO = Broad - leaved Deciduous, FO2 = Needle- leaved Deciduous, FO3 = Broad - leaved Evergreen, FO4 = Needle - leaved Evergreen, FO5 = Dead, FO6 = Deciduous, and FO7 = Evergreen. SS: Scrub /Shrub —Woody vegetation less than 6 meters (20 feet) tall. The species include true shrubs, young trees (saplings) or trees that are small or stunted because of environmental conditions. Subclass determination is based on: which type represents more than 50 percent of the areal canopy coverage during the leaf -on period and include: SS 1 = Broad - leaved Deciduous, SS2 = Needle- leaved Deciduous, SS3 = Broad - leaved Evergreen, SS4 = Needle - leaved Evergreen, SS5 = Dead, SS6 = Deciduous (used if deciduous woody vegetation cannot be identified on aerial photography as either Broad - leaved or Needle - leaved), and SS7 = Evergreen (used if evergreen woody vegetation cannot be identified on aerial photography as either Broad - leaved or Needle - leaved). UB: Unconsolidated Bottom — Includes all wetlands and deepwater habitats with at least 25 percent cover of particles smaller than stones (less than 6 -7 cm.), and a vegetative cover less than 30 percent. 16.4.1.4 Water Regime Precise description of hydrologic characteristics requires detailed knowledge of the duration and timing of surface inundation, both yearly and long -term, as well as an understanding of groundwater fluctuations. Because such information is seldom available, the water regimes that, in part, determine characteristic wetland and deepwater plant and animal communities are described here in only general terms (Cowardin, et al., 1979). Water regimes are grouped under two major categories, Tidal and Nontidal. The Tidal Water Regime does not occur in the City so is not described here. A: Temporarily Flooded— Surface water present for brief periods during the growing season, but the water table usually lies well below the soil surface. Plants that grow both in uplands and wetlands are characteristic of this water regime. The temporarily flooded regime also includes wetlands where water is present for variable periods without detectable seasonal periodicity. Barr Engineering Company 16 -12 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx Weeks; months, or even years may intervene between periods of inundation. The.dominant plant communities under this regime may change as soil moisture conditions change. B: Saturated —The substrate is saturated to the surface for extended periods during the growing season, but surface water is seldom present. C: Seasonally Flooded- Surface water is present for extended periods especially early in the growing season, but is absent by the end of the growing season in most years. When surface water.is absent, the water table is often near the land surface. The water table after flooding ceases is highly variable, extending from saturated to a water table well below the ground surface. F: Semi permanently Flooded— Surface water persists throughout the growing season in most years.,When surface water is absent, the water table is usually at or very near the land surface. G: Intermittently Exposed— Surface water is present throughout the year except in years of extreme drought. H: Permanently Flooded —Water covers the land surface throughout the year in all years. Vegetation is composed of obligate hydrophytes. 16.4.1.5 Special Modifiers Many wetlands and deepwater habitats are man -made and natural ones have been modified to some degree by the activities of man or beavers. Since the nature of these modifications often greatly influences the character of such habitats, special modifying terms have been included here to' emphasize their importance.(Cowardin, et al'., 1979). b: Beaver— Created or modified by a beaver dam. d: Partly Drained —The water level has been artificially lowered, but he area is still classified as wetland because soil moisture is sufficient to support hydrophytes. Drained areas are not considered wetland if they can no longer support hydrophytes. f:. Farmed —The soil surface has been mechanically or physically altered for production of clops, but hydrophytes will become reestablished if farming is discontinued. h: Diked /Impounded- Created or modified by a barrier or, dam which purposefully or unintentionally obstructs the outflow of water. Both man -made and beaver dams are included. r: Artificial— Refers to substrates classified as Rock Bottom, Unconsolidated Bottom, Rocky Shore, and Unconsolidated Shore that were emplaced by humans, using either natural materials such as dredge spoil or synthetic materials such as discarded automobiles, tires, or concrete. Barr Engineering Company 16 -13 P:\Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAFnEdina SWMP FINAL DRAFT 121511REV.docx s: Spoil— Refers to the placement of spoil materials which have resulted in the establishment of wetland. x: Excavated —Lies within a basin or channel excavated by humans. 16.5Public Waters The Minnesota Department of Natural Resources (MnDNR) has designated certain waters of the state as public waters (Minn. Rules 6115.1060). MnDNR "Protected Waters and Wetlands" maps show public waters within the city. A MnDNR permit is required for work that would alter the course, current, or cross - section of a designated public water. Protected waters and wetlands maps show public waters as one of the following: protected waters; protected wetlands; protected watercourses; or, protected public ditches. Table 16.3 lists the MnDNR Protected Waters and Wetlands within the city. The table includes the MnDNR identifier for each pond, as well as the corresponding subwatershed for this stormwater study. Protected waters are identified with a number and the letter "P ". Protected wetlands are identified with a number and the letter "W ". Protected wetlands include, and are limited to, Type 3, 4, and 5 wetlands that have been designated as protected waters and are 2'/z acres or more in size (10 acres in unincorporated areas). Protected water courses and ditches in Edina include: • Minnehaha Creek • North Fork of Nine Mile Creek • South Fork of Nine Mile Creek • Braemar Branch of Nine Mile Creek Table 16.3 MnDNR Protected Waters and Wetlands within Edina MnDNR Protected Waters and Wetlands Corresponding Subwatershed ID(s) 804W NMN 5 805W NMN 24 1106W NMN_4 803W MD 21 802W MD 25 801W NMN 50 80OW NMN 75 799W NMN_76, NMN 55 55P ML_ 1, ML 32 781W ML 28 Barr Engineering Company P: \Mpls\23 MN\27\23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report\December 15 2011 FINAL DRAF71Edina SWMP FINAL DRAFT 121511REV.docx 16 -14 MnDNR Protected Waters and Wetlands Corresponding Subwatershed ID(s) 782W ML 16 668P HI —1 56P HL —1 780W EI 32 667W El —1 666W El-1 9 41 P Segment of Minnehaha Creek 670W MHS 22 669W ML —8 675P LP_14, LP 26 676W NC-5 677W NC —2 678W NC 30 679W NC —3 680W NC —4 28P NC_62, SC_1 671P NMC 112 50P MD-50, MD _1 672W CO —1 673P NMC 1 674W N M C_77 29P LE —1 1041W NMS —3 1038W SWP 3 1040W SWP_4, SWP_2, SWP 1 1039W SWP_5, SWP_35, SWP_14 45P AH 1 806W AH 6 807W EP —2 808W EP —2 44P 11-11 1013W NMSF_1, NMSF 12 Barr Engineering Company 16 -15 P:\Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAF'REdina SWMP FINAL DRAFT 121511REV.docx E 3 E a U J L 'a r., l r I' 1 i i i Minnetonka Eden Prairie U I St. Louis Park L is •e o 4 - o s � 0 6 c = Cfm* Minneapolis m Y CO a „ e W 769 "CI 9 0 0 ]Vine � ti Valley View Rd m 0 r G�'it�O Gib C �- a Richfield v ,e e� r j� IL 789 ° V 0 Bloomington A, owe�� O K • City of Edina Boundary Roads /Highways Creek /Stream Lake/Wetland'° C3 Watershed District Boundary W Feet 3,000 0 3,000 FM MENEd Meters 1,000 0 1,000 Figure 16.1 WETLANDS Comprehensive Water Resource Management Plan City of Edina, Minnesota �o E c m y U 3 i I I I I I L__ I I I I r I i I I I j I ' I_ Minnetonka 169 ft Y m I St. Louis Park 0 I to ti rn s A n i 1 oms n Je �o � � • Minneapolis f_ se Valley View Rd o %%%W MDld t � • Richfield Eden Prairie 169 f �� 4A Bloomington o • lVcz) RPUR�'twO Ia88 City of Edina Boundary Roads /Highways C3Watershed District Boundary Wetland Type' f a Unclassified f Type 1 f Type 1 Predominant + Others Type 2 Type 2 Predominant + Others Type 3 G> Type 3 Predominant + Others Sp Type 4 f Type 5 f Type 5 Predominant + Others f Type 6 So Type 7 I& Type 7 Predominant + Others " Based on the Fish and Wildlife Service Circular 39 Classification System. Wetlands within the Minnehaha Creek Watershed District were identified and assessed in 2005 as part of the Minnehaha Creek Functional Assessment of Wetlands. Wetlands located in the remaining portion of the city were identified and assessed in 1999 as part of the City of Edina's wetland inventory. O Feet 3,000 0 3,000 Meters 1,000 0 1,000 Figure 16.2 WETLAND CLASSIFICATIONS Comprehensive Water Resource Management Plan City of Edina, Minnesota References 17.0 References Barr Engineering Company, 1999a. Glen Lake. Use Attainability Analysis. Barr Engineering Company, 1999b. Round Lake Use Attainability Analysis. Barr Engineering Company, 2001. Bloomington Use Attainability Analysis. Prepared for Nine Mile Creek Watershed. District. Barr Engineering Company, 2004a. Comprehensive Water Resources Management Plan, Prepared for City of Edina. Barr Engineering Company, 2004b. Draft Arrowhead and Indianhead Lakes Use Attainability Analysis. Barr Engineering Company, 2004c. Draft Mirror Lake Use Attainability Analysis. Barr Engineering Company, 2006a. Draft Lake Cornelia Use Attainability Analysis. Barr Engineering Company, 2006b. Weber Park Pond Feasibility Study. Barr Engineering Company, 2007. Nondegradation Report Submittal to the Minnesota Pollution Control Agency for Selected MS4 Permit Requirements. Prepared for City of Edina. City of Edina; 2009. Edina Comprehensive Plan. Cowardin; L.M., V. Carter, F.C. Golet, and E.T. LaRoe, 1979. Classification of Wetlands and Deepwater Habitats of the United States. U.S. Fish and Wildlife Service, FWS /OBS- 79/31. Federal Emergency Management Agency (FEMA), 1979. Flood Insurance Study for the City of Edina. Federal Emergency. Management Acency (FEMA), 2004. Flood Insurance Study for Hennepin County, MN All Jurisdictions. Hennepin County,' 1994. Draft Hennepin County.. Groundwater Plan. Hennepin Conservation District, 2003. Functional Assessment of Wetlands, Minnehaha Creek Watershed District. Minnehaha Creek Watershed District, 2007. Minnehaha Creek Watershed District Comprehensive Water Management Plan. Barr Engineering Company 17=1 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP.FINAL DRAFT 121511REV.docx Minnesota Department of Health, 2007. Evaluating Proposed Stormwater Infiltration Projects in Vulnerable Wellhead Protection Areas. Minnesota Department of Natural Resources, 1983. Protected Waters and Wetlands, Hennepin County, Minnesota, Division of Waters, Sheet 2 of 4. Minnesota Department of Natural Resources, 1998. Minnesota Routine Assessment Method for Evaluating Wetland Functions (MnRAM). Minnesota Pollution Control Agency (MPCA), 2000. Protecting Water Quality in Urban Areas, March 2000. Minnesota Pollution Control Agency (MPCA), 2005. Minnesota Stormwater Manual. Mitsch, W.J. and J.G. Gosselink, 2000. Wetlands. Mohseni, O., Kieffer, J.M., and J.A. Koehler, 2009. "A Tool for the Performance Assessment of Hydrodynamic Seperators." World Environmental and Water Resources Congress 2009: Great Rivers. Nine Mile Creek Watershed District, 1996. Nine Mile Creek Watershed District Water Management Plan. Nine Mile Creek Watershed District, 2008. Nine Mile Creek Watershed District Amended Rules. Schwab, G.O., D. Fangmeier, W. Elliot, and R. Frevert, 1993. Soil and Water Conservation Engineering. Shaw, S.P., and C.G. Fredine, 1959. Wetlands of the United States: Their Extent and Their Value to Waterfowl and Other Wildlife. U.S. Fish and Wildlife Service. Circular 39. State of Minnesota, Storm Water Advisory Group, 1997. Storm Water and Wetlands: Planning and Evaluation Guidelines for Addressing Potential Impacts of Urban Storm Water and Snow Melt Runoff on Wetlands. June 1997. U.S. Army Corps of Engineers, U.S. Department of Agriculture Soil Conservation Service, U.S. Environmental Protection Agency, U.S. Fish and Wildlife Service, 1989. Federal Manual for Identifying and Delineating Jurisdictional Wetlands. January 1989. U.S. Department of Agriculture, Soil Conservation Service, 1974. Soil Survey, Hennepin County, Minnesota, April 1974. U.S. Department of Commerce, Weather Bureau, 1961. "Technical Paper No. 40. Rainfall Frequency Atlas of the United States. " Barr Engineering Company 17 -2 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update\WorkFiles \Report\December 15 2011 FINAL DRAF'nEdina SWMP FINAL DRAFT 121511REV.docx U.S. Environmental Protection Agency, 1988. Storm Water Management Model, Version 4: User's Manual. U. S. Geological Survey, 1999. Sources of Phosphorus in Stormwater and Street Dirt from Two Urban Residential Basins in Madison, Wisconsin, 1994 -95. Water Resources Investigations Report 994021. R.J. Waschbusch, W.R. Selbig, and R.T. Bannerman. Barr Engineering Company 17 -3 P: \Mpls\23 MN\27 \23271072 Edina Water Resources Mgmt Plan Update \WorkFiles \Report \December 15 2011 FINAL DRAFT\Edina SWMP FINAL DRAFT 12151IREV.docx SWPPP C. 3 Q k D Nondegradation Report CL V CL x n Planned Street Reconstruction MNRAM Version 2.0 CL u GIS Wetlands Inventory Database V CL x m