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HomeMy WebLinkAboutSIDEWALK FRANCE AVE 57TH TO 58THThe City Council City of Edina Petition Petition Instructions This petition form is to be used to ask the Edina City Council to consider the following types of improvements: SIDEWALK ALLEY PAVING WATER MAIN STORM SEWER PERMANENT STREET SURFACING WITH CURB AND GUTTER CURB AND GUTTER ONLY (WITHOUT PERMANENT STREET SURFACING) SANITARY SEWER STREET LIGHTING or another improvement you describe (called OTHER on this form). You may use another petition form if you wish but the city council may reject such petitions unless they contain the following infoimation: 1. Type of improvement(s) requested, e.g., SIDEWALK, STORM SEWER, WATER MAIN, ETC. 2. Precise locations(s) of the requested improvements. 3. A statement that all who sign the petition understand that the city council may assess the costs of these improvements against the properties benefiting from the improvements in amounts determined by the Council. 4. Printed name of property owner, owner's signature and phone number, and property address. 5. Signature of person circulating the petition. If you have questions, please call the City Clerk at 952-927-8861 between 8:00 a.m. and 4:30 p.m. DEBRA MANGEN CITY CLERK APRIL 2008 PROPERTY ADDRESS (PRINTED) 321i (A) £7-01 --snA Si g Not_ 5-c7r7 'Fe z-IC Fe-4"ACC Aa-c OWNER'S NAME (PRINTED) prri• 1A4 cd'Ot vcWS 0.4.1..t, C c_plopi?) PROPERTY OWNER'S SIGNATURE (.- City of Edina, Minnesota CITY COUNCIL 4801 West 50th Street • Edina, Minnesota 55424 (952) 927-8861 • (952) 927-7645 FAX • (612) 927-5461 TDD DAT REC f? II9 PETITION TO THE CITY COUNCIL SIDEWALK q ALLEY PAVING Ei WATER MAIN O STORM SEWER El SANITARY SEWER q STREET LIGHTING q CURB AND GUTTER ONLY 0 PERMANENT STREET q OTHER: SURFACING WITH CURB AND GUTTER To the Mayor and City Council:: The persons who have signed this petition ask the City Council to consider the improvements listed above to the locations listed below. f;ralq 06 V6 5°14 -th between 6-1 and W 6$4`1 LOCATION OF IMPROVEMENT BY STREET NAME ADDRESS ADDRESS between between between and and and LOCATION OF IMPROVEMENT BY STREET NAME ADDRESS ADDRESS LOCATION OF IMPROVEMENT BY STREET NAME ADDRESS ADDRESS LOCATION OF IMPROVEMENT BY STREET NAME ADDRESS ADDRESS IMPORTANT NOTE: THE PERSONS WHO HAVE SIGNED THIS PETITION UNDERSTAND THAT THE CITY COUNCIL MAY ASSESS THE COSTS OF THESE IMPROVEMENTS AGAINST THE PROPERTIES BENEFITING FROM THE IMPROVEMENTS IN AMOUNTS DETERMINED BY THE COUNCIL AS AUTHORIZED BY CHAPTER 429, MINNESOTA STATUTES. This petition as circulated by: -.0/ J r MTh 1/0 6E)) 3 w 7tk CI CO-V7-5gV NAME ADDRESS PHONE There is space for more signatures on the back. APRIL 2008 PROPERTY ADDRESS (PRINTED) 51 2-1 Fa_AN CA A rt; tfCe This petition was circulated by: NAME The Minnesota Data Practices Act requires that we inform you of your rights about the private data we are requesting on this form. Under the law, your telephone number is private data. This petition when submitted will become public information. There is no consequence for refusing to supply this information. You may attach extra pages with signatures. APRIL 2008 PROPERTY OWNER'S OWNER'S NAME GNATURE (PRINTED) ADDRESS PHONE resourceful. naturally. BARR engineering and environmental consultants Technical Memorandum To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 c: Drew McGovern and Kristy Morter (Hennepin County) 1.0 Introduction Along France Avenue, just south of Wood End Drive and West 57th Street, there is a low area in the topography which extends from France Avenue to the backyards of the properties on the east side of France Avenue. This low area is subject to flooding even during relatively small rain events. Additionally, this low area along France Avenue can overflow to the west down Wood End Drive where there is another low area drained by four catch basins. This area has also been subject to flooding during relatively small rain events. Multiple residents, particularly those on the east side of France Avenue, have reported these flooding concerns to City of Edina (City) staff in recent years. The City and Hennepin County (County) have been actively working to address this known flooding issue. This technical memorandum is intended to briefly describe the issues that have been identified by the City, County, and residents, and also describe possible short- and long-term solutions. 2.0 Identified Issues Multiple issues have been identified through investigation of the storm sewer system in this area. The following sections discuss the data provided by a resident and data provided by the County. 2.1 Resident Data The resident at 3811 West 57th Street provided data to the City via videos and pictures taken during recent rainfall events that has been invaluable for helping understand the problem and the impacts in this area. For example, a rain event on September 20th totaled about 3 to 4 inches over 24 hours in this area (Figure 1). The resident captured video during a high intensity portion of the rainfall event where 0.6 inches fell in about 5 minutes, which is approximately an intensity that has only a 10% chance of occurring each year. While the overall depth of the event over 24 hours was not very significant, the brief and high intensity was similar to what we would expect from a 10-year event and the intensity can make it difficult for catch basins to drain roads quickly. Barr Engineering Co. 4300 Market Pointe Drive, Suite 200, Minneapolis, MN 55435 952.832.2600 www.barr.com ?212 „ill( :hair 71- 3.491 4.05 3.40 A 0 1 rip Figure 1 Map of total rainfall over 24 hours from September 20th to September 21st, 2018 (MN State Climatology Office) 0 1,1 3.52 'Inse lir I 3.65 51 2.97- —3. 3812 57” St W e ,av 4005 Wood ' End Dr. 4000 Wood End Dr. 4001 Wood End Dr. 5709 France Ave. S — 5717 France Ave. S West 57° Street 3811 57" St. W 5705 France Ave. S To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 2 Based on the video that was provided, water was observed to be flowing west along West 57th Street towards France Avenue, as expected based on topography. The two catch basins along West 57th Street appeared to be largely ineffective, potentially due to the silt bags that are temporarily installed in the catch basins due to nearby home construction (Figure 2). Therefore, much of the flow generated from West 57th Street was bypassing the catch basins and flowing south along France Avenue. Figure 2 West 57th Street catch basin (image capture from video) and location circled in red on the image to the right. Jr. Wild 61W West 57'h Street 3812 57'h St. W 3811 571h St. W 5705 France Ave. S 8 Srdr.rd01 CR 17 5709 France Ave. S >MILANO/ 5717 France Ave. S 5112 [WNW 3/16 CTINOI 4001 Wood \ End Dr. ild111.14¢AVI. 9 AW. 4000 Wood \ End Dr. To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 3 The water in the northbound lane of France Avenue that was flowing south largely exceeded the capacity of the catch basin near 3811 West 57th Street, and water continued to flow south to the next, lowest inlet (Figure 3). This grated inlet at 5709 France Avenue was completely submerged and a vortex was occasionally observed indicating at least intermittent flow into the storm sewer system at this location. Additionally, the entire width of France Avenue was under water in this area, including the road centerline, suggesting that the water level was up to at least 871.2 feet and likely a few inches higher. Figure 3 France Avenue catch basin (image capture from video) and location circled in red on the image to the right. The video footage also captured flooding conditions in the backyards east of France Avenue and south of 57th Street. There is an inlet behind the home at 5709 France Avenue with a rim elevation of 869.4 feet. This inlet is connected to the main storm sewer line along France Avenue. Water was observed bubbling up through this inlet into (and filling) the backyards east of France Avenue (Figure 4). Given the water level in France Avenue, it is possible that the water coming out of the inlet may have been flowing back through the pipe from France Avenue, adding to the amount of flood water in the backyards. It is also possible that this water was coming from the east (from within the upstream storm sewer), but with flow through the pipes restricted by the flooding on France Avenue, the water from the east (Ewing Avenue storm sewer) bubbled up to the surface. To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 4 SI 0 3812 57. St. W West Sr, Street 4000 Wood End Dr. 381157^ St. W 5705 France Ave. S 5709 France Ave. S 5717 France Ave. 4001 Wood End Dr. Figure 4 Backyard inlet bubbling water (image capture from video) and location circled in red on the image to the right. During this storm event, the resident also observed a significant amount of stormwater flowing north from the inundation at the low area along France and westward to Wood End Drive. Water was pooled in the low area along Wood End Drive up to an elevation of about 869.5 feet (roughly estimated based on LiDAR elevation data and video). This is equivalent to over one foot of water in many places, and up to 1.5 feet of water near the four catch basins along Wood End Drive. In the video, the four catch basins were not visible due to the depth of water, but it does not appear that water was flowing quickly into the catch basins. This restriction could be due to temporary silt bags in the catch basins (Figure 5) which are in place for the purpose of catching sediment from construction upstream along Wood End Drive. Figure 5 Google Street View image of Wood End Drive catch basins pipe hydraulic grade line —with sediment ow .. so, mui . ••• pipe hydraulic grade line —without sediment sediment build-up downstream most pipe To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 5 The videos provided suggest that there are inlet capacity issues both along France Avenue where the catch basins are intended to drain water as it flows both north and south to the low area, and along Wood End Drive where the catch basins are intended to drain water from the road surface to Minnehaha Creek. The inlet capacity issues may be driven by either the presence of the silt bags, the number of catch basins, or both. 2.2 Hennepin County Data Hennepin County staff investigated the storm sewer pipes north of West 57th Street along France Avenue and up to the discharge point to Minnehaha Creek. The trunk system in this area includes a 235 foot, 15- inch reinforced concrete pipe (RCP), followed by a shorter 15-inch plastic pipe that discharges to the creek. There were two issues found during this investigation. First, in the catch basin manhole where these two pipes meet, the invert (controlling elevation) of the downstream plastic pipe was nearly 2 feet higher than the invert of the upstream RCP. Figure 6 shows a longitudinal profile of the storm sewer system under France Avenue (flowing from right to left, with the left side being north). This elevation difference significantly reduces the efficiency of the storm sewer system at passing flow. When the longer RCP is clean and open, it will always be flowing full, which is less efficient than a pipe that is not flowing full. Additionally, the downstream-most 15-inch pipe with the elevated inverts will have less pressure driving flow through the pipes. This will further reduce the efficiency or capacity of the storm sewer to pass flow. Figure 6 Longitudinal profile of the storm sewer system with pipes that are not aligned Second, because the downstream plastic pipe invert is nearly 2 feet higher than the upstream RCP, sediment had deposited and collected in this longer RCP, further reducing the conveyance capacity of this Elevation, feet (NGVD29) 875 870 865 860 To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 6 pipe. Hennepin County jetted and vacuumed out the sediment from this pipe and removed two truckloads of sediment. 3.0 Potential Improvement Options We considered several potential improvement options that can be implemented to help solve, or at least improve, the flooding issue in this area. Some options are immediate or short-term and have already been completed or can be completed soon. Others are longer-term solutions and can be implemented in the years to come. These short-term options are expected to provide some improvement, but not significant improvement on the peak flood elevations. The City's stormwater model was used as a tool to demonstrate and quantify the benefits that each of these options provides during the 10-year, 24-hour storm event. This event was chosen because of the readily available boundary conditions required, and because of the ability to compare this storm to the recent event in September, 2018. The improvement options are discussed in the next section. 3.1 Short-Term Options Three short-term improvement options were considered: • Increased inspection/maintenance frequency to keep pipe sediment free • Removal of catch basin sediment control silt bags • Review Wood End Dr system for condition The first short-term improvement option is to clean out the sediment in the pipe and restore flow capacity (maintenance). This has already been completed by Hennepin County. This option was evaluated with the City's stormwater model by running two model simulations — (1) representing a condition of the pipe half full of sediment and (2) representing a "clean" pipe (free of sediment). During a 10-year, 24-hour storm event (design event from NOAA Atlas 14 simulating 4.3 inches of rainfall over a 24-hour period) this short-term maintenance option reduces peak flood elevations as follows: • The peak flood elevation in the low area along France Avenue is not affected. • , The peak flood elevation in the backyards east of France Avenue is not affected. • The peak flood elevation in the low area along Wood End Drive is decreased by 0.1 feet. While the removal of the sediment may reduce flooding during events smaller than the 10-year event, in this particular case, the removal of the sediment has more of an impact on flooding duration, rather than the peak flood elevation. The removal of the sediment shortens the duration because the system can ultimately drain more quickly; the peak elevations are less affected largely because of (1) the limited inlet capacity in the roads and (2) the high inverts of the downstream-most pipe. For example, the flooding duration in France Avenue during the 10-year, 24-hour storm event is reduced from about 9 hours to about 4 hours by conducting the pipe maintenance. To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 7 In addition to the removal of the built up sediment (which has already been completed), the second short-term option is to remove the silt bags at the catch basins in this area, along Wood End Drive and West 57th Street. This solution was also evaluated with the City's stormwater model by running two model simulations — (1) representing a condition of almost no inlet capacity at these catch basins and (2) restored inlet capacity. During a 10-year, 24-hour storm event this short-term maintenance option reduces peak flood elevations as follows: • The peak flood elevation in the low area along France Avenue is not affected. • The peak flood elevation in the backyards east of France Avenue is not affected. • The peak flood elevation in the low area along Wood End Drive is decreased by 0.2 feet, relative to the base condition (silt bags and sediment). The third short-term option is to inspect the catch basins, pipes, and the treatment structure manhole at the low point along Wood End Drive. This inspection option has not been performed but may identify restrictions in the storm sewer system that are currently unknown. Additional short-term options may also be identified as a result of this inspection. 3.2 Long-Term Options We considered five long-term options, in addition to the short-term options described in Section 3.1, which could help solve or at least improve the flooding issue at this location. Any of these individual options, or any combination of these options, could be implemented in the future as opportunities arise. Performance for each option was reviewed for the following criteria and is reported in the recommendations summary table below (Table 1). • Reduction of peak flood elevation along France Avenue (MHS_1) • Reduction of peak flood elevation in rear yards (MHS_74) • Reduction of peak flood elevation on Wood End Drive (MHC_4, un-delineated) To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 8 Table 1 Summary of long-term improvement options and the incremental reductions in the peak flood elevations for the 10-year, 24-hour storm event Condition Flood Elevation (France Avenue, MHS_1) Flood Elevation (Rear Yards, MHS_74) Flood Elevation (Wood End Drive, MHC_4) Existing (Base) Condition 871.0 872.3 870.9 Long Term Improvement Option Flood Elevation Reduction (France Avenue, MHS_1) Flood Elevation Reduction (Rear Yards, MHS_74) Flood Elevation Reduction (Wood End Drive, MHC_4) Option 1 - lower inverts and increase capacity, Section 3.2.1, recommended 0.2 feet 1.7 feet 1.0 feet Option 2 - Option 1 plus additional France Ave. inlet capacity, Section 3.2.2, recommended Option 1 + 0.8 feet Option 1 - 0.2 feet Option 1 + 0.3 feet Option 3 - Option 2 plus additional Wood End Dr. inlet and pipe capacity, Section 3.2.3, recommended pending review Option 2 + 0.0 feet Option 2 + 0.0 feet Option 2 + 1.5 feet Option 4a - Option 1 plus diverting Ewing Ave., Section 3.2.4, recommended if not 4b Option 1 + 0.0 feet Option 1 + 0.2 feet Option 1 + 0.0 feet Option 4b - Option 2 plus diverting Ewing Ave., briefly discussed in Section 3.2.4, recommended Option 2 + 0.2 feet Option 2 + 0.4 feet Option 2 + 0.0 feet Option 5 - Backflow preventers, not recommended 0.0 feet 0.0 feet 0.0 feet 3.2.1 Lower Pipe Invert to Increase Capacity of France Avenue System The first long-term option is to lower the invert of the downstream-most pipe, and increase the size of the storm sewer system under France Avenue to 36-inch pipes (Figure 7). During a 10-year, 24-hour storm event (design event from NOAA Atlas 14 simulating 4.3 inches of rainfall over a 24-hour period) this improvement option reduces peak flood elevations as follows: • The peak flood elevation in the low area along France Avenue is decreased by 0.2 feet, from 871.0 feet in the base condition to 870.8 feet. With this change, there would still be significant flooding on France Avenue, albeit for a much shorter duration. • The peak flood elevation in the backyards east of France Avenue is decreased by 1.7 feet, from 872.3 feet in the base condition to 870.6 feet. Based on the 2011 LiDAR data, this appears to remove all impacts to homes along France Avenue and 57th Street from the backyard area. • The peak flood elevation in the low area along Wood End Drive is decreased by 1.0 feet, from 870.9 feet in the base condition to 869.9 feet. This is an improvement, but there would still be substantial flooding on Wood End Drive. / 311WCOOLAND CO4 ,. , \ WOC.,01.AND OR To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 9 uea • WOODEAN3 %ow , 1.3.33 WI. AVE 5 A111 increase pipe size of these to 36-inch I lower inverts of this pipe 57131 Sr * 3-571.3 Si W.,bas 517,151 35. 3S 51711 ST IN 11257/11 ST • RNA W000 ENO 014 4331 WOOD LN3 DR 5511 5/ PI 5I V14 5/021.0.115VJ AVL S 57th St 5791 EY 40013 WOOD END OR I 5705 FRANCE V& S. 5704E,WINGAWL S 5,25 L./ ODD ENO OR .. • 14401 WOOD ENO OR la $935 WOOD END OR WOOD DID OR 5.101RANE.1..1.14., 15719 174ANcE AVE S 57111 RAWL AVL . r 57.4ITRANCL31.V1.5 5705EWitGAVE S 5112 EWING AVE S •i:4;3 5711 12.0 S S '111€ WING AVE S SifYi EJ 5,1.. L.' Figure 7 First proposed long-term improvement option —*ncreasing capacity of France Avenue storm sewer system and lowering downstream-most pipe invert 3.2.2 Additional catch basins in the low point on France Avenue In addition to the first long-term option described in Section 3.2.1, the second long-term option considered is the addition of three catch basins in the low point on France Avenue (and connection to the larger (36-inch) France Avenue system (Figure 8). During a 10-year, 24-hour storm event (design event from NOAA Atlas 14 simulating 4.3 inches of rainfall over a 24-hour period) this improvement option reduces peak flood elevations as follows: • The peak flood elevation in the low area along France Avenue is decreased by 1.0 feet, from 871.0 feet in the base condition to 870.0 feet. With this change, there would be no flooding along France Avenue. • The peak flood elevation in the backyards east of France Avenue is decreased by 1.5 feet, from 872.3 feet in the base condition to 870.8 feet. This improvement is not as good as long-term option 1 alone, because of the additional water that is allowed to enter the system along France lower inverts of this pipe P 333, 571.451 OV 3 It 57141 ST Wiliam 5/TH STN 362) 57TH SI* 712111,1 ST 7.:09 Le 5 '33 s NINL: AVE S SORW3 AYE S J 5 n3S EWING AVE S 5712E0154G AYES 57rh Si 5'3I Lf 5,35 LO VII LI add three catch basins =176 ViLX.> 0 LI 0 UR,, • • 14W1111N:X.LI L*0 UR D aliS YFUOD LND DR ISFDI F RAM= Aft DOD L40 DR W. • J L.114 141WANLI AYE 5 F. All. 5 514104.RWL AIL To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 10 Avenue, thus restricting drainage from the backyards. However, homes still appear to be not impacted from the backyard at this elevation based on LiDAR data. • The peak flood elevation in the low area along Wood End Drive is decreased by 1.3 feet, from 870.9 feet in the base condition to 869.6 feet. This is a greater improvement, because there is now no flow coming from France Avenue into Wood End Drive. However, the front yards of two properties are inundated. 54350 RANGS AVCS Lt..; ANL, ;.:114 AtOGULAMD UR Lal 40011.33.3i C tR . '•5453T R.554531. '. increase pipe size of these to 36-inch .5.1.3.1 FY003 CND DR 134 "DUO LW ON 1511 51 PI LIN ,._ 1I T 5.8750 RANCL RA. S .J15 L5iD UR " 21 Figure 8 Second proposed long-term improvement option — increasing capacity of France Avenue storm sewer system, lowering invert of downstream-most pipe, and adding three catch basins along France Avenue 3.2.3 Additional catch basins in the low point on Wood End Drive, and larger 18-inch pipes to Minnehaha Creek In addition to the second long-term option described in Section 3.2.2, the third long-term option is to add two catch basins at the low point on Wood End Drive and increase the pipe sizes (to 18-inch) to To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 11 Minnehaha Creek (Figure 9). During a 10-year, 24-hour storm event (design event from NOAA Atlas 14 simulating 4.3 inches of rainfall over a 24-hour period) this improvement option reduces peak flood elevations as follows: • The peak flood elevation in the low area along France Avenue is decreased by 1.0 feet, from 871.0 feet in the base condition to 870.0 feet. With this change, there would be no flooding along France Avenue. The option described in this section provides no additional benefit to the low area along France Avenue that is not already provided by the option described in Section 3.2.2. • The peak flood elevation in the backyards east of France Avenue is decreased by 1.5 feet, from 872.3 feet in the base condition to 870.8 feet. The option described in this section provides no additional benefit to the backyards east of France Avenue that is not already provided by the option described in Section 3.2.2. • The peak flood elevation in the low area along Wood End Drive is decreased by 2.8 feet, from 870.9 feet in the base condition to 868.1 feet. With this change, there would be no flooding on Wood End Drive. This option provides greater benefit to the low area along Wood End Drive than the options described in Sections 3.2.1 and 3.2.2. %A...PRA/ILL AVE 5 I lower inverts of this pipe G\ si H 51#2 3312 S 7DI Si WJ5 ',71.151 Ott IA 23 5711.1 SSW 712 5111A Si 57th St Z.0151/4•1000 E40 DR C(vj NOOD END DR 3305 WOOD L4E1 S !DA EWING AVE 5 575E14111G AVE 5 r S '12 E WING AVE 5 To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 12 ID C WOODLAND OR 01 WOODLAND . '25 MOO LA-AND COR , VLtd 1 RANCE AVE 5 increase pipe size of these to 36-inch -AND CAI tD C 5,'JJ L.VIN. AVE 31111 57 I54 5 1.5 57115 111, LOU E41.1 DR (0. *.r3S W-JOD E4D DR increase pipe size of these to 18-inch 5 itl. RANCE AK 5 .J15 .5L_11-4_, EIRANEAVE -I I Figure 9 Third proposed long-term improvement option — increasing capacity of France Avenue storm sewer system, lowering invert of downstream-most pipe, adding three catch basins along France Avenue, adding two catch basins on Wood End Drive, and increasing pipe size from Wood End Drive to Minnehaha Creek 3.2.4 Diverting water from Ewing Avenue In the base condition, restricted flow capacity in the France Avenue storm sewer system limits outflow from the low backyard area east of France Avenue. Additionally, this capacity limitation forces water from Ewing Avenue to surcharge from the storm sewer system, bubbling out at the surface in the backyards. Diverting water from Ewing Avenue could provide additional benefit to the backyard areas. In addition to the first long-term option described in Section 3.2.1, the fourth long-term option is to abandon the existing pipe draining Ewing Avenue towards France Avenue, and install a new 18-inch pipe from Ewing Avenue north to 57th Street (Figure 10). During a 10-year, 24-hour storm event (design event from NOAA Atlas 14 simulating 4.3 inches of rainfall over a 24-hour period) this long-term improvement option reduces peak flood elevations as follows: ,11.1 fen4a AKS add three catch basins 1_ 5711 L.. I L. To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 13 • The peak flood elevation in the low area along France Avenue is decreased by 0.2 feet, from 871.0 feet in the base model to 870.8 feet. With this change, there would still be significant flooding on France Avenue, albeit for a much shorter duration. If the three additional catch basins were included in this option, such as described in Section 3.2.2, the peak flood elevation would be reduced to 869.8 feet, a 1.2 foot reduction from the base condition. • The peak flood elevation in the backyards east of France Avenue is decreased by 1.9 feet, from 872.3 feet in the base condition to 870.4 feet. This appears to remove all impacts to homes along France Avenue and 57th Street from the backyard area based on LiDAR, and is an improvement in this area over long-term options 1 through 3. • The peak flood elevation in the low area along Wood End Drive is decreased by 1.0 feet, from 870.9 feet in the base condition to 869.9 feet. This is an improvement, but there would still be substantial flooding on Wood End Drive. The additional catch basins and increased pipe sizes that are described in Section 3.2.3 would prevent the flooding at Wood End Drive. AS-1OLLAND CR - add these 18- inch pipes C ' 25714151 WJIKIP S11,191 W increase pipe size of these to 36-inch 9/40 EWING AVE 59 9I 191.111.9 AV, S _AND Cal \ V4 ROWLAND 0-a 10 • WOQI.11..44t1 .14.% I IjRNI;LAVL 5 31111 511)151 W 5200 EWING AVE 5 9 .11 L.. 5/051 RANCE AVL 920A LVVOR:AVE S 5205 Li1 14051WODD L NU De Q u•5 WOOD END OR •DU iNU DR 2119 FRANCE AVL 5209 AOlv WOOD END OR C lower inverts of this pipe L To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 14 Figure 10 Fourth proposed long-term improvement option — increasing capacity of France Avenue storm sewer system, lowering invert of downstream-most pipe, abandoning the existing pipe from Ewing Avenue to the west, and adding new 18-inch pipe to divert stormwater from Ewing Avenue 3.2.5 Backflow preventers between France Avenue and the backyards to the east There was initially some suspicion that the flow bubbling up from the storm sewer system in the backyards (described in Section 2.1, and Figure 4) was coming from France Avenue flooding. However, further analysis indicates that the surcharging will continue to occur in the backyard area if backflow preventers are installed due to the limited flow capacity in the France Avenue system and incoming stormwater flows from the Ewing Avenue storm sewer system. Therefore, we do not recommend installing backflow preventers in the existing pipes between France Avenue and the backyards (Figure 11). 11..1 C r•! WOODLAND '. / 1 - ~,A)03 WOOD VID DR VII Li 1 51.i 5716EW1NGAVE z 5712EW1NG AVE 7'I!/RAWL AVE. 5 W WOODLANDCIR RAYCI. AVL JU )15/I1151 W s7 WOODLAND Q11.4 CI CO " WA (RANCE AVE Ilk c,„,„„ AM MOOD [NJ DR 14001 WOOD EMU DR 1 0.15 WOOD CND OR 510-ii IRA. Art 5 5.*ris L Orrg, AVL 3212 srrti 51. 57I11 SI At 30 511)1 ST W 712 5114151 VW EV 5/111f ROUX AK 5705111ANCL 57th St Val LI, 5 ed AVL backflow preventers 4.us WOOD DID Lk ODD CIO DR To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 15 Figure 11 Fifth proposed long-term improvement option — backflow preventers between France Avenue and the backyards east of France Avenue (not recommended). 4.0 Conclusions The area around the intersection of France Avenue and West 57th Street experiences flooding, even during relatively small rain events. There are short-term and long-term improvement options that can be implemented to reduce both the peak flood elevations and flood durations. In the short term, Hennepin County has already removed sediment that was restricting flow capacity of the storm sewer system under France Avenue. The City could also remove the temporary silt bags from the catch basins on West 57th Street and Wood End Drive, although the flooding benefit from this would be marginal. The relationship between sediment controls and flooding is rather complex. The temporary inlet protection (silt bags) can exacerbate flood elevations due to reduced inlet capacity. However, without silt bags, the sediment that accumulates in the pipe can also exacerbate flood elevations in the long term due to reduced pipe capacity (until periodic maintenance occurs). In the long term, we recommend that the city consider lowering the upstream invert of the downstream- most pipe under France Avenue, increasing the pipe size along France Avenue to 36-inch pipes, and installing additional catch basins to the low points on both France Avenue and Wood End Drive. To: Ross Bintner From: Cory Anderson and Sarah Stratton Subject: Stormwater Issues and Findings at West 57th Street and France Avenue Date: January 3, 2019 Page: 16 Additional reductions in the flood elevations in the backyard area could be achieved by diverting flow from Ewing Avenue north to West 57th Street. Please let us know if you have questions about the data, the analysis, or the conclusions as you are reviewing this technical memorandum. If so, please contact Cory Anderson, PE, at 952-832-2872 or at canderson@barr.com. You're West 58th Street Reconstruction Invited: Oper,House c c oA Pamela Park Tell us your experience on West 58th Street from Wooddale Avenue to Xerxes Avenue. Edina would like to design a solution for your transportation challenges. Join us at an open house Monday February 25, 2019 from 6 - 8 p.m. at the Public Works Building, 7450 Metro Blvd, Edina. • le Better Together Unable to Attend? Participate online at www.BetterTogetherEdina.org to start the conversation, provide ideas, sign-up for email updates, sign-up to participate in a project focus group, and stay ur*,4-' i West 58th Street progress. 0 • West 58th Street Reconstruction — Open House You're Invited Monday, February 25, 2019 6 — 8 p.m. Public Works Building 7450 Metro Blvd Edina, MN 55424 For more information visit: www.BetterTogetherEdina.org PRSRT STD US POSTAGE PAID TWIN CITIES MN PERMIT 30308 *********************ECRWSS"C 006 Terri E Matavovsky Or Current Resident 3811 W 57th St Edina MN 55410-2370 1 69 W 58th St O S any So ueJd SAV el Epp OOM West 58th Street Reconstruction Participate online at www.BetterTogetherEdina.com to start the conversation, provide ideas, sign-up for email updates, sign-up to pariticpate in a project focus group, and stay up-to-date on West 58th Street progress. - — Better Together EDINA All paved streets have a limited life-cycle and will require reconstruction. Reconstruction is required when normal maintenance like pothole patching is no longer effective. Reconstruction is an opportunity for the residents to consult Edina on the needs for the corridor. Reconstruction may allow for changing the street width, installing new pedestrian facilities, upgrading bike lanes, and a variety of other options. Changes to the existing roadway design will take into account residents feedback. You are invited to provide feedback and help Edina determine needs along West 58th Street. Project Development Process Timeline EIE,E IE.ERE MAY Ut APR' FEBRUARY MARCH APRIL c12 a a Final Des1211111 Construction Open House Design Alternatives Development Feedback • Identify • Resident and Stakeholder Focus Group discussions • Opportunity • Provide feedback resident needs to provide feedback on alternatives. for feedback on for final design — Sign-up for a focus group. initial design adjustments — Comments are accepted online