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HomeMy WebLinkAboutArrowhead_Lake_Summaryhybrid sunsh History of Arrowhead Lake 1960s1930s 2022 Arrowhead Lake Watershed District: Nine Mile Creek Public water ID: 27004500 2015 Arrowhead Lake Association incorporated after decades of informal organization. How You Can Help Steps that you can take to help Arrowhead Lake include: Lake Management Aquatic Plants Water quality data is available from the Nine Mile Creek Watershed District for 2014, 2019, and 2020. Summer-average highs and lows of water quality parameters over those years are provided above. The available data shows Arrowhead Lake generally fails to meet the state’s goals for water quality within shallow lakes. Elevated total phosphorus levels promote algal growth, which reduces water clarity. Water LevelsWater Quality bluegill sunsh Fish population: Lowest recorded water level: 871.3 ft (February 18, 1981) Highest recorded water level: 878.6 ft (July 24, 1987) Denotes current Arrowhead Lake drainage area; historical drainage areas may have varied 1960 Lakeshore owners install a well to augment lake levels. 1978 The rst permit for chemical treatment of submerged aquatic vegetation and algae in Arrowhead Lake is issued by the DNR. 1992 DNR issues a permit for mechanical harvesting of aquatic plants, an activity that continues until 1998. 1994 Residents stock the lake with 400 bluegill sunsh and 600 largemouth bass. 1995 A DNR sheries survey nds bullhead, green sunsh, and fathead minnows in the lake—all species tolerant of low oxygen conditions (hypoxic). No sh from the previous year’s stocking efforts were recaptured, indicating high mortality. 1996 Pump for lake-level-augmen tation well fails and is replaced. 1994 An aerator, a tool to increase the amount of dissolved oxygen in a lake, is installed and operated year-round, with a goal of managing algae blooms and preventing winter sh kill. 1998 The DNR issues a ood-control permit for Arrowhead Lake. 1994 The DNR issues a permit for excavating a channel to connect the small basin at the southeast end of the lake to provide access for mechanical harvesting of submerged aquatic plants. Chemicals continue to be used to control algae. Mechanical harvesting is abandoned and chemical control of submerged aquatic plants and algae resumes. 1997, 2002, 2008, 2019 Arrowhead Lake pumped for ood control. 2006 Water quality study conducted by NMCWD indicates watershed runoff as the largest source of phosphorus to the lake, based on one year of monitoring data. ~ 2013 Lake-level-management well inoperable; no longer used to control lake water levels. 2020, 2021 NMCWD monitors algal levels within the lake and observes high-levels of blue-green algae. Blue-green algae can produce toxins that may irritate the skin or be harmful if ingested or inhaled. NMCWD and the City issue public alerts to stay out of the water until conditions improve. 2017-2022 The City of Edina conducts aquatic plant surveys. All surveys show invasive curly-leaf pondweed in the lake. 2017 A report for the NMCWD shows poor water quality. 2021-2022 A sheries survey suggests that stocking efforts were successful and that oxygen levels have increased. Follow-up surveys in the spring of 2022 will assess the status of the shery following the 2021 winter. 2006 water quality study, updated by the NMCWD, identies potential management activities to improve the lake's overall health. 2021-2022 The City of Edina begins work on a lake-level management plan for Arrowhead Lake 2016 Residents stock the lake with 1,000 bluegill ngerlings and 1,000 yearlings, 430 largemouth bass ngerlings, and 90 yearlings. 2017 The City of Edina begins annual treatments for curly-leaf pondweed. Eliminating curly-leaf pondweed improves the native aquatic plant community and reduces the phosphorus released into the water when it dies and decays in mid-summer. Arrowhead Lake is a shallow lake located in southwest Edina. The lake is land-locked, with no surface outlet. The lake’s watershed extends north of Highway 62 and is bordered on the west side by Highway 169 and generally bordered on the east and south side by Indian Hills Road Arrowhead Lake has no public boat launch. Non-motorized boats only. fathead minnow large mouth bass21 acres (surface area) 1.0 miles (shoreline) Amenities: Algae Level (Chlorophyll-a) Water ClarityTotal Phosphorous Levels 20 g/L 60 g/L Recent water quality data 80 65 38 18 1.0 Meters Lake depth Mixed land use (single-family, medium-density residential, institutional). Portions of Highways 62 and 169 are tributary to the lake. 179 acres (watershed drainage area) ftMin ftMin 6 6 7 7 5 5 3 3 3 4.8 ft Avg 9 ftMax 62 169 Learn more about these strategies at ninemilecreek.org Diverse aquatic vegetation is critical to the health of Edina lakes—providing food and shelter for sh and waterfowl and improving water quality. Aquatic plant data from Nine Mile Creek Watershed District indicates the Arrowhead Lake plant community has few and poor-quality species. Invasive plant species within the lake are shown above. Eurasian watermilfoil is a rooted, submerged aquatic plant, and purple loosestrife is a colorful, perennial wetland plant. Both species outcompete native plants, and neither provides suitable shelter, food, or nesting habitat for native animals. White water lilies within the lake are not invasive and provide valuable aquatic habitat. State goalHighestLowest NMCWD = Nine Mile Creek Watershed District Curly-leaf pondweed Purple loosestrife Eurasian watermilol 1964-2002, 2012-2022 Water level data is from the Minnesota Department of Natural Resources and Nine Mile Creek Watershed District Other species present: primarily green sunsh, black bullhead 1.0 Meters 0.5 Meters Interactive ood map Water resources library Find more information from the City of Edina: Installing rain gardens and planting shoreline buffers Cleaning up grass clippings and leaves Participating in the adopt-a-drain program (mn.adoptadrain.org) Redirecting gutter downspouts towards vegetated areas Minimizing use of fertilizer on lawns