Meadow Lake Management Plan
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Meadow Lake in the City of New Hope is a small (12 acres), very shallow lake with an average depth of just under two feet and a maximum depth of about four feet. Historically it has had very poor water quality. It has had significant summer algae blooms and is occasionally infested with invasive curly-leaf pondweed. The historical fishery was almost entirely composed of fathead minnows, bottom feeders who disturb the sediments and prey on zooplankton who would ordinarily keep algae in check.
The City, residents, and Meadow Lake Watershed Association (MLWA) have all been active in restoring the shoreline and reducing the nutrients and sediment reaching the lake from its drainage area. However, overall water quality and biology in the lake has not improved. In 2021, the Watershed Commission and City with the help of MLWA began a multi-year project called the Meadow Lake Management Plan, a series of actions over several years to restore the lake. The specific actions and schedule are guided by a decision tree showing the various potential lake responses to management actions and the follow-up actions that would be appropriate. This work is funded by two grants from the Minnesota Board of Water and Soil Resources through the Legacy Amendment, and by the Shingle Creek Watershed Management Commission. Two news stations have published stories on the success of Meadow Lake management. Check them out below: |
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2021: Lake Drawdown
The first major management action was a whole-lake drawdown to consolidate sediments, eliminate fathead minnows and prevent recolonization, and reduce curly-leaf pondweed growth. in Late 2021 a large pump was installed on the northwest shoreline and a 700 foot intake pipe extended to the deeper part of the lake, outletting to storm sewer. Pumping began on November 18, 2021, and was discontinued on December 6, 2021. Approximately 75% of the lake's surface area was completely drawn down, with 3-6 inches of standing water in the remaining area. The lake remained drawn down through the winter and early spring, when it naturally refilled. CCX News did a short story on the drawdown: Meadow Lake Almost Full Again After Winter Drawdown - CCX Media 2022: Follow-Up Following the drawdown, staff observed hundreds of painted turtles sunning themselves, a good sign that the ecosystem is in healthy condition. In 2022 the Commission undertook a year of water quality and aquatic vegetation monitoring and took additional sediment cores. The fish survey confirmed that there were no fathead minnows present, and the sediment cores showed some good sediment consolidation. Curly-leaf pondweed was still present. 2023: Phase 2 In spring 2023 the Commission and City moved to Phase 2 of the Management Plan, which included chemical treatment of the curly-leaf pondweed followed by a dose of aluminum sulfate (alum). The alum applied to the lake removed phosphorus from the water column and formed a floc, which settled on the lake bottom where it inactivates the release of phosphorus from the bottom sediments. Learn more about lake alum treatments here. Water quality, vegetation, and sediment monitoring were completed, and sediment cores taken to document the effectiveness of the lake management. 2024: Follow-up Additional monitoring will be the primary activities in 2024. Based on those findings there may be more treatment in 2024 or 2025. |
Painted turtles sunning themselves on 5/6/2022
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