Edina
Project Description:
The District is conducting surveys on Mirror Lake in Edina. These surveys are to help the District identify potential water quality improvement projects that will help improve the overall health of Mirror Lake.
Project Updates:
The 2023 water quality study identified that a significant portion of the phosphorus in Mirror Lake originates from internal phosphorus loading from lake bottom sediments. The recommended approach to control internal phosphorus loading is to conduct a series of up to three adaptive aluminum sediment (alum) treatments during a ten year or more period.
An alum treatment involves adding aluminum to the lake, which chemically binds with phosphorus in the water. When aluminum present in oxygenated conditions, phosphorus attaches to these elements rather than remaining in the water column. This process effectively locks phosphorus in the sediments, limiting its availability to fuel algae growth.
Our bid packet went out to potential contractors for this treatment earlier this year, and We received no bids. Our hope is that by packaging projects together, we will create a more competitive bid opportunity and increase contractor interest for Alum treatments in the spring of 2027.
Past Studies:
The District completed an initial water quality study in 2023, which includes high-level management recommendations:
Summary: Mirror Lake Water Quality Summary
Full Report: Mirror Lake Water Quality Report
The following feasibility study of the recommendations from the water quality study was completed January 2025: Mirror Lake Feasibility Report
Outreach:
Resources:
Shallow Lakes Webinar
Learn more about shallow lakes and their functions and values. What does a shallow lake look like, and why are plants so important? What are the rules and regulations regarding shallow lakes? Joe Bischoff, a Senior Aquatic Ecologist and Certified Lake Manger with Barr Engineering Co, presented a webinar on April 12, 2022, to answer these questions and more.
View the full recording: Shallow Lakes Webinar Recording
Shallow Lakes: Minnesota’s Natural Heritage (PDF)
Questions?
Contact Jordan Wein, Water Resources Project Manager, at 952-800-8307 jwein@ninemilecreek.org