The Thompson Lake Restoration Project is now complete. The $2.6 million project started in the fall of 2018 and finished in June 2019 with the goal of addressing water quality issues and restoring wetlands. A new boardwalk and trail improvements were also added. The completion of the project will be marked by a public event on Sunday, June 9.
“We want this to be as natural as possible, long term.”-Joe Barten (South-West Review)
What Was Wrong With the Lake?
Stormwater runoff from 180 acres is directed to Thompson Lake, which means all kinds of sediment and pollutants. That degrades water quality, diminishes habitat, and reduces ecological diversity. The project aims to fix all of that, resulting in improved water quality and better habitat.
Back in 1945, much of the watershed was grassland, marsh, and wetlands. That meant stormwater could soak into the ground and be filtered before entering the lake. Since then the area has been built up, and now 64% of the land in the watershed is covered by impervious surfaces.
So the rain water was no longer filtered, and picked up all kinds of pollutants and debris on the its way to the lake. It was so bad that contaminants in the lake sediment exceeded Minnesota Pollution Control Agency standards.
The Restoration Project
The restoration project addressed these issues by first dredging the lake and removing the contaminated sediment. Then the project installed a new forebay to filter out pollutants and keep the problem from happening again. It will be cheaper and easier to clean the debris and pollutants from the filtering system and keep the lake clean.
“The more we can catch, the more we’re going to improve the water quality of the lake and the clarity of the lake, and the recreation capacity of the lake,” Joe Barten, a resource conservationist with the Dakota County Soil and Water Conservation District and an administrator with the Lower Mississippi River Watershed Management Organization, told the South-West Review.
The Thompson Lake Restoration Celebration event is scheduled for June 9, 2019 at 2:30 p.m. It’s part of the annual Take a Kid Fishing event, which starts at noon. Community leaders will make some short remarks and native seed balls will be used for a “confetti” toss to disperse seeds into the restored project area—all to celebrate the restored lake.
Future Thompson Park Updates
While Thompson County Park will have a cleaner lake, a new boardwalk, and a new paved trail all the way around the lake, it’s not the end of work on Thompson Park. Dakota County is in the process of updating the 2005 master plan for the park. They’ve already collected public input and are currently developing a draft plan. It should be ready for public review in the fall and come before the Dakota County Board of Commissioners by the end of the year.
The plan will identify long-term, 10-year, and five-year priorities, with some design work potentially beginning as soon as 2020 and improvements happening in 2021-2022.
What kind of updates? The draft concepts included two proposals, which featured ideas such as a lighted sledding hill, hammock grove, expanded lodge, observation tower, entry plaza, amphitheater, public art, and a daylighted water feature.