The city of Mitchell, South Dakota, will invest $25 million to restore the local lake. The Lake Mitchell Restoration Project will include building infrastructure, making improvements to filter run-off and dredging the lake. The project is anticipated to begin in fall 2025.
Lake Mitchell faces ongoing water quality issues due to algae blooms caused by runoff from crop and pastureland, as well as phosphorus released from lakebed sediments. The city will have to drain and dredge the lake to address these issues by removing phosphorous-laden elements and mitigating exposure to exterior runoff sources.
In preparation for the project’s dredging start date in 2026, plans call for draining the lake in late 2025. The project will cut a hole in the spillway dam’s sidewall, providing an exit for waterflow during the dredging phase. Once the lake level has been lowered, the city will move forward with mechanically removing phosphorous-laden sediment.
The sediment will be taken from the lake and placed at Firesteel Park. The city will also make various improvements to help improve the lake’s filtering capacity to address watershed runoff that would impact nutrient and sediment loading in the future.
After dredging is complete, the city will build a drawdown structure, using pumps to remove lake water. The structure will ensure the city can perform maintenance on the wetlands running along Firesteel Creek. As part of the project’s final phase, the city will refill the lake and restore its shoreline.
