Area fisheries managers with the Minnesota Department of Natural Resources will begin the drawdown process on Sibley County's Clear Lake this spring. The temporary lowering of water levels on this 505-acre lake is taking place to improve fish and wildlife habitat as well as water quality.
Clear Lake has been overwhelmed by large populations of common carp, causing turbid water and impeding aquatic plant growth. Common carp can have a negative impact on water quality when they uproot native plants and disturb phosphorous-rich bottom sediments through their feeding habits. A Minnesota Pollution Control Agency watershed assessment performed in 2017 (https://webapp.pca.state.mn.us/surface-water/impairment/72-0089-00) found that Clear Lake had phosphorus levels more than three times the acceptable level.
Clear Lake is susceptible to wind and wave action that has eroded the lakeshore and further impaired submerged vegetation growth.
"Clear Lake has been hampered by impaired water quality for two decades," said Scott Mackenthun, Hutchinson area fisheries supervisor. "Common carp have had a negative impact on this lake for a number of years, and the goal of the drawdown is to greatly reduce the number of common carp."
Plans call for the lowering of water levels by about 4 feet to create conditions for a winterkill and reduce common carp populations. The drawdown will also allow sediments to consolidate, which will permit new growth of submergent and emergent vegetation. The lowered water levels mimic a drought, which can act as a natural "reset" to an ecosystem. The drawdown will occur throughout the open water season of 2024.
Once water quality improves and aquatic vegetation stands are reestablished, DNR will stock walleye, northern pike, yellow perch and bluegill in Clear Lake. These fish will create a recreational angling opportunity as well as a measure of population control on common carp.
Anyone with questions about the Clear Lake project can contact Scott Mackenthun, Hutchinson area fisheries supervisor, at [email protected] or at 320-753-0324. More general questions on lake drawdowns and the shallow lakes program can be directed to Nicole Hansel-Welch, shallow lakes program supervisor, at [email protected] or at 218-203-4333.