Lake Byllesby water level to change

Sept. 25, 2026

The annual drawdown of the Lake Byllesby reservoir to its winter elevation will begin on Oct. 1.

The reservoir is gradually lowered 3 feet from the summer elevation to a winter elevation of 853.7 feet above sea level. The winter drawdown lowers adjacent groundwater levels to accommodate local agricultural needs based on research from the Minnesota Department of Natural Resources (DNR). The DNR requires the drawdown as part of the county’s operating permit for the Byllesby Dam.

To lower the water level in the reservoir without causing an abrupt change, about a half inch of water is released daily. The reservoir will remain at its winter level until May 15, when refilling 3 feet to the summer elevation of 856.7 feet above sea level is permitted.

For more information, visit the Lake Byllesby Water Levels webpage.