Lake levels can change in a matter of hours due to weather. Seiches occur when strong winds and rapid changes in atmospheric pressure push water from one end to the other. When the wind or pressure changes, the water moves to the other side of the lake. Lake Erie is especially susceptible to large seiches.

The water levels on the Great Lakes also change with the changing seasons. In autumn, water freezes and becomes snow and ice which reduces flow into the lakes. Water levels will fall through the winter. In the spring, the ice and snow melts and rainfall become abundant. Water levels will rise through the summer. Lake levels will generally change 1-2 feet from season to season.

Great Lakes’ water levels cycle several feet between periods of high water and low water over decades. During long-term periods of dry weather, lake levels fall. In the early 2010’s, prolonged dry and warm weather resulted in record lows for some lakes. When precipitation remains above average, water levels rise. This happened in 2015 to 2020, one of the wettest 5-year periods on record for the Great Lakes region and resulted in the 2020 record high water event.

The variability of Great Lakes water levels is necessary for the continued health of the Lakes but can create challenges for waterfront communities and homeowners. Giving the Lakes the space they need to change will protect our infrastructure and ensure healthy Great Lakes for future generations. If you are planning a construction project on or near the Great Lakes, a permit from EGLE may be required.