Great Lakes Water Levels Fluctuating, Lake Superior Remains Deepest
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Lansing, MI – August 8, 2025 – Water levels in the Great Lakes are experiencing typical seasonal variability, but remain a key concern for coastal communities across Michigan, Illinois, Indiana, Ohio, Pennsylvania, New York, and Wisconsin. While fluctuations are normal, high water levels can exacerbate erosion and damage infrastructure, according to the Michigan Department of Environment, Great Lakes, and Energy (EGLE).
EGLE officials emphasize that Great Lakes water levels can change rapidly,even within hours,due to a complex interplay of factors. These include seasonal weather patterns, precipitation rates, evaporation levels, wind conditions, and localized phenomena like seiches – standing waves caused by wind – and the operation of water regulation structures.
The International Lake Ontario – St. Lawrence River Board, such as, manages water flow through the St. Lawrence Seaway, impacting Lake Ontario levels. Similarly,the Lake Superior Board of Control regulates outflows from Lake superior.
Great Lakes Depths: Lake Superior Leads
Lake Superior, the largest of the Great lakes by surface area (31,700 square miles), is also the deepest.The U.S. Environmental Protection Agency (EPA) reports an average depth of 483 feet and a maximum depth of 1,332 feet. This contrasts considerably with the other Great Lakes:
- Lake Ontario: average depth of 283 feet; maximum depth of 802 feet.
- Lake Michigan: average depth of 279 feet; maximum depth of 925 feet.
- Lake Huron: average depth of 195 feet; maximum depth of 750 feet.
- Lake Erie: average depth of 62 feet; maximum depth of 210 feet.
these depth variations influence water temperatures, mixing rates, and overall ecosystem health within each lake.
Staying Informed: Great Lakes Conditions and Safety
The National Weather Service (NWS) provides real-time details for those enjoying the Great Lakes. The Great Lakes Beach Hazards interactive map details swim risk levels, water temperatures, wave heights, wind speeds, water quality, and incident statistics. As of August 8, 2025, elevated swim risks are reported along the Lake Michigan shoreline near Holland, Michigan, due to strong currents.
Boaters and those interested in broader lake conditions can consult the NWS Great Lakes Portal for wave height predictions and other relevant data. The Great Lakes Environmental Research Laboratory (GLERL) in Ann Arbor, michigan, also provides long-term forecasts and research data on Great Lakes water levels and conditions.
Contact Sarah Moore @ smoore@lsj.com
