Lake Michigan water levels continue their seasonal incline, increasing by 3 inches from April to May. Though Lake Michigan is now about 25 inches below the highest monthly water level recorded for May in 2020, the Lake is still about 10 inches above the long-term average water level. Water levels are expected to continue their seasonal incline until late summer and to remain above the long-term average.
Watch the USACE’s “On the Level” Youtube channel for monthly updates and information about the Great Lakes’ water levels and forecasts from Detroit District Hydraulics and Hydrology experts.
Water Levels on Lake Michigan-Huron
Here are five things to know about water levels on Lake Michigan for June 2022.
What are the current water levels on Lake Michigan?
The water level of Lake Michigan as of May 20, 2022, was at an elevation of 577.5 feet above sea level (from the International Great Lakes Datum). To put this level into perspective, here are some statistics for Lake Michigan relative to the period of water level records measured from 1918 to present (statistics from USACE’s Weekly Water Level Update and USACE’s Water Level Summary).
|Current Water Levels are…
|One month ago
|3 inches higher
|One year ago
|7 inches lower
|Long-term April monthly average (1918 to 2021)
|10 inches higher
|Record April monthly mean (set in 2020)
|25 inches lower
What is the outlook for future water levels?
Water levels on Lake Michigan have increased by about 2 inches from April to May. The USACE is projecting that water levels will increase by another 3 inches by mid June 2022 (see the water level forecast issued for May 2022 below). The increasing water levels are a seasonal occurrence. In the springtime, water levels gradually increase due to precipitation and runoff from snow melt. Additionally, evaporation decreases due to the increasing air temperatures while the water is cool. In an average year, water levels vary seasonally by about one foot from a peak in summer to a low in winter, though every year is different. You can read more about this as well as other myths about water level fluctuations in this blog.
What is behind Great Lakes water level fluctuations?
The story of Great Lakes water level changes is told by Net Basin Supply. Net Basin Supply (NBS) accounts for the water going into a lake in the form of precipitation and runoff minus water leaving a lake due to evaporation of water from the lake surface. In general, when Net Basin Supply is positive, more water enters the lake than leaves, causing a rise in lake levels. When Net Basin Supply is negative, more water leaves the lake than enters, causing a drop in lake levels. Click here for more detail.
What is making water levels go up?
Since record highs in 2020, the Great Lakes water levels have been trending downwards. This trend has continued through 2022 and water levels are lower than they were at the same time in 2021. The graph below visualizes the monthly difference from the long-term average NBS for the past five years. Red bars represent below average NBS, whereas blue bars represent above average NBS. Since the peak water level averages in 2020, the NBS has gradually decreased due to more water leaving through evaporation than entering the lakes through precipitation and runoff. April and March have seen an above-average NBS, while February is below average in lake Michigan. Despite the above-average NBT this past month, these averages are lower than the previous year.
Places you can find more relevant information:
- Our Coastal Hazards page for details about the impacts of high water levels, including erosion, flooding, and navigation issues.
- Our blog post Resources for Great Lakes Coastal Property Owners: Where do I start? has links to many resources to help
- understand coastal hazards
- weigh the risks coastal hazards pose to property
- understand options for addressing these hazards
- get started on implementing actions if necessary.
- The Great Lakes Water Budgets from the University of Michigan gives more information about what makes the lakes go up and down.
- The US Army Corps’ Great Lakes Information page has tons of details on view water level data, water level forecasts, basin conditions, outflows, etc.
- Our Resource of the Month on US Army Corps of Engineers Monthly Bulletin of Great Lakes Water Levels.