Lake Superior Water Levels

Lake Superior water levels came down over the summer of 2021; a welcome sign for many coastal property owners.

Image credit: M. Thoms

Lake Superior's Record-Long Stretch of High Water Ends

Lake Superior water levels came down over the summer of 2021; a welcome sign for many coastal property owners.   

August 2021

August 2021 was the first time since April 2014 that Lake Superior was at its long-term monthly average (183.54 cm) water level, ending 87 consecutive months above average.  When I look back at Lake Superior water levels since 1918, those 87 months turn out to be the longest stretch where the monthly average water level was above the long-term average for that month. The next longest stretch of above-average water levels was from June 1970 to September 1976 - a "mere" 76 months.    

September 2021

In September 2021 Lake Superior was about 1 inch below its long-term September average. It was the only Great Lake below its long-term average for September, thanks to an extreme drought in the western Great Lakes. In October 2021, the lake was 11 inches below where it was in October of 2020.  

What Goes Down Must Go Up

While lower Lake Superior water levels mean we’re at less risk from the gales of November, it’s important to remember that as quickly as the water levels came down, they can go back up again. Precipitation trends in Minnesota show our state getting wetter. And, based on data from the Minnesota Department of Natural Resources, the watersheds* that drain into Lake Superior gained 0.26 inches of rain per decade since 1895. While it doesn’t sound like much, that’s nearly four inches more rain per year now than the late 1800s, and long-term predictions suggest this trend will continue.   

*Watershed include: Lake Superior North, Lake Superior South, St. Louis River, Cloquet River, and Nemadji River.  

Community Efforts

There have been several recent projects that address coastal erosion in the Duluth area: 

The Duluth Lakewalk project, which was massive, just finished up in the summer of 2021.

  • Beach nourishment (adding sand) along Duluth’s Park Point (Minnesota Point) helped build up the sand dunes and protect shoreline properties. There were issues with shredded drink cans found in the added sand.

  • Duluth’s Brighton Beach restoration project to move the lakeshore road further away from the shoreline to prevent it from washing out during a storm is underway.  

  • There have also been a number of projects along Scenic 61 north along the shore to fix and/or protect lakeside areas from eroding and, in some places, falling into Lake Superior.  

There are still at-risk areas that need to be addressed; some with eroding banks a few feet off a roadway. The needs are great and the city of Duluth and St. Louis County officials are trying to figure out how to identify options and prioritize these areas. The work already completed and the amount of work still to be done are important stories.   

Lake Superior coastal communities have a reprieve from high lake levels at the moment, but we do not know how long that reprieve will last. We do know the weather for Minnesota is trending toward greater amounts of precipitation. While Minnesota’s current drought has reduced water levels for the time being, we know it can change fast!   

Rather than breathing a sigh of relief that the risk is over, we might think of this as a chance to make our coasts and ourselves ready for when lake levels increase again. We’re here to help communities do just that.  

Minnesota Sea Grant’s Community Resilience Program includes the following ongoing projects: Coastal Hazards of Superior Community of Practice, Great Lakes One Water Resilient Future, The Watershed Game, and the Twin Ports Climate Conversations seminar series. I encourage you to contact our Resilience Extension Educator Madison Rodman for more information.  

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Useful Resources:

U.S. Army Corps of Engineers video explaining Lake Superior water level regulation, outflow and compensating works gate settings and their On the Level video series.

Image credit: M. Thoms