Climate change impacts: Lake Superior record water levels appear at record speed

Waves on Lake Superior crash against the Duluth, Minn. waterfront Sept. 10, 2014. Photo Credit: Randen Pederson, CC BY

 

Lake Superior is aptly named for many reasons, including its stature as Minnesota’s largest and most iconic freshwater resource. As the largest freshwater lake on Earth (by surface area), it contains 10 percent of our planet’s surface freshwater. It may surprise you that this massive body of water is experiencing the effects of climate change, right now, right here.

As recently as 2013, levels on Lake Superior were nearing historic lows and many who study the water cycle were predicting climate change trends would send the lake to even lower levels. Many others were concerned, too. The shipping industry worried about the need for dredging to access North Shore ports and maintain navigation at critical points near the Soo Lock located at Sault St. Marie (for shipments of grain, iron ore, wind turbine blades, and many other products and commodities). Communities from Duluth to Grand Portage that depend on Lake Superior for drinking water as well as industrial use asked whether it would continue to be available and safe. Business owners wondered what a shrinking Lake Superior might mean for tourism and recreation.

Now, just six short years later, many are shocked to learn that Lake Superior is predicted to set record high water levels as soon as August 2019. Observers report that the lake has risen over three feet since low levels were recorded in 2013. That six-year span of time for a three-foot rise is remarkably fast given the size of the lake, and scientists are now pondering whether the changing climate is accelerating this transition from low to high lake levels, and if this is a new normal.

The other Great Lakes are also experiencing record high levels occurring over a short period of time, a phenomenon unique to the entire Great Lakes region. “Increasing precipitation, the threat of recurring periods of high evaporation, and a combination of both routine and unusual climate events – such as extreme cold air outbursts – are putting the region in uncharted territory,” state University of Michigan professors Drew Gronewold and Richard B. (Ricky) Rood in The Conversation.

Of note: The level of Lake Superior rose three feet in a six-year period only once before in its history (from 1926-1932, approximately), and the level fell by almost three feet from 1996-2001.

Photo: KARE 11

This new territory for lake level fluctuations has many scratching their heads and concerned that we in Minnesota and across the Great Lakes region are now experiencing the climate change impacts we normally associate with flooding on the ocean coasts. Storm surges, like the one that flooded Canal Park in Duluth on October 10, 2017, are becoming more common in other Great Lake communities as well. Shoreline erosion and stirred up sediments are also increasing concerns for lakeshore owners, and for community infrastructure such as seawalls and storm drainage systems.

What will the future hold? It’s time to increase our emphasis on resilience – working with changing water levels and adapting our methods to withstand the uncertain future of climate change impacts.

— John Linc Stine, Freshwater executive director

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