Often referred to as the country’s third coast, the Great Lakes have been the wettest on record for the past five years.
While lakes are not exactly associated with rising sea levels, Chicago is now in the same perilous position as cities on the ocean. Heavy rainfall and more frequent droughts are now causing large fluctuations in the water levels in Lake Michigan and the Chicago River, wreaking havoc on the city and prompting urgent action to find a solution.
In the winter of 2020, the water level in Lake Michigan reached an all-time high and heavy rain continued to fall. Waves rumbled over Lakeshore Drive, spilling water up to the third floor of some buildings. The Chicago River also began to overflow into the city center.
The balance between river and lake has always been fragile, since the city dug canals over a century ago to keep waste from the river out of the lake that supplies the city with drinking water.
A flood backup system has also been set up: flood gates that turn the river back into a lake when the river gets too high. However, last year’s rains were so heavy that for the first time this backup system did not work. The lake was above the level of the river, so the water could not be turned back.
The Lockmasters had to wait for the river to rise above the lake before they could begin the U-turn process. The delay was devastating. Downtown Chicago was hit by severe flooding, resulting in a power outage at the Willis Tower, formerly known as the Sears Tower.
Experts say this was not a once-in-a-lifetime event, but a sign of something to come, as climate change causes heavier rains and stronger storms.
“The biggest risk is that these changes in climate, hydrology or water level will exceed the infrastructure or the ability of cities, coastlines and homes to cope with these changes,” said Drew Gronevold, an assistant professor at the University. Michigan Schools for Environment and Sustainable Development.
Gronevold said Chicago and other cities around the Great Lakes are at risk of being unable to handle these extreme highs – and extreme lows. Just seven years before that storm, Lake Michigan’s water had dropped to an all-time low due to a prolonged drought. This jeopardized the city’s water supply, as well as shipping critical to the Midwest’s economy.
“When the water level drops, they have to do the so-called light exercise. They have to reduce the amount of cargo they can carry and are actually losing millions, if not billions of dollars, ”Gronevold said.
In the aftermath of the 2020 floods, the U.S. Army Corps of Engineers installed large concrete barriers along parts of Lake Michigan bordering downtown. This was necessary even after the corps began to fortify the Chicago coastline as part of a half-billion-dollar project that began 20 years ago. It is now launching a new, multi-year EPA-funded program to assess future conditions taking into account climate change.
“We are trying to predict what these conditions will be in the future so that we can plan these conditions and create sustainable structures,” said David Bukaro, chief of project management, Army Corps of Engineers, Chicago County.
These can be structural or natural features. The city is currently working on planting tens of thousands of trees that can also help trap rain where it falls and prevent it from entering the river.
The Chicago Metropolitan Planning Council is pushing the city to cut carbon emissions because the only real solution at the local level is to limit global warming.
“A lot of people look to the Midwest like it’s a safe bet for the future of climate change, but if we have this problem, it might just not be as safe a bet as people thought,” said Justin Keller, manager. in the metropolitan planning council.
“The City and the Army Corps are hoping for additional funding from the trillion dollar infrastructure bill that is still going through Congress. Infrastructure projects of the past are no longer valid, and while new research on precipitation and drought around the Great Lakes is certainly beneficial, engineers need funding to translate this knowledge into a critical fix. “
“I would say that the economy of the Midwest is completely dependent on water,” Gronevold said. “We really need to pay more attention to the future of this area and, in particular, how we are going to improve the infrastructure to cope with these changes.”