Fluctuating water levels in Lake Michigan and increasing storms cause increasingly overwhelmed stormwater systems and erosion in Evanston


Joshua Hoffman/The Daily Northwestern

As lake level fluctuations become harder to predict, local experts say Evanston needs to protect its lakefront against erosion, flooding and storm damage.

Lily Carey and Avani Kalra

After City Council declared a climate emergency in April, councilmembers said they hope to double down on the city’s Climate Action and Resilience Plan, a policy plan enacted in 2018 to guide the city’s response to climate change through 2050. 

CARP includes specific goals for stormwater-drainage system upgrades and protective green infrastructure, which advocates hope could prove crucial to shield lakefront residents from future threats. 

Two ecological challenges the plan aims to address are rising water levels on Lake Michigan and higher amounts of precipitation. Lake Michigan’s water levels have been rising since 2014 and are expected to continue to do so long-term; simultaneously, the amount of precipitation in the area is increasing due to climate change.

The overall water increase is expected to cause overflow in Evanston’s drainage systems and increase erosion on the lakefront — something Evanston’s lakefront community needs to prepare for, longtime resident Richard Lanyon said.  

“There’s no perfect science on this, and we don’t know exactly what’s going to happen,” Lanyon  said. “But I expect that the water level increases over time could really seriously damage Evanston or the Chicago area.”

Lanyon, who is now retired, spent his entire career working in local stormwater management, and is now working with the city on drainage system upgrades. Stormwater systems, which help redirect water from flooding and rainstorms, are essential to protecting the city from storm damage, Lanyon said.

In 1990, Evanston began to remodel its stormwater drainage system. Since then, Lanyon said he hasn’t seen much flooding in the city, but city officials are working on analyzing places in the current stormwater system which might be especially vulnerable to flooding.

“Historically, topography here is not made for intense urban development,” Lanyon said. “Flooding problems are basically a result of soils we have here, like clay, and a very poor natural drainage system.”

As cities like Evanston build more roads, there is more pavement and fewer places where the land can absorb water. This means that water is pushed into Evanston’s drainage systems, largely overwhelming them. 

Overflow in the city’s drainage system also perpetuates energy waste cycles that worsen climate change. As drains overflow, wastewater mixes with road runoff and untreated sewage, and is pumped through sewer systems south through Chicago. Moving that water requires money and significant energy.

Civil and Environmental Engineering Prof. Neal Blair said continued overflow could cause flooding in Evanston to increase exponentially.

“You can only pipe away the water so fast,” Blair said. “If you have low spots that accumulate the water, you’re going to have flooding in people’s yards and basements. We’ve created this situation by having a lot of pavement, which doesn’t absorb water.”

This flooding tends to impact lower-income communities in particular, who tend to live in areas with a higher concentration of industrial waste systems due to the effects of redlining, said Patricia Beddows, the director of Northwestern’s Environmental Sciences program.  

Beddows said Evanston’s historical infrastructure is breaking down in some communities faster than others.

“They are our communities that have been systematically marginalized, communities of color, communities that are under-resourced,” she said. 

Along with flooding, Evanston’s Sustainability and Resilience Coordinator, Cara Pratt said overwhelmed stormwater systems can also lead to increased lakefront erosion.

“In the case of Lake Michigan erosion in recent years, it’s really rapid, and you can really see noticeable differences before and after a storm,” Pratt said.

One way to minimize the impact of increasing water levels and rainstorms on the city, Beddows said, is increasing road permeability, or potential to absorb water. 

Beddows said Perma-Crete bricks are one way to increase permeability. Chicago has used these bricks to implement “green alleys,” which utilize permeable pavements that allow storm water to filter through the pavement and drain into the ground, instead of directing excess water through the sewage system. 

Evanston has begun to experiment with permeable bike lanes along Church Street, Blair said.

Blair recommended residents take individual action to make their properties water-absorbent. Tools like gardens that convert sewage and storm water into planting beds can be implemented, she said, to avoid flooding each neighborhood’s sewer system. 

There are also infrastructure solutions that could slow erosion. Pratt said cities can add rocks to the lakefront, providing a barrier against the water. The city could also “naturalize” the shore, she said, building wetlands or dunes that can naturally protect against storms.

Though naturalizing beaches can provide benefits to local ecosystems, Pratt noted this option can be more expensive, and that it’s important to take into account how communities want to use the space.

In terms of weighing the costs and benefits, Pratt said, community input and decisions from engineering teams could prove essential to finding the best way to protect the city’s shores.

“Short term, (we could see) continued beach loss and probably damage to private property,” Pratt said. “And then we’ll have to get really creative with what types of infrastructure we’d like to deploy to protect our coasts.”

Email: [email protected]

Twitter: @lilylcarey

Email: [email protected]

Twitter: @avanidkalra

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