Why Metro Detroit keeps flooding—and how to fix it
Heavy rain in Southeast Michigan over the weekend left many residents dealing with massive flooding. There was several feet of water in some basements, vehicles stranded on flooded streets, and some people also lost power. Wayne County remains in a state of emergency due to ongoing public health threats.
Such heavy flooding is only expected to occur once every 100 years or so, but the area saw similarly devastating rains in 2014 and 2016. Nick Schroeck, an associate professor of law at Detroit Mercy School of Law, told Stateside that these once-rare storms are becoming the new normal.
“It’s a changing climate. Maybe call it ‘global weirding’ - whatever term you want to use. We have these more intense rainstorms that are coming on a regular basis,” Schroek said.
Why is Detroit so prone to flooding?
Cities like New Orleans sit below sea level, making them naturally prone to flooding. In Detroit’s case, however, man-made structures have been a major factor in altering the landscape and increasing flood risk.
“This was an area, prior to European colonization, [that had] a lot of wetlands. An area that has a lot of clay that drains toward the Detroit River, or drains through the Rouge River, or the Clinton River toward our Great Lakes,” Schroeck said.
Today, those wetlands have been excavated to make way for highways that sit below the surface of the earth. Pumps have been designed to clear water from those roads, but they often fail due to mechanical issues or power outages.
Detroit’s combined sewer system, which connects sanitary sewers to storm drains, also plays a role in the city’s frequent floods.
“When you have rain, even just a couple of inches of rain, that combined sewer system gets overwhelmed. And that can lead to backups into people's basements. . . And what's important to note is that those basement backups often include human waste, right? They often include sewage as well as other contaminants.” Schroeck explained.
Schroeck noted that, for more than 30 years, Detroit was under a federal court order to resolve issues related to the combined sewer system. Improvements were made to treat sewer and storm water before the waste mixture reaches the Detroit River, but overflow continues to be a problem.
“It would cost a lot of money to separate our combined sewer into storm drains and sanitary sewers. . . We've looked at building deep tunnels below ground to store this extra waste water until it can be treated and discharged into the rivers, but that's also been cost prohibitive,” Schroeck said.
Schroeck and others have advocated for developing more “green infrastructure,” which would divert water to wetlands, parks, and vacant property rather than through pipes.
Chicago embraced this approach several years ago, bulldozing foreclosed properties and leaving basements intact to act as floodwater receptacles. Schroeck said similar work is being done in parts of Detroit, but developers have to be wary of leftover chemicals from former gas stations, dry cleaners, and manufacturing plants. These contaminants can seep into the earth and contaminate groundwater over time.
Schroek also acknowledged that developers should be mindful of how green infrastructure solutions might impact the city’s residents, especially in Black communities, which have been disproportionately affected by foreclosure.
“We wouldn't want those neighborhoods to be overly burdened as a stormwater retention area. I mean, you want to do this in such a way that actually beautifies neighborhoods. . .” Schroeck said. “If there are blighted and abandoned properties, maybe it's worth it to remove them and put in more of like a park like setting that, at times will flood when you would have rainwater diverted there, but then otherwise would be nice green space for the community.”
President Biden’s infrastructure bill
The city will receive funding as a result of both COVID-19 relief efforts and President Joe Biden’s infrastructure deal, but details remain up in the air.
It is unlikely that COVID-19 relief money will go toward improving Detroit’s sewage system. However, some funding may go toward developing public transit, possibly leading to less reliance on roads prone to flooding. Schroeck is more hopeful about the infrastructure bill.
“I would think with the flooding in Detroit, as well as the excessive heat out west, that this discussion of climate change, you know, again, should be front and center. And hopefully there will be dollars to help communities adapt and be more resilient in the face of a warming climate,” Schroeck said.
Who will take the lead on development?
The Michigan Department of Transportation is expected to take the lead in working with the various municipalities affected by highway flooding, but major change has yet to happen.
“What's frustrating is this isn't new. I mean, there are many advocates who have been calling for additional flood planning, for green infrastructure planning to be a part of highway projects for many years. . . Really, the state’s behind the curve on this, and they need to get ahead of that curve or we're going to continue to have these problems,” Schroeck said.