Devastating floods leave Detroiters with toxic mold

In 2019, the city of Detroit installed sandbags on private properties on the canals to stave off flooding, but it didn’t prevent Wilma Price’s home from flooding multiple times. In 2023, the city said the sandbags could be removed and made residents responsible for removing them.

Wilma Price was sleeping in her basement bedroom in 2021 when she woke up to a cacophony of noise, including an alarm coming from her sump pump, a device meant to prevent basement flooding. 

As she sat up in bed she saw her freezer and its contents floating by on several inches of water. The bedroom of her home in Detroit’s Jefferson Chalmers neighborhood was quickly flooding with water coming in from the toilet and shower. 

“I thought I was dreaming,” said Price, 69. “It was gushing out of my toilet like a geyser, it was coming out of my shower. … I just couldn’t believe my eyes. It was so terrifying.” 

The alarm she heard was the crying sound of her sump pump failing as approximately four feet of water accumulated, almost entirely engulfing the stairs from her basement and destroying computers, furniture, appliances, and most tragically, photos of her siblings, parents, and husband, all of whom have died. After a few days the water receded, but black mold — a toxic fungus — developed.

As fossil fuel pollution traps heat, flooding is intensifying and disasters are becoming more frequent and more intense. The floods are wreaking financial damages, and they’re exacerbating health hazards as flooded streets and basements foster mold and release pathogens from raw sewage. In Rust Belt cities like Detroit with combined sewer and rainwater systems, untreated sewage can back up into streets and homes when pipes become overwhelmed with stormwater.

Price paid thousands of dollars to eradicate the mold by ripping out the floors, several feet of her walls, and all of her new bathroom fixtures. 

Sometime this spring, Price moved the winter coats she had stored in a closet on the home’s first floor and found black mold crawling up about a foot of the wall. Then she found it in a second room on the opposite side of the house. 

Price wonders where else the mold might be silently growing from that day in 2021.

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Extreme rainfall events like Detroit’s historic flood in 2021 are growing more common because of climate change. The floods of years past will likely be dwarfed by the deluges of the future, powered by a warmer atmosphere that’s able to hold more moisture, climate scientists say.

“It doesn’t take much imagination to think about how serious this problem is, especially for children born in Detroit and living in those environments,” said Peter Larson, a postdoctoral researcher at the University of Michigan and one of the lead authors on a 2021 study, published in the International Journal of Environmental Research and Public Health, that found more than half of almost 4,000 Detroit homes surveyed had experienced recurrent flooding between 2012 and 2020.

“They face lifelong problems from asthma,” Larson said.

Among the Detroit homes included in the study, 84 percent that had flooded in the past were found to have mold in the basement. An additional 55.4 percent of homes that had not flooded during those years still had moldy basements — underscoring the fact that more frequent, climate-induced rainfall can pose problems even for homes that haven’t flooded, because with more rain comes more moisture.

More than half of Detroit homes experience recurrent flooding, 84% of which have mold. Additionally, approximately half of Detroit homes that have not flooded still have mold. (Credit: Climate Central)

Detroit received more than 25,000 calls on June 25, 2021, when six to eight inches of rain washed across the city over two days, leading to disaster declarations in four Detroit-area counties and 67,000 damage claims with the Federal Emergency Management Agency. About 24,000 damage claims were also filed with the regional water authority in Metro Detroit, all of which were denied because water officials deemed widespread basement flooding to be inevitable. Several pump stations that move water out of the east side of Detroit failed that day due to electrical issues. Still, authorities said there was just too much rain for the system to handle.

Following the flood, President Joe Biden declared an emergency for the state of Michigan, opening up more federal funding for flood victims. Before that, in 2014, four to six inches of rain left Detroit with $1.8 billion in direct flood damages, according to the National Weather Service. Then again in 2016, 2019, and 2020, major rainfall caused severe flooding in Detroit.  

“The last flood was the worst of them all. It was devastating,” said LeJuan Council, a Detroit resident whose home has flooded. Council lives in the Jefferson Chalmers neighborhood, which has experienced some of the worst effects of Detroit flooding because of its low elevation, its proximity to the Detroit River, and the way the sewer system is designed. “We are all very clearly in a depressing situation around this time of year — you should typically be able to enjoy the sun, but summer rain is becoming violent for us.”

This has profoundly concerning health implications for Detroit residents.

“What you have is a situation where residents are facing just an enormous amount of potential challenges because of this,” said Lyke Thompson, director of Wayne State University’s Center for Urban Studies and a mold researcher. “A number of older and younger adults in that neighborhood already have asthma, and we have found from a larger study … an association between flooding and asthma occurrence in Detroit.

“The mold was the major thing that was still there months after [the 2021 flood]. And we still are going into homes and finding mold in that neighborhood,” he said.

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Other research conducted after extreme weather events, including Hurricane Katrina in 2005, has shown high mold levels indoors can lead to or exacerbate a host of health problems, including asthma, respiratory infections, bronchitis, allergies, and even neurological damage. A number of studies have shown that mold can even increase the risk of developing asthma for the first time in both children and adults.

This is particularly concerning in Detroit, which has some of the highest asthma rates in the country. Larson and other researchers found a positive association between mold growth and asthma in the thousands of Detroit homes they surveyed: A whopping 74.4 percent of households that had flooded in recent years reported having at least one adult in the home who had been diagnosed with asthma.

“We’re seeing an overburdened set of communities who keep experiencing a lot of the local industry and commercial truck traffic, and you just keep adding these layers on top,” said Natalie Sampson, a professor of public health at the University of Michigan’s College of Education, Health and Human Services, and another author on the 2021 study. “Mold from flooding is just one more contributor that can really spark asthma symptoms, that’s for sure.”