Storms and climate change force Metro communities to think differently about flooding

With recent historic floods in Iowa and Nebraska and the Great Lakes predicted to hit all-time highs this summer, there are plenty of reminders of the kinds of storms that are emerging as one of the major consequences of climate change in Southeast Michigan.

 

“With climate change, it’s certainly getting more unpredictable,” Anne Vaara Chief Deputy Water Commissioner for the Oakland County Water Resource Commission or WRC says. “We’re getting more, larger storms in a shorter period of time and it puts a lot of pressure on the system.”

 

Anne Vaara. Photo by Doug Coombe.The system includes not only drains, sewers, treatment plants, and rivers, but nearly anything that rain can run off of and then enter a drain or sewer. Responding to stormwater issues could mean a serious reconfiguration of aboveground infrastructure. This response will likely include green infrastructure, often attractive combinations of plantings, porous pavers, and bio-swales that help keep water out of the sewer system or at least delay its entry to prevent sewers overloading and flooding areas as happened on a large scale in 2014. More prosaic measures like reducing the size of parking lots may also be called for.

 

But the question remains if any of this will be enough to meet the challenge of climate change? City officials don’t even like to talk about preventing floods “because Mother Nature has a tendency to always have a larger storm event than we design and plan for,” as Jennifer Lawson Water Resources Manager for the City of Ann Arbor, says. But mitigating the impact of large-volume rainstorms will likely require rebuilding underground infrastructure with a corresponding financial outlay that would strain city and county budgets.

 

Added pressure is coming from class action lawsuits against various municipalities which lawyers say haven’t adequately prepared for climate change. In 2014, Farmer’s Insurance Group filed a suit against a number of municipalities outside of Chicago, who they said hadn’t done enough to prevent widespread flooding. Although this suit was later dropped, some experts believe it signaled the beginning of a wave of litigation from insurers as well as rising premiums that could change how we respond to climate change. “

 

It was the first salvo,” says Andrew Hoffman, a professor at the U of M’s Ross School of Business. “Insurance, in my opinion, is going to be the key driver to force entities to start to address this because they’re just not going to be able to deal with the insurance rates for catastrophes and disasters.”

 

But whether it’s lawsuits, rising insurance rates for cities and private citizens, or other pressures, municipalities and counties will have to beef up their response to storms that are already a major problem, but likely to get much worse, according to the National Climate Assessment.

 

“In every single city that I sued, the common response has always been it rained too much,” David Dubin, a lawyer with Liddle and Dubin who has led a number of class-action lawsuits against Metro Detroit cities, says. “I think that type of mindset only leads to further flooding.”

 

Matt Callahan, city engineer for the City of Royal Oak, is working on the problem. He says part of the issue is a mismatch between the region’s existing infrastructure and how the suburbs have grown over a span of decades.

 

They’re 50, 60, 70, 80 years old, these sewers,” Callahan says. “They maybe didn’t anticipate all of the growth, and that the region would have the hard surfaces that would be installed, which don’t absorb any water at all.”

 

Reducing the amount of paved area in the city and perhaps changing the nature of the pavement itself and what it runs off into is one way to reduce the load on sewers.

 

You drive by any large parking lot, like a Meijer, Kroger, or Home Depot,” Vaara says. “There’s way more parking than they need. Simply changing those codes to provide for less parking is going to help with some of the stormwater runoff issues.”

 

In general, city codes seem to be a problem for a number of cities and part of the WRC’s job is helping municipalities change them.

 

Callahan says that Royal Oak has also been working on removing pavement and roadways where possible and installing landscaping that can infiltrate rainwater rather than send it into the sewer. However, large roads like Woodward Avenue still take up acres of the city and send all the water directly into the sewer. And Woodward, as a state highway, is not under city control.Matt Callahan, Royal Oak.. Photo by David Lewinski.

 

Ann Arbor found that roads make up roughly 25 percent of the impervious area in the city. To hold themselves accountable for this they instituted a guideline that all new road construction allows at least one inch of rainwater to infiltrate the soil during storms, although in sandy areas of the city the requirement is closer to two inches.

 

Green infrastructure projects also seem to be a relatively easy pitch for elected officials—at least compared to fixing below ground infrastructure—because they’re visible and provide multiple benefits.

 

“You can do a lot of things that are aesthetically pleasing and create walkable areas that have grass pavers or pervious pavers that can be welcoming to the public,” she says.

 

Vaara cites the work that the City of Rochester has done on the Paint Creek as an example of green infrastructure that catches and cleans runoff but also provides attractive open space.

Projects like these keep water out sewers and waterways but also filter out pollutants.

 

“Basically, let Mother Nature do her thing,” Vaara says. “Use the natural soils as a filter rather than putting it in pipes and trying to treat it at the end.” This is especially important in communities that have a combined sewer system where—during times of heavy rain—sewage and stormwater flower into the same pipes, which can mean discharging untreated, raw-sewage into waterways.) Again, Ann Arbor seems to be a leader with 124 unique green infrastructure areas that they estimate treated 403 million gallons of precipitation in 2018.

 

However, funding these sorts of projects is an issue for many communities.

 

“We’ve been lucky to find grant opportunities,” Callahan says, “…because it’s not really built into our water and sewer rates.” Royal Oak now has a person working full time on applying for these sorts of grants. Vaara encourages communities to prioritize funding these projects, or at least put money aside for matching funds for grants from organizations like the Erb Family Foundation or the Michigan Department of Environmental Quality. Ann Arbor has been able to more or less circumvent this problem by charging a fee for their separate stormwater system that supplies millions of dollars yearly for green infrastructure and other initiatives.

 

Proposed legislation may also make it easier for cities to fund infrastructure by creating a “stormwater management utility” layer for local governments that allows them to charge customers according to the impervious surface on their property. This will protect municipalities from lawsuits that have won significant damages claiming such fees are an unfair tax.

 

As far as the class-action lawsuits filed by Dubin and others in response to flooding, Vaara says, “Those suits were based on huge, major storms and you couldn’t build a system large enough to handle some of those major storms.”

 

And yet, more major storms like this seem inevitable. One thing is clear: The answers aren't going to come cheap.


“We need to really do some soul searching about how the future infrastructure will service our society’s needs,” says Lawson.” There’s a lot of really tough decisions.”
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