Urban flooding a regional dilemma

Urban flooding impacts people in cities throughout the Great Lakes region, some as many as 30 to 40 times over the course of their lives. Photo: Center for Neighborhood Technology

Urban flooding impacts people in cities throughout the Great Lakes region, some as many as 30 to 40 times over the course of their lives. Photo: Center for Neighborhood Technology

More people in Great Lakes cities are falling victim to urban flooding, some as often as 30 to 40 times in their lifetimes, according to a Chicago-based sustainability nonprofit organization.

“We did a brief survey of people in the Chicago region, and we heard some actually devastating stories about flooding from some of them,” said Harriet Festing, director of the Center for Neighborhood Technology’s water program. “We came away from it pretty shocked.”

The September report defines urban flooding as when buildings, streets or open property are inundated by rain, sewage or overflowing bodies of water. Festing characterized the problem in Chicago as not catastrophic, but frequent.

It’s also hidden. Property owners often don’t want to talk about it, she said. “They’re somewhat ashamed of it, having sewage in their living space. They’re afraid of what it might do to their property values.

Chicago flood victims are not alone. The survey led the center to investigate urban flooding across the Great Lakes region. “We wanted to find out if it was more widespread than just Chicago, to see if other cities were suffering the same problem,” Festing said.

Thirty of 48 cities surveyed responded. They represent approximately 19.7 million people, almost 23 percent of the region’s population.

Every city reported flooding, with 80 percent characterizing those issues as medium or large. While most municipalities track flooding, only about half have a plan for dealing with it. Only 20 percent could estimate the cost of flooding damage.

The goal of the survey is to begin a dialog across the Great Lakes region regarding urban flooding.

“We found that there isn’t a language for discussing this problem across the region,” Festing said.“It’s prevalent, but there isn’t a set of common terms for talking about it. We spent a lot of time developing that, because once you have a language you can really discuss these issues across regions.”

The frequency of heavy rain in the Great Lakes region has risen approximately 31 percent between 1958 and 2007, according to researchers from the Rocky Mountain Climate Organization, the National Resources Defense Council and the U.S. Global Change Research Program. Heavy rain can overwhelm urban drainage and sewage systems, which are among the primary causes of urban flooding. This increase has been linked to climate change, according to these studies.

Some of the region’s cities are already combating urban flooding. In Chicago, a number of techniques reducing the strain on the city’s aging sewer system and safeguarding homes from flooding.

“Many of our sewers were built over a hundred years ago when the city’s population grew dramatically,” said Thomas LaPorte, a Chicago Department of Water Management spokesperson. “They built a lot of sewers back then, and they built them in a hurry. They didn’t anticipate the kind of storms we’re getting now.”

According to LaPorte, Chicago flooding has been on the rise for the last five years, connected with the increasing storm activity. To better handle the problem, the city developed the Deep Tunnel Project in the 1960s, a series of subterranean reservoirs connected by a large tunnel that divert storm water from the city. Construction began in the mid-1970s and remains ongoing.

“Our progress is behind schedule because we’re not getting the federal funding we need,” LaPorte said. Current projections are that the project will be completed by 2029.

While the large project is moving slowly, Chicago and other cities are pursuing alternative strategies According to LaPorte, the city is installing rain gardens and rain blockers to keep storm water out of the sewer system. Rain gardens are comprised of plants that absorb lots of water and are positioned to maximize their exposure to rainfall. Rain blockers are installed in storm water catch basins to restrict the flow of water into the sewers.

Rain gardens are among the many techniques being employed to control stormwater and prevent urban flooding. Photo: City of Chicago

Rain gardens are among the many techniques being employed to control stormwater and prevent urban flooding. Photo: City of Chicago

With the causes for flooding on the rise, Festing and the center continue to build tools for municipalities across the region. They are surveying households to better understand the effect of flooding and to compile information from across the region into a database. The information will be used to help secure Chicago-area homes against flood damage by offering to retrofit them against flood damage.

The program, called Wetrofit, aims to help families and businesses alike secure their property against flooding. It involves installing overhead sewer pumps, disconnecting home downspouts that channel storm water into basements, providing rain barrels and retrofitting streets with porous pavement.

Festing hopes that the service will serve as a model for similar endeavors in other cities.

“This is a problem that people haven’t spoken out about, but that affects people across the region,” Festing said. “We want to get them talking about it, because until you understand the problem you can’t develop the best solutions to it. We’re really keen to get stories from people and create that conversation.”

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  • Harold

    There are basically two primary causes of urban flooding. One is that we have foolishly allowed people to build houses in floodplains. Since a floodplain is an essential part of a river system, it should be no surprise that when people build in a river they will get wet. If someone has a house in a floodplain and they continue to get flooded time and time again, I suppose it just verifies the old saying that “you can’t fix stupid”.

    The other primary cause of so-called “urban flooding” is the basement flooding associated with overflowing sewer systems. This, too, is the result of our inability to respect natural water cycles. One key aspect of overflowing sewer systems is never mentioned–that we have enclosed numerous creeks and tributaries into sewers, eliminating the natural purification processes while also eliminating the natural flood storage capacity of a creek and its floodplain. This water then has only one place to go: into a municipal sewer system. Of course, when it rains, that burden is then shifted from what was a free natural resource into a very expensive and costly man-made sewer. We added insult to injury by funneling rain water from rooftops and roadways into these sewer systems instead of allowing natural percolation to take place into the soil. The entire water cycle is interrupted–and truly obstructed–due to the fact that civil engineers had no concept or concern about the free services provided by nature. Our problems with urban flooding are entirely man-made.

  • Anonymous

    Excellent story. Thanks for sharing this report.