View from a park bench overlooking the Detroit River with the Detroit skyline in the background.
Detroit Park Bench View of the Detroit River and city skyline. © Michael D-L Jordan/dlp

Stories from Michigan

Managing Stormwater in Detroit

After years of economic tough times, Detroit is experiencing unprecedented revitalization. However, as with many major cities across the United States, aging infrastructure and vast expanses of concrete create problems for the city when faced with high volumes of stormwater.

An intersection is flooded in front of an old building in Detroit.
Urban Flooding Standing water on roadways results when stormwater systems are overwhelmed by too much rain in a short period of time. © Michael D-L Jordan/dlp

In 2012, an estimated 7.8 billion gallons of untreated sewage were discharged from the city of Detroit into the Detroit River and, ultimately, the Great Lakes. The sewer system in place now collects rainwater runoff, domestic sewage and industrial wastewater in the same pipes. 

During heavy rains, this overwhelms the system’s capacity and leads to flooding called combined sewer overflow discharges (CSO). These discharges create a water quality issue, not only for city residents who struggle with health risks and repair costs associated with sewage-contaminated water flooding their basements, but also for the larger Great Lakes ecosystem. 

The Nature Conservancy is committed to building healthy cities by demonstrating how green stormwater infrastructure can address urban challenges, such as stormwater runoff. With increasing heavy rain and storms due to climate change, along with the requirement in the EPA’s Clean Water Act to completely eliminate CSO’s, the city of Detroit is under considerable pressure to improve its existing stormwater and sewage system.

The estimated cost of traditional "gray" infrastructure improvements to eliminate CSO’s in Detroit is a staggering $1.2 billion. TNC is working with the city and local neighborhood communities to provide nature-based solutions—or, "green" infrastructure—for stormwater management that will offset the cost of infrastructure improvements.

Green infrastructure leads to improved water quality, as well as attractive green spaces that contribute to neighborhood revitalization.

A sidewalk runs alongside a Detroit city street. A parking lot sits to the right.
City Sidewalk Detroit is covered in miles of impervious pavement, causing contaminated stormwater runoff to flow into low-lying roadways, homes and businesses, and local waterways. © Michael D-L Jordan/dlp
Green algae sits atop the water at the Lake Erie shoreline.
Toxic Algae Polluted stormwater runoff leads to issues for wildlife and the environment, including increased algal growth in response to excess nutrients. © Randal L. Schieber
Boy drinking water from a drinking fountain.
Drinking Water If left untreated, stormwater runoff can also contaminate city water sources, including drinking water, putting residents at risk of illness. © Michael D-L Jordan/dlp
× A sidewalk runs alongside a Detroit city street. A parking lot sits to the right.
× Green algae sits atop the water at the Lake Erie shoreline.
× Boy drinking water from a drinking fountain.
A small area with trees and plants sits between a sidewalk and road.
Bioswale Small installations like this can make a big difference by slowing the flow of rainwater entering sewers, as well as adding aesthetic value to a streetscape. © Kevin Arnold

Green Stormwater Infrastructure

Green stormwater infrastructure (GSI) uses engineered design that employs green space and natural plant material to absorb, retain and slow stormwater runoff. In contrast to traditional infrastructure, GSI is less costly and with proper maintenance will not require updates every few years.

Green stormwater infrastructure helps to:

  • reduce the amount of water entering a storage facility for treatment, 
  • reduce CSO’s, and 
  • decrease surface flooding by providing pervious surfaces and holding spaces through which stormwater slowly filters. 
A blue heron glides above a wetland near the Detroit River. A jogger runs along a path in the background.
Urban Wildlife In addition to capturing excess rainwater, wetlands and retention ponds provide habitat for birds and other animals. © Michael D-L Jordan/dlp

Partnering for People and Nature

Thanks to a grant from the Ralph C. Wilson Jr. Foundation, TNC is partnering with the Eastern Market Corporation and the City of Detroit, enabling infrastructure improvements at a scale that will help significantly reduce sewage discharges and surface flooding. The partnership will also benefit local businesses by adding attractive green spaces that are pedestrian friendly and help inform the city about tools and strategies they can implement to achieve their stormwater management goals. 

This leads to improved water quality in adjacent rivers and lakes, as well as attractive green spaces that contribute to neighborhood revitalization by offering recreational areas and beautification opportunities.

A park with a retention pond and walking path next to the Detroit River in the foreground, with the Renaissance Center in the background.
Urban Green Space Green infrastructure uses built green spaces to catch and filter stormwater and ease surface flooding by providing permeable pathways for stormwater to go into the ground. © Michael D-L Jordan/dlp

Developing Sustainable Stormwater Management Policies

In addition to working with the city to integrate green infrastructure into new stormwater management plans, TNC is providing technical assistance in developing new policies that will help to finance and encourage green infrastructure solutions within Detroit.

These policies will create the enabling conditions for economic markets and private investment in support of public amenities in a number of innovative ways.

A crowded outdoor market in Detroit on a sunny day.
Eastern Market This outdoor market pavilion sits at the heart of the Eastern Market District, one of Detroit's oldest and most vibrant neighborhoods. © Michael D-L Jordan/dlp

For example, TNC is working to develop a stormwater management district within the Eastern Market Corporation's property footprint. In concept, the district is designed to provide a legal framework for centralized stormwater management by aggregating individual property owners.

Being privately funded, the district is intended to provide property owners with incentives and alternatives to more easily and sustainably meet stormwater management goals, at scale, for neighborhood improvement, economic vitality and improved water quality.

A Bright Future

TNC offers cross-cutting expertise in conservation science, environmental engineering, law and innovative finance, all of which has enabled us to develop a strong relationship with the city of Detroit and unique insight into potential solutions to the conservation challenges facing one of North America's most storied cities.

With new, cost-saving green infrastructure and improved stormwater management policies in place, Detroit can be on a path to a future where people and nature can thrive.

The sun sets behind the Detroit skyline.
Detroit at Sunset Along Detroit's eastern edge flows the Detroit River, a critical waterway for commerce, recreation and wildlife. The river runs south, eventually emptying into Lake Erie. © Michael D-L Jordan/dlp