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.
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 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.
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.
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.
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.