• What is the drainage charge, why does it exist, what is impervious surface, and are there opportunities to reduce my charge?



Each year, billions of gallons of storm water runoff and snow melt flow from roofs, sidewalks, parking lots and similar hard, impervious surfaces into the City’s combined sewer system. This drainage is contaminated with dirt and debris, flows into the same underground pipe via the combined sewer system as unsanitary wastewater and must be treated at the wastewater treatment plant before it can be released back into the environment. Transporting and treating this drainage costs the Detroit Water and Sewerage Department (DWSD) more than $125 million annually.

Federal and State regulatory mandates required DWSD to invest more than $1 billion in combined sewer overflow control facilities to help prevent untreated overflows and preserve Detroit’s water quality. The combination of this investment plus drainage treatment costs account for the drainage charge. Revenue from drainage charges pays for the capital, operations and maintenance costs associated with Detroit’s combined sewer overflow facilities as well as treating wet weather flows at the wastewater treatment plant. Drainage charges are applied on all parcels of real property within the city that drain to the city’s combined sewer system.

Since 1975, most DWSD customers have been paying for drainage as part of their water and sewer billsTogether with the City Assessor’s Office, DWSD is working to ensure all parcels that drain to the city’s combined sewer system are billed for their fair share of drainage costs.

DWSD will launch a Green Infrastructure Credit program in October 2016. Customers who reduce the peak flow and volume of storm water runoff on their property – by disconnecting downspouts or planting rain gardens, for example – can earn credits to be applied to their bill. DWSD, in collaboration with local non-profit organizations, will offer implementation assistance to property owners and developers.

Each of us shares the benefits of clean waterways.  We also share the responsibility of managing drainage. Equitable and accurate billing together with a citywide embrace of Green Infrastructure practices will help Detroit become one of the “greenest” cities in America.


What is the Impervious (Hard) Surface for My Property?

The DWSD Parcel Viewer allows you to search for parcel information by address. Impervious surface area is used to calculate drainage charges (some customers will be phased in over the next year). Open the viewer and type in your street address. DWSD uses data from the City of Detroit Assessor's Office and flyover images to determine the impervious surface for water runoff. If you disagree with the data, please complete the drainage survey form.


Drainage Videos



New Parcels Notification Letter and FAQ

More than 20,000 parcels that contribute to the city’s storm water runoff and snow melt flows but are not being charged for drainage will be added to DWSD’s billing system in October 2016.  Notification letters with frequently asked questions (FAQ) were mailed to parcel owners. Customers should contact DWSD to verify parcel information, ensure drainage charges are accurate and discuss storm water management options.                 


Drainage Survey Form

Customers who need to update parcel information must complete and submit the drainage survey form along with the required documents.


Drainage Charge Information and Forms



DWSD will host a Drainage Charge Credit Workshop for nonresidential property owners on Tuesday, January 24, 2017  at SEMCOG in downtown Detroit. Register for the nonresidential property owners' workshop morning session or afternoon session. More information is available on the online registration page. Registration is required to attend. Space is limited.

Download the presentation from the DWSD Drainage Charge Credit Workshop on November 9, 2016.

Workshops for residential property owners will be scheduled in 2017. Keep posted to www.detroitmi.gov/dwsd and the DWSD Facebook page for updates.


Customer Meetings