Detroit, MI Environmental Rules: Stormwater Management (2026)

The City of Detroit Post-Construction Stormwater Ordinance (adopted 2018) is the central rule for managing runoff from new development and redevelopment. It is administered by the Detroit Water and Sewerage Department (DWSD) and applies to 'regulated development and redevelopment' projects — typically those that disturb a minimum threshold of land or add a threshold amount of impervious surface (roofs, parking lots, pavement). Applicants must submit a Post-Construction Stormwater Management Plan, install controls (detention/retention, green infrastructure, bioswales, permeable pavement, infiltration) to manage stormwater volume and peak flow per the DWSD Stormwater Management Design Manual, and maintain those controls in perpetuity. DWSD also operates a Drainage Charge for non-residential parcels billed based on measured impervious area; property owners can earn drainage-charge credits by installing on-site detention, disconnecting downspouts from the combined sewer, or implementing other green-infrastructure measures. Detroit's combined sewer system means that uncontrolled runoff contributes to combined sewer overflows into the Detroit and Rouge Rivers, so the ordinance and drainage charge work in tandem to reduce that load. Erosion and sediment control during construction is regulated separately through BSEED in coordination with EGLE's Part 91 Soil Erosion and Sedimentation Control rules.