Troy, MI Environmental Rules: Stormwater Management (2026)

02 of Troy's Zoning Ordinance, effective July 23, 2026, ties stormwater control to the site plan review process required under Article 8: any project going through that review must use best management practices (BMPs) to prevent flooding, protect water quality, reduce soil erosion, and preserve wildlife habitat. Stormwater management plans must meet the City Engineer's Engineering Design Standards and rely on nonstructural techniques wherever feasible, including limiting land disturbance and grading, keeping vegetated buffers and natural vegetation, minimizing impervious surfaces, and using terraces, contoured landscapes, runoff spreaders, swales, and infiltration devices.

New development and redevelopment must provide on-site storage of stormwater at a volume and discharge rate the City sets, and site design must prioritize natural drainage patterns so alterations do not cause flooding or water-quality degradation for downstream neighbors. Where large volumes of grease and oil could accumulate, such as commercial and industrial parking areas, oil separators are required, and any site storing or using chemicals must submit a spill response plan for City approval. Wetlands may be used for stormwater management only if the developer obtains permits from the Michigan Department of Natural Resources and Environment (Michigan's EGLE) and any applicable federal agency. 03, which take precedence over the base zoning district's standards whenever the two conflict.