Farmington Hills, MI Environmental Rules: Grading & Drainage (2026)

Grading and drainage controls in Farmington Hills sit at the intersection of four documents: the Farmington Hills Engineering Design Standards (March 2024 revisions), Chapter 33 Article IX (Stormwater Management) of the Code, NREPA Part 91 (Soil Erosion and Sedimentation Control, MCL 324.9101 et seq.), and EGLE NPDES MS4 Permit MIS040000. Post-construction Stormwater Control Measures (SCMs) — detention basins, bioretention cells, sand filters, infiltration trenches, level spreaders, and stormwater wetlands — are designed to capture the runoff treatment volume (typically the first 0.5 inch of impervious-area runoff) and the channel-protection storm (typically the 1-year 24-hour event), with peak-flow control to predevelopment levels for the 10-year and 100-year design storms. Site designers must follow the City's Engineering Design Standards for drainage easements, swale and pipe sizing, headwall and outlet protection, basin freeboard, and emergency overflow. Concentrated discharge that crosses a property line, enters a county drain, or modifies an established drainage course implicates the Michigan Drain Code (Act 40 of 1956, MCL 280.1 et seq.) — the Oakland County Water Resources Commissioner has jurisdiction over established county drains and can require petition, easement, and bond before alterations. Riparian buffer and floodplain rules under NREPA Part 31 / Part 301 (MCL 324.30301 et seq.) apply to any work within or adjacent to the Rouge River system, with EGLE floodplain permits required for fill or structure within the 100-year floodplain. The Alliance of Rouge Communities Rouge River Watershed Management Plan and the EGLE-approved Rouge TMDLs for E. coli and biota set the long-term load reduction targets that the City's grading and drainage controls must support. Submit drainage studies, SCM design calculations, and grading plans to the Farmington Hills Engineering Division at (248) 871-2560.