Flowood, MS Environmental Rules: Grading & Drainage (2026)

Municipal codes in Brandon, Pearl, Flowood, and Richland require grading permits for excavation or fill exceeding thresholds that typically range from 50 to 100 cubic yards, slope cuts over 4 feet, or any work that alters natural drainage. Unincorporated Rankin County applies similar standards through its land use regulations at the subdivision review stage. Site drainage must be directed to public storm systems or on-site retention rather than sheet-flowed onto adjacent property. Mississippi follows a reasonable-use rule with civil-law overlay (see Hall v. Wood and related Mississippi Supreme Court cases): upper landowners may not materially increase the flow or change the location of surface water onto lower neighbors without liability. Retaining walls over 4 feet require engineered drawings and separate permits. Structural fill under foundations requires compaction testing (typically 95% standard Proctor). Work in the Pearl River or Ross Barnett Reservoir floodway requires no-rise certification. Rolling terrain around Castlewoods, Grants Ferry, and the Spillway Road corridor makes drainage design particularly important.