Compton, CA Environmental Rules: Flood Zones (2026)

Compton adopted its floodplain rules under Ordinance 2000 after FEMA identified an AR Zone, a special flood hazard area created when a previously accredited flood-control system is decertified and is in the process of being restored to a 100-year (1%-annual-chance) level of protection. 1 applies the rules to all properties FEMA maps into that AR Zone, based on the Flood Insurance Study dated July 6, 1998, and its accompanying Flood Insurance Rate Map, both on file with the City Clerk and the Department of Building and Planning.

5 requires a Development Permit, issued by the Department of Building and Planning, before any construction, filling, grading, dredging, mining, paving, excavation, drilling or storage of equipment or materials begins in the mapped zone. Applicants must submit scaled plans showing the proposed elevation of the lowest floor, including any basement, relative to mean sea level and the elevation of the highest adjacent grade, plus a description of any watercourse the project will alter or relocate. 7 to confirm state and federal permits are also in hand and that the site is reasonably safe from flooding.

4(c) exempts additions, modifications, improvements or rehabilitations to legally existing buildings from the permit requirement. A hardship variance is available, but the ordinance warns that granting one without an exceptional, unusual circumstance particular to the property, rather than mere inconvenience or cost, risks fraud on or victimization of the public because a below-grade structure remains at increased flood risk for 50 to 100 years.