Environmental Rules in Costa Mesa, CA (2026)
5 verified environmental rules for Costa Mesa, California, sourced directly from the municipal code and official government pages.
Verified from official government sources
Stormwater Management
Costa Mesa regulates stormwater runoff as a co-permittee under the Orange County NPDES MS4 Permit issued by the Santa Ana Regional Water Quality Control Board. New development and significant redevelopment must incorporate best management practices and Low Impact Development strategies to prevent polluted runoff from reaching storm drains and waterways.
Costa Mesa Stormwater Management Requirements
Some RestrictionsErosion Control
Costa Mesa requires erosion and sediment control measures for all construction and grading activities. The city has adopted Article 8 of Title 7 of the Orange County Codified Ordinances (Grading Manual) with local modifications, requiring developers to prevent soil erosion and sedimentation during and after construction.
Costa Mesa Erosion and Sediment Control Requirements
Some RestrictionsCoastal Development
Portions of Costa Mesa fall within the California Coastal Zone. Because Costa Mesa does not have a certified Local Coastal Program (LCP), the California Coastal Commission retains permit authority over development in the coastal zone, requiring Coastal Development Permits for most construction and development activities in those areas.
Costa Mesa Coastal Development Regulations
Heavy RestrictionsFlood Zones
Costa Mesa participates in the National Flood Insurance Program (NFIP) and regulates floodplain development under Title 13 (Planning, Zoning and Development), Chapter V, Article 8 of the Costa Mesa Municipal Code. Sections 13-81 through 13-83 govern uses permitted in designated floodway fringe and Special Flood Hazard Areas (SFHAs) shown on FEMA Flood Insurance Rate Maps, development standards for floodway areas, and exceptions. The Santa Ana River forms Costa Mesa's western boundary and Upper Newport Bay borders the city's eastern edge - both are primary regulated drainages. State authority for floodplain regulation derives from California Water Code Sections 9100 et seq. (Flood Control) and Section 8400 (state floodway designation). FEMA's currently effective Orange County FIRM panels apply to all floodplain determinations within city limits.
Flood Zone Regulations (Costa Mesa, CA)
Heavy RestrictionsGrading & Drainage
Costa Mesa requires grading permits for most earth-moving activities and enforces drainage standards to prevent water from flowing onto neighboring properties. The city has adopted the Orange County Grading Manual with local modifications governing excavation, fill, and drainage requirements.
Costa Mesa Grading and Drainage Permit Requirements
Some RestrictionsLooking for Orange County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Costa Mesa city rules.
Environmental Rules in Orange County →