Rancho Cucamonga, CA Environmental Rules: Grading & Drainage (2026)

Grading and drainage activities in Rancho Cucamonga are regulated by Municipal Code Title 19, which adopts California Building Code Appendix J with local amendments. A grading permit is required for any earthwork moving 50 cubic yards or more, any excavation or fill exceeding 5 feet in depth, any work within the hillside management overlay area, and any alteration of natural drainage patterns. Grading plans prepared by a licensed civil engineer must include existing and proposed contours at 2-foot intervals, drainage calculations for 10-year and 100-year storm events, erosion control BMPs, and haul route exhibits if material is imported or exported. Drainage design must route runoff to approved public or private outfalls (curb and gutter, storm drain inlets, or engineered detention basins) without increasing flows or concentrating water onto adjacent properties, which would create nuisance liability under California Civil Code Section 3479. Alta Loma hillside properties require additional geotechnical review due to debris flow and alluvial fan conditions. Final inspection by Engineering Services is required before certificate of occupancy.