Moreno Valley, CA Environmental Rules: Grading & Drainage (2026)

Moreno Valley Municipal Code Title 8, consistent with California Building Code Appendix J, regulates grading, excavation, fill, and drainage modification on private property. A grading permit is required for movement of more than 50 cubic yards of earth, for any cut or fill over 3 feet in height, for any grading on a hillside exceeding specified slopes, and for any alteration of natural drainage patterns. Applicants must submit a grading plan prepared or stamped by a California-licensed civil engineer for projects exceeding state thresholds (typically 200+ cubic yards or more complex conditions). Plans must show existing and proposed contours, cut/fill calculations, slope stability analysis, drainage paths, BMPs for erosion control, and how runoff will be managed without impacting neighbors or the public right-of-way. California law and common-law principles prohibit redirecting surface water onto adjacent properties — the natural flow concept means water must continue in its pre-development path or be routed to an approved drainage system. Moreno Valley soils include expansive clay in many neighborhoods, requiring careful compaction and moisture control. Final grading must be signed off by the engineer of record before Building and Safety will sign off on a certificate of occupancy. Unauthorized grading can trigger stop-work orders, required restoration, and fines.