Gardena, CA Environmental Rules: Erosion Control (2026)

Gardena Municipal Code § 15.06.090 adds several sections to Appendix J (Grading) of the 2022 California Building Code, and Section J112.1, Sediment Control, is the operative erosion rule. It requires that sediment caused by a grading project be retained on the site to the greatest extent feasible, and sets the maximum permanent post-project sediment-loss rate at the natural erosion rate that existed before grading began; if the Building Official finds excessive erosion occurring from the project, erosion and sediment control measures must be implemented immediately to bring the rate back down.

Section J112.1(B) lets the Building Official require sediment basins, sediment traps or similar temporary or permanent control measures before clearing and grading operations start, and requires that temporary erosion facilities be removed once construction is complete and soils are stabilized, with the Building Official's written approval. The same amendment package adds companion sections read together with J112.1: Section J113.1 lets the Building Official or a civil, soils or geotechnical engineer increase the minimum setbacks in Appendix J for safety, stability or drainage access; Section J114.1 requires approved erosion and sediment control devices for all grading and filling, including energy-absorbing devices and sedimentation basins; and Section J115.1 requires mulching, seeding or other stabilization of exposed slopes, preferring native or locally adapted plants.