Irvine, CA Environmental Rules: Erosion Control (2026)

Section 5-10-137 requires that, prior to grading permit issuance, an erosion and sediment control plan for the proposed development be approved by the Chief Building Official, who may order design or operational changes if weather-driven problems arise. Cut and fill slope faces must be protected against erosion, often through effective planting installed before final approval, and the code lists specific device categories: desilting basins, gravel bags, check dams, cribbing, and riprap, all fully implemented per the approved plan. Streets, sidewalks and site improvements must stay clean; street sweeping or an equally effective method is required, and watering to clean streets is expressly prohibited.

The owner must retain a civil engineer responsible for inspecting the erosion and sediment control system, approving installation of permanent and semi-permanent devices, and periodically reviewing field conditions throughout each rainy season. Desilting basins must meet current City design-capacity standards and, where built of compacted earth, reach 90 percent relative compaction, verified by a soil engineering report. Section 5-10-137(K) requires a "rain event" action plan under the statewide general construction permit, with standby BMPs deployable within 48 hours of a forecasted 50-percent chance of rain, and Section 5-10-137(L) requires effective planting on any slope over five feet high, with irrigation potentially required above 15 feet.

Section 5-10-138 adds post-storm duties: silt and debris must be removed from basins after every rainstorm, the system's performance evaluated and repaired, and if the Chief Building Official must perform emergency maintenance because the responsible party fails to, the grading permit can be revoked in writing and withheld until compliance and any penalty fee are satisfied. Grading commenced without a permit still triggers the erosion-control obligations under Section 5-10-138(F).