National City, CA Environmental Rules: Erosion Control (2026)

Section 15.70.140 adds Subsection J110.3 to Appendix J of the 2019 California Building Code, as the section heading prints it. The erosion control plan submitted with a grading permit application must name the owner or responsible party with a twenty-four-hour phone number, carry the signature of the civil engineer who prepared it, and show desilting basins, debris basins, silt traps, gravel bags, diverters, check dams and slope planting, plus access routes to those facilities in wet weather. Section 15.70.075 makes the City's Storm Water Best Management Practices Manual the minimum BMPs and requires a SUSMP checklist with the plans.

On site, removable protective devices must be in place at the end of each working day when there is a fifty percent chance of rain within a forty-eight hour period. If the permittee does not install or maintain them within two hours of notification at the twenty-four hour number, the City Engineer can send City crews or hire contractors and charge the cost plus reasonable overhead to the permittee's deposit, and only erosion control work can continue until the deposit is restored. Temporary desilting basins of compacted earth are compacted to ninety percent of maximum density with a gravel bag or plastic spillway.

The dry season runs May 1 through September 30. It requires perimeter, sediment control and off-site tracking BMPs, at least 125% of the materials for standby BMPs stored on site, and a weather triggered response plan able to deploy standby BMPs within 48 hours of a storm with a 50% chance of rain. The wet season, October 1 through April 30, adds upgraded protection, stabilized slopes before October 1, and full protection for any incomplete disturbed area left for 10 days or more. The City Engineer can bar grading from October 1st through April 30th without an approved erosion control system. Exposed area is capped at what can be protected before a predicted storm or 17 acres, whichever is smaller, unless the City Engineer approves more in writing.

Cut and fill slopes over 3 feet in vertical height are planted, and slopes over fifteen feet get shrubs or one-gallon trees at ten feet on center. Final approval is withheld until erosion-control measures are complete (Section 15.70.150).