Mission Viejo, CA Environmental Rules: Erosion Control (2026)

10, Division 13 of the Mission Viejo Municipal Code governs erosion and sediment control on every graded construction site. Sec. 1310(a) makes erosion prevention, not cleanup, the primary tool: sediment controls only supplement it. Subsection (c) requires the permittee to implement best management practices drawn from the city's engineering standard plans and the current California Stormwater Quality Association Construction BMP Handbook, covering erosion, sediment, wind erosion, tracking, nonstormwater management and waste materials on every project. Subsection (d) caps rainy-season grading at 200 cubic yards on any single permitted site unless the director has approved or waived an erosion control system.

Streets and sidewalks must stay free of loose soil and debris under subsection (e); street sweeping is the required method, and washwater must be fully recovered before it can enter the city storm drain system rather than being discharged there. Subsection (g) requires desilting facilities at drainage outlets sized for a 25-year storm, and subsection (m) requires effective planting on any slope exceeding five feet, with a sprinkler system possibly required above 15 feet. Removable protective devices must be in place at the end of every working day whenever the five-day rain forecast tops a 40 percent probability.

Sec. 1320 requires an erosion control plan filed with the director by September 1 each year for permitted projects, though single residential lots can skip the plan if an approved system is already installed before the city's rainy season begins.