Moreno Valley, CA Environmental Rules: Erosion Control (2026)

Moreno Valley's semi-arid climate produces intense, erosive rainstorms from October through April, often falling on bare or disturbed soil and carrying sediment directly into the MS4 storm drain system. Moreno Valley Municipal Code and the California Building Code Chapter 18 (Soils and Foundations) together with Appendix J (Grading) require erosion and sediment control plans for all grading permits. During the rainy season, any site with exposed soil must implement BMPs before forecast rain events — common measures include silt fencing on the downgradient perimeter, fiber rolls or straw wattles along contours, stabilized construction entrances (crushed rock pads) to prevent track-out, covered stockpiles, and hydroseeding or mulch on slopes. Sites disturbing 1 acre or more must comply with the California Construction General Permit and prepare a Stormwater Pollution Prevention Plan (SWPPP) with site-specific BMPs and monitoring. Even small residential projects — adding a pool, retaining wall, or ADU — must prevent sediment from leaving the property. Violations can trigger stop-work orders, city clean-up at owner expense, and state fines up to $37,500 per day under the Clean Water Act. Homeowners grading slopes or clearing lots should consult with Public Works before the rainy season begins each fall.