10 county-level rules, plus city-specific rules for 6 cities in Riverside County, California.
Verified from official government sources
Riverside County operates under two NPDES Municipal Separate Storm Sewer System (MS4) permits: the Santa Ana River Region permit (R8-2010-0033) and the Whitewater River Region permit (R7-2013-0011), plus the San Diego Region permit in the southwest. All construction over 1 acre requires a state SWPPP, and new development must implement LID BMPs.
Riverside County Ordinance 457 (Grading Ordinance) requires erosion and sediment control on all graded sites year-round, with heightened requirements during the rainy season (October 1 through April 30). Best Management Practices must be in place before any soil disturbance and maintained until permanent stabilization.
Riverside County participates in the National Flood Insurance Program (NFIP) and regulates development in FEMA Special Flood Hazard Areas under Ord. 458 (Flood Damage Prevention) and Ord. 460 Art. III. New structures in the 100-year floodplain (Zone A, AE, AH, AO) must have the lowest floor elevated at least 1 foot above the Base Flood Elevation.
Riverside County Ord. 457 (Grading) regulates earth moving and Ord. 458 (Drainage) regulates stormwater conveyance. A grading permit is required for any earth movement exceeding 50 cubic yards on a single lot, any fill over 3 feet deep, or any cut over 5 feet deep. Onsite drainage may not be redirected onto neighboring property.
Riverside County enforces 100-foot defensible space around structures in State Responsibility Areas and Local Responsibility Areas, with two clearance zones inspected annually by Cal Fire/Riverside County Fire.
California Public Resources Code Section 4291 (Chapter 3. Mountainous, Forest-, Brush- and Grass-Covered Lands)
(a) A person who owns, leases, controls, operates, or maintains a building or structure in the state responsibility area shall at all times do all of the following: (1)(A) Maintain defensible space of 100 feet from each side and from the front and rear of the structure, but not beyond the property line, except as provided in subparagraph (B). The amount of fuel modification necessary shall cons...
California restricts heavy-duty diesel vehicle idling to five minutes statewide, enforced in Riverside County by CHP, sheriff, and South Coast and Mojave Desert air districts, with heightened focus near schools.
Riverside County adopted a Climate Action Plan setting countywide targets for greenhouse gas reduction, addressing transportation emissions, building efficiency, and renewable energy across unincorporated areas and partner cities.
Riverside County coordinates with the South Coast and Imperial air districts on Salton Sea dust mitigation, where receding shorelines expose playa generating PM10 and PM2.5 exceeding federal standards in nearby communities.
California Title 24 Part 6 requires cool roofing on most new and replacement low-slope roofs in Climate Zones 14 and 15, which cover most of Riverside County including the Coachella Valley and desert communities.
Riverside County integrates heat mitigation into General Plan and Coachella Valley specific plans, requiring shade trees, cool roofing, and pedestrian shelter for new commercial and multifamily projects in extreme-heat zones.
6 cities in Riverside County have their own environmental rules rules. Each link goes to that city's dedicated page with code citations.
10 verified rules • Climate Emergency Mobilization, Coastal Development
4 verified rules • Erosion Control, Flood Zones
4 verified rules • Erosion Control, Flood Zones
4 verified rules • Erosion Control, Flood Zones
4 verified rules • Erosion Control, Flood Zones
4 verified rules • Erosion Control, Flood Zones
See every category we cover for Riverside County — parking, noise, fences, fires, animals, pools, and more.
Riverside County Ordinance Hub →