Riverside County Ord. 348 hillside-development standards limit grading, building height, and lot coverage on slopes above 10 percent, addressing wildfire risk, erosion, and viewshed protection in mountain communities.
Ord. 348 sets density and design controls based on natural slope, calculated through topographic analysis. Slopes from 10 to 25 percent face reduced lot coverage and required slope-density formulas. Slopes above 25 percent typically require discretionary review and may be designated open space. Mountain communities such as Idyllwild, Pine Cove, and Anza Valley apply additional fire-safety standards including ignition-resistant materials, secondary access, and water flow. Grading exceeding 1,000 cubic yards or 50 vertical feet of cut requires plot-plan or conditional-use approval.
Unpermitted grading triggers stop-work orders, restoration requirements, daily code-compliance penalties, and disqualification from future entitlement on the parcel.
See how Moreno Valley's hillside overlay rules rules stack up against other locations.
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