LACO Title 22.110.090 governs Hillside Management Areas in unincorporated LA County, applying a slope-density formula, requiring vegetation protection, and triggering geotechnical review and CEQA evaluation for steep-lot development.
The Hillside Management Area (HMA) regulations under LACO Title 22.110.090 cover unincorporated parcels mapped on the county's hillside layer. Maximum residential density is calculated through a slope-density formula: as average parcel slope increases, the allowed dwelling units per acre drops, with very steep parcels (over 50 percent slope) often limited to one unit per several acres. Significant native vegetation, ridgelines, and prominent landforms are protected. Projects trigger geotechnical and soils reports, grading review, haul-route approval, and CEQA evaluation for slope stability, fire risk, and biological resources. Many hillside parcels also lie inside Very High Fire Hazard Severity Zones, layering Title 32 fire code rules on top.
Unpermitted grading, exceeding density limits, removing protected vegetation, or skipping geotech review triggers stop-work orders, daily fines, and required restoration to pre-violation conditions.
Los Angeles County, CA
LA County maintains roughly 30 community plans plus several specific plans under LACO Title 22 that overlay base zoning across unincorporated areas like Alta...
Los Angeles County, CA
Grading in unincorporated LA County requires permits from Building & Safety. The LA County Flood Control District manages the regional drainage system with 4...
Los Angeles County, CA
Brush clearance is critical in unincorporated LA County, which includes extensive wildfire-prone areas. LA County Fire Department requires 200 ft vegetation ...
See how Los Angeles County's hillside overlay rules rules stack up against other locations.
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