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.
South San Gabriel, CA
South San Gabriel is an unincorporated community in Los Angeles County, so amplified music is governed by County Code Title 12, Chapter 12.08 (Noise Control)...
Los Angeles County, CA
The 2022 LA County Curb Management Strategy prioritizes pickup and dropoff over parking and loading in commercial corridors. DPW retrofits curb zones using a...
Los Angeles County, CA
LA County Code Title 12.84 bans expanded polystyrene takeout containers at unincorporated-area food businesses. California AB-1201 sets ASTM compostability l...
Los Angeles County, CA
LA County Code Title 12.84 (Ord. 2008-0006) bans expanded polystyrene foam cups at all county facilities and food vendors operating on county property. Calif...
Los Angeles County, CA
California AB-1276 prohibits restaurants and food vendors from automatically providing single-use foodware accessories. Utensils, straws, condiments, and sti...
Los Angeles County, CA
FilmLA processes commercial filming permits for unincorporated LA County, coordinating with Public Works on road closures, LA County Sheriff for traffic and ...
Side-by-side rule comparisons with other cities in Los Angeles County.
See how South San Gabriel's hillside overlay rules rules stack up against other locations.
Help us keep this page accurate. If you notice an error or outdated information, let us know.