Sierra County, CA Fence Regulations: Retaining Walls (2026)

Sierra County's code recognizes retaining walls as a distinct structure. In the grading provisions, SCC 12.08.520 (Setbacks - General) states that its cut-and-fill slope setbacks apply to property boundaries, easements, buildings and structures 'other than fences and retaining walls,' confirming that retaining walls are handled separately from ordinary grading-slope setbacks. That section sets slope setbacks measured from the top of a cut or fill (height divided by five, no less than 2 feet and no more than 10 feet) and from the toe (height divided by two, no less than 2 feet and no more than 20 feet) for the slopes themselves. For the walls, permit requirements come through the county's adopted building code (SCC Chapter 12.04, adopting the California Building Code and California Residential Code). Under the standard California Residential Code exemption that the county adopts, retaining walls are typically exempt only when they are not over 4 feet measured from the bottom of the footing to the top of the wall and are not retaining a surcharge or impounding flammable liquids; taller or loaded walls generally require a permit and engineering. Because terrain in unincorporated Sierra County is steep and geologically variable, the Planning Director may also require a soils or geologic report. Confirm requirements with the Sierra County Building Division before constructing a wall.