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

Alpine County's published zoning chapters address fences, yards, and building height rather than setting a separate numeric height limit for retaining walls, so the controlling standard is the statewide building code that the county enforces through its Building Safety Division. Under the California Residential Code and California Building Code, a retaining wall is exempt from a building permit only when it is not over four feet in height measured from the bottom of the footing to the top of the wall, and any retaining wall that supports a surcharge (such as a slope, structure, or roadway above it) requires a permit regardless of height. Because much of Alpine County is steep and at high elevation, county building submittals require two-foot topographic contours, grade elevations, cross-slope information, and erosion-control measures, and engineered retaining structures typically need calculations stamped by a California-licensed engineer. A retaining wall combined with a fence on top is evaluated against both the retaining-wall rules and the fence height limits in Chapter 18.68. Work within a County road right-of-way also requires an Encroachment Permit. Always confirm requirements with the Building Safety Division before grading or building a wall.