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

Retaining walls in the unincorporated county are regulated mainly through the California Building Code, administered by the Shasta County Department of Resource Management Building Division. Under CBC Section 105.2, 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 is not supporting a surcharge or impounding Class I, II or III-A liquids. A 'surcharge' is any added load above the retained soil - such as a sloping backfill, a driveway, a pool, or a structure near the wall - and a surcharged wall requires a permit regardless of height. Tiered walls that are not properly offset are treated as a single tall wall: two three-foot walls too close together can be read as one six-foot wall needing a permit. Permitted retaining walls require engineered drawings showing the wall, footings, and how lateral earth pressure is resisted. Separately, the Zoning Plan height rules in Section 17.84.030 can affect a wall that doubles as a fence: a wall in a required front yard is limited to three feet and a wall in a rear or side yard to six feet in residential districts, with a use permit needed to exceed those caps. Grading associated with a wall may require a grading review. Confirm requirements with the Building Division and Planning Division before construction.