Selma, CA Fence Regulations: Retaining Walls (2026)

The California Building Code Section 105.2 establishes the threshold for retaining wall permits: any retaining wall that retains a fill or cut of more than 4 feet of unbalanced material, measured from the bottom of the footing to the top of the wall, requires a building permit. Walls at or below this threshold are generally exempt from the permit requirement but must still comply with applicable zoning setbacks and property line requirements. In Selma, the Building Division within the Community Development Department processes retaining wall permits and conducts plan review for structural adequacy. For walls exceeding 4 feet, engineered plans prepared by a California-licensed civil or structural engineer are typically required. These plans must include foundation design, wall thickness and reinforcement specifications, drainage provisions, and soil bearing capacity assumptions. The engineering requirements reflect the structural complexity of taller retaining walls, which must resist lateral earth pressure from the retained soil, hydrostatic pressure from groundwater or irrigation, and any surcharge loads from structures, vehicles, or slopes above the wall. Retaining walls that support a surcharge present special engineering challenges because the additional loading increases the lateral forces the wall must resist. Common surcharge scenarios in Selma include retaining walls along driveways where vehicle traffic loads the soil behind the wall, walls supporting elevated pool decks or swimming pool structures, walls below buildings or building foundations, and walls retaining slopes steeper than 2:1 horizontal to vertical. In these cases, the Building Division may require permits and engineered plans even for walls shorter than 4 feet, because the surcharge fundamentally changes the structural demands on the wall. Drainage behind retaining walls is a critical design consideration in Selma. The Central Valley experiences moderate winter rainfall and year-round agricultural and landscape irrigation, both of which can saturate soils behind retaining walls and create hydrostatic pressure that significantly increases lateral loads. Proper drainage systems typically include weep holes at the base of the wall, perforated drain pipe wrapped in filter fabric behind the wall, and free-draining gravel backfill between the wall and the retained soil. Without adequate drainage, even properly engineered retaining walls can fail due to pressure buildup during wet periods. Retaining walls that serve a dual function as both earth retention and property boundary fencing are subject to the combined height requirements of SMC 11-20-14. The total height is measured from the lower grade level, which is the grade on the downhill side of the retaining wall, to the top of any fence mounted on top of the wall. In front yard locations, this combined height must not exceed the 42-inch (solid) or 48-inch (open) limits. In side and rear yard locations, the combined height of retaining wall and fence must not exceed the six-foot maximum unless the retaining wall serves solely an engineering function and the fence on top does not exceed the standard limits. Setback requirements for retaining walls follow the zoning district standards for the property, and the wall must not redirect drainage onto neighboring properties or the public right-of-way. Retaining walls visible from public streets should use materials and finishes compatible with the neighborhood character.