Retaining Walls: Fillmore vs Simi Valley

Do I need a permit for a retaining wall in Fillmore?

Retaining walls over 4 feet in height require a building permit with structural engineering plans. Walls supporting a surcharge (driveway, slope, or structure above) may need permits at any height.

Does a retaining wall need drainage in Fillmore?

Yes. All retaining walls should include drainage provisions such as weep holes or French drains to prevent hydrostatic pressure buildup behind the wall, which can cause failure.

Are there special requirements for hillside retaining walls in Fillmore?

Yes. Retaining walls in hillside areas north of town may require geotechnical investigation. Walls in the floodplain may need additional engineering for flood forces. Consult Community Development.

Do I need a permit for a retaining wall in Simi Valley?

Yes, if the wall exceeds 4 feet from the bottom of the footing to the top. Walls supporting surcharges (slopes, driveways) need permits regardless of height.

Do retaining walls need to be engineered?

Walls requiring permits must have plans prepared by a licensed civil or structural engineer. Hillside properties may also need geotechnical review.

Can I build tiered retaining walls to avoid permit requirements?

Multiple tiered walls within close proximity may be measured as one wall for height purposes. The Building Division determines whether a permit is required based on the total effective height.