Scottsdale, AZ Fence Regulations: Retaining Walls (2026)

2, gives retaining walls their own permit-exempt threshold separate from the general fence rule. 9144m) in height, measured from the bottom of the footing to the top of the wall, do not need a City building permit, unless the wall does one of three things: redirects stormwater runoff, supports a surcharge, or impounds Class I, II or IIIA liquids. Any one of those three conditions removes the exemption even for a wall under 3 feet, meaning a low retaining wall built to divert drainage toward a neighboring lot, hold up a loaded driveway or parking surcharge, or contain flammable or combustible liquids needs a permit and engineering review regardless of its height.

1) give the building official authority to require additional review where a wall sits in an established flood hazard area shown on the adopted Flood Insurance Rate Map. As with fences, the permit exemption for short retaining walls only removes the building-permit step; it does not exempt the wall from the City's Zoning Ordinance or from stormwater and floodplain requirements under Scottsdale Revised Code Chapter 37.