Maricopa, AZ Fence Regulations: Retaining Walls (2026)

Retaining walls in the City of Maricopa are addressed in the city's Fence and Wall Guide and the zoning standards of MCC 18.80.090. A Commercial Retaining Wall Permit is required for retaining walls over four (4) feet measured from the bottom of the footing, and for any retaining wall supporting a surcharge (an added load such as a slope, driveway, or structure behind the wall) regardless of height. A critical measurement rule applies when a solid freestanding fence is built on top of a retaining wall: the height of that fence is measured from the ground level on the lowest side of the combined fence-and-wall assembly. This prevents stacking a full-height fence atop a tall retaining wall to gain extra effective height. If the freestanding portion is set back from the retaining wall by a distance equal to or greater than the height of the freestanding portion, the two can be treated as separate structures for height purposes. Retaining walls must still meet building code structural requirements, and engineered designs are typically required for taller or surcharge-loaded walls. In Maricopa's master-planned subdivisions, grading and retaining walls are also frequently governed by the approved subdivision grading plan and HOA standards, so confirm both before construction.