Key Facts Full Breakdown Violations FAQ Sources

Maricopa County, AZ Fence Regulations: Retaining Walls (2026)

Some Restrictions

Verified 1 month ago|Source: https://www.maricopa.gov/6481/Fence-Wall-and-Pool-Barriers-Requirement →

Recently verified

Key Facts

Permit: Required for all retaining walls
Engineering: Required over 4 feet total height
Drainage: Must comply with FCDMC standards
Authority: Planning and Development Department

City-specific rules exist: Mesa, Phoenix, Tempe, Chandler, Gilbert, Surprise, Goodyear, Glendale, Peoria, and Scottsdale have their own retaining walls rules that differ from Maricopa County's county-level regulations. If you live in one of those cities, check the city-specific page instead.

Summary

Retaining walls in unincorporated Maricopa County require building permits. Walls over 4 feet in height (including any fence or surcharge on top) require engineered plans sealed by an Arizona Registered Professional. Retaining walls must comply with grading and drainage standards enforced by the Flood Control District.

Full Breakdown

Retaining walls exceeding four feet in height in unincorporated Maricopa County require a building permit and engineered plans reviewed by Maricopa County Planning and Development at (602) 506-3301. Desert lot grading often necessitates retaining walls to manage elevation changes and direct monsoon stormwater runoff away from structures. Walls within FEMA-designated flood zones require additional review by the Flood Control District of Maricopa County at (602) 506-1501 to ensure they do not redirect floodwater onto adjacent parcels. Drainage weep holes and proper backfill are essential given the caliche-heavy desert soils that impede water absorption. Multiple tiered walls under four feet each may still trigger permit requirements if combined height exceeds the threshold.

Violations & Fines

Specific penalty amounts for this ordinance are not published in a publicly accessible fine schedule. Contact Maricopa County code enforcement directly for current fines, enforcement procedures, and hearing options.

Frequently Asked Questions

Do I need a permit for a retaining wall in Maricopa County?

Yes. Building permits are required for retaining walls. Walls over 4 feet (including surcharge) require professionally engineered plans.

Do tiered retaining walls count as one wall in Maricopa County?

They may. Multiple tiered walls under four feet each can still trigger engineered-plan requirements if the combined height exceeds four feet. Contact Planning and Development at (602) 506-3301.

How does Maricopa County compare?

See how Maricopa County's retaining walls rules stack up against other locations.

Compare to Another Location View Arizona Overview

Maricopa County, AZ Fence Regulations: Retaining Walls (2026)

Key Facts

Summary

Full Breakdown

Violations & Fines

Frequently Asked Questions

Sources & Official References

Related Maricopa County Ordinances

Parking Rules: Loading Zones

Parking Rules: Curb Color Rules

Fire Regulations: Smoke Detectors

Home Business: Home Occupation Permits

Short-Term Rentals: Night Caps

Rental Inspections: Lead-Hazard Inspections

More Fence Regulations in Maricopa County

Retaining Walls in Other Cities

How does Maricopa County compare?

See something wrong?