Miami, FL Fence Regulations: Retaining Walls (2026)
Key Facts
- Minimum wall height
- 12 inches above highest grade
- Governing chapter
- Ch. 20, Flood Damage Prevention
- Engineering requirement
- 100-year storm drainage calculation
- Enforcement
- Building official, Sec. 20-14 penalties
Summary
Miami requires any elevated or filled residential lot to be enclosed by a perimeter retaining wall at least 12 inches above the highest grade, plus a drainage calculation confirming stormwater stays on site during a 100-year storm.
Elevated or filled lots are required to meet the following requirements: (1)Be enclosed by a perimeter retaining wall, minimum elevated 12 inches above highest existing and proposed grade elevations.(2)Provide a drainage calculation that demonstrates retention of rainwater within surrounding property lines based on 100-year storm, 20 minutes time of concentration, per design standards - Miami Dade County - Public Works Manual - Part 2 - Design and Construction - WC 1.1 Rainfall Intensities—5 min. to 24 hrs.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 23 | Ordinance 11000 (Previous Zoning Code): Supplement 22 | Miami 21 (Zoning Code): ?).
Full Breakdown
Under Chapter 20, the city's flood damage prevention code, any lot elevated or filled above the crown of road or Miami-Dade County flood criteria maps must be enclosed by a perimeter retaining wall rising at least 12 inches above the highest existing or proposed grade. The applicant must also submit a drainage calculation, per Miami-Dade County Public Works Manual design standards, showing the fill retains a 100-year, 20-minute storm entirely within the property lines rather than shedding water onto neighboring lots. The rule exempts work needed for reasonable vehicular access and grade below 6.00' NAVD 88. Violations are enforced by the building official under Sec. 20-14, with each day a separate offense.
Violations & Fines
Violating Chapter 20 is a code enforcement offense under Sec. 20-14, punishable as provided in Sec. 1-13, with each day of noncompliance a separate violation; the building official may also pursue injunctive relief or revoke permits.
Frequently Asked Questions
Does every retaining wall in Miami need to be 12 inches tall?
Do I need an engineer's drainage calculation for a retaining wall?
Sources & Official References
Other rules in Miami
Florida rules heatmap·Compare Miami to another location·View the Florida fence regulations overview
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Retaining Walls in Nearby Cities
How other cities in Miami-Dade County handle retaining walls.