Dover, FL Fence Regulations: Retaining Walls (2026)

Hillsborough County splits retaining-wall regulation between two codes. The Land Development Code, Part 6.07.00 (Fences and Walls) within Article VI (Design Standards and Improvement Requirements), sets dimensional, location, and setback rules and treats retaining walls as walls subject to those provisions. The Hillsborough County Construction Code (County Code Chapter 8, Article I) adopts the 2023 Florida Building Code (8th Edition), under which Section 105.2 generally exempts retaining walls four feet or less in height (measured from the bottom of the footing to the top of the wall) from a building permit unless the wall supports a surcharge (e.g., a driveway, pool deck, structure, or sloped fill above) or impounds Class I, II, or IIIA liquids. Walls over 4 feet, walls supporting any surcharge, and walls in Special Flood Hazard Areas require a permit from Hillsborough County Building Services along with structural plans signed and sealed by a Florida-registered Professional Engineer. For new residential construction, the Hillsborough County site-plan checklist requires applicants to identify special design techniques (tree wells, aeration systems, retaining walls, grade dishing) wherever there is a grade differential between existing and proposed conditions. Grading must follow one of three paths: (1) match the county-approved subdivision lot grading plan; (2) submit grading and finished-floor plans signed and sealed by a Florida-registered Professional Engineer; or (3) use the NO FILL Attestation, which restricts fill to septic drainfields and building foundations, caps foundation grading at 6 feet from the building footprint, requires a 3-foot setback from side property lines, and limits slopes to 4:1 (horizontal to vertical) maximum. Retaining walls cannot redirect stormwater onto adjacent properties (LDC stormwater and grading provisions, plus F.S. 373.4595 and SWFWMD rules), cannot be located within easements without utility-provider written consent, and must respect property-line setbacks identified in Part 6.07.00. In V Zones and Coastal A Zones, retaining walls are subject to additional FBC and ASCE 24 review because they can act as obstructions to flood flow. Tampa, Plant City, and Temple Terrace administer their own retaining-wall codes within incorporated city limits.