Pinellas County, FL Fence Regulations: Retaining Walls (2026)

Pinellas County Code § 58-576 sets minimum standards for 'All seawalls, bulkheads, and retaining walls constructed or altered, projected or prolonged, on or adjacent to waters of the county, other than those of the Gulf of Mexico,' requiring them to be 'of concrete, aluminum, or wood construction.' The article's definitions section makes clear this covers waterfront structures, not ordinary yard retaining walls: a 'seawall' is defined to specifically exclude 'upland retaining walls located outside of the waters of the county' (§ 58-501).

The concrete standard alone runs several pages of engineering detail: concrete must test to a minimum 3,500 psi at 28 days, sheet piling must be at least five and five-eighths inches thick with steel reinforcement, the poured cap must be at least nine and one-half inches thick and 16 inches wide, and tieback rods must be no shorter than 12 feet and spaced no more than ten feet apart. The wall's elevation on the bay must reach at least five feet USCGS datum mean sea level. Aluminum seawalls are capped at five feet of exposed height and must use a specific 6061-T6 alloy sheet pile; wooden seawalls require pressure-treated Southern pine piles at least nine inches in diameter, penetrating the ground 50 percent of their total length.

Walls facing the open Gulf of Mexico follow a stricter, masonry-only standard under § 58-577, with thicker seven-and-one-half-inch sheet piling, a 12-inch cap, and a minimum elevation of six feet USCGS datum. Before this design work begins, § 58-530 requires a permit, and § 58-573(1) requires the construction permit itself to come from the county building department if the property sits in the unincorporated area, or from the municipality if it's inside city limits. Existing seawalls needing replacement after storm damage may skip the usual dredge-and-fill permit if the county formally activates its emergency-repair exemption (§ 58-507(d)).