Composite dock decking in Miami

Who re-decks

Owners with splintering or soft boards on sound framing, and owners building a new dock who want less upkeep.

Bayfront lots sit on Outstanding Florida Waters

The Biscayne Bay Aquatic Preserve covers 64,607 acres from the Oleta River to Card Sound and is treated as Outstanding Florida Waters. On open bay frontage that halves the state dock exemption to 500 sq ft of over-water area, against 1,000 sq ft on an artificial canal, and seagrass damage in the preserve can bring a fine of up to $1,000.

Over grass, deck height and plank spacing matter as much as the board colour.[1][2][3]

What DERM charges in Miami

A DERM short-form permit costs $470 plus $25 for each $1,000 of construction above $10,000, and every fee carries a 7.5% surcharge. A seawall cap or tie rod job on DERM's expedited track has a $75 review fee, and after-the-fact applications for work already done pay double.

A deck-only replacement on the same frame is usually the simplest permit here.[4]

The 25% waterway rule on the county short form

Miami-Dade DERM handles a single-family dock, davit, boat lift or mooring pile on its short form only if the structure does not protrude more than 25% of the waterway width. On the narrower canals off the Miami River and Little River, that width test is often what decides how far a dock or lift can reach.

A redeck is the moment to check that the dock still fits the limit if you add width.[4]

What makes Miami waterfront work different

Most of Biscayne Bay and its natural tributaries, including the Miami River and Little River, are state-owned submerged lands, so docks over them need the state's consent alongside the DERM permit. The Biscayne Bay Aquatic Preserve is listed by DERM as a permitting contact, and FDEP's free online dock self-certification is not available in aquatic preserves. The federal seagrass range used in dock design reaches central Biscayne Bay.[4][3][5]

City of Miami seawall height

In 2020 the City considered an ordinance (File 7338) to set a 6 ft NAVD 88 minimum for new and rebuilt seawalls east of US-1, outside the Miami River. We have not confirmed that it was adopted, so for every Miami seawall job we confirm the current height rule with the City before design.[6]

Permits in Miami

• Miami-Dade DERM, Coastal Resources Section: Class I permit for any work in, on or over tidal water, the Miami River included, with exempt, expedited and short-form routes for small jobs. Phone (305) 372-6575.
• City of Miami Building Department: Structural and zoning approval for seawalls, docks and lifts inside city limits.
• Florida DEP or South Florida Water Management District: State permit or exemption, and consent to use the state-owned bottom of Biscayne Bay, the Miami River and Little River, which DERM grants for most of the bay on the state's behalf.
• US Army Corps of Engineers, Jacksonville District: Federal sign-off for work in the bay and the river. SPGP VI, the small-project route, passed its stated 27 July 2026 expiry, so we confirm the current route for each job.

What we check before re-decking

• Joists and stringers for rot
• Fasteners and hardware for corrosion
• Pilings at the waterline
• Board spacing rules for your waterway

Decking and permits

A like-for-like re-deck is DERM-exempt in Miami-Dade, but your city may still need a permit. Making the dock bigger changes the over-water area, which FDEP counts toward the 500 or 1,000 sq ft exemption limits, so it needs a permit review.[4][3]

Frequently asked questions