Composite dock decking in Miami Beach

Who re-decks

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

Two permits, one elevation certificate

A Miami Beach seawall or dock job needs a City building permit with a site plan, structural plans and an elevation certification, plus Miami-Dade DERM Coastal Resources approval. FDEP and the Army Corps come in where the work reaches state or federal waters, which on the island canals is common.

A deck-only replacement on the same frame is usually the simplest permit here.[1]

Narrow island canals and the 25% rule

On the narrower Miami Beach canals, DERM's short form allows a dock, lift or davit to reach no more than 25% of the waterway width. DERM also uses a D-5 boundary to protect a neighbour's view and access, so it may ask for a letter of consent from the lot next door.

A redeck is the moment to check that the dock still fits the limit if you add width.[2]

Bay-side lots and the aquatic preserve

Lots that face open Biscayne Bay rather than a dredged canal sit on the Biscayne Bay Aquatic Preserve, which counts as Outstanding Florida Waters. There the state dock exemption is 500 sq ft of over-water area, and the preserve says manatees move into the bay in the cooler months.

Over grass, deck height and plank spacing matter as much as the board colour.[3][4][5]

What makes Miami Beach different

The city has about 55 miles of seawall, of which only about 5 miles are publicly owned, so most of it is the responsibility of private owners. Its seawall ordinance dates from Resolution R2016-4009 in May 2016, was strengthened in January 2021 and amended again in July 2025.[1][7]

Groundwater and flooding

The city notes that groundwater rises through the porous bedrock under Miami Beach, so a seawall alone cannot stop flooding. A raised wall stops tidal overtopping; drainage and flood protection handle the rest.[8]

Permits in Miami Beach

• City of Miami Beach Building Department: Building permit with a site plan, structural plans and an elevation certification.
• Miami-Dade DERM, Coastal Resources Section: Class I permit or exemption for seawalls, docks and lifts on the island canals and the bay, issued alongside the City permit. Phone (305) 372-6575.
• Florida DEP or South Florida Water Management District: State review where a dock or wall reaches open Biscayne Bay, part of the aquatic preserve, where FDEP's free online self-certification is not available.
• US Army Corps of Engineers, Jacksonville District: Federal authorisation for work in Biscayne Bay and Indian Creek; we confirm the small-project route since SPGP VI's stated July 2026 expiry.

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.[2][5]

Frequently asked questions