Seawall replacement in Miami Beach

When replacement makes sense

Replacement is the answer when panels are cracked through, the wall leans, repairs would cost more than half of a new wall, or the wall is too low for your city's new standard.

• Panels cracked through or leaning
• Repeated sinkholes despite repairs
• A city notice to raise or rebuild
• Planned dock or lift work that needs a sound wall

The 5.7 ft NAVD standard

New seawalls, new construction and substantial seawall improvements in Miami Beach must reach 5.7 ft NAVD. A wall may stop at 4 ft NAVD only if it is designed to take a future raise to 5.7 ft, so the footing and panels have to be sized for the taller wall from day one.

A replacement wall is built to the current height from the start, so the panels, piles and cap are sized for it.[1]

Tide at Government Cut

NOAA's Miami Harbor Entrance gauge at Government Cut, beside South Beach, shows a 2.46 ft mean range and a 2.70 ft great diurnal range, with mean higher high water about 0.33 ft above NAVD 88 (1983 to 2001 epoch). A wall at 5.7 ft NAVD therefore stands roughly 5.4 ft above an average high tide, the margin the City wants for king tides and sea level rise.

The tide also sets how much of the wall can be worked on dry at low water, which changes crew time.[2]

What bringing a wall to code has cost

The City's 2017 rule of thumb was $1,000 to $1,500 per linear foot to bring an old private seawall up to code. Prices have moved since, but the figure shows why owners plan raises with the grant, PACE financing and the City's seawall elevation tool in hand.

Replacement sits at the top of that range when the waterway is deep or the barge access is tight.[3][4]

The $300 per foot line

Miami Beach measures a substantial repair by cost per linear foot: repairs costing $300 or more per foot must bring the wall to 5.7 ft NAVD. A $20,000 repair on 100 ft of wall is $200 per foot and stays under the line; the same spend on 50 ft is $400 per foot and crosses it.

Knowing where that line sits lets you choose between a repair now and a full raise later with your eyes open.[1]

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][4]

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.[3]

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 a seawall replacement involves

A Florida engineer designs the wall to the site's soil, water depth and the local top elevation. Most replacements go in front of the old wall, which stays in place as backing, because removing it can undermine the yard.

1. Survey and engineered drawings
2. DERM, city and state approvals
3. Turbidity barrier and manatee watch in the water
4. New panels or sheet piles, tiebacks and cap
5. Backfill, drainage and yard restoration

How far out can the new wall go?

Florida Statute 403.813 exempts restoring a seawall at its previous location, upland of it, or within 18 inches waterward of it. Miami-Dade's short form and the federal SPGP VI use the same 18 inch line, measured wet face to wet face, and need no seagrass survey within it.[9][6][10]

Federal permits

Under SPGP VI, the Florida DEP could verify the federal Army Corps authorisation for qualifying seawall work along with the state decision. That permit's stated expiration date was 27 July 2026, and we have not been able to confirm a replacement, so for each job we confirm the federal route with the agencies before we file.[10][11]

Working around manatees

Permits attach the state's Standard Manatee Conditions: all in-water work stops if a manatee comes within 50 ft, and resumes only once it has moved beyond 50 ft or 30 minutes pass without it reappearing. Turbidity barriers must not entangle or block manatees.[12]

Frequently asked questions