Seawall caps in Miami Beach

When a new cap is the right fix

A cap replacement suits a wall whose panels are sound but whose cap is cracked, spalled or too low.

• Cracked or spalled cap with rust staining
• Wall a little below the city's new height
• Panels separating at the top

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 new cap is often the cheapest way to reach that height, if the old wall can carry the extra weight.[1]

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.

A cap replacement can count as substantial work, so we check the trigger before design.[1]

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.

Cap work is priced per linear foot, so those figures translate directly to your frontage.[2][3]

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.

Caps are formed and poured above the water, but the tide decides how high the new cap must sit to give real freeboard.[4]

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][3]

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.[2]

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.

Can the wall take a new cap?

Not always. Whether a cap can be added depends on whether the existing wall can bear the weight, which a marine or structural engineer must assess. A wall that cannot take it needs replacing instead.[8]

Permits for cap work

Miami-Dade DERM gives cap repair or replacement an expedited administrative authorisation when the building department has approved the structural plans. At the state level, seawall caps, batter piles and king piles used only to stabilise and repair seawalls fall under an exemption in rule 62-330.051(12)(d).[6][9]

Caps and city height rules

In Miami Beach a wall may be built to 4 ft NAVD if it is designed to support a future 5.7 ft NAVD, so the cap and footing need to be designed for that later raise. In Boca Raton the city must approve a location survey before the cap is poured, and a final engineer report confirms the cap elevation.[1][10]

Frequently asked questions