Seawall raising in Fort Lauderdale

Who needs a seawall raised

Owners whose walls overtop at king tides, owners who have been cited, and owners planning a repair big enough to trigger the city's height rule.

• Water over the cap at high tide
• A city citation for overtopping
• A repair of $300 or more per linear foot in Miami Beach
• Plans to sell, rebuild or add a dock

Planning a two-step raise

The 4 ft option only works if the wall and cap are designed now to take the extra foot later, so the decision is made at design stage, not after the wall is built.[1]

King tides

The City's king tide guidance asks owners to build new seawalls to a minimum top elevation of 5 ft, and it spends $1.5 million a year on City-owned seawalls.[2]

Fort Lauderdale's flood insurance class

Fort Lauderdale is a Class 7 community in FEMA's Community Rating System: a 15% flood premium reduction in Special Flood Hazard Areas (zones AE, AO, AH and VE) and 10% in Zone X. The City's list includes coastal VE zones, where FEMA does not allow floodproofing below the base flood elevation at all.

Raising the wall stops tidal overtopping, but the home behind it still relies on its own flood protection.[3][4]

Cap repairs and cap additions, priced

The same City material priced cap spall repair at $60 per cubic foot of epoxy mortar and adding a 12 in cap to an existing wall at $75 to $125 per linear foot (2016 figures). Whether an old wall can carry a taller cap is an engineering question, so a marine or structural engineer checks it first.

Use those figures as a starting point and expect a quote based on your wall's length, depth and access.[5]

River tide and inlet tide

NOAA's South Port Everglades gauge shows a 2.79 ft great diurnal range, while the Andrews Avenue bridge gauge up the New River shows 2.28 ft, with mean higher high water about 0.45 to 0.57 ft above NAVD 88 (1983 to 2001 epoch). Lifts and floating docks near the inlet need more travel than those up the river.

Those numbers show how much margin a raised wall really gives above an ordinary high tide.[6][7]

What makes Fort Lauderdale different

The City treats seawalls as tidal barriers. It presumes a wall is in disrepair if it lets upland soil erode, lets material pass through it, or lets tidal water flow unimpeded onto neighbours or the street, and gives owners 60 days to show progress and 365 days to finish. The City also spends $1.5 million a year on its own seawalls.[1][2]

The county layer

Broward County requires a license before any work in, on, over or under its waters, including repairing or replacing a dock or seawall. Broward's regional policy is a consistent top elevation of 5 ft NAVD for seawalls, banks and berms.[8][1]

Permits in Fort Lauderdale

• Broward County environmental licensing: A county license before any work in, on, over or under Broward County waters, including dock and seawall repair.
• City of Fort Lauderdale: Building permits; waivers of the dock and lift projection limit go to the City Commission with a Marine Advisory Board recommendation.
• Florida DEP or South Florida Water Management District: State permit or exemption for docks and walls on the New River and the Intracoastal, on top of the Broward County license.
• US Army Corps of Engineers, Jacksonville District: Federal authorisation for work in the Intracoastal Waterway and other navigable waters.

Seawall height rules by city

Each city sets its own standard, and they do not all use the same vertical datum (NAVD 88 or the older NGVD 1929), so the engineer's survey must state the wall height in the same datum as your city's rule.

Miami Beach: 5.7 ft NAVD for new walls and substantial repairs, or 4 ft NAVD designed to reach 5.7 ft. Coral Gables: a minimum of 6 ft NGVD 1929, structurally able to support 7.5 ft. Fort Lauderdale: a minimum of 5 ft NAVD88, and walls permitted before 1 January 2035 may be built at 4 ft if designed to reach 5 ft by 1 January 2050. Boca Raton: new or replaced walls between 4.0 and 6.0 ft NAVD88, designed to take another 12 to 18 inches.

City of Miami: a 2020 proposal set 6 ft NAVD 88 east of US-1. We have not confirmed it was adopted, so we check with the City for each job.[10][14][1][16][13]

Help with the cost

Miami Beach's Private Property Adaptation program accepts seawall applications on a rolling basis and reimburses 50% of costs up to $20,000, including the $2,500 assessment value; qualifying low to moderate income households need no match up to $17,500. Homes built at least 1 ft above base flood elevation are not eligible. Coral Gables waives a fee for existing homes raising seawalls for sea level rise.[11][15]

Frequently asked questions