Seawall repair in Islamorada

Signs you need seawall repair

Call us when you see any of these. Each one lets water and soil move through the wall, and the damage speeds up once it starts.

• Cracks, spalling or rust stains on the cap or face
• Open or leaking joints between panels
• Sinkholes or soft ground just behind the wall
• Water seeping through the wall at high tide
• A cap or panels leaning toward the water

Seawalls and riprap inside the setback

Islamorada's shoreline setback keeps buildings 20 to 50 ft from mean high water, but it does not apply to seawalls, riprap and bulkheads whose purpose is erosion control or upland protection. Because the Keys are an area of critical state concern, the 2024 ordinance was approved by the Florida Department of Commerce.

Many crack, spall and cap repairs move faster than a rebuild because of that permit route.[1]

Bay side and ocean side tides differ fourfold

NOAA's Florida Bay gauge at Upper Matecumbe Key shows a great diurnal range of only 0.61 ft, with mean higher high water about 0.41 ft below NAVD 88, while the Hawk Channel gauge a short way across the key shows 2.28 ft (1983 to 2001 epoch). A lift or floating dock sized for one side of Islamorada is wrong for the other.

Repairs low on the wall face are timed to the lowest tides of the month.[2][3]

Flood maps from 2005, new ones pending

Islamorada still builds to effective flood maps dated 18 February 2005. Preliminary maps went through appeals between March and June 2021, FEMA has not announced when they take effect, and the Village has promised six months' notice once it does.

A repair that leaves the cap below that height can be the right call, as long as you know a raise may come later.[4]

Watch the datum: about 1.5 ft

The Village notes that converting from NGVD29 to NAVD88 shifts elevations by about -1.5 ft on average in Monroe County, and the shift varies from place to place. Old plans and new maps use different datums, so a cap or floor height has to be converted before anyone compares numbers.[4]

What makes Islamorada different

Principal buildings sit 20 ft from the mean high water line on altered shorelines such as canals, 30 ft on open water with conditions, and 50 ft on unaltered shorelines. Docks, lifts, davits, seawalls and riprap are water-dependent structures that may sit inside that setback under the Village's standards.[1]

Sanctuary and manatee layers

The federal small-project permit, SPGP VI, required Sanctuary sign-off before any Islamorada project in Keys waters, and crews follow the state manatee conditions on every in-water job.[5][6]

Permits in Islamorada

• Islamorada, Village of Islands, Planning and Development Services: Docks, lifts and shoreline structures under Village Code Chapter 30.
• Florida Keys National Marine Sanctuary: Sanctuary waters surround every Islamorada key from the mean high water mark; we confirm what Sanctuary approval each project needs.
• Florida DEP or South Florida Water Management District: State permit or exemption; part of the Village's water is the Lignumvitae Key Aquatic Preserve.
• US Army Corps of Engineers, Jacksonville District: Federal authorisation for work in the Sanctuary waters around the Village.

How do you repair a seawall?

We start with a close inspection at low tide to find where water and soil are moving. Then the fix matches the fault: crack injection or patching for the face, rebuilt concrete for spalled caps, new tie rods and anchors where the wall is leaning, and compacted fill behind the wall once it is sealed.

1. Inspect the cap, face, joints and toe at low tide
2. Confirm the permit path (exempt, expedited or short form)
3. Seal joints and cracks, repair spalls
4. Replace tiebacks or the cap if needed
5. Backfill and restore the yard

Which seawall repairs need a permit?

Miami-Dade DERM lists as exempt: sealing cracks and spall repair on the cap or face, repair or sealing of pilasters, backfilling landward of an existing seawall, riprap or gunite tubes under an undercut wall no more than 2 ft waterward, and sand-cement bags at the toe no more than 2 ft waterward. Cap and tieback repair or replacement need structurally approved plans from the building department and an expedited DERM authorisation. Your city may still need a building permit.[7]

Repair or replace?

If the panels are sound and the wall is tall enough for local rules, repair is usually the better value. If repairs would cross a city's substantial repair line, such as $300 per linear foot in Miami Beach, you may have to raise the whole wall anyway, and replacement can make more sense.[8]

Frequently asked questions