Seawall repair in Miami

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

Exempt, expedited or short form?

Exempt: crack sealing and spall repair on the cap or face, pilaster repair, backfilling, riprap or sand-cement bags at the toe no more than 2 ft waterward. Expedited: cap or tieback repair and replacement with structurally approved plans. Short form: rebuilding or replacing the wall at the mean high water line or up to 18 inches waterward.[1]

Repairs along the Miami River and the bay

Under DERM's rules, a contractor replacing fender or mooring piles in the same spot must hold a certificate of competency and give DERM 24 hours' notice. Where repairs disturb the bottom, the seagrass range that reaches central Biscayne Bay can bring a survey requirement.[1][2]

What would count as a substantial repair

The 2020 Miami proposal defined a substantial seawall repair three ways: work on 50% or more of the barrier length, work costing 50% or more of a new wall, or a change in elevation along 50% or more of the length. It also asked for new walls that can be raised to at least 8 ft NAVD 88 later, with a variance route for undue hardship.

Before we price a repair we check whether its cost or extent would trigger the full height rule.[3]

Two seawall heights split by the Rickenbacker Causeway

The City code text that File 7338 set out to replace puts seawall tops at +5.00 ft NGVD north of the Rickenbacker Causeway and +6.00 ft NGVD south of it, so the same job can have a different minimum depending on which side of the causeway the lot sits. The 2020 proposal would have moved every wall east of US-1 to 6 ft NAVD 88, with the Miami River left to its own section of the code.

A repair that leaves the cap below that height can be the right call, as long as you know a raise may come later.[3]

The tide at the Miamarina gauge

NOAA's Miami Miamarina station on Biscayne Bay records a mean tidal range of 2.17 ft and a great diurnal range of 2.37 ft, with mean higher high water about 0.26 ft above NAVD 88 (1983 to 2001 tidal epoch). Those numbers set how far a lift has to travel, how far a floating dock rises and falls, and how much freeboard a seawall cap really has.

Repairs low on the wall face are timed to the lowest tides of the month.[4]

What makes Miami waterfront work different

Most of Biscayne Bay and its natural tributaries, including the Miami River and Little River, are state-owned submerged lands, so docks over them need the state's consent alongside the DERM permit. The Biscayne Bay Aquatic Preserve is listed by DERM as a permitting contact, and FDEP's free online dock self-certification is not available in aquatic preserves. The federal seagrass range used in dock design reaches central Biscayne Bay.[1][5][2]

City of Miami seawall height

In 2020 the City considered an ordinance (File 7338) to set a 6 ft NAVD 88 minimum for new and rebuilt seawalls east of US-1, outside the Miami River. We have not confirmed that it was adopted, so for every Miami seawall job we confirm the current height rule with the City before design.[3]

Permits in Miami

• Miami-Dade DERM, Coastal Resources Section: Class I permit for any work in, on or over tidal water, the Miami River included, with exempt, expedited and short-form routes for small jobs. Phone (305) 372-6575.
• City of Miami Building Department: Structural and zoning approval for seawalls, docks and lifts inside city limits.
• Florida DEP or South Florida Water Management District: State permit or exemption, and consent to use the state-owned bottom of Biscayne Bay, the Miami River and Little River, which DERM grants for most of the bay on the state's behalf.
• US Army Corps of Engineers, Jacksonville District: Federal sign-off for work in the bay and the river. SPGP VI, the small-project route, passed its stated 27 July 2026 expiry, so we confirm the current route for each job.

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.[1]

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.[9]

Frequently asked questions