Riprap and toe protection in Miami

Signs the toe needs work

Look for these at low tide.

• A gap or hollow under the base of the wall
• Wall tipping toward the water
• Soil loss behind the wall with no visible crack
• Strong wakes or currents along the lot

Riprap rules on Miami's bay and river edges

DERM treats limerock boulders on a 2:1 slope no more than 10 ft waterward of mean high water as an expedited job once its staff have inspected the site, with a $170 riprap inspection fee. Riprap tucked under an undercut wall no more than 2 ft out is exempt, which covers many first repairs.

Riprap is one of the few shoreline jobs that can stay on a simpler permit when it is sized to that limit.[1]

Bayfront lots sit on Outstanding Florida Waters

The Biscayne Bay Aquatic Preserve covers 64,607 acres from the Oleta River to Card Sound and is treated as Outstanding Florida Waters. On open bay frontage that halves the state dock exemption to 500 sq ft of over-water area, against 1,000 sq ft on an artificial canal, and seagrass damage in the preserve can bring a fine of up to $1,000.

Rock footprints are kept off grass beds, so a survey of the bottom comes before the rock order.[2][3][4]

What DERM charges in Miami

A DERM short-form permit costs $470 plus $25 for each $1,000 of construction above $10,000, and every fee carries a 7.5% surcharge. A seawall cap or tie rod job on DERM's expedited track has a $75 review fee, and after-the-fact applications for work already done pay double.

Toe protection usually costs a fraction of a new wall and fits that permit route.[1]

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.

Knowing where that line sits lets you choose between a repair now and a full raise later with your eyes open.[5]

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][4][6]

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.[5]

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.

What riprap does

Riprap is a sloped layer of large rock at the base of a seawall. It breaks wave energy and stops the water from scouring sand out from under the toe. Red mangroves can grow between the rocks, which is the idea behind living shorelines.

Riprap limits and permits

Under SPGP VI, new riprap may extend no more than 10 ft waterward of the mean high water line, and repair or replacement no more than 18 inches beyond the previous footprint. Miami-Dade allows natural limerock boulder riprap on a 2:1 slope up to 10 ft waterward through an expedited authorisation after inspection.[6][1]

Frequently asked questions