Which seawall guide fits what you see?
Most seawall trouble shows up as one of a few signs. Find yours below, then open the guide in the last column.
| What you see | What it often means | Read first |
|---|---|---|
Rust stains, or concrete flaking off the cap | Steel inside the concrete is rusting and swelling | |
A crack where a davit or boat lift bolts to the cap | Load concentrated at one connection | Cap repair, then docks and lifts |
A sinkhole or soft ground behind the cap | Fill washing out through a joint, a crack or under the wall | |
Water standing behind the wall after rain or a king tide | Drains that are blocked or missing | |
The wall leans toward the water, or the cap is out of line | A tie rod, anchor or toe problem | |
The bottom is scouring away at the base of the wall | Toe erosion | |
A dock, lift or davit damaged in a storm | Dock damage, and possibly the wall it ties into | |
Damage along most of the wall, or a notice from the city | The wall may be near the end of its life | |
Not sure what you are looking at | Unknown |
Two signs often share one cause. A sinkhole plus a lean points to what holds the wall up, not just its fill. Book an assessment before you collect quotes.
Seawall repair guides that find the cause
Start here when something changed and you do not know why yet.
- Seawall assessment. An engineer names the failing part and the cause, and lists what could not be seen, such as buried tie rods. Book it before you compare prices.
- Cap repair. The cap is the concrete beam along the top. When the steel inside rusts, it swells and splits the concrete. The guide covers patches, new caps and the cap rules in Marathon and Key Colony Beach.
- Soil loss and drainage. A hole behind the wall means fill is leaving through it. The guide covers filter fabric, weep holes and the 6-inch swale Marathon requires. Marathon code 106.36
- Foam injection. Foam can fill a confirmed void or seal a joint. It does not hold up a moving wall, and Key Colony Beach has warned owners about unlicensed foam firms. KCB soil amendment warning
- Tiebacks and anchors. A typical Key Colony Beach wall hangs on steel rods tied to a deadman 10 to 12 feet back. When a wall leans, that system is the first suspect. KCB Seawall Owner’s Manual
Guides for seawall replacement and shoreline projects
- Seawall replacement. In most of the Keys a new wall goes in the old footprint. Unincorporated Monroe County and Marathon ban new vertical walls on open water. Monroe County code 118-12(k)(3) Marathon code 106.36
- Riprap and shoreline stabilization. Riprap is loose rock on a slope or at the foot of a wall. Key West’s code makes it the first alternative to a hard wall. Key West Code 110-182
- Docks and boat lifts. A dock on a dredged canal can be twice the size of an open-water dock before it loses the state exemption: 1,000 versus 500 square feet. F.S. 403.813(1)(b) Rule 62-302.700
- Living shorelines. Native plants, sometimes with rock, can protect sheltered shores. NOAA does not treat them as an open-ocean option. NOAA Fisheries
Why does the same seawall job follow different rules on each key?
Five local governments issue permits between Key West and Long Key. Their seawall policies point in different directions.
| Jurisdiction | Policy on vertical seawalls | Source |
|---|---|---|
Unincorporated Monroe County | New walls only on manmade canals, channels and basins, only for severe erosion, and only where plants or riprap will not work. None on open water. | |
City of Key West | Hardening only when erosion is a critical peril and plants have failed. Riprap first, and generally not vertical walls. | |
City of Marathon | Hard walls only where riprap will not do, as the City Biologist decides. No new vertical walls on open water. | |
Key Colony Beach | Seawalls required wherever state or federal agencies allow them. | |
City of Layton | The comprehensive plan calls for riprap, plants or cantilevered platforms instead of vertical bulkheads. |
State and federal reviews sit on top of all five. See the permit guide, or start with the Lower Keys or Middle Keys overview.
Who issues the seawall permit for my key?
| Where the lot is | Local permit office | Phone |
|---|---|---|
Key West, inside city limits | City of Key West Building Department, 1300 White Street | (305) 809-3956 Key West Building Department |
Knight Key to Grassy Key and Coco Plum | City of Marathon Building Department, 9805 Overseas Highway | |
Key Colony Beach | Key Colony Beach Building Department, 600 West Ocean Drive | (305) 289-1212, ext. 3 Key Colony Beach Building Department |
Layton, on Long Key | Layton City Hall, which routes building questions to its contracted administrator | |
Every other key, including Key Haven, Rockland Key and the south side of Stock Island | Monroe County Building Department, any office | Stock Island (305) 295-3990, Marathon (305) 289-2501, Big Pine Key (305) 289-2877 Monroe County Building, Stock Island Monroe County Building, Marathon Monroe County Building, Big Pine Key Key West floodplain page |
Mile markers are approximate, so confirm your parcel’s city status with the Monroe County Property Appraiser. Marathon Charter, Sec. 10 Monroe County takes applications only online, through its OPAL system. Monroe County online permitting
Turn a seawall guide into a plan
- Read the guide that matches what you see, and write down the questions it raises.
- Pull old permits and surveys. The assessment guide lists each portal.
- Price the work with the cost guide, including permit fees and barge access.
- Check the license with the contractor check guide.
- Tell us what your seawall needs, and we will help you plan the next step.
Show sourcesHide sources
- LDR Sec. 106.36 Criteria For Approval (Hardened Shorelines)Source reviewed 2026-10-28
- Warning: Soil Amendment ServicesSource reviewed 2026-10-28
- City of Key Colony Beach Seawall Owner's ManualSource reviewed 2026-10-28
- Monroe County Land Development Code, Chapter 118 - Environmental ProtectionSource reviewed 2026-10-28
- Code of Ordinances, Subpart B Land Development Regulations, Ch. 110 Resource Protection, Art. IV Coastal ResourcesSource reviewed 2026-10-28
- Section 403.813, Florida Statutes (2026)Source reviewed 2026-10-28
- Rule 62-302.700, F.A.C. (Special Protection, Outstanding Florida Waters)Source reviewed 2026-10-28
- NOAA Fisheries: Understanding Living ShorelinesSource reviewed 2026-10-27
- Code of Ordinances Ch. 5, Art. III Marine Construction and Improvements, Docking of BoatsSource reviewed 2026-10-28
- Comprehensive Plan Amendment Package (Ord. No. 2022-11-01), adopted June 1, 2023Source reviewed 2026-10-28
- Building Department - About UsSource reviewed 2026-10-28
- BuildingSource reviewed 2026-10-28
- City of Marathon Charter, Sec. 10 Land DescriptionSource reviewed 2026-10-28
- Building Department and Code EnforcementSource reviewed 2026-10-28
- Contact UsSource reviewed 2026-10-28
- City StaffSource reviewed 2026-10-28
- Building and PermittingSource reviewed 2026-10-28
- Floodplain Management (FEMA)Source reviewed 2026-10-28
- Online Permitting ServicesSource reviewed 2026-10-28