Repair or replace: the short answer
Short answer: repair when the damage is local and the panels, tie-backs and toe are sound. Plan a replacement when the wall is failing along much of its length. Monroe County county code 118-12(k)(4)
In the Keys, replace in the same footprint where you can. County code expects it, and an open-water lot may not get a new vertical wall at all. Monroe County county code 118-12(k)(3)
Many local walls are past their design life. Key Colony Beach says most of its seawalls were designed for 30 years, and many have reached or passed that. KCB Seawall Owner's Manual
What a typical Keys canal seawall is made of
Know your wall before you judge it. The Key Colony Beach seawall manual describes the common design on that island: KCB Seawall Owner's Manual
- Reinforced concrete panels about 6 inches thick, 5 to 8 feet wide and 10 to 16 feet long.
- A poured concrete cap along the top.
- Steel tie-back rods running to a buried anchor, called a deadman, about 10 to 12 feet behind the wall.
- Weep holes and French drains that let water out from behind the wall.
Each part fails in its own way. The manual lists joint separation and sinkholes, broken tie-back rods, toe and berm failure, and cracking at the waterline. KCB Seawall Owner's Manual
Walls on other keys vary. Ask your assessor what yours is built from before comparing prices.
Which signs point to repair, and which to replacement?
Use this table to sort what you see, then have a professional confirm the cause. The toe is the bottom of the wall at the mud line.
| What you see | Often repairable when | Points toward replacement when |
|---|---|---|
Hairline cracks in the cap | The wall below is straight and the yard is level | Cracks widen each season or follow a lean |
A small sinkhole behind the wall | The leak at one joint or weep hole is found and sealed | Holes keep returning along many panels |
Rust stains or exposed steel | A cap section can be patched or recast | Tie-back rods are broken or the cap has lost its grip |
Open joints between panels | Only a few joints leak | Panels have shifted out of line |
Wall leaning toward the water | Panels are sound and new anchors can hold them | The top has moved and keeps moving |
Scour or a gap at the toe | A toe footer or riprap can protect it | Panels have kicked out at the bottom |
Cracks at the waterline | They are limited to a few panels | Cracking runs along most of the wall |
A lean, a bulge or a moving crack is urgent. Keep people, cars and heavy loads away from the edge until someone qualified has looked. Prepare for an assessment.
Replacing in the same footprint: the rules that decide
Footprint means where the wall sits. Keeping it there is the easiest path through review in the Keys.
| Rule | What it allows | What to check |
|---|---|---|
Monroe County county code 118-12(k)(4) | Lawfully existing, deteriorated walls may be repaired or replaced, outside the nonsubstantial-improvement limits except on sea turtle nesting beaches. Monroe County county code 118-12(k)(4) | Keep the existing footprint "to the maximum extent practicable." Find the old permit, or proof the wall predates permitting. |
Marathon code 108.20 | Nonconforming open-water walls can be repaired or replaced outside the improvement cap. Marathon code 108.20 | Same footprint where practical, only what holds the upland, and only if riprap with filter cloth will not work. |
Key Colony Beach Secs. 5-50 and 5-51 | The cap edge sits on the platted property line, and cap height follows set rules. KCB Code Sec. 5-50 | A new wall in front of a failing one needs a variance. The city heard one in 2021 for sheet pile about 12 inches out. KCB P&Z minutes, July 2021 |
Florida DEP exemption | Restoring a wall up to 18 inches waterward of its old spot, after a discrete event damaged it within the last year. Rule 62-330.051(12) | Date your damage. After a year, this restoration exemption no longer fits. |
Aquatic preserves | Restoration at, behind or within one foot waterward of the old location needs no consent application. Rule 18-20.004 | One foot, not 18 inches. Coupon Bight Aquatic Preserve lies south of Big Pine Key. Coupon Bight Aquatic Preserve |
State-owned bottom | A letter of consent covers a seawall up to three feet waterward of mean or ordinary high water. Rule 18-21.005(1)(c) | Find out who owns the bottom first. Many canal bottoms are private. |
Moving the wall out also changes the federal path. The Corps' recent Keys permit, SAJ-82, limited replacement walls on bare shores to 18 inches waterward of mean high water. It expired June 24, 2026. SAJ-82 shoreline conditions
Canal or open water: why it changes the answer
The biggest Keys rule is about which water your wall faces. On open water, losing a wall can mean losing the right to a vertical one.
| Jurisdiction | Manmade canal or basin | Open water (ocean, bay or sound) |
|---|---|---|
Unincorporated Monroe County | Only to stop severe erosion, and only if plants or riprap with filter cloth will not work Monroe County county code 118-12(k)(3) | No new seawalls or other hardened vertical structures |
Marathon | Only where riprap or sloped rock will not do, as the City Biologist decides Marathon code 106.36 | No new vertical seawalls Marathon code 106.36 |
Key West | New hardening only for a critical peril after plants have failed; riprap comes first, and generally not a vertical wall Key West Code Sec. 110-182 | Same rule as canals |
Key Colony Beach | Seawalls are required wherever state or federal agencies allow them KCB Code Sec. 5-25 | Same rule |
Layton | The comprehensive plan calls for riprap, plants or cantilevered platforms instead of vertical bulkheads Layton Comprehensive Plan Policy 5.d | Same policy |
State water rules split the same way. The Florida Keys Outstanding Florida Waters cover natural shores and open water but leave out dredged canals. Rule 62-302.700
If you own open-water frontage with an existing wall, keep it maintained and keep its permit records. The county protects lawfully existing walls; it does not allow new ones there.
Key Colony Beach: the clock after a city notice
If Key Colony Beach sends you a seawall notice, the deadlines start that day. Ordinance 2026-509, adopted March 19, 2026, added Code Sec. 6-45. KCB Code Sec. 6-45
| Step | Deadline |
|---|---|
Temporary safety measures in place | 15 days |
Florida-licensed engineer's evaluation and repair plan submitted | 60 days |
City, DEP and Army Corps permit applications filed | 120 days |
Repairs finished | 12 months after permit approval |
Every repair or replacement plan must be signed and sealed by a Florida-licensed engineer. For homes with a vacation rental license, noncompliance is grounds for immediate revocation of that license. KCB Code Sec. 6-45
The city began citywide marine structure inspections in December 2025. In March 2026 a commissioner reported that some walls needed immediate attention. KCB inspection letter, Dec. 2025 KCB Commission minutes, March 2026
The building official may extend deadlines for documented progress. Start the engineer search early, because 60 days is short. See the Key Colony Beach guide.
What the engineer should check before you choose
Ask for written findings, not a verbal opinion. A good assessment answers one question: which parts of this wall can be kept, and for how long?
- Cap elevation, yard grade and both neighbors' caps, surveyed in one datum, ideally NAVD88. NOAA datum FAQ
- Tie-back condition, found by digging test holes behind the wall.
- Toe condition and water depth along the face.
- Every void, sinkhole and open joint, with locations.
- Flood zone. In V and Coastal A zones the county wants a design professional's analysis that the wall will not push floodwater or waves onto neighbors. Monroe County county code 122-31(d)
- Mangroves, seagrass or coral near the work area.
Florida engineers are not licensed by specialty, so ask for similar seawall jobs. FBPE engineering directory See how to check a contractor and engineer.
Compare repair and replacement on one worksheet
Price both paths against the same survey. Then compare what each one buys you, not just the total.
| Question | Repair | Replacement |
|---|---|---|
What it fixes | The failing part: a cap, joints, a void, the toe | The whole wall, anchors and cap |
Local permit | Usually yes; in unincorporated Monroe County, work waits for a Notice to Proceed when state or federal approvals apply Monroe County county code 118-12(k)(9) | Yes, with the same Notice to Proceed step |
Sanctuary review | Possible: NOAA lists seawall repairs that could affect coral NOAA sanctuary nearshore permits | Likely, often with a seafloor (benthic) survey NOAA sanctuary nearshore permits |
Footprint risk | None if nothing moves | Low if it stays in place; higher if it moves out |
Dock and lift | Often stays in place | Usually removed and reset |
Expected life | Ask how many years the repair is meant to last, in writing | Ask the design life of the system, in writing |
A repair that buys five good years can be the right call before a sale or a planned rebuild. A string of repairs on a failing wall rarely is.
After a hurricane: date the damage, then decide
A storm does not change the footprint rules. It does start some clocks.
- DEP's seawall restoration exemption covers damage from a discrete event within the last year. Rule 62-330.051(12)
- DEP's dock repair exemption uses the same one-year test. Section 403.813(1)(d)
- Marathon lets emergency repairs start if the permit application follows within 48 hours. Marathon Building Department
Keep the emergency work and the permanent fix in separate contracts. Then the crew that shores up your wall is not locked into the rebuild. See the storm guide.
Questions to ask before you sign either scope
- Which parts of the wall did you inspect, and which could you not see?
- What caused the damage, and how does this scope stop it coming back?
- Does the new wall stay in the existing footprint? If not, why, and which extra approvals does that add?
- Who files the local permit, DEP, Army Corps and sanctuary paperwork?
- What happens to my dock, lift and davits during the work?
- How many feet of wall, anchors and cap does the price cover?
- What is the warranty, and what voids it?
Bring the answers to a planning call. Get help with your seawall.
Show sourcesHide sources
- Monroe County Land Development Code, Chapter 118 - Environmental ProtectionSource reviewed 2026-10-28
- City of Key Colony Beach Seawall Owner's ManualSource reviewed 2026-10-28
- LDR Sec. 108.20 Nonconforming Docks And Shoreline Stabilization StructuresSource reviewed 2026-10-28
- Code of Ordinances Ch. 5, Art. III Marine Construction and Improvements, Docking of BoatsSource reviewed 2026-10-28
- Planning & Zoning Regular Meeting Minutes, July 21, 2021Source reviewed 2026-10-28
- Rule 62-330.051, F.A.C. (Exempt Activities)Source reviewed 2026-10-28
- Rule 18-20.004, F.A.C. (Management Policies, Standards, and Criteria - Aquatic Preserves)Source reviewed 2026-10-28
- Coupon Bight Aquatic PreserveSource reviewed 2026-10-28
- Rule 18-21.005, F.A.C. (Forms of Authorization)Source reviewed 2026-10-28
- Regional General Permit SAJ-82Source reviewed 2026-10-28
- LDR Sec. 106.36 Criteria For Approval (Hardened Shorelines)Source reviewed 2026-10-28
- Code of Ordinances, Subpart B Land Development Regulations, Ch. 110 Resource Protection, Art. IV Coastal ResourcesSource reviewed 2026-10-28
- Comprehensive Plan Amendment Package (Ord. No. 2022-11-01), adopted June 1, 2023Source reviewed 2026-10-28
- Rule 62-302.700, F.A.C. (Special Protection, Outstanding Florida Waters)Source reviewed 2026-10-28
- Code of Ordinances Ch. 6 Buildings, Art. II, Sec. 6-45 Seawall conditions; compliance requirements; enforcementSource reviewed 2026-10-28
- Waterway Safety and Marine Structure Inspections (letter to residents)Source reviewed 2026-10-28
- 03-19-2026 City Commission Regular Meeting Minutes (ADOPTED)Source reviewed 2026-10-28
- NOAA National Geodetic Survey datum FAQSource reviewed 2026-10-23
- Monroe County Land Development Code, Chapter 122 - Floodplain ManagementSource reviewed 2026-10-28
- Engineering DirectorySource reviewed 2026-10-23
- Nearshore Construction PermitsSource reviewed 2026-10-28
- BuildingSource reviewed 2026-10-28