What does a living shoreline mean in the Keys?
Short answer: in the Keys, the softer options are mostly rock riprap, riprap at the toe of an existing wall, and mangroves or native plants left in place. Local codes ask for them before a new vertical wall. Monroe County county code 118-12(k)
NOAA describes living shorelines as options for sheltered coasts, bays and estuaries, not open-ocean beaches. NOAA living shorelines Many Keys canals and bay shores fit that description; exposed ocean frontage often does not.
Monroe County code places riprap at the toe of solid seawalls to absorb wave energy and give marine life a habitat. Monroe County county code 118-12(k)
Keys codes put riprap and plants first
Three of the four cities and the county push away from new vertical walls. Key Colony Beach is the exception.
| Jurisdiction | Rule | In plain words |
|---|---|---|
Unincorporated Monroe County | county code 118-12(k)(3) Monroe County county code 118-12(k)(3) | A new vertical wall only on a manmade canal with severe erosion, when plants or riprap with filter cloth will not work. None on open water. |
Key West | Code Sec. 110-182 Key West Code Sec. 110-182 | Plants first, then riprap. Where hardening is allowed, use the least damaging design, with pervious interlocking tiles and filter mats preferred, plus replanting. |
Marathon | Marathon code 106.36 Marathon code 106.36 | Riprap or sloped rock with biotechnical erosion control, unless the City Biologist finds it will not do. See the Marathon guide. |
Layton | Comprehensive Plan Policy 5.d Layton Comprehensive Plan | Riprap, plants or cantilevered platforms instead of vertical bulkheads. See the Long Key and Layton guide. |
Key Colony Beach | Code Secs. 5-25 and 5-54 KCB Code Sec. 5-25 KCB Code Secs. 5-52 to 5-55 | Seawalls are required wherever state or federal agencies allow them, and sloping seawalls are not allowed. See the Key Colony Beach guide. |
Key West also asks shoreline applicants along the Salt Ponds, Riviera Canal and open coast to show how they protect vegetation, seagrass and water quality. Key West Code Sec. 110-181 See the New Town guide.
Riprap: the state and Marathon specs side by side
Riprap is loose rock placed on a slope or at a wall's toe. Two rule sets apply in Marathon, and the stricter one governs.
| Spec | State general permit (Rule 62-330.431) | Marathon code 106.36 |
|---|---|---|
Where | At the toe of an existing vertical seawall, or up to 100 feet of a single-family shore Rule 62-330.431 | Landward of existing mangroves; encouraged at the base of solid seawalls Marathon code 106.36 |
Slope | No steeper than 2 to 1 | No steeper than 2 horizontal to 1 vertical |
How far out | No more than 10 feet waterward | No more than 8 feet from the landward edge or mean low water line |
Stone | Natural boulders or clean concrete rubble, 1 to 3 feet across, no rebar | Natural boulders or clean rubble, 6 inches to 3 feet, no rebar sticking out |
Seagrass, coral, fill | No filling of seagrass or coral, no backfill to gain upland | No filling or dredging |
On state-owned bottom, riprap up to ten feet waterward needs a letter of consent. Rule 18-21.005(1)(c) The sanctuary lists riprap placement among activities that need its review. NOAA sanctuary nearshore permits
Monroe County adds a $10 environmental education fee to riprap and restoration permits. Res. 277-2025 See riprap and shoreline stabilization.
Mangroves: the state decides, not the county
Mangrove questions in the Lower and Middle Keys go to DEP's Marathon office, (305) 289-7070. Neither Monroe County nor any Keys city is delegated to run the state's mangrove law. DEP mangrove delegation list DEP Marathon office
- Growing into your wall: DEP treats trimming or altering mangroves that grow into a seawall as exempt maintenance. Send DEP a description and photos first. DEP mangrove FAQ
- Trimming without a permit: up to 10 feet of pretrimmed height, never below 6 feet, on shorelines of 150 feet or less. Section 403.9326
- Marathon canals: owners must keep mangroves within 10 feet of mean high water or 20% of the canal width, whichever is less. Marathon Code Sec. 36-88
- Key West: removing shoreline plants needs a permit, and replanting runs three to ten times the area affected. Key West Code Sec. 110-182
- Flood zones: altering mangroves in V or Coastal A zones needs DEP approval and an engineer's analysis. Monroe County county code 122-27
Trimming is not removal, and removal has its own rules. Ask DEP before anything is cut. Monroe County county code 118-10
Seagrass, coral and the sanctuary
Your shoreline meets the Florida Keys National Marine Sanctuary at mean high water. 15 CFR 922.161 That shapes where rock can go.
- Seagrass surveys happen only from June 1 to September 30. Sanctuary survey protocol, 2022
- Key West protects seagrass, hardbottom and reef communities up to 600 feet into tidal water off the city. Key West Code Sec. 110-183
- The state riprap permit bars filling seagrass or coral. Rule 62-330.431
- Open water and natural shores are Outstanding Florida Waters; dredged canals are not. Rule 62-302.700
On a calm dredged canal, toe riprap is usually simpler to permit than rock on open water over seagrass.
Sandy beaches and sea turtles
A few Keys shores are sandy nesting beaches, and hard structures are kept off them.
- Monroe County bars seawalls, riprap and other hardening on or waterward of a known or potential turtle nesting berm. Monroe County county code 118-12(k)(7)
- Marathon bars hardening on a nesting beach or within its setback. Marathon code 106.36
- Monroe County has no Coastal Construction Control Line. Its critically eroded sandy beaches fall under a 50-foot setback law that names seawalls. DEP CCCL page Section 161.052
Canal, bay and mangrove shores are outside that beach program.
When a hybrid makes sense
A hybrid keeps your repaired wall and adds rock at its base. Both the county and Marathon encourage riprap at the toe of solid seawalls. Monroe County county code 118-12(k) Marathon code 106.36
NOAA lists what decides fit: wave energy, tide range, slope, elevation, soil, plants, neighboring shores and drainage. NOAA living shorelines
- Does your wall face open water with waves, or a calm canal?
- Is there seagrass or coral within 10 feet of the toe?
- Would rock narrow a canal your neighbors use for boats?
- Do mangroves already hold part of the shore?
- Will your lift, dock or davits sit where the rock would go?
Armoring changes how sand and sediment move, so design for your own site, not your neighbor's. NOAA shoreline armoring
Softer still needs permits
A living shoreline or riprap job needs the same local, state and federal checks as other shoreline work. NOAA living shorelines
- Local permit from your city or Monroe County.
- DEP general permit or exemption from the Marathon office.
- A letter of consent if the rock sits on state-owned bottom.
- Army Corps review. The expired SAJ-82 permit had allowed new riprap up to 10 feet waterward of mean high water. SAJ-82 shoreline conditions
- Sanctuary review, likely with a seafloor (benthic) survey.
The permit guide lists each office and the order to file.
Who can help you plan one
- DEP Marathon office for mangroves, exemptions and state-owned bottom: (305) 289-7070. DEP Marathon office
- Monroe County Environmental Resources for unincorporated lots: (305) 289-2502. The office also links the county's list of qualified biologists. Monroe County Environmental Resources
- Key West Planning Department for city shorelines: (305) 809-3746. Key West Planning Department
- Marathon's City Biologist decides when riprap will not do, under Marathon code 106.36. Ask the Building Department to connect you. Marathon Building Department
Not sure which option fits your shore? Talk it through.
Show sourcesHide sources
- Monroe County Land Development Code, Chapter 118 - Environmental ProtectionSource reviewed 2026-10-28
- NOAA Fisheries: Understanding Living ShorelinesSource reviewed 2026-10-27
- Code of Ordinances, Subpart B Land Development Regulations, Ch. 110 Resource Protection, Art. IV Coastal ResourcesSource reviewed 2026-10-28
- LDR Sec. 106.36 Criteria For Approval (Hardened Shorelines)Source reviewed 2026-10-28
- Comprehensive Plan Amendment Package (Ord. No. 2022-11-01), adopted June 1, 2023Source reviewed 2026-10-28
- Code of Ordinances Ch. 5, Art. III Marine Construction and Improvements, Docking of BoatsSource reviewed 2026-10-28
- Rule 62-330.431, F.A.C. (General Permit for Installation of Riprap)Source reviewed 2026-10-28
- Rule 18-21.005, F.A.C. (Forms of Authorization)Source reviewed 2026-10-28
- Nearshore Construction PermitsSource reviewed 2026-10-28
- Resolution No. 277-2025 (Building Department permitting fee schedule)Source reviewed 2026-10-28
- Mangrove Trimming Delegated Local GovernmentsSource reviewed 2026-10-28
- SED Marathon OfficeSource reviewed 2026-10-28
- Mangrove Frequently Asked QuestionsSource reviewed 2026-10-28
- Section 403.9326, Florida Statutes (2026)Source reviewed 2026-10-28
- Code Sec. 36-88 Mangrove MaintenanceSource reviewed 2026-10-28
- Monroe County Land Development Code, Chapter 122 - Floodplain ManagementSource reviewed 2026-10-28
- 15 CFR 922.161 and Appendix I to Subpart P (Sanctuary boundary)Source reviewed 2026-10-28
- Resource Assessment Survey Protocols for Nearshore Construction ProjectsSource reviewed 2026-10-28
- Rule 62-302.700, F.A.C. (Special Protection, Outstanding Florida Waters)Source reviewed 2026-10-28
- LOCATE the Coastal Construction Control Line (CCCL)Source reviewed 2026-10-28
- Section 161.052, Florida Statutes (2026)Source reviewed 2026-10-28
- NOAA shoreline armoringSource reviewed 2026-10-27
- Regional General Permit SAJ-82Source reviewed 2026-10-28
- Environmental ResourcesSource reviewed 2026-10-28
- Planning DepartmentSource reviewed 2026-10-28
- BuildingSource reviewed 2026-10-28