Living shorelines in Key Largo

Who this is for

Owners replacing a wall who want a softer edge, owners with mangroves along the shore, and Coral Gables owners who want the fee incentive.

Where a seawall is allowed at all

Monroe County allows vertical seawalls only to stabilise severely eroding shorelines on man-made canals, channels or basins, and never on open water. Lawfully existing walls may be repaired or replaced on the same footprint, the yard behind must sit at least 6 in below the top of the wall, and riprap goes at the toe wherever feasible.

Living features can sit in front of a wall that still meets the height rule.[1]

Four feet of water, and more over grass

A Key Largo dock must end in at least 4 ft of water at mean low water. Over seagrass or hard bottom, the water must be 4 ft deep above the organisms, the deck at least 5 ft above mean high water, and the terminal platform no larger than 160 sq ft (8 by 20 ft), with a benthic survey to prove it.

Planting and rock placement stay off existing grass.[1]

Mangrove fringes shape the design

Where a Key Largo shoreline has a mangrove fringe 10 ft wide or more, a T or L dock with a walkway perpendicular to the shore is the primary design. Riprap and walls go landward of existing mangroves wherever feasible, and a walkway through mangroves is limited to 4 ft.

Mangroves are the backbone of a living shoreline here, so the rules on them shape the design.[1]

What makes Key Largo different

The special exception application asks owners to describe the submerged lands the dock crosses, such as sand, seagrass or coral, and the minimum extra length needed to reach adequate water depth. The site plan must be prepared by a Florida registered architect, engineer or landscape architect and show the mean high water line and shoreline setbacks.[2]

Sanctuary, seagrass and manatees

Projects inside the Florida Keys National Marine Sanctuary needed prior Sanctuary approval under SPGP VI. The same permit let boat lifts and minor structures in Monroe County go into existing boat slips without a seagrass survey. All in-water work follows the state manatee conditions.[3][4]

Permits in Key Largo

• Monroe County Planning and Environmental Resources Department: Dock length special exceptions under County Code section 118-12(m)(15).
• Florida Keys National Marine Sanctuary: The Sanctuary starts at mean high water, so Key Largo canal and bay work is inside it; SPGP VI required its prior approval.
• Florida DEP or South Florida Water Management District: State permit or exemption, which Monroe County needs to see before it issues a Notice to Proceed for docks, seawalls and ramps.
• US Army Corps of Engineers, Jacksonville District: Federal permit, also required before the County's Notice to Proceed.

Permits for living shorelines

Riprap follows the riprap rules: up to 10 ft waterward under SPGP VI and a state general permit for up to 100 linear feet at 2:1. In Miami-Dade, mangrove permits are valid for 3 years and limerock boulder riprap on a 2:1 slope gets an expedited authorisation after a DERM inspection.[3][7]

Frequently asked questions