WallDockDeck
Marathon · Monroe County

What are the deck setback and railing rules in Marathon?

10 ftminimum buffer from MHW or mangrove roots for accessory structures on canal lots

Marathon's water-resource buffer table puts houses 20 ft from mean high water on canal lots (10 ft on lots under 4,500 sq ft) and accessory structures, including non-enclosed decks, gazebos and pools, at least 10 ft back. On unaltered shorelines accessory structures need 25 ft.

Source: City of Marathon LDRs Sec. 106.28 Water Resource and Wetland Buffers, Table 106.28.1 (Ord. 2011-04, 2022-08; municipalcodeonline); Florida Building Code, Residential, 8th Ed. (2023) R312.1.1-R312.1.3 (ICC Digital Codes) · Verified 2026-10

The detail

Buffer tablePrincipal structure on manmade canals, channels, basins and lawfully altered shorelines 20 ft; small lots under 4,500 sq ft 10 ft; open water unaltered 50 ft; measured from the MHWL or the landward extent of the mangrove root system, whichever is further landward. LDR Sec. 106.28, Table 106.28.1.
Accessory structures10 ft minimum on canals and altered shorelines, 15 ft on filled open-water shorelines, 25 ft on unaltered shorelines; footnote lists outdoor recreational accessory structures such as non-enclosed decks, gazebos, pools, spas, permanent barbecues and fish cleaning tables. Docks, pilings, fences, ramps, seawalls and walkways are excepted. Table 106.28.1.
Buffer protectionThe buffer keeps existing undisturbed vegetation; wetlands may not be filled to meet the buffer; unpermitted alteration requires restoration at a 3:1 ratio. Sec. 106.28.
Wetland buffersWetlands without listed species need a 50 ft buffer, reducible to an average of 25 ft (never under 15 ft) if the whole setback is planted in native vegetation with a stormwater plan, a conservation easement and a solid wall or fence at least 6 ft tall. Table 106.28.1.
Guards (state rule)Florida Building Code, Residential, 8th Edition (2023), Sec. R312.1.1-R312.1.3: a guard is required on open sides of a walking surface located more than 30 inches above the floor or grade below at any point within 24 inches of the open edge; it must be at least 36 inches high; openings must not let a 4-inch sphere pass. No local guard amendment was found in this city's code.

Your city's height sheet

The elevation your city requires, the datum it is measured in, and the section of code that says so. One page.

Available for the cities whose rule we have verified and sourced.

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The county rule behind this

What applies across Monroe County, and where each city departs from it.

Monroe CountySeawall requirements county-wide

The same question, nearby

The rule changes at the city line, not the county line.

MonroeIslamorada

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Twelve signs a seawall is failing

What to look for, where to look for it, and what it means when you find it. Walk your wall in twenty minutes.

A screening sheet for owners, not an engineering inspection.

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