How to check a lot for wetlands with the Wetlands Mapper

The Wetlands Mapper is the free federal map most people use to see whether a piece of land has wetlands. It's a good first look and a poor final answer. Here is how to use it, how to read it, and what to do when it shows something on the lot you want to buy.

Check any Florida lot for wetlands in secondsMapped wetland on the lot and within 500 ft, plus flood zone and soil.See how it works

The short version: the Wetlands Mapper shows the US Fish and Wildlife Service's National Wetlands Inventory, mapped from aerial imagery. If it shows a wetland on or near a lot, treat that as a reason to look closer, not a verdict. Only a wetland delineation on site shows where the regulated boundary really is, and in Florida building near one usually means state and sometimes federal permits.

How to use the Wetlands Mapper

Open the Wetlands Mapper on the Fish and Wildlife Service website.
Search the address, or zoom in on the lot. A parcel map from the county property appraiser helps you find the exact lot lines.
Look for colored shapes on or next to the lot. Each color is a wetland type.
Click a shape to see its classification code and type.
Check how close the nearest wetland is. One at the back of a neighbor's lot matters less than one across the middle of yours.

How to read the codes

The map uses the Cowardin classification. The first letter is the system:

Code starts with	System	What it usually is
P	Palustrine	Freshwater marshes, swamps, wet prairies and ponds. The most common on Florida lots.
E	Estuarine	Salt and brackish marshes and mangroves along the coast.
L	Lacustrine	Lakes and their edges.
R	Riverine	Rivers, creeks and canals.

The letters after that describe the type, for example FO for forested (a cypress dome or swamp), EM for emergent (a marsh) or UB for open water.

What the map can't tell you

The Fish and Wildlife Service is clear about the limits of its own data:

It's drawn from aerial imagery. Wetlands are identified from vegetation, visible water and landscape, not from a visit to the lot.
Boundaries are approximate. They're not meant to match a ground survey.
Some wetlands are missing. Older maps in particular missed many forested and drier wetlands.
It can be out of date. The land may have changed since the imagery was taken.
It isn't the legal definition. The inventory uses a biological definition of a wetland, which may not match the boundary regulators use.

So a clean map doesn't prove a lot is dry, and a mapped wetland doesn't prove it's unbuildable. Both mean: check further.

How common wetlands are on Florida lots

It depends heavily on the market. Share of our sampled points with mapped wetland on the point or within 500 feet:

Market	Within 500 ft
Cape Coral	87%
Lehigh Acres	69%
Port Charlotte	60%
Marion Oaks	7%

Our numbers: 121 evenly spaced points per market, sampled against the National Wetlands Inventory, the same layer the Wetlands Mapper shows. In Cape Coral much of it is canals and their banks.

Who regulates wetlands in Florida

The state: work in or near wetlands usually needs an Environmental Resource Permit from the Florida Department of Environmental Protection or the regional water management district.
The federal government: filling wetlands that count as federal waters needs a Section 404 permit from the US Army Corps of Engineers. Florida ran its own version of that program from 2020 until a federal court ended it in 2024, and the Corps took it back over.
The county or city: many add their own setbacks or buffers around wetlands.

Before you buy a lot with a mapped wetland on it, ask a wetland consultant for a delineation, and ask the county what setbacks apply. The answer can change what the lot is worth.

A faster first check

Land in Seconds reads the same National Wetlands Inventory layer for any Florida lot and tells you whether wetland is mapped on the lot itself or within 500 feet, next to the flood zone and soil drainage. It's the same screening, without lining up a parcel map and a wetlands map by hand. For the rest of the checklist, see buying land in Florida: what to check before you buy.

Sources: USFWS Wetlands Mapper, USFWS wetlands data limitations, Florida DEP Environmental Resource Permitting, US Army Corps of Engineers, Jacksonville District regulatory. Checked 26 October 2026. This is general information, not legal or environmental advice.

Common questions about wetlands on a lot

Is the Wetlands Mapper accurate?

It's a screening map, not a survey. The US Fish and Wildlife Service draws it from high-altitude imagery, so boundaries are approximate, some wetlands are missed and others may have changed since the photos were taken. A wetland delineation on site is the only way to settle a boundary.

Does a wetland on the map mean I can't build?

Not necessarily. It means the lot needs a closer look. A delineation shows where the regulated wetland really is, and building in or next to it usually needs state and sometimes federal permits, which can shrink the buildable area or add cost and time.

How do I find out for sure if land has wetlands?

Hire a wetland scientist or environmental consultant to do a delineation on site. For a formal answer on federal jurisdiction, ask the US Army Corps of Engineers for a jurisdictional determination.

Who regulates wetlands in Florida?

The state, through Environmental Resource Permits from the Florida Department of Environmental Protection or the regional water management district, and the federal government, through Section 404 permits from the US Army Corps of Engineers.

What do the wetland codes on the map mean?

They follow the Cowardin classification. The first letter is the system: P for palustrine (freshwater marshes, swamps and ponds), E for estuarine, L for lacustrine (lakes) and R for riverine. The next letters describe the type, such as FO for forested or EM for emergent marsh.

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