Flood Zones and Wetlands: What to Check Before You Buy Land

By LandyDandy

Some cheap land is cheap because it is wet. A flood zone can raise building costs and insurance. Wetlands can limit where, or whether, you can build. You can start checking both online in a few minutes, then confirm with a phone call.

General information, not legal, tax or financial advice. Rules differ by state and county and change over time. LandyDandy is a land marketplace, not a law firm, lender or title company. Each seller on LandyDandy sets their own terms. Before you sign or pay anything, check with the county and a licensed real estate attorney or title company in the state where the land is.

The short answer

• Look up the parcel on FEMA's Flood Map Service Center, the official public source for flood maps [S13].
• Zones starting with A or V are Special Flood Hazard Areas, the high-risk areas. Zone X is moderate or minimal risk [S12].
• Most homeowners insurance does not cover flood, and a federal flood policy typically has a 30-day wait [S14].
• The national wetlands map is a starting point, not a legal boundary [S15].
• Filling a wetland usually needs a federal permit [S16]. Ask before you buy, not after.

What FEMA flood zones mean

FEMA maps flood risk in zones. The key idea is the base flood: a flood with a 1% chance of being equaled or exceeded in any given year. People call it the "100-year flood" [S12]. The name is misleading. The chance is the same every year, so it can happen two years in a row.

The main zones you will see:

• Special Flood Hazard Areas — zones such as A, AE, V and VE. This is the area the base flood would cover [S12].
• Zone X (shaded) — moderate risk. It sits between the base flood and the 0.2% ("500-year") flood [S12].
• Zone X (unshaded) — minimal risk, outside the high-risk area and above the 0.2% flood level [S12].

Many rural areas have older or less detailed flood maps. If the parcel is in or near a flood zone, ask the county what it will need before it permits a home.

How to look up a parcel's flood zone

1. Go to FEMA's Flood Map Service Center [S13].
2. Enter an address, a place name or latitude/longitude coordinates [S13]. Raw land often has no address, so use the parcel's coordinates from the county GIS map.
3. Open the map view and find the parcel's shape.
4. Note the zone, and whether the flood area covers the whole parcel or only a strip along a creek.
5. Some county GIS maps also show the FEMA layer. Turning it on over the parcel lines can be easier.

A parcel can be partly in a flood zone. If the high ground where you would build is in Zone X, the lot may still work. Measure how much usable dry ground there is.

Flood insurance basics

• Most homeowners insurance does not cover flood. You need a separate flood policy [S14].
• There is typically a 30-day waiting period before a federal (NFIP) flood policy starts [S14]. Do not wait until a storm is coming.
• Lenders may require it. Properties in high-risk flood zones with mortgages from government-backed lenders must carry flood insurance [S14].

With owner-financed raw land there is often no bank loan and no building yet. But once you build, flood risk affects your insurance cost, your building permit and your resale value. Ask an insurance agent for a quote before you buy if you plan to build in or near a flood zone.

Wetlands: what the maps can and cannot tell you

The U.S. Fish and Wildlife Service runs a free Wetlands Mapper [S15]. It shows mapped wetlands across the country. It is useful for a first look.

But it has limits, and the agency says so:

• It uses a biological definition of wetlands, not a legal one [S15].
• It does not try to set the limits of any government's regulatory program [S15].
• For work that might affect wetlands, it tells you to contact your local Army Corps of Engineers regulatory office [S15].

So a parcel with no wetlands on the map can still have them. And mapped wetlands may be smaller or larger on the ground.

When you need a wetlands permit

Under Section 404 of the Clean Water Act, you need a permit before you put dredged or fill material into waters of the United States, including wetlands, unless the work is exempt [S16]. Certain farming and forestry work is exempt [S16]. The Army Corps of Engineers runs the day-to-day permits and makes or checks decisions on which areas fall under the rule [S16].

In plain terms: if you want to fill a wet area to build a pad, a driveway or a septic field, you may need a federal permit. States and counties can have their own wetland rules too. Getting a permit takes time. A permit may not be granted if a less damaging option exists [S16].

Signs to look for on the ground

Visit the land, ideally after a rainy spell. Look for:

• Standing water or soggy ground days after rain.
• Cattails, reeds, sedges or moss on low ground.
• Water stains or debris lines on trees.
• Dark, mucky soil when you dig a little.
• A creek, ditch or pond on or next to the parcel.
• Neighbors' homes built up on fill or piers.

Photos on a listing may be taken in dry weather. Ask the seller when the photos were taken and whether the land holds water.

Who to call

• County floodplain manager (often in the planning or building office). Ask: "What flood zone is this parcel in, and what would I need to build a home here?"
• Army Corps of Engineers district regulatory office. Ask whether the parcel may have regulated wetlands and how to request a determination.
• County health department. A septic drainfield is built in unsaturated soil [S11], so wet ground can be a problem for septic.
• Insurance agent. Ask for a flood insurance quote for a home on this parcel.

Frequently asked questions

How do I check if a piece of land is in a flood zone?

Search the location on FEMA's Flood Map Service Center, using an address or coordinates, or turn on the flood layer in the county GIS map if it has one. Note the zone and how much of the parcel it covers. Then confirm with the county floodplain manager.

What is the difference between flood zone X and AE?

Zone AE is a Special Flood Hazard Area, the high-risk area the 1%-a-year flood would cover. Zone X is outside that area: shaded X is moderate risk and unshaded X is minimal risk.

Can I build on land in a flood zone?

Often yes, but the county may add building rules. That can raise costs. In a high-risk zone, flood insurance is required if you get a mortgage from a government-backed lender. Ask the county floodplain manager before you buy.

Is the national wetlands map enough to know if land has wetlands?

No. The U.S. Fish and Wildlife Service says its mapper uses a biological definition and does not set regulatory limits. For a firm answer, contact your local Army Corps of Engineers regulatory office.

Do I need a permit to fill wetlands on my land?

Usually yes. Putting fill into wetlands that are waters of the United States needs a Section 404 permit unless the work is exempt, such as certain farming and forestry. State or county rules may also apply.

Next steps on LandyDandy

Each listing shows the seller's description and terms, and you can message the seller with questions. Before you commit, look up the flood zone and wetlands map for the parcel yourself. Browse land for sale across the United States or owner-financed land. Before you sign, talk to the county floodplain manager, a local real estate attorney or title company, and the Army Corps if wetlands may be involved.

Sources

1. [S12] FEMA — Flood zones (glossary) — https://www.fema.gov/about/glossary/flood-zones — base flood (1% annual chance, "100-year flood"); list of SFHA zones incl. A, AE, V, VE; Zone X shaded (between base flood and 0.2% flood) and unshaded (outside SFHA, above 0.2% flood).
2. [S13] FEMA — Flood Map Service Center — https://msc.fema.gov/portal/home — official public source for flood hazard information; search by address, place or coordinates.
3. [S14] FEMA — Flood insurance — https://www.fema.gov/flood-insurance — most homeowners insurance does not cover flood; typical 30-day NFIP waiting period; required in high-risk zones with government-backed mortgages.
4. [S15] U.S. Fish and Wildlife Service — Wetlands Mapper — https://www.fws.gov/program/national-wetlands-inventory/wetlands-mapper — biological definition; no attempt to define regulatory limits; contact the local USACE regulatory office.
5. [S16] U.S. EPA — Permit program under CWA Section 404 — https://www.epa.gov/cwa-404/permit-program-under-cwa-section-404 — permit needed to discharge dredged or fill material into waters of the US incl. wetlands; farming/forestry exemptions; Corps role; no permit if a practicable less-damaging alternative exists.
6. [S11] U.S. EPA — How your septic system works — https://www.epa.gov/septic/how-your-septic-system-works — drainfield is a shallow, covered excavation in unsaturated soil.