Blog · October 14, 2026 · New Hampshire
Using the Sullivan County Flood Zone Map
Flood zones are set by FEMA, and checking one near Croydon takes a few minutes.
Main page: Sullivan County, NH GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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Weighing a property around Charlestown? Checking the Sullivan County flood zone map reveals whether FEMA puts it in a high-risk zone, and the lookup is free. What this Sullivan County guide covers: finding the address on FEMA's map, decoding A, AE and X, and pairing it with the NHDOT Parcel Mosaic Viewer.
Checking the Sullivan County flood zone map step by step
For parcel-by-parcel detail, try the National Flood Hazard Layer viewer, which lets you click a spot and read its zone, whether the land is near Georges Mills or elsewhere in the county. Vacant ground around Cornish Flat can still be found: zoom in from the nearest road and click inside the land.
Where the parcel data lives
For a home near Cornish, the public parcel map for this area is the NHDOT Parcel Mosaic Viewer, and anyone can open it without signing up. If you only know roughly where the land is, pan along the nearest road and select the outline, for land near Charlestown included. For a tract near Claremont, the parcel card usually lists the owner of record, assessed acreage, the parcel number and in many cases the last transfer.
What the map can't tell you
Acreage on the record is a tax-roll number; just a licensed surveyor sets the real boundary for a parcel near Balloch. With a lot near Cornish Flat, owner names and values update on a schedule, so a deed recorded last month might lag behind.
Zones on the Sullivan County flood zone map
Zone AE comes with a base flood elevation, which plain A zones lack; builders around Claremont design to it. In and around Georges Mills, shaded Zone X is moderate risk, between the 1% and 0.2% annual chance floods; unshaded X means minimal mapped risk.
What to request from a seller
On ground around Georges Mills, ask the seller about past flood claims before closing; an insurance quote early avoids surprises.
Sections, lots and bearings
Tracts outside towns near Goshen commonly use metes-and-bounds descriptions, which trace the boundary call by call. Platted lots around Balloch refer to a recorded plat, which is simpler to follow. Keep the legal description for land near Claremont before you request a deed or survey.
When a parcel crosses a boundary
The county touches Cheshire County, Grafton County, Hillsborough County, Merrimack County, and Windham County, VT, and each of those keeps its own parcel map around Newport. A tract near the line by East Lempster can show up in two county records, so look at the neighboring map too. Closer to East Lempster, our state page lists each bordering county map across New Hampshire.
Water near Goshen
Low-lying fields near Balloch aren't always studied in detail, so walk the land after rain. Wetlands near Plainfield can limit building even outside a flood zone; the National Wetlands Inventory mapper shows mapped wetlands.
Recorded documents worth pulling
The map is an index, not the title: deeds, plats and easements for land near Charlestown are kept by the county Registry of Deeds. For land near Cornish Flat, have ready the instrument number from the tax record so staff can find the deed fast.
Use the county map alongside FEMA
FEMA's map shows zones but not ownership, so check the NHDOT Parcel Mosaic Viewer too to confirm you have the right parcel near East Lempster.
On site with the map
The parcel map usually runs in a mobile browser, useful out on a road near Cornish Flat, though signal can drop in rural spots. A saved image of the lot near Balloch and its lines keeps working without signal.
Getting your bearings
Newport serves as the county seat, home to the main records offices. Other places on the map include Claremont, Acworth, Charlestown, and Cornish. Roughly 43,969 people call Sullivan County home (Census Bureau estimate, 2023) spread over roughly 538 square miles. The county was organized in 1827, which matters when you trace an old farm's title for land near East Lempster.
Money questions tied to the zone
In and around Croydon, an Elevation Certificate from a surveyor helps: it records the building's elevation against the base flood. Remodeling a house in a zone near Claremont usually means extra permit review; check with the county or town building office early.
Frequently asked
Is Zone X safe from flooding in Sullivan County?
Closer to Georges Mills, shaded X is moderate risk and unshaded X is minimal risk; FEMA notes that a large share of claims come from these areas.
What is a base flood elevation in Sullivan County?
For acreage around Croydon, the base flood elevation is the water level expected in the 1% annual chance flood; local rules may require building above it.
How often are flood maps updated for land near Claremont?
Out toward Georges Mills, FEMA revises flood maps panel by panel as new studies finish, so look at the panel date.
Will my lender require flood insurance near Goshen?
For a building near Plainfield in an A or V zone with a federally backed or regulated mortgage, it's generally required, in communities that take part in the NFIP.
What's a legal description in Sullivan County?
In and around Balloch, Deeds use lot and block, metes and bounds or survey descriptions, and the parcel record often summarizes it.
Open the official Sullivan County, NH parcel map See it in the Platbookmapper directory
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey, especially for fences, setbacks, or boundary disputes.