Blog · Water risk

18 North Dakota counties have no countywide digital flood map

· 4 min read

Eighteen of North Dakota's 53 counties have no countywide map in FEMA's digital flood layer. Fourteen have no digital flood map at all, and four are mapped only around some towns. Ward County, home of Minot, is one of the fourteen.

We found this while building Prism Water Risk, and checked it against FEMA's own live map service as of 27 September 2026. It is worth knowing whether or not you ever use anything we make.

What a flood map is, and why the digital one matters

A flood map shows where the land is expected to flood. The line that matters most is the edge of the 1%-a-year flood zone: land that has a one-in-a-hundred chance of flooding in any given year. Lenders use it to decide whether a mortgage needs flood insurance. Insurers use it to price that insurance. Counties use it for permits and planning.

FEMA publishes these maps. The digital version is the one that other systems read: a bank's lending software, an insurer's pricing model, a county's planning map, a buyer checking an address online. A county without a digital map is not a county without flood risk. It is a county where that risk is harder to see.

Which counties

The fourteen counties with no digital flood map in FEMA's layer are Ward, Mountrail, Ramsey, Sargent, Kidder, Divide, Pierce, Burke, Towner, Adams, Griggs, Sheridan, Billings and Slope. The four mapped only around some towns are Williams, Dunn, Cavalier and Renville.

Together they hold 195,970 buildings. That is more than a quarter of the state's 732,016.

A missing digital map does not always mean no map exists anywhere. Some places have older paper maps, and some have new maps in draft. North Dakota's Department of Water Resources also publishes approximate floodplains on its Risk Assessment MapService, from a large-scale FEMA study finalised in June 2019; these are, in the department's words, a "non-regulatory product", so they inform planning but do not set insurance requirements. The point is narrower and practical: anyone relying on FEMA's regulatory digital layer, which is what most lending and insurance software reads, gets no answer for these counties.

Minot is the clearest example

Ward County has no digital flood map in FEMA's layer. It also has one of the largest flood insurance histories in the state.

Across 1978 to 2025, FEMA's records show 1,107 flood insurance claims in Ward County, with $69.5 million paid. In 2011 alone, the year the Souris River flooded Minot, 640 claims were paid there, totalling $66.9 million.

Ramsey County, around Devils Lake, is also on the list. It appears in the insurance record in almost every major flood year.

These figures are what flood insurance paid, not what the floods cost. Many buildings are not insured for flood, so the true losses were higher.

What this means if you lend, insure or plan

We cannot give advice on any single property or policy; your own adviser should. In general terms:

  • For lenders: a property in an unmapped county may need a closer look than the flood map alone suggests.
  • For insurers: the absence of a mapped zone is missing information, not evidence of low risk.
  • For counties: the digital map is how most outside systems see your flood risk. Its absence can show up in lending and insurance decisions you never hear about.

How we checked

Every number here comes from public records: FEMA's flood hazard layer for North Dakota and FEMA's flood insurance claims, counted by county and year. A separately written checker then re-read every original file and matched it record by record, 1,759,122 records in all, with none unaccounted. The receipt behind each figure is kept, in the way data provenance describes. We also compared the county list with FEMA's live map service, which agreed.

This product is not endorsed by FEMA.

Where Prism fits

Prism Water Risk is flood and water risk for insurers, lenders and counties in North Dakota. It is in development. It is built on the same seven steps as everything we make: gather the public record, keep a receipt for every record, check it, and answer only from what is stored.

If you insure, lend or plan in North Dakota and want to see this for your own portfolio or county, request a pilot. For the wider picture of what we build, start with why Prism Labs exists.

Sources

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