FEMA Flood Zones in Washington County, Maryland

FEMA has mapped 20,732 acres of Washington County, Maryland inside a Special Flood Hazard Area — the 1% annual chance floodplain, often called the 100-year floodplain. The map below shows every mapped flood zone inside the county boundary.

Washington County, Maryland at a glance

Land in a FEMA Special Flood Hazard Area20,732 acres
Share of mapped land in a Special Flood Hazard Area7%
Share of the county with a published FEMA flood map99.3%
Largest mapped flood hazard area100-year flood (1% annual chance) — 19,469 acres
Distinct flood hazard categories mapped3
Distinct FEMA flood zone codes mapped3
Most widespread FEMA flood zoneZone X — 275,015 acres
Land in the 0.2% annual chance (500-year) floodplain901 acres
Land in a regulatory floodway1,263 acres

Washington County, Maryland is home to 157,731 residents. Land Owl's FEMA flood zone layer records the following within the county boundary — Land in a FEMA Special Flood Hazard Area: 20,732 acres. Share of mapped land in a Special Flood Hazard Area: 7%. Share of the county with a published FEMA flood map: 99.3%. Largest mapped flood hazard area: 100-year flood (1% annual chance) — 19,469 acres. Distinct flood hazard categories mapped: 3. Distinct FEMA flood zone codes mapped: 3. Most widespread FEMA flood zone: Zone X — 275,015 acres. Land in the 0.2% annual chance (500-year) floodplain: 901 acres. Land in a regulatory floodway: 1,263 acres. Every feature shown on the map above is clickable, and the figures on this page are derived from the same data the map renders, so they always agree. A free Land Owl account adds parcel boundaries, ownership records, soils, wetlands and topography over the same view.

Frequently asked questions

How much of Washington County, Maryland is in a FEMA flood zone?
Land Owl maps 20,732 acres of Washington County, Maryland inside a Special Flood Hazard Area, which is 7% of the land FEMA has flood-mapped in the county. That is a regulatory designation used for floodplain management and federal flood-insurance requirements — it is not a prediction that the land will flood.
Is this flood zone map free to use?
Yes. This map is free to view. A free Land Owl account unlocks the other data layers, parcel boundaries and ownership records.
Where does this data come from?
Land Owl maps flood zones from FEMA's National Flood Hazard Layer (NFHL), the digital record of the effective Flood Insurance Rate Maps. It is a screening view, not a flood determination: FEMA revises maps, 495 US counties have never had a digital FIRM published at all, and a lender or insurer will ask for the official record. Check the FEMA Map Service Center, or ask your local floodplain administrator, before you rely on a zone.
Is land outside the flood zone safe from flooding?
No. A Special Flood Hazard Area marks where FEMA has studied and mapped a 1% annual chance of flooding; ground outside one has a lower mapped risk, not no risk, and some of it has never been studied at all. Roughly a quarter of US flood-insurance claims come from outside high-risk zones.
What is the difference between a 100-year and a 500-year flood zone?
They are shorthand for annual probability, not for how often a flood happens. A 100-year flood zone has a 1% chance of flooding in any given year; a 500-year zone has a 0.2% chance. Either can flood twice in a decade — the odds reset every year.

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