FEMA flood zones · Montana

Beaverhead County, Montana Flood Zone Map

12 flood insurance claims·$2,464 paid

1% of Beaverhead County’s area is in FEMA’s high-risk flood zones.

Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.

Coastal high risk (V, VE)FloodwayHigh risk (A, AE)Moderate (X, 500-year)Minimal (X)Undetermined (D)

Shaded areas are FEMA’s mapped flood hazard zones in and around Beaverhead County, Montana. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.

How deep the water got

outlet80″ door12″24″36″48″60″72″84″

In flood insurance claims here that reported a flood depth, the average was 1 inches.

Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.

Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.

Flood claims, year by year

The worst year was 1984, with 8 claims and $95 paid.

1982: 1 claims1984: 8 claims1995: 1 claims1998: 1 claims2011: 1 claims1980199020002010

Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.

In their words

3 NOAA storm reports from Beaverhead County describe what happened, in the words of the forecasters who covered it. Read the Montana flood stories →

Federal disasters

5 federal disaster declarations since 2000.

DisasterBegan
Hurricane Katrina EvacuationAug 29, 2005
Mt - Central Zone 3c Fire ComplexAug 8, 2000
WildfiresJul 13, 2000

Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.

Recorded flood events

8 since 1996: 4 flash floods and 4 river or area floods.

EventDateDamage
FloodJan 16, 2024$100,000
FloodApr 10, 2023$100,000
Flash FloodJul 17, 2013—
FloodJan 4, 2011—
Flash FloodJul 22, 2008—
Flash FloodJul 9, 2005—

— = no damage estimate in the record. Source: NOAA Storm Events Database.

From the storm reports

Flood · Jan 16, 2024. A series of weather systems brought impactful winter weather to the area with light snow developing across north central Montana, becoming more widespread across the region. Dangerously cold wind chills persisted along the Hi-Line. Warming temperatures elsewhere led to ice jamming, resulting in flooding concerns across portions of the Treasure State. ||** Isolated 9 inch snowfall report 6 WSW Forestgrove left out…

Flood · Apr 10, 2023. Unseasonably warm temperatures occurred in the first two weeks of April, with highs near 80 degrees occurring at times. These warm temps, along with occasional rain, resulted in melting of a deep snowpack on top of frozen ground which led to significant runoff into area waterways. Moderate to major flooding occurred along portions of the Milk River and its tributaries. Impactful snowmelt flooding also occurred acr…

Flash Flood · Jul 17, 2013. Convective activity developed early in the afternoon with thunderstorms rapidly developing over West and Southwest Montana in response to an upper trough moving across Northwest Montana into southern Alberta. Though jet streak energy supported the system, convective parameters were not overly impressive. Additionally, precipitable water values were very high across the CWA translating to heavy rain with some isola…

Flood · Jan 4, 2011. An ice jam formed on the Beaverhead River in Twin Bridges causing localized flooding in portions of the town.

National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.

The zones you’ll see on the map

Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.

Cross-section of a river floodplainDiagram: a river valley. The floodway is the channel and the land beside it; the 1%-annual-chance flood surface (the base flood elevation) covers the valley floor as zone A or AE; a narrow band higher up is shaded X, the 0.2% floodplain; higher ground is X.0.2% CHANCE A YEAR (500-YEAR)BASE FLOOD ELEVATION · 1% A YEARXAEFloodwayAEX
  1. A / AE Inside the 1%-a-year floodplain: about a 26% chance of flooding over a 30-year mortgage. AE has a mapped base flood elevation; plain A does not.
  2. Floodway The channel and the land beside it that has to be kept clear enough to carry the flood. Building here is tightly limited.
  3. X shaded The 0.2% (500-year) floodplain, plus some levee-protected and very shallow flood areas.
  4. X Outside both lines. No federal requirement to insure, which is not the same as no risk.

Every flood zone code explained →

Flood insurance in Beaverhead County

If a building in Beaverhead County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.

Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.