FEMA flood zones · Idaho

Clark County, Idaho Flood Zone Map

FEMA’s digital flood map shows no high- or moderate-risk zones in Clark County. That can mean the area was never studied in detail or has no digital map, not that it can’t flood; the county floodplain administrator can say which.

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 Clark County, Idaho. 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.

In their words

4 NOAA storm reports from Clark County describe what happened, in the words of the forecasters who covered it. Read the Idaho flood stories →

Federal disasters

4 federal disaster declarations since 2005.

DisasterBegan
Grassy Ridge FireJul 28, 2018
Hurricane KatrinaAug 29, 2005

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

Recorded flood events

9 since 1996: 2 flash floods and 7 river or area floods.

EventDateDamage
FloodDec 24, 2025$3,000
FloodMar 13, 2018$680,000
FloodJan 9, 2017—
FloodFeb 5, 2017$67,000
FloodMar 1, 2017$10,000
Flash FloodJul 6, 2013—
FloodMar 10, 2012—
FloodMay 1, 2011—

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

From the storm reports

Flood · Dec 24, 2025. Medicine Lodge Creed near Small went into flood stage around 950 PM on the 24th and reached an all time record at 1230 AM on the 25th and didn't drop below flood stage until 545 AM on the 25th. Two road washouts occurred. One was near the convergence of Medicine Lodge and Middle Creeks. The second was a mile further into the canyon where the Medicine Lodge Creek was flowing over the road. Four to five famili…

Flood · Mar 13, 2018. A return to heavy mountain snows in late February and early March added significantly to the snow pack especially in the Upper Snake River Highlands and snow melt and heavy rains occurred sporadically from the middle of the month onward. The worst of the flooding occurred in Clark and Madison which were both declared state disaster areas by the end of the month. Low elevations in the central mountains also beg…

Flood · Jan 9, 2017. A long dawn out atmospheric river event brought a variety of impacts to southeast Idaho including extremely heavy mountain snow, valley snow then rain on snow leading to flooding and roads covered with ice in the Snake River Plain, and many mountain avalanches. Many roads were closed for extended periods due to the heavy snow and avalanches. Custer County was declared a disaster area due to the prodigious snow…

Flood · Feb 5, 2017. A trend toward above normal temperatures in February after extreme snowfall amounts in both December and January led to extensive flooding issues during the entirety of the month. The brunt of the flooding occurred in Cassia, Minidoka, Jefferson, Lincoln and Bingham Counties but all counties did receive at least minor flooding. The floding began February 4th and continued to affect low lying areas until the end…

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 Clark County

If a building in Clark 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.