Lewis and Clark County flood history
Montana · From FEMA's flood insurance and disaster data · Updated 2026-10-08
FEMA's National Flood Insurance Program (NFIP) data lists 102 flood insurance claims in Lewis and Clark County, Montana since 1978. The NFIP paid $431,717 on them (building, contents and Increased Cost of Compliance payments, in the dollars of the year paid).
The year with the most claims was 2018, with 38.
In the last ten years (2017–2026) there were 40 claims, and the average paid claim was $5,569.
69% of the claims with a recorded flood zone came from buildings outside FEMA's high-risk zones (rated zones B, C and X).
About 0.6% of homes in Lewis and Clark County, Montana had an NFIP flood policy in FEMA's latest count (176 of 29,914 residential buildings). In the high-risk flood zones (Special Flood Hazard Areas), it was 14% (123 of 897).
Since 2000, FEMA has made 2 flood-related disaster declarations covering Lewis and Clark County, Montana. The most recent was DR-4405-MT (Flooding), declared October 31, 2018.
NFIP claims by year
Show as a table
| Year | Claims | Paid |
|---|---|---|
| 2024 | 1 | $0 |
| 2019 | 1 | $2,416 |
| 2018 | 38 | $175,800 |
| 2014 | 3 | $455 |
| 2011 | 17 | $93,507 |
| 2010 | 1 | $0 |
| 2009 | 1 | $0 |
| 1998 | 1 | $678 |
| 1997 | 1 | $0 |
| 1996 | 7 | $26,169 |
| 1986 | 6 | $8,977 |
| 1983 | 2 | $0 |
| 1982 | 1 | $1,160 |
| 1981 | 14 | $112,600 |
| 1980 | 2 | $1,337 |
| 1979 | 3 | $2,001 |
| 1978 | 3 | $6,618 |
How many homes have flood insurance
FEMA counts 176 residential NFIP policies in Lewis and Clark County, against 29,914 residential buildings (0.6%). Of the 897 residential buildings in high-risk flood zones (Special Flood Hazard Areas), 123 have an NFIP policy (14%). Private flood policies aren't in these counts.
Whether you're required to carry flood insurance depends on your flood zone and your mortgage. See do I need flood insurance?
Flood-related disaster declarations
| Declaration | Declared | Event | Help for individuals |
|---|---|---|---|
| DR-4405-MT | Oct 31, 2018 | Flooding | No |
| DR-1996-MT | Jun 17, 2011 | Severe Storms and Flooding | Yes |
Check your own address
County numbers can't tell you about a single building. Look up your property on FEMA's flood map, then read what your flood zone means. More counties: all of Montana.
Where these numbers come from
All figures on this page are calculated from FEMA's public OpenFEMA datasets:
- NFIP Redacted Claims (v3) (FEMA (OpenFEMA)): NFIP claims since 1978, downloaded 2026-10-08. Dollar amounts are what the NFIP paid, not adjusted for inflation. Claims filed under private flood insurance aren't included.
- NFIP Residential Penetration Rates (v1) (FEMA (OpenFEMA)): NFIP residential policy contracts in force (as of August 3, 2026) divided by FEMA's count of residential buildings from the National Structure Inventory. FEMA notes that inventory is incomplete in some counties, which can inflate the rate. Private flood policies aren't counted.
- Disaster Declarations Summaries (v2) (FEMA (OpenFEMA)): disaster declarations, downloaded 2026-10-08. We count a declaration as flood-related when FEMA lists flooding (or a dam or levee break) as its incident type or a designated incident type, or the declaration's title mentions flooding.
FEMA's redacted claims data doesn't identify properties, and FEMA notes that some records lack a county or flood zone. See how we use the data.