Photo: NHRHS2010 · CC BY-SA 3.0FEMA expects more hazard damage per building in Los Alamos than almost anywhere in the U.S., led by river and rain flooding
On FEMA’s National Risk Index, Los Alamos gets a D− for hazard risk: among the highest expected damage per building of U.S. towns. Most of that expected damage is river and rain flooding (49%), then landslides (32%). FEMA’s files show no paid flood insurance claims here.
Graded on FEMA’s expected yearly building damage per dollar of building value (NRI v1.20, December 2025), weighted by where residents live; flood claims are shown, not graded. How hazard risk is graded
What Los Alamos faces
Each hazard’s share of the building damage FEMA expects here, and how its rate compares with the rest of the country.
River and rain flooding
Landslides
Wildfire
Earthquakes
Shares are of FEMA’s expected building damage, the measure the grade uses; ranks compare each hazard’s building-damage rate with all 85,154 U.S. census tracts. In FEMA’s terms, river and rain flooding is FEMA’s “Inland Flooding” (rivers and streams overflowing their banks, or rain overwhelming drainage). FEMA defines coastal flooding as high or rising tides and storm surge, so surge damage is counted there. Drought isn’t listed: FEMA counts its losses in crops only.
What’s behind Los Alamos’ grade
River and rain flooding is 49% of the building damage FEMA expects in Los Alamos, and Los Alamos’ rate of river and rain flooding damage is in the top 1% of U.S. census tracts. Landslides add 32%, at a rate in the top 1% of U.S. census tracts.
D− among the highest expected damage per building of U.S. towns (21,298).
Los Alamos’ residents live in 2 census tracts; FEMA’s figures are combined by where they live.
In dollars, FEMA expects about $6.8M a year in losses across Los Alamos: $3.5M to buildings, the rest to people and crops.
Does Los Alamos flood? No paid flood claims on record
FEMA’s records show no paid flood insurance claims in Los Alamos. That’s not a promise: most homes don’t carry flood insurance, so small floods go unrecorded.
Los Alamos isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Santa Barbara County.2 federal disasters brought FEMA money to Los Alamos
Disasters that paid out in Los Alamos itself (aid to households or repair grants to Los Alamos), newest first, with that year’s flood claims.
- 2004Severe Storms, Flooding, Debris Flows, and Mudslides2 households applied for aid$1K aid approved
- 2003Earthquake1 households applied for aid$943 aid approved
Santa Barbara County has had 32 natural disasters declared by the President since 1953, most often severe storms, then floods. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Also 8 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Santa Barbara County, 2004–2021.
Old photos of Los Alamos after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Los Alamos archive →Get ready for what Los Alamos faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- Turn around at flooded roads: a foot of moving water can carry off a car.
- Flood insurance usually takes 30 days to start, so buy it before the forecast.
- Keep papers and medicines up high, in a grab-and-go bag.
- Watch for new cracks, tilting trees or suddenly muddy streams after heavy rain.
- Stay off steep slopes in a downpour.
- Leave if you hear rumbling upslope.
- Clear dead leaves and brush within 5 feet of the house.
- Sign up for local alerts and know two ways out.
- Keep N95 masks for smoky days.
- Drop, cover and hold on.
- Strap tall furniture and the water heater to the wall.
- Know how to shut off the gas.
- Look up the address on FEMA’s flood map.
- Ask the seller or landlord whether it has ever flooded, and what flood insurance costs there.
- Get a flood insurance quote early: policies usually start 30 days after you buy.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Questions about natural hazards in Los Alamos
Is Los Alamos at risk for natural disasters?
On FEMA’s National Risk Index, Los Alamos has among the highest expected damage per building of U.S. towns: D− for hazard risk. Most of the expected damage is river and rain flooding (49%) and landslides (32%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Is Los Alamos in a flood zone?
Flood zones are drawn street by street, so the answer depends on the address: look it up on FEMA’s flood map. In Santa Barbara County, 27% of homes in mapped flood zones carry federal flood insurance, and 1.9% of all homes do.
How much is flood insurance in Los Alamos?
FEMA’s Community Rating System list shows no discount for Los Alamos’ flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
What was the biggest storm in Los Alamos?
By FEMA money that reached Los Alamos, Severe Storms, Flooding, Debris Flows, and Mudslides (2004): 2 households applied for aid, $1K approved.
Is Los Alamos at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (49%), and Los Alamos’ rate for it is in the top 1% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Los Alamos.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Los Alamos’ residents lived in the 2020 census; OpenFEMA: NFIP redacted claims, multiple-loss properties, community status book and residential penetration rates, housing assistance (owners and renters), public assistance funded projects, hazard mitigation properties and disaster declarations. Homes: Census ACS 2020–24. Preparedness tips: Ready.gov. FEMA’s model is an average of expected damage, not a forecast. How hazard risk is graded.