FEMA expects more hazard damage per building in Santa Susana than almost anywhere in the U.S., mostly from river and rain flooding
On FEMA’s National Risk Index, Santa Susana 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 (56%), then wildfire (23%). 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 Santa Susana 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
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 Santa Susana’s grade
River and rain flooding is 56% of the building damage FEMA expects in Santa Susana, and Santa Susana’s rate of river and rain flooding damage is in the top 3% of U.S. census tracts. Wildfire adds 23%, 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).
Santa Susana’s residents live in 2 census tracts; FEMA’s figures are combined by where they live.
In dollars, FEMA expects about $1.3M a year in losses across Santa Susana: $1.2M to buildings, the rest to people and crops.
Does Santa Susana flood? No paid flood claims on record
FEMA’s records show no paid flood insurance claims in Santa Susana. That’s not a promise: most homes don’t carry flood insurance, so small floods go unrecorded.
Santa Susana isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Ventura County.1 federal disaster brought FEMA money to Santa Susana
Disasters that paid out in Santa Susana itself (aid to households or repair grants to Santa Susana), newest first, with that year’s flood claims.
- 2022Severe Winter Storms, Flooding, Landslides, and Mudslides1 households applied for aid$300 aid approved
Ventura 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 17 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Ventura County, 2003–2026.
Old photos of Santa Susana after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Santa Susana archive →Santa Susana and its neighbors
Santa Susana is 2nd of the 2 graded towns here, from least expected damage per building to most. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Simi Valley | D−more damage than 97% | river and rain flooding | 33 |
| Santa Susana | D−among the highest damage | river and rain flooding | 0 |
Hazard risk = FEMA’s expected yearly building damage per dollar of building value, vs. the 21,298 U.S. towns we grade; the map is shaded by fifths of the same scale. Flood claims = paid federal flood insurance claims on record.
Get ready for what Santa Susana 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.
- 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 Santa Susana
Is Santa Susana at risk for natural disasters?
On FEMA’s National Risk Index, Santa Susana 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 (56%) and wildfire (23%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Is Santa Susana 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 Ventura County, 31% of homes in mapped flood zones carry federal flood insurance, and 1.6% of all homes do.
How much is flood insurance in Santa Susana?
FEMA’s Community Rating System list shows no discount for Santa Susana’s 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 Santa Susana?
By FEMA money that reached Santa Susana, Severe Winter Storms, Flooding, Landslides, and Mudslides (2022): 1 households applied for aid, $300 approved.
Is Santa Susana at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (56%), and Santa Susana’s rate for it is in the top 3% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Santa Susana.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Santa Susana’s 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.