FEMA expects more hazard damage per building in Castaic than almost anywhere in the U.S., led by river and rain flooding
On FEMA’s National Risk Index, Castaic gets a D− for hazard risk: among the highest expected damage per building of U.S. towns, #792 of 847 in California. Most of that expected damage is river and rain flooding (48%), then wildfire (26%). Flood insurance has paid 1 claim here since 2005.
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 stands out about Castaic’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Castaic 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 Castaic’s grade
River and rain flooding is 48% of the building damage FEMA expects in Castaic, and Castaic’s rate of river and rain flooding damage is in the top 3% of U.S. census tracts. Wildfire adds 26%, at a rate in the top 1% of U.S. census tracts.
D− #792 of 847 in California; among the highest expected damage per building of U.S. towns (21,298).
Castaic’s residents live in 5 census tracts; FEMA’s figures are combined by where they live.
The typical California town has higher expected damage than 92% of U.S. towns; within the state, Castaic has more expected damage per building than 93% of California towns.
In dollars, FEMA expects about $24.5M a year in losses across Castaic: $19.9M to buildings, the rest to people and crops.
Does Castaic flood? Rarely: 1 flood claim since 2005
Every paid claim on a federal flood insurance policy in Castaic, from FEMA’s records: 0.2 per 1,000 homes, fewer than 98% of the 13,809 U.S. towns with a flood insurance record.
Castaic isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Los Angeles County.3 federal disasters brought FEMA money to Castaic
Disasters that paid out in Castaic itself (aid to households or repair grants to Castaic), newest first, with that year’s flood claims.
- 2025Wildfires and Straight-line Winds310 households applied for aid$80K aid approved
- 2007Wildfires, Flooding, Mud Flows, and Debris Flows24 households applied for aid$15K aid approved
- 2004Severe Storms, Flooding, Debris Flows, and Mudslides168 households applied for aid$295K aid approved
Los Angeles County has had 40 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 44 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Los Angeles County, 2002–2025.
Old photos of Castaic after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Castaic archive →Castaic and its neighbors
Castaic 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 |
|---|---|---|---|
| Hasley Canyon | D−among the highest damage | wildfire | — |
| Castaic | D−among the highest damage | river and rain flooding | 1 |
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 Castaic 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 Castaic
Is Castaic at risk for natural disasters?
On FEMA’s National Risk Index, Castaic has among the highest expected damage per building of U.S. towns: D− for hazard risk, #792 of 847 in California. Most of the expected damage is river and rain flooding (48%) and wildfire (26%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Castaic flood?
Flood insurance has paid 1 claim in Castaic since 2005, $3K in all, or 0.2 per 1,000 homes, fewer than 98% of U.S. towns with a flood insurance record.
Is Castaic 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 Los Angeles County, 33% of homes in mapped flood zones carry federal flood insurance, and 0.5% of all homes do.
How much is flood insurance in Castaic?
FEMA’s Community Rating System list shows no discount for Castaic’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 Castaic?
By FEMA money that reached Castaic, Severe Storms, Flooding, Debris Flows, and Mudslides (2004): 168 households applied for aid, $295K approved.
Is Castaic at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (48%), and Castaic’s rate for it is in the top 3% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Castaic.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Castaic’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.