FEMA expects more hazard damage per building in Rossmoor than in 96% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Rossmoor gets a D− for hazard risk: higher expected damage per building than 96% of U.S. towns, #605 of 847 in California. Most of that expected damage is river and rain flooding (69%), then earthquakes (31%). Flood insurance has paid 3 claims here since 1983.
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 Rossmoor 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
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 Rossmoor’s grade
River and rain flooding is 69% of the building damage FEMA expects in Rossmoor, and Rossmoor’s rate of river and rain flooding damage is in the top 4% of U.S. census tracts. Earthquakes add 31%, at a rate in the top 8% of U.S. census tracts.
D− #605 of 847 in California; higher expected damage per building than 96% of U.S. towns (21,298).
Rossmoor’s residents live in 3 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, Rossmoor has more expected damage per building than 71% of California towns.
In dollars, FEMA expects about $9.1M a year in losses across Rossmoor: $8.2M to buildings, the rest to people and crops.
Does Rossmoor flood? Rarely: 3 flood claims since 1983
Every paid claim on a federal flood insurance policy in Rossmoor, from FEMA’s records: 0.8 per 1,000 homes, fewer than 84% of the 13,809 U.S. towns with a flood insurance record.
- The Pineapple Express - Southern1 claim · $15K
Rossmoor isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Orange County.The storms Rossmoor remembers
None of the 27 disasters declared for Orange County shows FEMA aid or repair money reaching Rossmoor itself in FEMA’s records, so these are its biggest flood-claim years.
- 19831 flood claims paidThe year of Coastal Storms, Floods, Slides and Tornadoes, declared for Orange County
- 19951 flood claims paidThe year of Severe Winter Storms, Flooding Landslides, Mud Flow, declared for Orange County
- 19981 flood claims paidThe year of Severe Winter Storms and Flooding, declared for Orange County
Orange County has had 27 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 11 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Orange County, 2002–2022.
Old photos of Rossmoor after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Rossmoor archive →Rossmoor and its neighbors
Rossmoor is 2nd of the 3 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 |
|---|---|---|---|
| Los Alamitos | Dmore damage than 94% | earthquakes | 2 |
| Rossmoor | D−more damage than 96% | river and rain flooding | 3 |
| Seal Beach | D−more damage than 97% | river and rain flooding | 107 |
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 Rossmoor 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.
- 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 Rossmoor
Is Rossmoor at risk for natural disasters?
On FEMA’s National Risk Index, Rossmoor has higher expected damage per building than 96% of U.S. towns: D− for hazard risk, #605 of 847 in California. Most of the expected damage is river and rain flooding (69%) and earthquakes (31%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Rossmoor flood?
Flood insurance has paid 3 claims in Rossmoor since 1983, $18K in all, or 0.8 per 1,000 homes, fewer than 84% of U.S. towns with a flood insurance record. The most claims came from Pineapple Express - Southern (1).
Is Rossmoor 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 Orange County, 19% of homes in mapped flood zones carry federal flood insurance, and 1.0% of all homes do.
How much is flood insurance in Rossmoor?
FEMA’s Community Rating System list shows no discount for Rossmoor’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 Rossmoor?
By flood claims, Pineapple Express - Southern: 1 paid, $15K.
Is Rossmoor at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (69%), and Rossmoor’s rate for it is in the top 4% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Rossmoor.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Rossmoor’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.