FEMA expects about as much hazard damage per building in Casa de Oro-Mount Helix as in the typical U.S. town, mostly from river and rain flooding
On FEMA’s National Risk Index, Casa de Oro-Mount Helix gets a B− for hazard risk: higher expected damage per building than 50% of U.S. towns, #50 of 847 in California. Most of that expected damage is river and rain flooding (80%), then earthquakes (20%). Flood insurance has paid 12 claims here since 1979.
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 Casa de Oro-Mount Helix 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 Casa de Oro-Mount Helix’s grade
River and rain flooding is 80% of the building damage FEMA expects in Casa de Oro-Mount Helix, and Casa de Oro-Mount Helix’s rate of river and rain flooding damage is higher than 65% of U.S. census tracts. Next is earthquakes at 20% (higher than 81% of U.S. census tracts).
B− #50 of 847 in California; higher expected damage per building than 50% of U.S. towns (21,298).
Casa de Oro-Mount Helix’s residents live in 11 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, Casa de Oro-Mount Helix has less expected damage per building than 94% of California towns.
In dollars, FEMA expects about $5.1M a year in losses across Casa de Oro-Mount Helix: $4.7M to buildings, the rest to people and crops.
Does Casa de Oro-Mount Helix flood? Sometimes: 12 flood claims since 1979
Every paid claim on a federal flood insurance policy in Casa de Oro-Mount Helix, from FEMA’s records: 1.6 per 1,000 homes, fewer than 67% of the 13,809 U.S. towns with a flood insurance record.
- The San Diego Flooding2 claims · $88K
Casa de Oro-Mount Helix isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: San Diego County.The storms Casa de Oro-Mount Helix remembers
None of the 30 disasters declared for San Diego County shows FEMA aid or repair money reaching Casa de Oro-Mount Helix itself in FEMA’s records, so these are its biggest flood-claim years.
- 19792 flood claims paidNo declaration for the county that year
- 20102 flood claims paidThe year of Severe Winter Storms, Flooding, and Debris and Mud Flows, declared for San Diego County
- 20172 flood claims paidThe year of Wildfires, declared for San Diego County
San Diego County has had 30 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 18 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in San Diego County, 2002–2018.
Old photos of Casa de Oro-Mount Helix after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Casa de Oro-Mount Helix archive →Casa de Oro-Mount Helix and its neighbors
Casa de Oro-Mount Helix is 2nd of the 5 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 |
|---|---|---|---|
| La Mesa | B−less damage than 54% | river and rain flooding | 25 |
| Casa de Oro-Mount Helix | B−more damage than 50% | river and rain flooding | 12 |
| Spring Valley | C+more damage than 63% | river and rain flooding | 26 |
| Rancho San Diego | C−more damage than 77% | river and rain flooding | 4 |
| El Cajon | C−more damage than 80% | river and rain flooding | 26 |
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 Casa de Oro-Mount Helix 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 Casa de Oro-Mount Helix
Is Casa de Oro-Mount Helix at risk for natural disasters?
On FEMA’s National Risk Index, Casa de Oro-Mount Helix has higher expected damage per building than 50% of U.S. towns: B− for hazard risk, #50 of 847 in California. Most of the expected damage is river and rain flooding (80%) and earthquakes (20%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Casa de Oro-Mount Helix flood?
Flood insurance has paid 12 claims in Casa de Oro-Mount Helix since 1979, $138K in all, or 1.6 per 1,000 homes, fewer than 67% of U.S. towns with a flood insurance record. The most claims came from San Diego Flooding (2).
Is Casa de Oro-Mount Helix 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 San Diego County, 24% of homes in mapped flood zones carry federal flood insurance, and 0.7% of all homes do.
How much is flood insurance in Casa de Oro-Mount Helix?
FEMA’s Community Rating System list shows no discount for Casa de Oro-Mount Helix’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 Casa de Oro-Mount Helix?
By flood claims, San Diego Flooding: 2 paid, $88K.
Is Casa de Oro-Mount Helix at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (80%), and Casa de Oro-Mount Helix’s rate for it is higher than 65% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Casa de Oro-Mount Helix.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Casa de Oro-Mount Helix’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.