Photo: Cristiano Tomás · CC BY-SA 4.0FEMA puts Rio del Mar’s expected hazard damage per building above that of 91% of U.S. towns, mostly from earthquakes
On FEMA’s National Risk Index, Rio del Mar gets a D for hazard risk: higher expected damage per building than 91% of U.S. towns, #352 of 847 in California. Most of that expected damage is earthquakes (56%), then river and rain flooding (35%). Flood insurance has paid 29 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 Rio del Mar faces
Each hazard’s share of the building damage FEMA expects here, and how its rate compares with the rest of the country.
Earthquakes
River and rain flooding
Tsunamis
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 Rio del Mar’s grade
Earthquakes are 56% of the building damage FEMA expects in Rio del Mar, and Rio del Mar’s rate of earthquakes damage is in the top 5% of U.S. census tracts. Tsunamis add 8%, at a rate in the top 1% of U.S. census tracts.
D #352 of 847 in California; higher expected damage per building than 91% of U.S. towns (21,298).
Rio del Mar’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, Rio del Mar has less expected damage per building than 59% of California towns.
In dollars, FEMA expects about $8.0M a year in losses across Rio del Mar: $7.1M to buildings, the rest to people and crops.
Does Rio del Mar flood? Sometimes: 29 flood claims since 1983
Every paid claim on a federal flood insurance policy in Rio del Mar, from FEMA’s records: 6.0 per 1,000 homes, more than 64% of the 13,809 U.S. towns with a flood insurance record.
- The California Atmospheric River19 claims · $2.1M
- The December California Flooding4 claims · $204K
- The Pineapple Express - Southern2 claims · $26K
Rio del Mar 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 Cruz County.The storms Rio del Mar remembers
None of the 24 disasters declared for Santa Cruz County shows FEMA aid or repair money reaching Rio del Mar itself in FEMA’s records, so these are its biggest flood-claim years.
- 202323 flood claims paidThe year of Severe Winter Storms, Flooding, Landslides, and Mudslides, declared for Santa Cruz County
- 19982 flood claims paidThe year of Severe Winter Storms and Flooding, declared for Santa Cruz County
- 19831 flood claims paidThe year of Coastal Storms, Floods, Slides and Tornadoes, declared for Santa Cruz County
Santa Cruz County has had 24 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 6 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Santa Cruz County, 2002–2020.
Old photos of Rio del Mar after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Rio del Mar archive →Rio del Mar and its neighbors
Rio del Mar has the lowest expected damage per building of the 4 graded towns here. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Rio del Mar | Dmore damage than 91% | earthquakes | 29 |
| Seacliff | Dmore damage than 91% | earthquakes | 54 |
| La Selva Beach | Dmore damage than 94% | earthquakes | — |
| Aptos | Dmore damage than 95% | earthquakes | — |
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 Rio del Mar faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- Drop, cover and hold on.
- Strap tall furniture and the water heater to the wall.
- Know how to shut off the gas.
- 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.
- Strong shaking or a sudden drop in the sea means head for high ground now.
- Learn the tsunami route signs near the shore.
- Stay away until officials say it’s safe.
- 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 Rio del Mar
Is Rio del Mar at risk for natural disasters?
On FEMA’s National Risk Index, Rio del Mar has higher expected damage per building than 91% of U.S. towns: D for hazard risk, #352 of 847 in California. Most of the expected damage is earthquakes (56%) and river and rain flooding (35%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Rio del Mar flood?
Flood insurance has paid 29 claims in Rio del Mar since 1983, $2.4M in all, or 6.0 per 1,000 homes, more than 64% of U.S. towns with a flood insurance record. The most claims came from California Atmospheric River (19).
Is Rio del Mar 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 Cruz County, 33% of homes in mapped flood zones carry federal flood insurance, and 2.5% of all homes do.
How much is flood insurance in Rio del Mar?
FEMA’s Community Rating System list shows no discount for Rio del Mar’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 Rio del Mar?
By flood claims, California Atmospheric River: 19 paid, $2.1M.
Is Rio del Mar at risk from earthquakes?
It is the largest share of the building damage FEMA expects here (56%), and Rio del Mar’s rate for it is in the top 5% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Rio del Mar.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Rio del Mar’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.