Photo: FASTILY · CC BY-SA 4.0FEMA puts San Ramon’s expected hazard damage per building above that of 96% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, San Ramon gets a D− for hazard risk: higher expected damage per building than 96% of U.S. towns, #612 of 847 in California. Most of that expected damage is river and rain flooding (55%), then earthquakes (44%). Flood insurance has paid 15 claims here since 2002.
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 San Ramon 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 San Ramon’s grade
River and rain flooding is 55% of the building damage FEMA expects in San Ramon, and San Ramon’s rate of river and rain flooding damage is in the top 5% of U.S. census tracts. Earthquakes add 44%, at a rate in the top 5% of U.S. census tracts.
D− #612 of 847 in California; higher expected damage per building than 96% of U.S. towns (21,298).
San Ramon’s residents live in 20 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, San Ramon has more expected damage per building than 72% of California towns.
In dollars, FEMA expects about $84.2M a year in losses across San Ramon: $74.1M to buildings, the rest to people and crops.
Does San Ramon flood? Sometimes: 15 flood claims since 2002
Every paid claim on a federal flood insurance policy in San Ramon, from FEMA’s records: 0.5 per 1,000 homes, fewer than 90% of the 13,809 U.S. towns with a flood insurance record.
- The California Atmospheric River7 claims · $494K
San Ramon is in FEMA’s Community Rating System (class 6) for its flood-proofing work.
Insurance rates: Contra Costa County.4 federal disasters brought FEMA money to San Ramon
Disasters that paid out in San Ramon itself (aid to households or repair grants to the City of San Ramon), newest first, with that year’s flood claims.
- 2022Severe Winter Storms, Flooding, Landslides, and Mudslides100 households applied for aid$235K aid approved$1.3M to the City of San Ramon for repairs6 flood claims paid that year
- 2017Severe Winter Storms, Flooding, and Mudslides$230K to the City of San Ramon for repairs
- 2017Severe Winter Storms, Flooding, and Mudslides$104K to the City of San Ramon for repairs
- 2017Severe Winter Storms, Flooding, and Mudslides$56K to the City of San Ramon for repairs
Contra Costa County has had 17 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.
Old photos of San Ramon after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the San Ramon archive →San Ramon and its neighbors
San Ramon is 3rd of the 4 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 |
|---|---|---|---|
| Danville | D−more damage than 96% | river and rain flooding | 3 |
| Dublin | D−more damage than 96% | river and rain flooding | — |
| San Ramon | D−more damage than 96% | river and rain flooding | 15 |
| Norris Canyon | D−more damage than 97% | 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 San Ramon 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.
- San Ramon residents get 20% off flood insurance.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Questions about natural hazards in San Ramon
Is San Ramon at risk for natural disasters?
On FEMA’s National Risk Index, San Ramon has higher expected damage per building than 96% of U.S. towns: D− for hazard risk, #612 of 847 in California. Most of the expected damage is river and rain flooding (55%) and earthquakes (44%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does San Ramon flood?
Flood insurance has paid 15 claims in San Ramon since 2002, $676K in all, or 0.5 per 1,000 homes, fewer than 90% of U.S. towns with a flood insurance record. 1 properties have flooded more than once. The most claims came from California Atmospheric River (7).
Is San Ramon 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 Contra Costa County, 28% of homes in mapped flood zones carry federal flood insurance, and 0.9% of all homes do.
How much is flood insurance in San Ramon?
San Ramon is in FEMA’s Community Rating System (class 6), which takes 20% off federal flood insurance policies for its flood-proofing work. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
What was the biggest storm in San Ramon?
By FEMA money that reached San Ramon, Severe Winter Storms, Flooding, Landslides, and Mudslides (2022): 100 households applied for aid, $235K approved, and $1.3M to the City of San Ramon for repairs. By flood claims, California Atmospheric River: 7 paid, $494K.
Is San Ramon at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (55%), and San Ramon’s rate for it is in the top 5% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in San Ramon.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where San Ramon’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.