Photo: Pi.1415926535 · CC BY-SA 4.0FEMA expects more hazard damage per building in San Anselmo than in 98% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, San Anselmo gets a D− for hazard risk: higher expected damage per building than 98% of U.S. towns, #714 of 847 in California. Most of that expected damage is river and rain flooding (72%), then earthquakes (28%). Flood insurance has paid 230 claims here since 1978.
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 San Anselmo’s natural hazards
From FEMA’s model and FEMA’s records, below.
What San Anselmo 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 Anselmo’s grade
River and rain flooding is 72% of the building damage FEMA expects in San Anselmo, and San Anselmo’s rate of river and rain flooding damage is in the top 2% of U.S. census tracts. Earthquakes add 28%, at a rate in the top 8% of U.S. census tracts.
D− #714 of 847 in California; higher expected damage per building than 98% of U.S. towns (21,298).
San Anselmo’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, San Anselmo has more expected damage per building than 84% of California towns.
In dollars, FEMA expects about $16.2M a year in losses across San Anselmo: $14.8M to buildings, the rest to people and crops.
Does San Anselmo flood? Yes: 230 flood claims since 1978
Every paid claim on a federal flood insurance policy in San Anselmo, from FEMA’s records: 41.8 per 1,000 homes, more than 91% of the 13,809 U.S. towns with a flood insurance record.
- The Pineapple Express - Southern3 claims · $22K
- The California Atmospheric River1 claim · $10K
San Anselmo is in FEMA’s Community Rating System (class 8) for its flood-proofing work.
Insurance rates: Marin County.5 federal disasters brought FEMA money to San Anselmo
Disasters that paid out in San Anselmo itself (aid to households or repair grants to the Town of San Anselmo), newest first, with that year’s flood claims.
- 2019Severe Winter Storms, Flooding, Landslides, and Mudslides$587K to the Town of San Anselmo for repairs5 flood claims paid that year
- 2017Severe Winter Storms, Flooding, and Mudslides$26K to the Town of San Anselmo for repairs
- 2017Severe Winter Storms, Flooding, and Mudslides$110K to the Town of San Anselmo for repairs
- 2006Severe Storms, Flooding, Landslides, and Mudslides$470K to the Town of San Anselmo for repairs9 flood claims paid that year
- 2005Severe Storms, Flooding, Mudslides, and Landslides219 households applied for aid$443K aid approved$1.7M to the Town of San Anselmo for repairs139 flood claims paid that year
Marin County has had 22 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 Anselmo after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the San Anselmo archive →San Anselmo and its neighbors
San Anselmo is 4th 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 |
|---|---|---|---|
| Sleepy Hollow | Dmore damage than 92% | river and rain flooding | 64 |
| San Rafael | D−more damage than 96% | earthquakes | 454 |
| Fairfax | D−more damage than 97% | river and rain flooding | 90 |
| San Anselmo | D−more damage than 98% | river and rain flooding | 230 |
| Ross | D−among the highest damage | river and rain flooding | 199 |
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 Anselmo 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 Anselmo residents get 10% 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 Anselmo
Is San Anselmo at risk for natural disasters?
On FEMA’s National Risk Index, San Anselmo has higher expected damage per building than 98% of U.S. towns: D− for hazard risk, #714 of 847 in California. Most of the expected damage is river and rain flooding (72%) and earthquakes (28%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does San Anselmo flood?
Flood insurance has paid 230 claims in San Anselmo since 1978, $11.7M in all, or 41.8 per 1,000 homes, more than 91% of U.S. towns with a flood insurance record. 4 properties have flooded more than once. The most claims came from Pineapple Express - Southern (3).
Is San Anselmo 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 Marin County, 38% of homes in mapped flood zones carry federal flood insurance, and 5.4% of all homes do.
How much is flood insurance in San Anselmo?
San Anselmo is in FEMA’s Community Rating System (class 8), which takes 10% 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 Anselmo?
By FEMA money that reached San Anselmo, Severe Storms, Flooding, Mudslides, and Landslides (2005): 219 households applied for aid, $443K approved, and $1.7M to the Town of San Anselmo for repairs. By flood claims, Pineapple Express - Southern: 3 paid, $22K.
Is San Anselmo at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (72%), and San Anselmo’s rate for it is in the top 2% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in San Anselmo.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where San Anselmo’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.