Photo: SWENOWENSON · CC BY-SA 4.0On FEMA’s figures, Mill Valley faces more hazard damage per building than 86% of U.S. towns, led by earthquakes
On FEMA’s National Risk Index, Mill Valley gets a D for hazard risk: higher expected damage per building than 86% of U.S. towns, #239 of 847 in California. Most of that expected damage is earthquakes (48%), then river and rain flooding (47%). Flood insurance has paid 144 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 Mill Valley’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Mill Valley 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
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 Mill Valley’s grade
Earthquakes are 48% of the building damage FEMA expects in Mill Valley, and Mill Valley’s rate of earthquakes damage is in the top 9% of U.S. census tracts. Tsunamis add 2%, at a rate in the top 1% of U.S. census tracts.
D #239 of 847 in California; higher expected damage per building than 86% of U.S. towns (21,298).
Mill Valley’s residents live in 4 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, Mill Valley has less expected damage per building than 72% of California towns.
In dollars, FEMA expects about $10.4M a year in losses across Mill Valley: $9.0M to buildings, the rest to people and crops.
Does Mill Valley flood? Yes: 144 flood claims since 1978
Every paid claim on a federal flood insurance policy in Mill Valley, from FEMA’s records: 22.4 per 1,000 homes, more than 85% of the 13,809 U.S. towns with a flood insurance record.
- The Pineapple Express - Southern4 claims · $23K
- The Winter storm1 claim · $7K
Mill Valley isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Marin County.5 federal disasters brought FEMA money to Mill Valley
Disasters that paid out in Mill Valley itself (aid to households or repair grants to the City of Mill Valley), newest first, with that year’s flood claims.
- 2022Severe Winter Storms, Flooding, Landslides, and Mudslides$75K to the City of Mill Valley for repairs
- 2017Severe Winter Storms, Flooding, and Mudslides$396K to the City of Mill Valley for repairs
- 2017Severe Winter Storms, Flooding, and Mudslides$303K to the City of Mill Valley for repairs
- 2006Severe Storms, Flooding, Landslides, and Mudslides$408K to the City of Mill Valley for repairs3 flood claims paid that year
- 2005Severe Storms, Flooding, Mudslides, and Landslides42 households applied for aid$43K aid approved$340K to the City of Mill Valley for repairs43 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 Mill Valley after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Mill Valley archive →Mill Valley and its neighbors
Mill Valley is 2nd of the 7 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 |
|---|---|---|---|
| Strawberry | Dmore damage than 85% | river and rain flooding | 20 |
| Mill Valley | Dmore damage than 86% | earthquakes | 144 |
| Tamalpais-Homestead Valley | Dmore damage than 86% | river and rain flooding | 112 |
| Alto | Dmore damage than 89% | river and rain flooding | — |
| Kentfield | Dmore damage than 94% | river and rain flooding | 80 |
| Corte Madera | Dmore damage than 94% | earthquakes | 127 |
| Larkspur | D−more damage than 96% | river and rain flooding | 98 |
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 Mill Valley 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.
- 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 Mill Valley
Is Mill Valley at risk for natural disasters?
On FEMA’s National Risk Index, Mill Valley has higher expected damage per building than 86% of U.S. towns: D for hazard risk, #239 of 847 in California. Most of the expected damage is earthquakes (48%) and river and rain flooding (47%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Mill Valley flood?
Flood insurance has paid 144 claims in Mill Valley since 1978, $1.9M in all, or 22.4 per 1,000 homes, more than 85% of U.S. towns with a flood insurance record. 9 properties have flooded more than once. The most claims came from Pineapple Express - Southern (4).
Is Mill Valley 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 Mill Valley?
FEMA’s Community Rating System list shows no discount for Mill Valley’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 Mill Valley?
By FEMA money that reached Mill Valley, Severe Storms, Flooding, Landslides, and Mudslides (2006): $408K to the City of Mill Valley for repairs. By flood claims, Pineapple Express - Southern: 4 paid, $23K.
Is Mill Valley at risk from earthquakes?
It is the largest share of the building damage FEMA expects here (48%), and Mill Valley’s rate for it is in the top 9% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Mill Valley.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Mill Valley’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.