Photo: BrokenSphere · CC BY-SA 3.0On FEMA’s figures, Colma faces more hazard damage per building than 94% of U.S. towns, mostly from earthquakes
On FEMA’s National Risk Index, Colma gets a D for hazard risk: higher expected damage per building than 94% of U.S. towns. Most of that expected damage is earthquakes (72%), then river and rain flooding (28%). Flood insurance has paid 1 claim here since 1987.
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 Colma 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 Colma’s grade
Earthquakes are 72% of the building damage FEMA expects in Colma, and Colma’s rate of earthquakes damage is in the top 1% of U.S. census tracts. Next is river and rain flooding at 28% (higher than 67% of U.S. census tracts).
D higher expected damage per building than 94% of U.S. towns (21,298).
Colma’s residents live in 2 census tracts; FEMA’s figures are combined by where they live.
In dollars, FEMA expects about $2.3M a year in losses across Colma: $1.7M to buildings, the rest to people and crops.
Does Colma flood? Rarely: 1 flood claim since 1987
Every paid claim on a federal flood insurance policy in Colma, 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.
Colma 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 Mateo County.The storms Colma remembers
None of the 19 disasters declared for San Mateo County shows FEMA aid or repair money reaching Colma itself in FEMA’s records, so these are its biggest flood-claim years.
- 19871 flood claims paidNo declaration for the county that year
San Mateo County has had 19 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 2 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in San Mateo County, 2010–2020.
Old photos of Colma after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Colma archive →Colma and its neighbors
Colma is 2nd of the 3 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 |
|---|---|---|---|
| Daly City | Dmore damage than 92% | earthquakes | 23 |
| Colma | Dmore damage than 94% | earthquakes | 1 |
| South San Francisco | D−more damage than 96% | earthquakes | 76 |
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 Colma 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 Colma
Is Colma at risk for natural disasters?
On FEMA’s National Risk Index, Colma has higher expected damage per building than 94% of U.S. towns: D for hazard risk. Most of the expected damage is earthquakes (72%) and river and rain flooding (28%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Colma flood?
Flood insurance has paid 1 claim in Colma since 1987, $2K in all, or 1.6 per 1,000 homes, fewer than 67% of U.S. towns with a flood insurance record.
Is Colma 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 Mateo County, 31% of homes in mapped flood zones carry federal flood insurance, and 1.8% of all homes do.
How much is flood insurance in Colma?
FEMA’s Community Rating System list shows no discount for Colma’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
Is Colma at risk from earthquakes?
It is the largest share of the building damage FEMA expects here (72%), and Colma’s rate for it is in the top 1% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Colma.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Colma’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.