Photo: Pi.1415926535 · CC BY-SA 3.0FEMA expects more hazard damage per building in Antioch than in 86% of U.S. towns, mostly from earthquakes
On FEMA’s National Risk Index, Antioch gets a D for hazard risk: higher expected damage per building than 86% of U.S. towns, #246 of 847 in California. Most of that expected damage is earthquakes (50%), then river and rain flooding (48%). Flood insurance has paid 59 claims here since 1982.
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 Antioch’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Antioch 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 Antioch’s grade
Earthquakes are 50% of the building damage FEMA expects in Antioch, and Antioch’s rate of earthquakes damage is in the top 8% of U.S. census tracts. Next is river and rain flooding at 48% (higher than 72% of U.S. census tracts).
D #246 of 847 in California; higher expected damage per building than 86% of U.S. towns (21,298).
Antioch’s residents live in 22 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, Antioch has less expected damage per building than 71% of California towns.
Among the 400 U.S. cities of 100,000 or more, Antioch has higher expected damage per building than 79% (#318 of 400). Because it is so big, its total expected yearly loss, $52.8M, is the 230th largest of those 400.
Does Antioch flood? Sometimes: 59 flood claims since 1982
Every paid claim on a federal flood insurance policy in Antioch, from FEMA’s records: 1.5 per 1,000 homes, fewer than 68% of the 13,809 U.S. towns with a flood insurance record.
- The Pineapple Express - Southern8 claims · $218K
- The California Atmospheric River6 claims · $684K
Antioch isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Contra Costa County.2 federal disasters brought FEMA money to Antioch
Disasters that paid out in Antioch itself (aid to households or repair grants to the City of Antioch), newest first, with that year’s flood claims.
- 2022Severe Winter Storms, Flooding, Landslides, and Mudslides138 households applied for aid$115K aid approved$552K to the City of Antioch for repairs6 flood claims paid that year
- 2005Severe Storms, Flooding, Mudslides, and Landslides2 households applied for aid$9K to the City of Antioch for repairs3 flood claims paid that year
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 Antioch after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Antioch archive →Antioch and its neighbors
Antioch has the lowest expected damage per building of the 4 graded towns here. Tap a town to see its hazards.
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 Antioch 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 Antioch
Is Antioch at risk for natural disasters?
On FEMA’s National Risk Index, Antioch has higher expected damage per building than 86% of U.S. towns: D for hazard risk, #246 of 847 in California. Most of the expected damage is earthquakes (50%) and river and rain flooding (48%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Antioch flood?
Flood insurance has paid 59 claims in Antioch since 1982, $3.0M in all, or 1.5 per 1,000 homes, fewer than 68% of U.S. towns with a flood insurance record. 11 properties have flooded more than once. The most claims came from Pineapple Express - Southern (8).
Is Antioch 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 Antioch?
FEMA’s Community Rating System list shows no discount for Antioch’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 Antioch?
By FEMA money that reached Antioch, Severe Winter Storms, Flooding, Landslides, and Mudslides (2022): 138 households applied for aid, $115K approved, and $552K to the City of Antioch for repairs. By flood claims, Pineapple Express - Southern: 8 paid, $218K.
Is Antioch at risk from earthquakes?
It is the largest share of the building damage FEMA expects here (50%), and Antioch’s rate for it is in the top 8% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Antioch.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Antioch’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.