Photo: Tranistrider1979 · CC BY-SA 3.0More hazard damage per building is expected in Mountain House than in 83% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Mountain House gets a C− for hazard risk: higher expected damage per building than 83% of U.S. towns, #200 of 847 in California. Most of that expected damage is river and rain flooding (56%), then earthquakes (43%). FEMA’s files show no paid flood insurance claims here.
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 Mountain House 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 Mountain House’s grade
River and rain flooding is 56% of the building damage FEMA expects in Mountain House, and Mountain House’s rate of river and rain flooding damage is higher than 73% of U.S. census tracts. Next is earthquakes at 43% (higher than 90% of U.S. census tracts).
C− #200 of 847 in California; higher expected damage per building than 83% of U.S. towns (21,298).
Mountain House’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, Mountain House has less expected damage per building than 76% of California towns.
In dollars, FEMA expects about $10.5M a year in losses across Mountain House: $9.1M to buildings, the rest to people and crops.
Does Mountain House flood? No paid flood claims on record
FEMA’s records show no paid flood insurance claims in Mountain House. That’s not a promise: most homes don’t carry flood insurance, so small floods go unrecorded.
Mountain House 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 Joaquin County.1 federal disaster brought FEMA money to Mountain House
Disasters that paid out in Mountain House itself (aid to households or repair grants to the City of Mountain House), newest first, with that year’s flood claims.
- 2022Severe Winter Storms, Flooding, Landslides, and Mudslides4 households applied for aid$365 aid approved
San Joaquin County has had 22 natural disasters declared by the President since 1953, most often floods, then severe storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Mountain House after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Mountain House archive →Get ready for what Mountain House 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.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Questions about natural hazards in Mountain House
Is Mountain House at risk for natural disasters?
On FEMA’s National Risk Index, Mountain House has higher expected damage per building than 83% of U.S. towns: C− for hazard risk, #200 of 847 in California. Most of the expected damage is river and rain flooding (56%) and earthquakes (43%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Is Mountain House 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 Joaquin County, 25% of homes in mapped flood zones carry federal flood insurance, and 1.8% of all homes do.
How much is flood insurance in Mountain House?
FEMA’s Community Rating System list shows no discount for Mountain House’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 Mountain House?
By FEMA money that reached Mountain House, Severe Winter Storms, Flooding, Landslides, and Mudslides (2022): 4 households applied for aid, $365 approved.
Is Mountain House at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (56%), and Mountain House’s rate for it is higher than 73% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Mountain House.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Mountain House’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.