Photo: AstroDominant · CC BY 4.0FEMA expects more hazard damage per building in Grass Valley than in 72% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Grass Valley gets a C for hazard risk: higher expected damage per building than 72% of U.S. towns, #122 of 847 in California. Most of that expected damage is river and rain flooding (72%), then wildfire (20%). Flood insurance has paid 10 claims here since 1983.
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 Grass Valley 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
Wildfire
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 Grass Valley’s grade
River and rain flooding is 72% of the building damage FEMA expects in Grass Valley, and Grass Valley’s rate of river and rain flooding damage is higher than 75% of U.S. census tracts. Wildfire adds 20%, at a rate in the top 3% of U.S. census tracts.
C #122 of 847 in California; higher expected damage per building than 72% of U.S. towns (21,298).
Grass Valley’s residents live in 7 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, Grass Valley has less expected damage per building than 86% of California towns.
In dollars, FEMA expects about $6.2M a year in losses across Grass Valley: $5.9M to buildings, the rest to people and crops.
Does Grass Valley flood? Sometimes: 10 flood claims since 1983
Every paid claim on a federal flood insurance policy in Grass Valley, from FEMA’s records: 1.4 per 1,000 homes, fewer than 71% of the 13,809 U.S. towns with a flood insurance record.
Grass 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: Nevada County.5 federal disasters brought FEMA money to Grass Valley
Disasters that paid out in Grass Valley itself (aid to households or repair grants to the City of Grass Valley), newest first, with that year’s flood claims.
- 2023Severe Winter Storms, Straight-line Winds, Flooding, Landslides, and Mudslides190 households applied for aid$231K aid approved$80K to the City of Grass Valley for repairs
- 2021Wildfires134 households applied for aid$316K aid approved
- 2017Wildfires76 households applied for aid$68K aid approved
- 2017Severe Winter Storms, Flooding, and Mudslides$35K to the City of Grass Valley for repairs
- 2005Severe Storms, Flooding, Mudslides, and Landslides50 households applied for aid$34K aid approved$16K to the City of Grass Valley for repairs6 flood claims paid that year
Nevada 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.
Also 3 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Nevada County, 2009–2020.
Old photos of Grass Valley after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Grass Valley archive →Get ready for what Grass 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.
- 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.
- Clear dead leaves and brush within 5 feet of the house.
- Sign up for local alerts and know two ways out.
- Keep N95 masks for smoky days.
- 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 Grass Valley
Is Grass Valley at risk for natural disasters?
On FEMA’s National Risk Index, Grass Valley has higher expected damage per building than 72% of U.S. towns: C for hazard risk, #122 of 847 in California. Most of the expected damage is river and rain flooding (72%) and wildfire (20%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Grass Valley flood?
Flood insurance has paid 10 claims in Grass Valley since 1983, $188K in all, or 1.4 per 1,000 homes, fewer than 71% of U.S. towns with a flood insurance record. 2 properties have flooded more than once.
Is Grass 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 Nevada County, 23% of homes in mapped flood zones carry federal flood insurance, and 0.2% of all homes do.
How much is flood insurance in Grass Valley?
FEMA’s Community Rating System list shows no discount for Grass 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 Grass Valley?
By FEMA money that reached Grass Valley, Wildfires (2021): 134 households applied for aid, $316K approved.
Is Grass Valley at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (72%), and Grass Valley’s rate for it is higher than 75% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Grass Valley.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Grass 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.