Photo: Marine 69-71 · CC BY-SA 4.0More hazard damage per building is expected in Mammoth than in 96% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Mammoth gets a D− for hazard risk: higher expected damage per building than 96% of U.S. towns. Most of that expected damage is river and rain flooding (88%), then wildfire (11%). Flood insurance has paid 1 claim here since 1993.
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 Mammoth 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
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 Mammoth’s grade
River and rain flooding is 88% of the building damage FEMA expects in Mammoth, and Mammoth’s rate of river and rain flooding damage is in the top 2% of U.S. census tracts. Wildfire adds 11%, at a rate in the top 2% of U.S. census tracts.
D− higher expected damage per building than 96% of U.S. towns (21,298).
Mammoth’s residents live in 2 census tracts; FEMA’s figures are combined by where they live.
In dollars, FEMA expects about $964K a year in losses across Mammoth: $897K to buildings, the rest to people and crops.
Does Mammoth flood? Rarely: 1 flood claim since 1993
Every paid claim on a federal flood insurance policy in Mammoth, from FEMA’s records: 1.8 per 1,000 homes, fewer than 64% of the 13,809 U.S. towns with a flood insurance record.
Mammoth isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Pinal County.3 federal disasters brought FEMA money to Mammoth
Disasters that paid out in Mammoth itself (aid to households or repair grants to the Town of Mammoth), newest first, with that year’s flood claims.
- 2018Severe Storms, Tornadoes, Straight-line Winds, and Flooding$22K to the Town of Mammoth for repairs
- 2012Severe Storms and Flooding$2K to the Town of Mammoth for repairs
- 2006Severe Storms and Flooding$8K to the Town of Mammoth for repairs
Pinal County has had 10 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.
Also 10 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Pinal County, 2002–2025.
Old photos of Mammoth after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Mammoth archive →Mammoth and its neighbors
Mammoth is 2nd of the 2 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 |
|---|---|---|---|
| Oracle | Dmore damage than 93% | river and rain flooding | — |
| Mammoth | D−more damage than 96% | river and rain flooding | 1 |
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 Mammoth 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.
- 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 Mammoth
Is Mammoth at risk for natural disasters?
On FEMA’s National Risk Index, Mammoth has higher expected damage per building than 96% of U.S. towns: D− for hazard risk. Most of the expected damage is river and rain flooding (88%) and wildfire (11%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Mammoth flood?
Flood insurance has paid 1 claim in Mammoth since 1993, $23K in all, or 1.8 per 1,000 homes, fewer than 64% of U.S. towns with a flood insurance record.
Is Mammoth 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 Pinal County, 21% of homes in mapped flood zones carry federal flood insurance, and 0.5% of all homes do.
How much is flood insurance in Mammoth?
FEMA’s Community Rating System list shows no discount for Mammoth’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 Mammoth?
By FEMA money that reached Mammoth, Severe Storms, Tornadoes, Straight-line Winds, and Flooding (2018): $22K to the Town of Mammoth for repairs.
Is Mammoth at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (88%), and Mammoth’s rate for it is in the top 2% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Mammoth.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Mammoth’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.