FEMA expects more hazard damage per building in Riverdale than in 64% of U.S. towns, mostly from earthquakes
On FEMA’s National Risk Index, Riverdale gets a C+ for hazard risk: higher expected damage per building than 64% of U.S. towns, #73 of 119 in Utah. Most of that expected damage is earthquakes (61%), then river and rain flooding (36%). Flood insurance has paid 4 claims here since 1986.
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 Riverdale 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 Riverdale’s grade
Earthquakes are 61% of the building damage FEMA expects in Riverdale, and Riverdale’s rate of earthquakes damage is higher than 90% of U.S. census tracts. Next is river and rain flooding at 36% (lower than 78% of U.S. census tracts).
C+ #73 of 119 in Utah; higher expected damage per building than 64% of U.S. towns (21,298).
Riverdale’s residents live in 2 census tracts; FEMA’s figures are combined by where they live.
The typical Utah town has higher expected damage than 56% of U.S. towns; within the state, Riverdale has more expected damage per building than 61% of Utah towns.
In dollars, FEMA expects about $3.6M a year in losses across Riverdale: $2.5M to buildings, the rest to people and crops.
Does Riverdale flood? Rarely: 4 flood claims since 1986
Every paid claim on a federal flood insurance policy in Riverdale, from FEMA’s records: 1.1 per 1,000 homes, fewer than 76% of the 13,809 U.S. towns with a flood insurance record.
Riverdale isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Weber County.The storms Riverdale remembers
None of the 6 disasters declared for Weber County shows FEMA aid or repair money reaching Riverdale itself in FEMA’s records, so these are its biggest flood-claim years.
- 19861 flood claims paidThe year of Heavy Rains, Snowmelt and Flooding, declared for Weber County
- 19991 flood claims paidNo declaration for the county that year
- 20051 flood claims paidNo declaration for the county that year
Weber County has had 6 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 2 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Weber County, 2003–2017.
Old photos of Riverdale after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Riverdale archive →Riverdale and its neighbors
Riverdale is 4th of the 5 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 |
|---|---|---|---|
| Roy | Bless damage than 59% | earthquakes | 2 |
| South Ogden | Bless damage than 58% | earthquakes | 3 |
| Washington Terrace | C+more damage than 61% | earthquakes | 1 |
| Riverdale | C+more damage than 64% | earthquakes | 4 |
| Ogden | Cmore damage than 68% | earthquakes | 13 |
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 Riverdale 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 Riverdale
Is Riverdale at risk for natural disasters?
On FEMA’s National Risk Index, Riverdale has higher expected damage per building than 64% of U.S. towns: C+ for hazard risk, #73 of 119 in Utah. Most of the expected damage is earthquakes (61%) and river and rain flooding (36%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Riverdale flood?
Flood insurance has paid 4 claims in Riverdale since 1986, $8K in all, or 1.1 per 1,000 homes, fewer than 76% of U.S. towns with a flood insurance record.
Is Riverdale 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 Weber County, 8% of homes in mapped flood zones carry federal flood insurance, and 0.2% of all homes do.
How much is flood insurance in Riverdale?
FEMA’s Community Rating System list shows no discount for Riverdale’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
Is Riverdale at risk from earthquakes?
It is the largest share of the building damage FEMA expects here (61%), and Riverdale’s rate for it is higher than 90% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Riverdale.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Riverdale’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.