Glennmary · Photo: Nyttend · Public domainOn FEMA’s figures, Riverdale faces less hazard damage per building than 76% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Riverdale gets an A− for hazard risk: lower expected damage per building than 76% of U.S. towns. Most of that expected damage is river and rain flooding (74%), then hurricanes (14%). 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 Riverdale 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
Hurricanes
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
River and rain flooding is 74% of the building damage FEMA expects in Riverdale, and Riverdale’s rate of river and rain flooding damage is lower than 61% of U.S. census tracts. Next is hurricanes at 14% (higher than 82% of U.S. census tracts).
A− lower expected damage per building than 76% of U.S. towns (21,298).
Riverdale’s residents live in 3 census tracts; FEMA’s figures are combined by where they live.
In dollars, FEMA expects about $289K a year in losses across Riverdale: $196K to buildings, the rest to people and crops.
Does Riverdale flood? No paid flood claims on record
FEMA’s records show no paid flood insurance claims in Riverdale. That’s not a promise: most homes don’t carry flood insurance, so small floods go unrecorded.
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: the county.The storms Riverdale remembers
None of the 20 disasters declared for its 2 counties shows FEMA aid or repair money reaching Riverdale itself in FEMA’s records, so these are its biggest flood-claim years.
Its 2 counties have had 20 natural disasters declared by the President since 1953, most often severe storms, then hurricanes and tropical storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Riverdale and its neighbors
Riverdale 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 |
|---|---|---|---|
| South Boston | Aless damage than 90% | river and rain flooding | 33 |
| Riverdale | A−less damage than 76% | river and rain flooding | 0 |
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.
- 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.
- The season runs June through November and peaks from mid-August to mid-October.
- Bring in porch furniture and anything the wind can throw.
- Fill the gas tank and charge phones before the storm arrives.
- 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 lower expected damage per building than 76% of U.S. towns: A− for hazard risk. Most of the expected damage is river and rain flooding (74%) and hurricanes (14%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
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 the county, 9% of homes in mapped flood zones carry federal flood insurance, and 0.1% 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 river and rain flooding?
It is the largest share of the building damage FEMA expects here (74%), and Riverdale’s rate for it is lower than 61% 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.