Less hazard damage per building is expected in Riverdale than in 70% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Riverdale gets a B+ for hazard risk: lower expected damage per building than 70% of U.S. towns, #138 of 264 in Georgia. Most of that expected damage is river and rain flooding (72%), then tornadoes (15%). Flood insurance has paid 19 claims here since 1980.
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
Tornadoes
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 72% of the building damage FEMA expects in Riverdale, and Riverdale’s rate of river and rain flooding damage is lower than 57% of U.S. census tracts. Next is tornadoes at 15% (higher than 85% of U.S. census tracts).
B+ #138 of 264 in Georgia; lower expected damage per building than 70% of U.S. towns (21,298).
Riverdale’s residents live in 10 census tracts; FEMA’s figures are combined by where they live.
The typical Georgia town has lower expected damage than 72% of U.S. towns; within the state, Riverdale has more expected damage per building than 52% of Georgia towns.
In dollars, FEMA expects about $2.8M a year in losses across Riverdale: $2.0M to buildings, the rest to people and crops.
Does Riverdale flood? Sometimes: 19 flood claims since 1980
Every paid claim on a federal flood insurance policy in Riverdale, from FEMA’s records: 3.1 per 1,000 homes, fewer than 51% of the 13,809 U.S. towns with a flood insurance record.
- Tropical Storm Alberto5 claims · $35K
- Hurricane Dennis2 claims · $30K
- Tropical Storm Ivan1 claim · $4K
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: Clayton County.3 federal disasters brought FEMA money to Riverdale
Disasters that paid out in Riverdale itself (aid to households or repair grants to the City of Riverdale), newest first, with that year’s flood claims.
- 2024Hurricane Helene73 households applied for aid$67K aid approved
- 2009Severe Storms and Flooding4 households applied for aid$3K aid approved
- 2004Hurricane Ivan71 households applied for aid$246K aid approved1 flood claim paid for it, $4K
Clayton County has had 11 natural disasters declared by the President since 1953, most often hurricanes and tropical storms, then severe storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
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 →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.
- Pick your spot now: the lowest floor, an inside room, no windows.
- A watch means be ready; a warning means take cover now.
- Keep shoes and a flashlight by the bed.
- 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 70% of U.S. towns: B+ for hazard risk, #138 of 264 in Georgia. Most of the expected damage is river and rain flooding (72%) and tornadoes (15%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Riverdale flood?
Flood insurance has paid 19 claims in Riverdale since 1980, $119K in all, or 3.1 per 1,000 homes, fewer than 51% of U.S. towns with a flood insurance record. 3 properties have flooded more than once. The most claims came from Tropical Storm Alberto (5).
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 Clayton County, 22% of homes in mapped flood zones carry federal flood insurance, and 0.4% 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.
What was the biggest storm in Riverdale?
By FEMA money that reached Riverdale, Hurricane Ivan (2004): 71 households applied for aid, $246K approved. By flood claims, Tropical Storm Alberto: 5 paid, $35K.
Is Riverdale at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (72%), and Riverdale’s rate for it is lower than 57% 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.