On FEMA’s figures, few U.S. towns expect less hazard damage per building than Sully Square, mostly from river and rain flooding
On FEMA’s National Risk Index, Sully Square gets an A+ for hazard risk: among the lowest expected damage per building of U.S. towns. Most of that expected damage is river and rain flooding (71%), then hurricanes (15%). 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 Sully Square 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
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 Sully Square’s grade
River and rain flooding is 71% of the building damage FEMA expects in Sully Square, and Sully Square’s rate of river and rain flooding damage is lower than 93% of U.S. census tracts. Next is hurricanes at 15% (higher than 74% of U.S. census tracts).
A+ among the lowest expected damage per building of U.S. towns (21,298).
All of Sully Square’s residents live in one census tract; the figures are that tract’s.
In dollars, FEMA expects about $622K a year in losses across Sully Square: $559K to buildings, the rest to people and crops.
Does Sully Square flood? No paid flood claims on record
FEMA’s records show no paid flood insurance claims in Sully Square. That’s not a promise: most homes don’t carry flood insurance, so small floods go unrecorded.
Sully Square isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Fairfax County.The storms Sully Square remembers
None of the 16 disasters declared for Fairfax County shows FEMA aid or repair money reaching Sully Square itself in FEMA’s records, so these are its biggest flood-claim years.
Fairfax County has had 16 natural disasters declared by the President since 1953, most often winter storms, then hurricanes and tropical storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Sully Square and its neighbors
Sully Square has the lowest expected damage per building of the 4 graded towns here. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Sully Square | A+among the lowest damage | river and rain flooding | 0 |
| Floris | Aless damage than 88% | river and rain flooding | — |
| Franklin Farm | A−less damage than 76% | river and rain flooding | 9 |
| Chantilly | Bless damage than 60% | river and rain flooding | 4 |
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 Sully Square 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.
- 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 Sully Square
Is Sully Square at risk for natural disasters?
On FEMA’s National Risk Index, Sully Square has among the lowest expected damage per building of U.S. towns: A+ for hazard risk. Most of the expected damage is river and rain flooding (71%) and hurricanes (15%). The figures are for the one census tract the town shares with its neighbors. This is FEMA’s model of an average year for today’s buildings, not a forecast.
Is Sully Square 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 Fairfax County, 22% of homes in mapped flood zones carry federal flood insurance, and 1.1% of all homes do.
How much is flood insurance in Sully Square?
FEMA’s Community Rating System list shows no discount for Sully Square’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
Is Sully Square at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (71%), and Sully Square’s rate for it is lower than 93% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Sully Square.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Sully Square’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.