Photo: Smallbones at en.wikipedia · Public domainFEMA expects about as much hazard damage per building in Darby as in the typical U.S. town, mostly from river and rain flooding
On FEMA’s National Risk Index, Darby gets a B− for hazard risk: lower expected damage per building than 53% of U.S. towns, #730 of 1,037 in Pennsylvania. Most of that expected damage is river and rain flooding (81%), then earthquakes (10%). Flood insurance has paid 338 claims here since 1978.
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 stands out about Darby’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Darby 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
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 Darby’s grade
River and rain flooding is 81% of the building damage FEMA expects in Darby, and Darby’s rate of river and rain flooding damage is higher than 64% of U.S. census tracts. Next is earthquakes at 10% (higher than 76% of U.S. census tracts).
B− #730 of 1,037 in Pennsylvania; lower expected damage per building than 53% of U.S. towns (21,298).
Darby’s residents live in 3 census tracts; FEMA’s figures are combined by where they live.
The typical Pennsylvania town has lower expected damage than 71% of U.S. towns; within the state, Darby has more expected damage per building than 70% of Pennsylvania towns.
In dollars, FEMA expects about $2.5M a year in losses across Darby: $1.7M to buildings, the rest to people and crops.
Does Darby flood? Yes: 338 flood claims since 1978
Every paid claim on a federal flood insurance policy in Darby, from FEMA’s records: 74.4 per 1,000 homes, more than 95% of the 13,809 U.S. towns with a flood insurance record.
- Hurricane Floyd55 claims · $3.3M
- Hurricane Irene33 claims · $907K
- Hurricane Isaias20 claims · $1.5M
Darby isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Delaware County.5 federal disasters brought FEMA money to Darby
Disasters that paid out in Darby itself (aid to households or repair grants to the Borough of Darby), newest first, with that year’s flood claims.
- 2021Remnants of Hurricane Ida891 households applied for aid$1.5M aid approved3 flood claims paid for it, $271K
- 2011Tropical Storm Lee84 households applied for aid$68K aid approved
- 2011Hurricane Irene678 households applied for aid$614K aid approved33 flood claims paid for it, $907K
- 2004Tropical Depression Ivan47 households applied for aid$110K aid approved
- 2004Severe Storms and Flooding132 households applied for aid$192K aid approved
Delaware County has had 19 natural disasters declared by the President since 1953, most often hurricanes and tropical storms, then floods. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Darby after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Darby archive →Darby and its neighbors
Darby is 5th of the 6 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 |
|---|---|---|---|
| Collingdale | A+less damage than 96% | river and rain flooding | 40 |
| Yeadon | A−less damage than 82% | river and rain flooding | 13 |
| Upper Darby Township | B+less damage than 71% | river and rain flooding | 363 |
| Philadelphia | B−less damage than 54% | river and rain flooding | 1,177 |
| Darby | B−less damage than 53% | river and rain flooding | 338 |
| Colwyn | C+more damage than 57% | river and rain flooding | 90 |
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 Darby 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.
- 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 Darby
Is Darby at risk for natural disasters?
On FEMA’s National Risk Index, Darby has lower expected damage per building than 53% of U.S. towns: B− for hazard risk, #730 of 1,037 in Pennsylvania. Most of the expected damage is river and rain flooding (81%) and earthquakes (10%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Darby flood?
Flood insurance has paid 338 claims in Darby since 1978, $9.9M in all, or 74.4 per 1,000 homes, more than 95% of U.S. towns with a flood insurance record. 38 properties have flooded more than once. The most claims came from Hurricane Floyd (55).
Is Darby 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 Delaware County, 39% of homes in mapped flood zones carry federal flood insurance, and 0.7% of all homes do.
How much is flood insurance in Darby?
FEMA’s Community Rating System list shows no discount for Darby’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 Darby?
By FEMA money that reached Darby, Remnants of Hurricane Ida (2021): 891 households applied for aid, $1.5M approved. By flood claims, Hurricane Floyd: 55 paid, $3.3M.
Is Darby at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (81%), and Darby’s rate for it is higher than 64% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Darby.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Darby’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.