FEMA expects less hazard damage per building in Ridley Township than in 80% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Ridley Township gets an A− for hazard risk: lower expected damage per building than 80% of U.S. towns, #403 of 1,037 in Pennsylvania. Most of that expected damage is river and rain flooding (77%). Flood insurance has paid 85 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 Ridley Township’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Ridley Township 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
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 Ridley Township’s grade
River and rain flooding is 77% of the building damage FEMA expects in Ridley Township, and Ridley Township’s rate of river and rain flooding damage is lower than 62% of U.S. census tracts. Coastal flooding adds 1%, at a rate in the top 7% of U.S. census tracts.
A− #403 of 1,037 in Pennsylvania; lower expected damage per building than 80% of U.S. towns (21,298).
Ridley Township’s residents live in 7 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, Ridley Township has less expected damage per building than 61% of Pennsylvania towns.
In dollars, FEMA expects about $6.9M a year in losses across Ridley Township: $4.8M to buildings, the rest to people and crops.
Does Ridley Township flood? Sometimes: 85 flood claims since 1978
Every paid claim on a federal flood insurance policy in Ridley Township, from FEMA’s records: 6.8 per 1,000 homes, more than 66% of the 13,809 U.S. towns with a flood insurance record.
- Hurricane Isaias16 claims · $422K
- Tropical Storm Allison10 claims · $166K
- Hurricane Irene6 claims · $214K
Ridley Township 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.The storms Ridley Township remembers
None of the 19 disasters declared for Delaware County shows FEMA aid or repair money reaching Ridley Township itself in FEMA’s records, so these are its biggest flood-claim years.
- 202016 flood claims paidNo declaration for the county that year
- 200110 flood claims paidNo declaration for the county that year
- 20117 flood claims paidThe year of Tropical Storm Lee, declared for Delaware County
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 Ridley Township after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Ridley Township archive →Ridley Township and its neighbors
Ridley Township is 4th of the 7 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 |
|---|---|---|---|
| Ridley Park | Aless damage than 93% | river and rain flooding | 2 |
| Swarthmore | Aless damage than 86% | river and rain flooding | 13 |
| Nether Providence Township | Aless damage than 86% | river and rain flooding | 17 |
| Ridley Township | A−less damage than 80% | river and rain flooding | 85 |
| Chester | B+less damage than 74% | river and rain flooding | 148 |
| Prospect Park | B+less damage than 69% | river and rain flooding | 6 |
| Eddystone | B−less damage than 51% | river and rain flooding | 11 |
| Woodlyn | — | a Census area inside a town; graded with the town | |
| Folsom | — | a Census area inside a town; graded with the town | |
| Rutledge | — | 935 residents; we grade 1,000+ | |
| Darby Township | — | not graded yet | |
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 Ridley Township 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.
- 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 Ridley Township
Is Ridley Township at risk for natural disasters?
On FEMA’s National Risk Index, Ridley Township has lower expected damage per building than 80% of U.S. towns: A− for hazard risk, #403 of 1,037 in Pennsylvania. Most of the expected damage is river and rain flooding (77%) and earthquakes (9%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Ridley Township flood?
Flood insurance has paid 85 claims in Ridley Township since 1978, $1.6M in all, or 6.8 per 1,000 homes, more than 66% of U.S. towns with a flood insurance record. 16 properties have flooded more than once. The most claims came from Hurricane Isaias (16).
Is Ridley Township 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 Ridley Township?
FEMA’s Community Rating System list shows no discount for Ridley Township’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 Ridley Township?
By flood claims, Hurricane Isaias: 16 paid, $422K.
Is Ridley Township at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (77%), and Ridley Township’s rate for it is lower than 62% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Ridley Township.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Ridley Township’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.