Photo: Tim Tierney · CC BY-SA 4.0On FEMA’s figures, Sewickley faces more hazard damage per building than 72% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Sewickley gets a C for hazard risk: higher expected damage per building than 72% of U.S. towns, #923 of 1,037 in Pennsylvania. Most of that expected damage is river and rain flooding (97%). Flood insurance has paid 13 claims here since 1995.
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 Sewickley 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
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 Sewickley’s grade
River and rain flooding is 97% of the building damage FEMA expects in Sewickley, and Sewickley’s rate of river and rain flooding damage is higher than 87% of U.S. census tracts.
C #923 of 1,037 in Pennsylvania; higher expected damage per building than 72% of U.S. towns (21,298).
All of Sewickley’s residents live in one census tract; the figures are that tract’s.
The typical Pennsylvania town has lower expected damage than 71% of U.S. towns; within the state, Sewickley has more expected damage per building than 89% of Pennsylvania towns.
In dollars, FEMA expects about $1.9M a year in losses across Sewickley: $1.7M to buildings, the rest to people and crops.
Does Sewickley flood? Sometimes: 13 flood claims since 1995
Every paid claim on a federal flood insurance policy in Sewickley, 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.
- Tropical Storm Ivan1 claim · $6K
Sewickley isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Allegheny County.1 federal disaster brought FEMA money to Sewickley
Disasters that paid out in Sewickley itself (aid to households or repair grants to the Borough of Sewickley), newest first, with that year’s flood claims.
- 2004Tropical Depression Ivan142 households applied for aid$404K aid approved1 flood claim paid for it, $6K
Allegheny County has had 15 natural disasters declared by the President since 1953, most often severe storms, then floods. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Sewickley after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Sewickley archive →Sewickley and its neighbors
Sewickley is 3rd of the 4 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 |
|---|---|---|---|
| Moon Township | Aless damage than 91% | river and rain flooding | 19 |
| Aleppo Township | C+more damage than 56% | river and rain flooding | 6 |
| Sewickley | Cmore damage than 72% | river and rain flooding | 13 |
| Edgeworth | Dmore damage than 89% | river and rain flooding | 1 |
| Sewickley Heights | — | 690 residents; we grade 1,000+ | |
| Glen Osborne | — | 585 residents; we grade 1,000+ | |
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 Sewickley 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.
- 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 Sewickley
Is Sewickley at risk for natural disasters?
On FEMA’s National Risk Index, Sewickley has higher expected damage per building than 72% of U.S. towns: C for hazard risk, #923 of 1,037 in Pennsylvania. Most of the expected damage is river and rain flooding (97%). 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.
Does Sewickley flood?
Flood insurance has paid 13 claims in Sewickley since 1995, $81K in all, or 6.8 per 1,000 homes, more than 66% of U.S. towns with a flood insurance record. 2 properties have flooded more than once. The most claims came from Tropical Storm Ivan (1).
Is Sewickley 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 Allegheny County, 28% of homes in mapped flood zones carry federal flood insurance, and 0.4% of all homes do.
How much is flood insurance in Sewickley?
FEMA’s Community Rating System list shows no discount for Sewickley’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 Sewickley?
By FEMA money that reached Sewickley, Tropical Depression Ivan (2004): 142 households applied for aid, $404K approved. By flood claims, Tropical Storm Ivan: 1 paid, $6K.
Is Sewickley at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (97%), and Sewickley’s rate for it is higher than 87% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Sewickley.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Sewickley’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.