Photo: Canadian2006 · CC BY-SA 3.0FEMA puts Slippery Rock Township’s expected hazard damage per building below that of 76% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Slippery Rock Township gets an A− for hazard risk: lower expected damage per building than 76% of U.S. towns, #459 of 1,037 in Pennsylvania. Most of that expected damage is river and rain flooding (95%). Flood insurance has paid 24 claims here since 1979.
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 Slippery Rock Township’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Slippery Rock 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
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 Slippery Rock Township’s grade
River and rain flooding is 95% of the building damage FEMA expects in Slippery Rock Township, and Slippery Rock Township’s rate of river and rain flooding damage is higher than 56% of U.S. census tracts.
A− #459 of 1,037 in Pennsylvania; lower expected damage per building than 76% of U.S. towns (21,298).
Slippery Rock Township’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, Slippery Rock Township has less expected damage per building than 56% of Pennsylvania towns.
In dollars, FEMA expects about $1.4M a year in losses across Slippery Rock Township: $1.3M to buildings, the rest to people and crops.
Does Slippery Rock Township flood? Sometimes: 24 flood claims since 1979
Every paid claim on a federal flood insurance policy in Slippery Rock Township, from FEMA’s records: 8.7 per 1,000 homes, more than 71% of the 13,809 U.S. towns with a flood insurance record.
- Tropical Storm Ivan4 claims · $17K
- Tropical Storm Bill1 claim · $77K
Slippery Rock 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: Butler County.The storms Slippery Rock Township remembers
None of the 8 disasters declared for Butler County shows FEMA aid or repair money reaching Slippery Rock Township itself in FEMA’s records, so these are its biggest flood-claim years.
- 20047 flood claims paidThe year of Tropical Depression Ivan, declared for Butler County
- 20082 flood claims paidNo declaration for the county that year
- 20242 flood claims paidNo declaration for the county that year
Butler County has had 8 natural disasters declared by the President since 1953, most often floods, then hurricanes and tropical storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Slippery Rock Township after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Slippery Rock Township archive →Slippery Rock Township and its neighbors
Slippery Rock Township has the lowest expected damage per building of the 6 graded towns here. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Slippery Rock Township | A−less damage than 76% | river and rain flooding | 24 |
| Liberty Township | B+less damage than 67% | river and rain flooding | — |
| Mercer Township | Bless damage than 61% | river and rain flooding | 7 |
| Cherry Township | Bless damage than 60% | river and rain flooding | 1 |
| Worth Township | Cmore damage than 66% | river and rain flooding | 28 |
| Brady Township | Cmore damage than 66% | river and rain flooding | 11 |
| West Liberty | — | 327 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 Slippery Rock 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.
- 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 Slippery Rock Township
Is Slippery Rock Township at risk for natural disasters?
On FEMA’s National Risk Index, Slippery Rock Township has lower expected damage per building than 76% of U.S. towns: A− for hazard risk, #459 of 1,037 in Pennsylvania. Most of the expected damage is river and rain flooding (95%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Slippery Rock Township flood?
Flood insurance has paid 24 claims in Slippery Rock Township since 1979, $295K in all, or 8.7 per 1,000 homes, more than 71% of U.S. towns with a flood insurance record. 4 properties have flooded more than once. The most claims came from Tropical Storm Ivan (4).
Is Slippery Rock 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 Butler County, 20% of homes in mapped flood zones carry federal flood insurance, and 0.5% of all homes do.
How much is flood insurance in Slippery Rock Township?
FEMA’s Community Rating System list shows no discount for Slippery Rock 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 Slippery Rock Township?
By flood claims, Tropical Storm Ivan: 4 paid, $17K.
Is Slippery Rock Township at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (95%), and Slippery Rock Township’s rate for it is higher than 56% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Slippery Rock Township.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Slippery Rock 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.