Jacob Wingard Dreher House · Photo: Bill Fitzpatrick · CC BY-SA 3.0FEMA expects about as much hazard damage per building in Irmo as in the typical U.S. town, mostly from river and rain flooding
On FEMA’s National Risk Index, Irmo gets a B− for hazard risk: lower expected damage per building than 55% of U.S. towns, #85 of 169 in South Carolina. Most of that expected damage is river and rain flooding (64%), then hurricanes (14%). Flood insurance has paid 33 claims here since 1987.
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 Irmo’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Irmo 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
Tornadoes
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 Irmo’s grade
River and rain flooding is 64% of the building damage FEMA expects in Irmo, and Irmo’s rate of river and rain flooding damage is lower than 53% of U.S. census tracts. Ice storms add 4%, at a rate in the top 6% of U.S. census tracts.
B− #85 of 169 in South Carolina; lower expected damage per building than 55% of U.S. towns (21,298).
Irmo’s residents live in 11 census tracts; FEMA’s figures are combined by where they live.
The typical South Carolina town has lower expected damage than 55% of U.S. towns; within the state, Irmo has more expected damage per building than 50% of South Carolina towns.
In dollars, FEMA expects about $3.6M a year in losses across Irmo: $2.4M to buildings, the rest to people and crops.
Does Irmo flood? Sometimes: 33 flood claims since 1987
Every paid claim on a federal flood insurance policy in Irmo, 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.
- The October severe storms14 claims · $304K
- Hurricane Hugo1 claim · $3K
Irmo isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Richland County.4 federal disasters brought FEMA money to Irmo
Disasters that paid out in Irmo itself (aid to households or repair grants to the Town of Irmo), newest first, with that year’s flood claims.
- 2024Hurricane Helene1,659 households applied for aid$566K aid approved$67K to the Town of Irmo for repairs
- 2015Severe Storms and Flooding739 households applied for aid$512K aid approved16 flood claims paid that year
- 2014Severe Winter Storm$25K to the Town of Irmo for repairs
- 2004Severe Ice Storm$1K to the Town of Irmo for repairs
Its 2 counties have had 18 natural disasters declared by the President since 1953, most often hurricanes and tropical storms, then winter storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Irmo after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Irmo archive →Irmo and its neighbors
Irmo 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 |
|---|---|---|---|
| Lake Murray of Richland | Bless damage than 62% | river and rain flooding | 3 |
| Columbia | Bless damage than 60% | river and rain flooding | 472 |
| Irmo | B−less damage than 55% | river and rain flooding | 33 |
| Seven Oaks | B−more damage than 51% | river and rain flooding | 258 |
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 Irmo 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.
- Pick your spot now: the lowest floor, an inside room, no windows.
- A watch means be ready; a warning means take cover now.
- Keep shoes and a flashlight by the bed.
- 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 Irmo
Is Irmo at risk for natural disasters?
On FEMA’s National Risk Index, Irmo has lower expected damage per building than 55% of U.S. towns: B− for hazard risk, #85 of 169 in South Carolina. Most of the expected damage is river and rain flooding (64%) and hurricanes (14%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Irmo flood?
Flood insurance has paid 33 claims in Irmo since 1987, $403K in all, or 6.8 per 1,000 homes, more than 66% of U.S. towns with a flood insurance record. 3 properties have flooded more than once. The most claims came from October severe storms (14).
Is Irmo 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 Richland County, 69% of homes in mapped flood zones carry federal flood insurance, and 1.3% of all homes do.
How much is flood insurance in Irmo?
FEMA’s Community Rating System list shows no discount for Irmo’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 Irmo?
By FEMA money that reached Irmo, Hurricane Helene (2024): 1,659 households applied for aid, $566K approved, and $67K to the Town of Irmo for repairs. By flood claims, October severe storms: 14 paid, $304K.
Is Irmo at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (64%), and Irmo’s rate for it is lower than 53% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Irmo.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Irmo’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.