FEMA expects less hazard damage per building in Harrison than in 71% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Harrison gets a B+ for hazard risk: lower expected damage per building than 71% of U.S. towns, #28 of 177 in Tennessee. Most of that expected damage is river and rain flooding (67%), then tornadoes (15%). Flood insurance has paid 13 claims here since 2000.
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 Harrison’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Harrison 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
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 Harrison’s grade
River and rain flooding is 67% of the building damage FEMA expects in Harrison, and Harrison’s rate of river and rain flooding damage is lower than 64% of U.S. census tracts. Next is tornadoes at 15% (higher than 86% of U.S. census tracts).
B+ #28 of 177 in Tennessee; lower expected damage per building than 71% of U.S. towns (21,298).
Harrison’s residents live in 2 census tracts; FEMA’s figures are combined by where they live.
The typical Tennessee town has higher expected damage than 53% of U.S. towns; within the state, Harrison has less expected damage per building than 85% of Tennessee towns.
In dollars, FEMA expects about $1.9M a year in losses across Harrison: $1.1M to buildings, the rest to people and crops.
Does Harrison flood? Sometimes: 13 flood claims since 2000
Every paid claim on a federal flood insurance policy in Harrison, from FEMA’s records: 3.7 per 1,000 homes, more than 53% of the 13,809 U.S. towns with a flood insurance record.
- The Heavy rains2 claims · $65K
- The Early winter storms1 claim · $20K
Harrison isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Hamilton County.4 federal disasters brought FEMA money to Harrison
Disasters that paid out in Harrison itself (aid to households or repair grants to Harrison), newest first, with that year’s flood claims.
- 2020Severe Storms, Tornadoes, Straight-line Winds, and Flooding11 households applied for aid$4K aid approved
- 2012Severe Storms, Tornadoes, Straight-line Winds and144 households applied for aid$151K aid approved2 flood claims paid that year
- 2011Severe Storms, Tornadoes, Straight-line Winds, and Associated Flooding57 households applied for aid$19K aid approved
- 2003Severe Storms, Tornadoes, and Flooding26 households applied for aid$77K aid approved2 flood claims paid that year
Hamilton County has had 19 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.
Also 2 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Hamilton County, 2016–2016.
Old photos of Harrison after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Harrison archive →Harrison and its neighbors
Harrison has the lowest expected damage per building of the 2 graded towns here. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Harrison | B+less damage than 71% | river and rain flooding | 13 |
| Chattanooga | Cmore damage than 67% | river and rain flooding | 680 |
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 Harrison 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.
- 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 Harrison
Is Harrison at risk for natural disasters?
On FEMA’s National Risk Index, Harrison has lower expected damage per building than 71% of U.S. towns: B+ for hazard risk, #28 of 177 in Tennessee. Most of the expected damage is river and rain flooding (67%) and tornadoes (15%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Harrison flood?
Flood insurance has paid 13 claims in Harrison since 2000, $286K in all, or 3.7 per 1,000 homes, more than 53% of U.S. towns with a flood insurance record. The most claims came from Heavy rains (2).
Is Harrison 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 Hamilton County, 22% of homes in mapped flood zones carry federal flood insurance, and 1.0% of all homes do.
How much is flood insurance in Harrison?
FEMA’s Community Rating System list shows no discount for Harrison’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 Harrison?
By FEMA money that reached Harrison, Severe Storms, Tornadoes, Straight-line Winds and (2012): 144 households applied for aid, $151K approved. By flood claims, Heavy rains: 2 paid, $65K.
Is Harrison at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (67%), and Harrison’s rate for it is lower than 64% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Harrison.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Harrison’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.