Photo: Billwhittaker · CC BY-SA 3.0FEMA expects more hazard damage per building in Denison than in 66% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Denison gets a C for hazard risk: higher expected damage per building than 66% of U.S. towns, #109 of 140 in Iowa. Most of that expected damage is river and rain flooding (72%), then tornadoes (21%). Flood insurance has paid 75 claims here since 1990.
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 Denison 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
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 Denison’s grade
River and rain flooding is 72% of the building damage FEMA expects in Denison, and Denison’s rate of river and rain flooding damage is higher than 71% of U.S. census tracts. Tornadoes add 21%, at a rate in the top 1% of U.S. census tracts.
C #109 of 140 in Iowa; higher expected damage per building than 66% of U.S. towns (21,298).
Denison’s residents live in 2 census tracts; FEMA’s figures are combined by where they live.
The typical Iowa town has lower expected damage than 57% of U.S. towns; within the state, Denison has more expected damage per building than 78% of Iowa towns.
In dollars, FEMA expects about $5.9M a year in losses across Denison: $3.1M to buildings, the rest to people and crops.
Does Denison flood? Sometimes: 75 flood claims since 1990
Every paid claim on a federal flood insurance policy in Denison, from FEMA’s records: 23.1 per 1,000 homes, more than 86% of the 13,809 U.S. towns with a flood insurance record.
- The Midwest Flooding11 claims · $612K
- The Storm7 claims · $115K
Denison isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Crawford County.7 federal disasters brought FEMA money to Denison
Disasters that paid out in Denison itself (aid to households or repair grants to the City of Denison), newest first, with that year’s flood claims.
- 2019Severe Storms and Flooding$818K to the City of Denison for repairs
- 2013Severe Storms, Tornadoes, and Flooding$6K to the City of Denison for repairs
- 2010Severe Winter Storm$9K to the City of Denison for repairs
- 2008Severe Storms, Tornadoes, and Flooding154 households applied for aid$181K aid approved7 flood claims paid that year
- 2007Severe Storms, Flooding, and Tornadoes28 households applied for aid$18K aid approved$5K to the City of Denison for repairs
- 2007Snow$17K to the City of Denison for repairs
Show all 7
- 1999Severe Storms and Flooding$3K to the City of Denison for repairs2 flood claims paid that year
Crawford County has had 20 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 Denison after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Denison archive →Get ready for what Denison 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.
- 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 Denison
Is Denison at risk for natural disasters?
On FEMA’s National Risk Index, Denison has higher expected damage per building than 66% of U.S. towns: C for hazard risk, #109 of 140 in Iowa. Most of the expected damage is river and rain flooding (72%) and tornadoes (21%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Denison flood?
Flood insurance has paid 75 claims in Denison since 1990, $2.3M in all, or 23.1 per 1,000 homes, more than 86% of U.S. towns with a flood insurance record. 9 properties have flooded more than once. The most claims came from Midwest Flooding (11).
Is Denison 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 Crawford County, 0.0% of all homes carry federal flood insurance.
How much is flood insurance in Denison?
FEMA’s Community Rating System list shows no discount for Denison’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 Denison?
By FEMA money that reached Denison, Severe Storms and Flooding (2019): $818K to the City of Denison for repairs. By flood claims, Midwest Flooding: 11 paid, $612K.
Is Denison at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (72%), and Denison’s rate for it is higher than 71% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Denison.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Denison’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.