Photo: PopePompus · CC BY-SA 4.0Less hazard damage per building is expected in Norwalk than in 86% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Norwalk gets an A for hazard risk: lower expected damage per building than 86% of U.S. towns, #7 of 140 in Iowa. Most of that expected damage is river and rain flooding (67%), then tornadoes (22%). FEMA’s files show no paid flood insurance claims here.
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 Norwalk 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
Strong wind
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 Norwalk’s grade
River and rain flooding is 67% of the building damage FEMA expects in Norwalk, and Norwalk’s rate of river and rain flooding damage is lower than 78% of U.S. census tracts. Tornadoes add 22%, at a rate in the top 10% of U.S. census tracts.
A #7 of 140 in Iowa; lower expected damage per building than 86% of U.S. towns (21,298).
Norwalk’s residents live in 3 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, Norwalk has less expected damage per building than 96% of Iowa towns.
In dollars, FEMA expects about $3.2M a year in losses across Norwalk: $1.8M to buildings, the rest to people and crops.
Does Norwalk flood? No paid flood claims on record
FEMA’s records show no paid flood insurance claims in Norwalk. That’s not a promise: most homes don’t carry flood insurance, so small floods go unrecorded.
Norwalk isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Warren County.5 federal disasters brought FEMA money to Norwalk
Disasters that paid out in Norwalk itself (aid to households or repair grants to the City of Norwalk), newest first, with that year’s flood claims.
- 2018Severe Storms, Tornadoes, Straight-line Winds, and Flooding$45K to the City of Norwalk for repairs
- 2010Severe Storms, Flooding, and Tornadoes17 households applied for aid$58K aid approved
- 2008Severe Storms, Tornadoes, and Flooding142 households applied for aid$263K aid approved$52K to the City of Norwalk for repairs
- 2007Severe Winter Storm$21K to the City of Norwalk for repairs
- 2004Severe Storms, Tornadoes, and Flooding3 households applied for aid$4K aid approved
Warren 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 Norwalk after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Norwalk archive →Norwalk and its neighbors
Norwalk has the lowest expected damage per building of the 3 graded towns here. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Norwalk | Aless damage than 86% | river and rain flooding | 0 |
| Des Moines | A−less damage than 82% | river and rain flooding | 707 |
| West Des Moines | B+less damage than 71% | river and rain flooding | 307 |
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 Norwalk 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.
- Trim dead limbs over the house and driveway.
- Tie down trash cans and outdoor furniture.
- Stay clear of downed lines and call the utility.
- 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 Norwalk
Is Norwalk at risk for natural disasters?
On FEMA’s National Risk Index, Norwalk has lower expected damage per building than 86% of U.S. towns: A for hazard risk, #7 of 140 in Iowa. Most of the expected damage is river and rain flooding (67%) and tornadoes (22%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Is Norwalk 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 Warren County, 7% of homes in mapped flood zones carry federal flood insurance, and 0.1% of all homes do.
How much is flood insurance in Norwalk?
FEMA’s Community Rating System list shows no discount for Norwalk’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 Norwalk?
By FEMA money that reached Norwalk, Severe Storms, Tornadoes, and Flooding (2008): 142 households applied for aid, $263K approved, and $52K to the City of Norwalk for repairs.
Is Norwalk at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (67%), and Norwalk’s rate for it is lower than 78% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Norwalk.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Norwalk’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.