Coral Court Motel · Photo: Lori · CC BY-SA 2.0FEMA puts Marlborough’s expected hazard damage per building above that of 77% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Marlborough gets a C− for hazard risk: higher expected damage per building than 77% of U.S. towns. Most of that expected damage is river and rain flooding (66%), then earthquakes (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 Marlborough 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
Earthquakes
Hail
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 Marlborough’s grade
River and rain flooding is 66% of the building damage FEMA expects in Marlborough, and Marlborough’s rate of river and rain flooding damage is higher than 76% of U.S. census tracts. Hail adds 8%, at a rate in the top 6% of U.S. census tracts.
C− higher expected damage per building than 77% of U.S. towns (21,298).
Marlborough’s residents live in 3 census tracts; FEMA’s figures are combined by where they live.
In dollars, FEMA expects about $1.6M a year in losses across Marlborough: $770K to buildings, the rest to people and crops.
Does Marlborough flood? No paid flood claims on record
FEMA’s records show no paid flood insurance claims in Marlborough. That’s not a promise: most homes don’t carry flood insurance, so small floods go unrecorded.
Marlborough isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: St. Louis County.The storms Marlborough remembers
None of the 30 disasters declared for St. Louis County shows FEMA aid or repair money reaching Marlborough itself in FEMA’s records, so these are its biggest flood-claim years.
St. Louis County has had 30 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.
Marlborough and its neighbors
Marlborough 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 |
|---|---|---|---|
| Webster Groves | C+more damage than 65% | river and rain flooding | 64 |
| Affton | Cmore damage than 68% | river and rain flooding | 32 |
| Marlborough | C−more damage than 77% | river and rain flooding | 0 |
| Shrewsbury | C−more damage than 80% | river and rain flooding | 3 |
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 Marlborough 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.
- Drop, cover and hold on.
- Strap tall furniture and the water heater to the wall.
- Know how to shut off the gas.
- Park in a garage or under cover when storms are forecast.
- Stay away from windows while it falls.
- Photograph roof and car damage for your insurer.
- 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 Marlborough
Is Marlborough at risk for natural disasters?
On FEMA’s National Risk Index, Marlborough has higher expected damage per building than 77% of U.S. towns: C− for hazard risk. Most of the expected damage is river and rain flooding (66%) and earthquakes (22%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Is Marlborough 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 St. Louis County, 34% of homes in mapped flood zones carry federal flood insurance, and 0.6% of all homes do.
How much is flood insurance in Marlborough?
FEMA’s Community Rating System list shows no discount for Marlborough’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
Is Marlborough at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (66%), and Marlborough’s rate for it is higher than 76% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Marlborough.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Marlborough’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.