Photo: RM VM · CC BY-SA 4.0On FEMA’s figures, Sienna faces about as much hazard damage per building as the typical U.S. town, mostly from river and rain flooding
On FEMA’s National Risk Index, Sienna gets a B− for hazard risk: higher expected damage per building than 54% of U.S. towns, #353 of 642 in Texas. Most of that expected damage is river and rain flooding (59%), then hurricanes (35%). Flood insurance has paid 36 claims here since 2016.
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 Sienna 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
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 Sienna’s grade
River and rain flooding is 59% of the building damage FEMA expects in Sienna, and Sienna’s rate of river and rain flooding damage is lower than 50% of U.S. census tracts. Next is hurricanes at 35% (higher than 88% of U.S. census tracts).
B− #353 of 642 in Texas; higher expected damage per building than 54% of U.S. towns (21,298).
Sienna’s residents live in 4 census tracts; FEMA’s figures are combined by where they live.
The typical Texas town has higher expected damage than 50% of U.S. towns; within the state, Sienna has more expected damage per building than 55% of Texas towns.
In dollars, FEMA expects about $7.6M a year in losses across Sienna: $5.1M to buildings, the rest to people and crops.
Does Sienna flood? Sometimes: 36 flood claims since 2016
Every paid claim on a federal flood insurance policy in Sienna, from FEMA’s records: 4.8 per 1,000 homes, more than 59% of the 13,809 U.S. towns with a flood insurance record.
- Hurricane Harvey25 claims · $1.2M
- Hurricane Beryl10 claims · $855K
- The Early summer severe storms1 claim · $3K
Sienna isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Fort Bend County.1 federal disaster brought FEMA money to Sienna
Disasters that paid out in Sienna itself (aid to households or repair grants to Sienna), newest first, with that year’s flood claims.
- 2024Hurricane Beryl4 households applied for aid$7K aid approved10 flood claims paid for it, $855K
Fort Bend County has had 21 natural disasters declared by the President since 1953, most often hurricanes and tropical storms, then floods. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Also 1 FEMA wildfire suppression grant (Fire Management Assistance, not a disaster declaration) for fires in Fort Bend County, 2006–2006.
Old photos of Sienna after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Sienna archive →Sienna and its neighbors
Sienna 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 |
|---|---|---|---|
| Sienna | B−more damage than 54% | river and rain flooding | 36 |
| Arcola | Cmore damage than 70% | river and rain flooding | — |
| Missouri City | C−more damage than 76% | river and rain flooding | 558 |
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 Sienna 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.
- 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 Sienna
Is Sienna at risk for natural disasters?
On FEMA’s National Risk Index, Sienna has higher expected damage per building than 54% of U.S. towns: B− for hazard risk, #353 of 642 in Texas. Most of the expected damage is river and rain flooding (59%) and hurricanes (35%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Sienna flood?
Flood insurance has paid 36 claims in Sienna since 2016, $2.0M in all, or 4.8 per 1,000 homes, more than 59% of U.S. towns with a flood insurance record. The most claims came from Hurricane Harvey (25).
Is Sienna 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 Fort Bend County, 42% of homes in mapped flood zones carry federal flood insurance, and 15.4% of all homes do.
How much is flood insurance in Sienna?
FEMA’s Community Rating System list shows no discount for Sienna’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 Sienna?
By FEMA money that reached Sienna, Hurricane Beryl (2024): 4 households applied for aid, $7K approved. By flood claims, Hurricane Harvey: 25 paid, $1.2M.
Is Sienna at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (59%), and Sienna’s rate for it is lower than 50% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Sienna.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Sienna’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.