Water damage restoration · O'Fallon, Missouri
Water damage restoration in O'Fallon, MO
Burst pipe, failed water heater, or storm water? O'Fallon-area ZIPs: 347 flood claims since 1979[1]; 9% of homes built before 1980[2]. Request help from local restoration crews. O'Fallon, in St. Charles County — ZIPs 63366, 63368, counts 96,101 residents (2025 estimate)[3].
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The O'Fallon water damage picture in brief
- Population (2025 est.)
- 96,101[3]+5.2% since 2020
- County
- St. Charles[3]
- Land area
- 31.0 sq mi[4]
- Flood-insurance (NFIP) claims, local ZIPs
- 347 since 1979[1]$7,078,948 paid across 291 claims · ZIP 63366, 63368
- Flood & flash-flood reports within 10 mi
- 6[5]2016–2025 · latest Jun 4, 2025
- Winter-storm & freeze days, st. charles zone
- 12[5]2016–2025; hard freezes burst pipes
- Federal disaster declarations incl. flooding, St. Charles Co.
- 11[6]of 18 total declarations
- Homes built before 1980
- 9%[2]the lowest share of the 15 St. Louis–area suburbs we cover
- Households renting
- 19%[2]2020–2024
What the local data means for water damage in O'Fallon
O'Fallon is one of the fastest-growing St. Louis–metro suburbs tracked here: 96,101 people (2025 estimate), up 5.2% since 2020[3]. On the map that's 31.0 square miles holding 3,101 residents per square mile, the 6th densest of the suburbs here; it sits entirely in St. Charles County, with ZIP codes 63366, 63368[4].
O'Fallon mixes 20% of homes built since 2010 and 9% before 1980[2]: new supply lines and water heaters in one house, aging pipe and original valves in the next — so where a leak starts depends a lot on the address.
Mail to O'Fallon goes through 2 ZIP codes — 63366 (54% of the city's land), 63368 (30% of the city's land)[7].
The closest tracked neighbours are Lake St. Louis (3.4 mi W), St. Peters (6.3 mi E) and Wentzville (8.4 mi W)[4].
347 flood-insurance claims have come from O'Fallon-area ZIP codes (63366, 63368) since 1979, and $7,078,948 has been paid on them (about $24,326 per paid claim)[1]. 1993 was the worst year, with 79 claims. That is the 8th-most of the 15 St. Louis–area suburbs we cover; for comparison, Lake St. Louis (14), St. Peters (534), and Wentzville (13). Of the 339 claims rated in a flood zone, 307 were in FEMA's high-risk areas (zones A or V) and 32 outside them (zones B, C or X)[1][8] — flooding here is not only a high-risk-zone problem.
By month of loss, O'Fallon-area flood claims cluster in May (58), June (72), and July (80) — 210 of 347 dated claims[1].
Within 10 miles of central O'Fallon, weather observers filed 6 flood, flash-flood or heavy-rain reports in 2016–2025 (6 flash floods)[5]. Countywide: 11 flood declarations since 2000, latest Severe Storms and Flooding (DR-4665, 2022)[6]. Nearby: Lake St. Louis (5), St. Peters (8), and Wentzville (5).
9% of O'Fallon's 36,206 housing units predate 1980[2] — the lowest share of the 15 St. Louis–area suburbs we cover (Lake St. Louis (19%), St. Peters (25%), and Wentzville (10%)). In newer houses, check fittings, washer hoses and the water-heater pan first — and any builder warranty.
81% of O'Fallon households own their home[2], so most claims and rebuilds here are coordinated by the owner.
Measured against the 15 suburbs on this site, O'Fallon records the lowest pre-1980 housing share (9%)[2], the 2nd-newest housing (by median year built) (2000, tied with Lake St. Louis)[2], and the 3rd-fewest flood reports nearby (6)[5].
How a leak spreads inside a wall
Water on the move: it spreads across floors and wicks upward into drywall until it is stopped.
O'Fallon storm calendar
Within 10 miles of O'Fallon, 2016–2025: 6 flash-flood reports[5]. Peak: 83% in April, June, and July. Busiest year 2019 (2); 6 of 10 years had none. Busiest month May 2019 (1). Latest: flash-flood report, Jun 4, 2025, 9.5 mi out.
| Month | Flash flood | Flood | Heavy rain | All |
|---|---|---|---|---|
| Apr | 1 | – | – | 1 |
| May | 1 | – | – | 1 |
| Jun | 2 | – | – | 2 |
| Jul | 2 | – | – | 2 |
water damage help in O'Fallon: what to do next
Requests go to Water damage restoration contractors serving the O'Fallon area — ZIP codes 63366, 63368.
Before you call: what a restoration crew does first
Shared walls and ceilings: O'Fallon homes by building type
With 75%[2] of homes detached, most O'Fallon water-damage jobs stay inside one house — the owner's policy and the owner's call.
After detached houses, the biggest group is attached house (townhouse, rowhouse): 3,284 of 36,206 housing units[2].
O'Fallon also has 1,217 mobile homes (3.4%); for a leak under one, ask for a crew that works on manufactured homes.
| Building type | Units | Share | Margin of error |
|---|---|---|---|
| Detached house | 27,212 | 75.2% | ±721 |
| Attached house (townhouse, rowhouse) | 3,284 | 9.1% | ±415 |
| Duplex (2 units) | 154 | 0.4% | ±89 |
| 3–4 units | 656 | 1.8% | ±196 |
| 5–9 units | 915 | 2.5% | ±227 |
| 10–19 units | 1,083 | 3.0% | ±228 |
| 20–49 units | 740 | 2.0% | ±206 |
| 50 or more units | 945 | 2.6% | ±320 |
| Mobile home | 1,217 | 3.4% | ±280 |
Margins of error are the Census Bureau’s 90% intervals; small categories in small cities are rough.
The data underneath this O'Fallon page
| Measure | O'Fallon | Median of 15 | Difference |
|---|---|---|---|
| Built before 1980 | 9% | 54% | 45 pts lower |
| Flood reports (10 mi) | 6 | 14 | 8 fewer |
| Renter-occupied | 19% | 23% | 4 pts lower |
| Owner-occupied | 81% | 77% | 4 pts higher |
| Median year built | 2000 | 1977 | 23 years newer |
| NFIP flood claims (area ZIPs) | 347 | 347 | same as median |
| Median home value | $326,200 | $326,200 | same as median |
Largest differences first. Medians are the middle value across the covered St. Louis–area suburbs, from the same sources.
| City | NFIP claims | Flood reports ≤10 mi | Built before 1980 | Renting |
|---|---|---|---|---|
| O'Fallon | 347 | 6 | 9% | 19% |
| Lake St. Louis 3.4 mi | 14 | 5 | 19% | 24% |
| St. Peters 6.3 mi | 534 | 8 | 25% | 21% |
| Wentzville 8.4 mi | 13 | 5 | 10% | 18% |
| St. Charles 11.2 mi | 5,630 | 12 | 38% | 32% |
| Chesterfield 11.5 mi | 321 | 11 | 46% | 22% |
| ZIP | Claims | Paid | Busiest year | Outside high-risk zones |
|---|---|---|---|---|
| 63366 | 333 | $6,971,988 | 1993 (78) | 28 of 325 |
| 63368 | 14 | $106,960 | 1983 (2) | 4 of 14 |
ZIPs extend past city limits. Outside high-risk zones: claims rated in zone B, C or X, of the claims that carry a zone.
| Year | Claims |
|---|---|
| 2022 | 15 |
| 2021 | 1 |
| 2020 | 4 |
| 2019 | 40 |
| 2017 | 2 |
| 2016 | 1 |
| 2015 | 8 |
| 2014 | 4 |
| 2013 | 3 |
| 2011 | 1 |
| 2008 | 44 |
| 2006 | 1 |
| Month | Claims |
|---|---|
| January | 4 |
| February | 7 |
| March | 7 |
| April | 44 |
| May | 58 |
| June | 72 |
| July | 80 |
| August | 9 |
| September | 21 |
| October | 12 |
| November | 4 |
| December | 29 |
| Date | Type | Distance |
|---|---|---|
| Jun 4, 2025 | Flash Flood | 9.5 mi |
| Apr 4, 2025 | Flash Flood | 8.6 mi |
| Jul 26, 2022 | Flash Flood | 7.5 mi |
| Jun 22, 2020 | Flash Flood | 5.5 mi |
| Jul 10, 2019 | Flash Flood | 2.8 mi |
| May 6, 2019 | Flash Flood | 9.5 mi |
| ZIP (ZCTA) | Share of O'Fallon's land | Share of the ZIP inside the city |
|---|---|---|
| 63366 | 54% | 23% |
| 63368 | 30% | 55% |
water damage questions from O'Fallon homeowners
Do I need flood insurance in O'Fallon?
Homeowners policies exclude outside floodwater[9], and O'Fallon-area ZIPs have 63 NFIP claims in just the last ten years[1].
Which O'Fallon ZIP codes do these crews cover?
63366 and 63368[7], in St. Charles County. Nearby pages: Lake St. Louis (3.4 mi), St. Peters (6.3 mi), and Wentzville (8.4 mi)[4].
Which O'Fallon ZIP code has the most flood claims?
63366, with 333 NFIP claims and $6,971,988 paid[1].
When was the last flood report near O'Fallon?
Jun 4, 2025: a flash flood report 9.5 miles from the city center[5].
My O'Fallon home is fairly new — could the plumbing fixtures and water heater still be under warranty?
Possibly: 20% of O'Fallon's housing units were built in 2010 or later[2], the 3rd-highest share of the 15 St. Louis–area suburbs we cover. Check your closing paperwork for warranties before paying for a repair.
Sources
- OpenFEMA NFIP claims
- Census ACS 2020–2024 5-year (keyless bulk)
- Census population estimates, Vintage 2025
- Census Gazetteer 2025
- NOAA Storm Events Database
- OpenFEMA disaster declarations
- Census 2020 ZCTA–place file
- FEMA, Flood Zones (link unverified)
- FEMA FloodSmart (link unverified)
Data pulled Sep 28, 2026. Full citations and method.