Katy, Texas
Inside Katy's city limits, shrink-swell clay limits houses without basements on 8% of mapped land, the 4th-highest of 7 cities in Waller County. A shallow water table limits basements on 26%.
That clay share is below Waller County's 24%. FEMA's flood data list 857 flood losses since 2016 in the 2 ZIP codes overlapping the city. Of its 8,495 homes, 20% were built before 1980; the median dates from 2003.
Data as of October 13, 2026 · sources · in Waller County
expansive clay: shrink-swell limits slab homes
high water table: limits basements
flood losses since 2016 in 2 overlapping ZIPs
of homes built before 1980
Foundation repair in Katy
Foundation repair in Katy: shrink-swell clay limits slab homes on 8% of Katy's mapped land.
About 7,200 of Katy's 8,495 homes are detached houses.
| Who designs the repair | The ASCE Texas Section's repair guidelines say a Texas-licensed engineer should evaluate the foundation and design the repair (2022 guidelines) |
| Prices | Cost guide ranges compared |
Soil under Katy city limits
| Expansive clay (limits slab homes) | 8.3% |
| High water table (limits basements) | 25.5% |
| Septic fields very limited | 88.7% |
| Clay swell (LEP, by area) | 4.2% |
| High-swell land (LEP 6%+) | 10.8% |
| Urban land, not rated | 17.5% |
| Mapped soil | 9,803 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Katy | 57% | 0% |
| Cyfair | 9% | n/a |
| Edna | 8% | n/a |
| Gessner | 2% | n/a |
| Snakecreek | 2% | n/a |
| Clodine | 2% | n/a |
What the numbers mean here
On 26% of Katy's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
USDA rates 89% of the land very limited for septic absorption fields.
Drought in Waller County
18.5% of Waller County is in drought (D1 or worse) on the October 13, 2026 map. County detail.
Flood losses by ZIP code
FEMA flood records since 2016 in the ZIP codes that overlap Katy. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 77493 | 52% | 615 | $56.2 million |
| 77494 | 47% | 242 | $25.1 million |
Homes in Katy
| Housing units | 8,495 |
| Median year built | 2003 |
| Built before 1980 | 20% |
| Built 2000 or later | 54% |
| Owner-occupied | 81% |
| Median value, owner-occupied | $401,700 |
| Single-family detached | 85% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Brookshire | 7 mi | 2% | 18% |
| Fulshear | 7 mi | 17% | 27% |
| Pattison | 8 mi | 17% | 26% |
| Weston Lakes | 11 mi | 32% | 6% |
| Simonton | 11 mi | 41% | 2% |
| Brazos Country | 12 mi | 15% | 21% |
| South Frydek | 15 mi | 90% | 12% |
| Orchard | 15 mi | 37% | 69% |
Sources: USDA SSURGO (August 5, 2026) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · Census ACS 2020-2024. Methods · Data status