Waller County, Texas
Shrink-swell clay limits houses without basements on 24% of Waller County's mapped land, a higher share than 75% of US counties. A shallow water table limits basements on 40%.
18.5% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 643 flood losses here since 2016, 0% of them in buildings with basements. 20% of homes were built before 1980, against 50% nationally; the median home dates from 1998.
Data as of October 13, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, October 13, 2026
of homes built before 1980
Soil under Waller County
| Expansive clay (limits slab homes) | 23.8% |
| High water table (limits basements) | 40.2% |
| Septic fields very limited | 83.3% |
| Clay swell (LEP, by area) | 5.2% |
| High-swell land (LEP 6%+) | 24.4% |
| Mapped soil | 332,352 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Katy | 17% | 0% |
| Wockley | 11% | n/a |
| Brazoria | 6% | n/a |
| Hockley | 5% | n/a |
| Norwood | 3% | n/a |
| Cyfair | 3% | n/a |
How we count · survey areas TX600 (2025-09-05)
What the numbers mean here
Clay swell averages a linear extensibility of 5.2% by land area here, and 24% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 24% of the mapped land.
Clay shrinks as it dries: 18.5% of the county is in drought on the latest map, and 24% of Waller County's mapped land has shrink-swell clay.
On 40% of Waller County's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
Rain over the 12 months to August 2026: 33.56 in, 13.68 in below the 1991-2020 average year of 47.24 in.
USDA rates 83% of the land very limited for septic absorption fields.
Drought
18.5% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 37 of the last 52 weeks; the most was 100% of its area, in 17 weeks, most recently on the September 29, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 18.5% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
643 flood losses since 2016, $39.0 million paid. The worst year was 2017, with 334. Foundations of the buildings, where recorded: 85% slabs, 5% crawl spaces, 10% elevated. Median water depth outside the building: 15 in.
| Year | Flood losses |
|---|---|
| 2016 | 290 |
| 2017 | 334 |
| 2018 | 0 |
| 2019 | 3 |
| 2020 | 1 |
| 2021 | 7 |
| 2022 | 3 |
| 2023 | 0 |
| 2024 | 5 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 47.24 in |
| 12 months to August 2026 | 33.56 in (-13.68) |
| 2025 | 34.68 in (-12.56) |
| Wettest year since 1895 | 1973: 67.15 in |
| Driest year since 1895 | 1917: 19.02 in |
| Days with 1 inch or more, normal at BELLVILLE 6NNE (14 mi away) | 12.9 |
Homes
| Housing units | 20,345 |
| Median year built | 1998 |
| Built before 1980 | 20% |
| Built 2000 or later | 47% |
| Owner-occupied | 72% |
| Median value, owner-occupied | $318,700 |
| Single-family detached | 64% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Waller County
| City | Expansive clay | High water table | Homes |
|---|---|---|---|
| Brookshire | 2% | 18% | 1,934 |
| Hempstead | 49% | 39% | 2,088 |
| Katy | 8% | 26% | 8,495 |
| Pattison | 17% | 26% | 223 |
| Pine Island | 13% | 30% | 518 |
| Prairie View | 2% | 47% | 1,797 |
| Waller | 2% | 59% | 1,284 |
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Austin County, TX | 19 mi | 38% | 20% |
| Washington County, TX | 29 mi | 54% | 9% |
| Montgomery County, TX | 35 mi | 15% | 65% |
| Fort Bend County, TX | 36 mi | 64% | 42% |
| Grimes County, TX | 37 mi | 61% | 40% |
| Harris County, TX | 37 mi | 25% | 53% |
| Colorado County, TX | 43 mi | 37% | 24% |
| Brazos County, TX | 48 mi | 57% | 26% |
Sources: USDA SSURGO (September 5, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status