Austin County, Texas
Shrink-swell clay limits houses without basements on 38% of Austin County's mapped land, a higher share than 86% of US counties. A shallow water table limits basements on 20%.
96.2% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 248 flood losses here since 2016, 1% of them in buildings with basements. 32% of homes were built before 1980, against 50% nationally; the median home dates from 1992.
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 Austin County
| Expansive clay (limits slab homes) | 38.3% |
| High water table (limits basements) | 19.8% |
| Septic fields very limited | 81.8% |
| Clay swell (LEP, by area) | 6.7% |
| High-swell land (LEP 6%+) | 38.7% |
| Mapped soil | 419,872 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Katy | 6% | 0% |
| Frelsburg | 6% | 93% |
| Tremona | 5% | n/a |
| Brazoria | 5% | n/a |
| Catilla | 4% | n/a |
| Lake Charles | 4% | 97% |
How we count · survey areas TX600 (2025-09-05)
What the numbers mean here
Clay swell averages a linear extensibility of 6.7% by land area here, and 39% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 38% of the mapped land.
Clay shrinks as it dries: 96.2% of the county is in drought on the latest map, and 38% of Austin County's mapped land has shrink-swell clay.
On 20% of Austin 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: 32.44 in, 13.02 in below the 1991-2020 average year of 45.46 in.
USDA rates 82% of the land very limited for septic absorption fields.
Drought
96.2% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 39 of the last 52 weeks; the most was 100% of its area, in 28 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 | 96.2% |
| D2 severe or worse | 7.7% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
248 flood losses since 2016, $12.5 million paid. The worst year was 2016, with 126. Foundations of the buildings, where recorded: 1% basements, 69% slabs, 3% crawl spaces, 27% elevated. Median water depth outside the building: 25 in.
| Year | Flood losses |
|---|---|
| 2016 | 126 |
| 2017 | 94 |
| 2018 | 0 |
| 2019 | 10 |
| 2020 | 0 |
| 2021 | 14 |
| 2022 | 0 |
| 2023 | 1 |
| 2024 | 2 |
| 2025 | 0 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 45.46 in |
| 12 months to August 2026 | 32.44 in (-13.02) |
| 2025 | 31.73 in (-13.73) |
| Wettest year since 1895 | 2015: 67.44 in |
| Driest year since 1895 | 1917: 18.32 in |
| Days with 1 inch or more, normal at BELLVILLE 6NNE (10 mi away) | 12.9 |
Homes
| Housing units | 14,319 |
| Median year built | 1992 |
| Built before 1980 | 32% |
| Built 2000 or later | 37% |
| Owner-occupied | 77% |
| Median value, owner-occupied | $296,900 |
| Single-family detached | 70% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Austin County
| City | Expansive clay | High water table | Homes |
|---|---|---|---|
| Bellville | 45% | 26% | 1,656 |
| Brazos Country | 15% | 21% | 223 |
| Industry | 25% | 14% | 110 |
| San Felipe | 56% | 36% | 601 |
| Sealy | 10% | 32% | 2,946 |
| South Frydek | 90% | 12% | 124 |
| Wallis | 86% | 61% | 865 |
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Waller County, TX | 19 mi | 24% | 40% |
| Washington County, TX | 24 mi | 54% | 9% |
| Colorado County, TX | 25 mi | 37% | 24% |
| Fayette County, TX | 38 mi | 67% | 14% |
| Fort Bend County, TX | 39 mi | 64% | 42% |
| Wharton County, TX | 42 mi | 68% | 32% |
| Burleson County, TX | 47 mi | 50% | 17% |
| Grimes County, TX | 48 mi | 61% | 40% |
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