Tom Green County, Texas
Shrink-swell clay limits houses without basements on 43% of Tom Green County's mapped land, a higher share than 88% of US counties. A shallow water table limits basements on under 1%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 86 flood losses here since 2016, 0% of them in buildings with basements. 50% of homes were built before 1980, against 50% nationally; the median home dates from 1980.
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 Tom Green County
| Expansive clay (limits slab homes) | 43.1% |
| High water table (limits basements) | 0.4% |
| Septic fields very limited | 86.1% |
| Clay swell (LEP, by area) | 6.0% |
| High-swell land (LEP 6%+) | 58.8% |
| Mapped soil | 986,490 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Angelo | 34% | n/a |
| Tarrant | 18% | n/a |
| Cho | 9% | n/a |
| Ector | 9% | 0% |
| Mereta | 7% | n/a |
| Tulia | 4% | n/a |
How we count · survey areas TX451 (2025-09-05)
What the numbers mean here
Clay swell averages a linear extensibility of 6.0% by land area here, and 59% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 43% of the mapped land.
Clay shrinks as it dries: 100% of the county is in drought on the latest map, and 43% of Tom Green County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 19.65 in, 2.95 in below the 1991-2020 average year of 22.60 in.
USDA rates 86% of the land very limited for septic absorption fields.
Drought
100% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 20 of the last 52 weeks; the most was 100% of its area, in 4 weeks, most recently on the October 13, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 100% |
| D2 severe or worse | 100% |
| D3 extreme or worse | 19.1% |
| D4 exceptional | 0% |
Flood losses since 2016
86 flood losses since 2016, $5.4 million paid. The worst year was 2025, with 66. Foundations of the buildings, where recorded: 77% slabs, 19% crawl spaces, 4% elevated. Median water depth outside the building: 11 in.
| Year | Flood losses |
|---|---|
| 2016 | 7 |
| 2017 | 1 |
| 2018 | 1 |
| 2019 | 5 |
| 2020 | 1 |
| 2021 | 1 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 4 |
| 2025 | 66 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 22.60 in |
| 12 months to August 2026 | 19.65 in (-2.95) |
| 2025 | 24.79 in (+2.19) |
| Wettest year since 1895 | 1941: 37.62 in |
| Driest year since 1895 | 1917: 9.58 in |
| Days with 1 inch or more, normal at SAN ANGELO (2 mi away) | 5.7 |
Homes
| Housing units | 52,318 |
| Median year built | 1980 |
| Built before 1980 | 50% |
| Built 2000 or later | 22% |
| Owner-occupied | 65% |
| Median value, owner-occupied | $197,000 |
| Single-family detached | 71% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Tom Green County
| City | Expansive clay | High water table | Homes |
|---|---|---|---|
| San Angelo | 35% | under 1% | 44,176 |
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Irion County, TX | 31 mi | 21% | under 1% |
| Coke County, TX | 35 mi | 11% | under 1% |
| Schleicher County, TX | 35 mi | 32% | 0% |
| Concho County, TX | 36 mi | 32% | under 1% |
| Runnels County, TX | 42 mi | 42% | 1% |
| Sterling County, TX | 46 mi | 30% | under 1% |
| Menard County, TX | 50 mi | 12% | 0% |
| Sutton County, TX | 61 mi | 19% | under 1% |
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