Mills County, Texas
Shrink-swell clay limits houses without basements on 26% of Mills County's mapped land, a higher share than 76% 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 no flood losses here since 2016. 54% of homes were built before 1980, against 50% nationally; the median home dates from 1977.
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 Mills County
| Expansive clay (limits slab homes) | 26.2% |
| High water table (limits basements) | 0.1% |
| Septic fields very limited | 81.0% |
| Clay swell (LEP, by area) | 5.0% |
| High-swell land (LEP 6%+) | 32.3% |
| Mapped soil | 479,136 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Bolar | 14% | n/a |
| Tarrant | 10% | n/a |
| Real | 9% | n/a |
| Tarpley | 8% | n/a |
| Brackett | 7% | 0% |
| Doudle | 7% | n/a |
How we count · survey areas TX602 (2025-09-05)
What the numbers mean here
Clay swell averages a linear extensibility of 5.0% by land area here, and 32% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 26% of the mapped land.
Clay shrinks as it dries: 100% of the county is in drought on the latest map, and 26% of Mills County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 31.02 in, 0.18 in above the 1991-2020 average year of 30.84 in.
USDA rates 81% 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 21 of the last 52 weeks; the most was 100% of its area, in 5 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 | 10.5% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
FEMA's flood data list no flood losses in Mills County since 2016.
Rain
| Average year, 1991-2020 | 30.84 in |
| 12 months to August 2026 | 31.02 in (+0.18) |
| 2025 | 33.20 in (+2.36) |
| Wettest year since 1895 | 1919: 45.87 in |
| Driest year since 1895 | 1901: 14.51 in |
| Days with 1 inch or more, normal at GOLDTHWAITE 1 WSW (4 mi away) | 9.3 |
Homes
| Housing units | 2,597 |
| Median year built | 1977 |
| Built before 1980 | 54% |
| Built 2000 or later | 22% |
| Owner-occupied | 80% |
| Median value, owner-occupied | $223,700 |
| Single-family detached | 81% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Mills County
| City | Expansive clay | High water table | Homes |
|---|---|---|---|
| Goldthwaite | 22% | 0% | 904 |
| Mullin | 3% | 0% | 121 |
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| San Saba County, TX | 27 mi | 45% | 1% |
| Brown County, TX | 29 mi | 40% | 1% |
| Lampasas County, TX | 30 mi | 20% | under 1% |
| Comanche County, TX | 31 mi | 30% | 11% |
| Hamilton County, TX | 32 mi | 31% | under 1% |
| Coryell County, TX | 48 mi | 26% | under 1% |
| McCulloch County, TX | 49 mi | 29% | under 1% |
| Coleman County, TX | 52 mi | 48% | 0% |
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