Coryell County, Texas
Shrink-swell clay limits houses without basements on 26% of Coryell County's mapped land, a higher share than 77% 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 20 flood losses here since 2016. 39% of homes were built before 1980, against 50% nationally; the median home dates from 1987.
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 Coryell County
| Expansive clay (limits slab homes) | 26.4% |
| High water table (limits basements) | 0.1% |
| Septic fields very limited | 76.6% |
| Clay swell (LEP, by area) | 5.0% |
| High-swell land (LEP 6%+) | 27.3% |
| Mapped soil | 676,249 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Real | 10% | n/a |
| Nuff | 10% | n/a |
| Eckrant | 9% | 8% |
| Topsey | 8% | n/a |
| Doss | 8% | n/a |
| Bolar | 6% | n/a |
How we count · survey areas TX099 (2025-09-04)
What the numbers mean here
Clay swell averages a linear extensibility of 5.0% by land area here, and 27% 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 Coryell County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 29.25 in, 5.52 in below the 1991-2020 average year of 34.77 in.
USDA rates 77% 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 24 of the last 52 weeks; the most was 100% of its area, in 7 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 | 52.9% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
20 flood losses since 2016, $780,549 paid. The worst year was 2024, with 7.
| Year | Flood losses |
|---|---|
| 2016 | 1 |
| 2017 | 3 |
| 2018 | 2 |
| 2019 | 4 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 7 |
| 2025 | 3 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 34.77 in |
| 12 months to August 2026 | 29.25 in (-5.52) |
| 2025 | 34.14 in (-0.63) |
| Wettest year since 1895 | 1919: 53.00 in |
| Driest year since 1895 | 1954: 14.56 in |
| Days with 1 inch or more, normal at GATESVILLE (6 mi away) | 12.3 |
Homes
| Housing units | 29,512 |
| Median year built | 1987 |
| Built before 1980 | 39% |
| Built 2000 or later | 33% |
| Owner-occupied | 59% |
| Median value, owner-occupied | $195,300 |
| Single-family detached | 67% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Coryell County
| City | Expansive clay | High water table | Homes |
|---|---|---|---|
| Copperas Cove | 25% | 0% | 16,527 |
| Evant | 32% | 0% | 236 |
| Gatesville | 21% | under 1% | 3,288 |
| Oglesby | 30% | 0% | 206 |
| South Mountain | 17% | 0% | 154 |
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Hamilton County, TX | 29 mi | 31% | under 1% |
| Lampasas County, TX | 29 mi | 20% | under 1% |
| Bell County, TX | 31 mi | 55% | 1% |
| Bosque County, TX | 37 mi | 29% | 1% |
| McLennan County, TX | 37 mi | 56% | under 1% |
| Burnet County, TX | 48 mi | 27% | 0% |
| Mills County, TX | 48 mi | 26% | under 1% |
| Falls County, TX | 52 mi | 72% | 2% |
Sources: USDA SSURGO (September 4, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status