Trinity County, Texas
Shrink-swell clay limits houses without basements on 13% of Trinity County's mapped land, a higher share than 60% of US counties. A shallow water table limits basements on 74%.
28% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 30 flood losses here since 2016, 0% of them in buildings with basements. 33% of homes were built before 1980, against 50% nationally; the median home dates from 1988.
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 Trinity County
| Expansive clay (limits slab homes) | 13.0% |
| High water table (limits basements) | 74.1% |
| Septic fields very limited | 86.0% |
| Clay swell (LEP, by area) | 4.9% |
| High-swell land (LEP 6%+) | 39.0% |
| Mapped soil | 456,608 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Fuller | 22% | 1% |
| Kurth | 10% | n/a |
| Keltys | 9% | n/a |
| Koury | 7% | n/a |
| Herty | 7% | n/a |
| Moten | 5% | n/a |
How we count · survey areas TX455 (2025-09-05)
What the numbers mean here
On 74% of Trinity 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: 35.26 in, 14.69 in below the 1991-2020 average year of 49.95 in.
USDA rates 86% of the land very limited for septic absorption fields.
Drought
28% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 43 of the last 52 weeks; the most was 100% of its area, in 25 weeks, most recently on the September 1, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 28% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
30 flood losses since 2016, $861,977 paid. The worst year was 2024, with 14. Foundations of the buildings, where recorded: 60% slabs, 10% crawl spaces, 30% elevated. Median water depth outside the building: 25 in.
| Year | Flood losses |
|---|---|
| 2016 | 3 |
| 2017 | 3 |
| 2018 | 5 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 1 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 14 |
| 2025 | 4 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 49.95 in |
| 12 months to August 2026 | 35.26 in (-14.69) |
| 2025 | 47.61 in (-2.34) |
| Wettest year since 1895 | 2024: 74.66 in |
| Driest year since 1895 | 1917: 25.06 in |
| Days with 1 inch or more, normal at CROCKETT (23 mi away) | 15.6 |
Homes
| Housing units | 8,326 |
| Median year built | 1988 |
| Built before 1980 | 33% |
| Built 2000 or later | 32% |
| Owner-occupied | 79% |
| Median value, owner-occupied | $119,500 |
| Single-family detached | 57% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Trinity County
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Houston County, TX | 22 mi | 23% | 50% |
| Polk County, TX | 29 mi | 23% | 45% |
| Angelina County, TX | 34 mi | 27% | 44% |
| Walker County, TX | 35 mi | 40% | 63% |
| San Jacinto County, TX | 36 mi | 16% | 42% |
| Madison County, TX | 47 mi | 52% | 48% |
| Nacogdoches County, TX | 48 mi | 13% | 28% |
| Tyler County, TX | 51 mi | 18% | 34% |
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