San Jacinto County, Texas
Shrink-swell clay limits houses without basements on 16% of San Jacinto County's mapped land, a higher share than 65% of US counties. A shallow water table limits basements on 42%.
92.7% of the county is in drought on the October 13, 2026 Drought Monitor map, up from 45.6% a week earlier. FEMA's flood data list 150 flood losses here since 2016, 2% of them in buildings with basements. 32% of homes were built before 1980, against 50% nationally; the median home dates from 1991.
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 San Jacinto County
| Expansive clay (limits slab homes) | 15.9% |
| High water table (limits basements) | 42.5% |
| Septic fields very limited | 72.4% |
| Clay swell (LEP, by area) | 3.9% |
| High-swell land (LEP 6%+) | 15.9% |
| Mapped soil | 397,533 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Pinetucky | 11% | n/a |
| Conroe | 7% | 0% |
| Doucette | 6% | n/a |
| Woodville | 5% | n/a |
| Hatliff | 4% | n/a |
| Pluck | 4% | n/a |
How we count · survey areas TX617 (2025-09-05)
What the numbers mean here
Clay swell averages a linear extensibility of 3.9% by land area here, and 16% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 16% of the mapped land.
Clay shrinks as it dries: 92.7% of the county is in drought on the latest map, and 16% of San Jacinto County's mapped land has shrink-swell clay.
On 42% of San Jacinto 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: 36.77 in, 15.39 in below the 1991-2020 average year of 52.16 in.
USDA rates 72% of the land very limited for septic absorption fields.
Drought
92.7% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 41 of the last 52 weeks; the most was 100% of its area, in 23 weeks, most recently on the May 19, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 92.7% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
150 flood losses since 2016, $6.5 million paid. The worst year was 2017, with 78. Foundations of the buildings, where recorded: 2% basements, 69% slabs, 8% crawl spaces, 22% elevated. Median water depth outside the building: 33 in.
| Year | Flood losses |
|---|---|
| 2016 | 12 |
| 2017 | 78 |
| 2018 | 2 |
| 2019 | 11 |
| 2020 | 1 |
| 2021 | 3 |
| 2022 | 0 |
| 2023 | 1 |
| 2024 | 41 |
| 2025 | 1 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 52.16 in |
| 12 months to August 2026 | 36.77 in (-15.39) |
| 2025 | 46.41 in (-5.75) |
| Wettest year since 1895 | 1973: 79.18 in |
| Driest year since 1895 | 1917: 22.40 in |
| Days with 1 inch or more, normal at CLEVELAND (15 mi away) | 16.7 |
Homes
| Housing units | 15,011 |
| Median year built | 1991 |
| Built before 1980 | 32% |
| Built 2000 or later | 36% |
| Owner-occupied | 85% |
| Median value, owner-occupied | $209,300 |
| Single-family detached | 71% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in San Jacinto County
| City | Expansive clay | High water table | Homes |
|---|---|---|---|
| Coldspring | 2% | 5% | 540 |
| Point Blank | 63% | 67% | 501 |
| Shepherd | 7% | 50% | 1,078 |
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Polk County, TX | 24 mi | 23% | 45% |
| Walker County, TX | 27 mi | 40% | 63% |
| Montgomery County, TX | 28 mi | 15% | 65% |
| Liberty County, TX | 32 mi | 46% | 76% |
| Trinity County, TX | 36 mi | 13% | 74% |
| Tyler County, TX | 49 mi | 18% | 34% |
| Hardin County, TX | 49 mi | 12% | 67% |
| Grimes County, TX | 49 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