Lamar County, Texas
Shrink-swell clay limits houses without basements on 66% of Lamar County's mapped land, a higher share than 95% of US counties. A shallow water table limits basements on 31%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 89 flood losses here since 2016, 0% of them in buildings with basements. 38% 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 Lamar County
| Expansive clay (limits slab homes) | 66.3% |
| High water table (limits basements) | 31.3% |
| Septic fields very limited | 82.6% |
| Clay swell (LEP, by area) | 8.2% |
| High-swell land (LEP 6%+) | 75.0% |
| Mapped soil | 597,843 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Houston Black | 8% | 91% |
| Annona | 8% | n/a |
| Normangee | 7% | 72% |
| Freestone | 7% | 73% |
| Crockett | 5% | 94% |
| Wilson | 5% | 88% |
How we count · survey areas TX614 (2025-09-05)
What the numbers mean here
Clay swell averages a linear extensibility of 8.2% by land area here, and 75% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 66% of the mapped land.
Clay shrinks as it dries: 100% of the county is in drought on the latest map, and 66% of Lamar County's mapped land has shrink-swell clay.
On 31% of Lamar 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: 36.73 in, 10.95 in below the 1991-2020 average year of 47.68 in.
USDA rates 83% 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 46 of the last 52 weeks; the most was 100% of its area, in 26 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 | 100% |
| D4 exceptional | 0% |
Flood losses since 2016
89 flood losses since 2016, $2.2 million paid. The worst year was 2016, with 34. Foundations of the buildings, where recorded: 96% slabs, 4% crawl spaces. Median water depth outside the building: 8 in.
| Year | Flood losses |
|---|---|
| 2016 | 34 |
| 2017 | 12 |
| 2018 | 8 |
| 2019 | 2 |
| 2020 | 1 |
| 2021 | 1 |
| 2022 | 8 |
| 2023 | 1 |
| 2024 | 8 |
| 2025 | 5 |
| 2026 to date | 9 |
Rain
| Average year, 1991-2020 | 47.68 in |
| 12 months to August 2026 | 36.73 in (-10.95) |
| 2025 | 49.42 in (+1.74) |
| Wettest year since 1895 | 2015: 74.42 in |
| Driest year since 1895 | 1910: 21.18 in |
| Days with 1 inch or more, normal at PARIS (1 mi away) | 15.3 |
Homes
| Housing units | 22,824 |
| Median year built | 1987 |
| Built before 1980 | 38% |
| Built 2000 or later | 30% |
| Owner-occupied | 66% |
| Median value, owner-occupied | $200,700 |
| Single-family detached | 76% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in Lamar County
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Delta County, TX | 20 mi | 77% | 15% |
| Choctaw County, OK | 25 mi | 47% | 36% |
| Red River County, TX | 30 mi | 61% | 40% |
| Fannin County, TX | 31 mi | 66% | 23% |
| Hopkins County, TX | 36 mi | 63% | 31% |
| Franklin County, TX | 40 mi | 41% | 45% |
| Bryan County, OK | 45 mi | 42% | 19% |
| Titus County, TX | 47 mi | 50% | 50% |
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