La Salle County, Texas
Shrink-swell clay limits houses without basements on 35% of La Salle County's mapped land, a higher share than 84% 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 2 flood losses here since 2016. 45% of homes were built before 1980, against 50% nationally; the median home dates from 1984.
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 La Salle County
| Expansive clay (limits slab homes) | 34.7% |
| High water table (limits basements) | 0.3% |
| Septic fields very limited | 60.3% |
| Clay swell (LEP, by area) | 6.6% |
| High-swell land (LEP 6%+) | 30.8% |
| Mapped soil | 971,475 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Duval | 13% | n/a |
| Maverick | 8% | n/a |
| Cotulla | 7% | n/a |
| Webb | 7% | n/a |
| Brundage | 6% | n/a |
| Moglia | 6% | n/a |
How we count · survey areas TX283 (2025-09-04)
What the numbers mean here
Clay swell averages a linear extensibility of 6.6% by land area here, and 31% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 35% of the mapped land.
Clay shrinks as it dries: 100% of the county is in drought on the latest map, and 35% of La Salle County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 15.78 in, 6.80 in below the 1991-2020 average year of 22.58 in.
USDA rates 60% 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 52 of the last 52 weeks; the most was 100% of its area, in 40 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 | 16.4% |
| D4 exceptional | 0% |
Flood losses since 2016
2 flood losses since 2016, $45,000 paid. The worst year was 2026, with 1.
| Year | Flood losses |
|---|---|
| 2016 | 1 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 22.58 in |
| 12 months to August 2026 | 15.78 in (-6.80) |
| 2025 | 13.94 in (-8.64) |
| Wettest year since 1895 | 1919: 42.74 in |
| Driest year since 1895 | 1917: 6.86 in |
| Days with 1 inch or more, normal at LOS ANGELES 4 WSW (7 mi away) | 6.2 |
Homes
| Housing units | 2,271 |
| Median year built | 1984 |
| Built before 1980 | 45% |
| Built 2000 or later | 30% |
| Owner-occupied | 76% |
| Median value, owner-occupied | $97,800 |
| Single-family detached | 64% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Cities in La Salle County
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| McMullen County, TX | 32 mi | 35% | under 1% |
| Frio County, TX | 36 mi | 10% | under 1% |
| Dimmit County, TX | 41 mi | 30% | under 1% |
| Webb County, TX | 44 mi | 33% | under 1% |
| Atascosa County, TX | 51 mi | 34% | under 1% |
| Zavala County, TX | 54 mi | 28% | under 1% |
| Live Oak County, TX | 59 mi | 29% | under 1% |
| Duval County, TX | 59 mi | 4% | under 1% |
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