HomeTexasBexar CountyLeon Valley
Leon Valley, Texas
Inside Leon Valley's city limits, shrink-swell clay limits houses without basements on 64% of mapped land, higher than 69% of Texas cities. A shallow water table limits basements on 0%.
That clay share is above Bexar County's 51%. FEMA's flood data list 19 flood losses since 2016 in the 2 ZIP codes overlapping the city. Of its 5,110 homes, 56% were built before 1980; the median dates from 1978.
Data as of October 13, 2026 · sources · in Bexar County
expansive clay: shrink-swell limits slab homes
high water table: limits basements
flood losses since 2016 in 2 overlapping ZIPs
of homes built before 1980
Foundation repair in Leon Valley
Foundation repair in Leon Valley: shrink-swell clay limits slab homes on 64% of Leon Valley's mapped land, more than in 69% of Texas cities.
About 2,900 of Leon Valley's 5,110 homes are detached houses.
| Who designs the repair | The ASCE Texas Section's repair guidelines say a Texas-licensed engineer should evaluate the foundation and design the repair (2022 guidelines) |
| Prices | Cost guide ranges compared |
Soil under Leon Valley city limits
| Expansive clay (limits slab homes) | 64.2% |
| High water table (limits basements) | 0.0% |
| Septic fields very limited | 89.3% |
| Clay swell (LEP, by area) | 6.7% |
| High-swell land (LEP 6%+) | 50.9% |
| Mapped soil | 2,222 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Houston Black | 19% | 91% |
| Austin | 18% | 93% |
| Eckrant | 17% | 8% |
| Eddy | 14% | 0% |
| Whitewright | 8% | n/a |
| Lewisville | 6% | n/a |
What the numbers mean here
Clay swell averages a linear extensibility of 6.7% by land area here, and 51% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 64% of the mapped land.
Clay shrinks as it dries: 79.6% of Bexar County is in drought on the latest map, and 64% of Leon Valley's mapped land has shrink-swell clay.
USDA rates 89% of the land very limited for septic absorption fields.
Drought in Bexar County
79.6% of Bexar County is in drought (D1 or worse) on the October 13, 2026 map. County detail.
Flood losses by ZIP code
FEMA flood records since 2016 in the ZIP codes that overlap Leon Valley. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 78238 | 68% | 11 | $251,324 |
| 78240 | 32% | 8 | $97,841 |
Homes in Leon Valley
| Housing units | 5,110 |
| Median year built | 1978 |
| Built before 1980 | 56% |
| Built 2000 or later | 19% |
| Owner-occupied | 54% |
| Median value, owner-occupied | $253,200 |
| Single-family detached | 57% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Balcones Heights | 4 mi | 52% | 0% |
| San Antonio | 6 mi | 61% | under 1% |
| Castle Hills | 6 mi | 67% | 0% |
| Helotes | 7 mi | 53% | 0% |
| Shavano Park | 7 mi | 54% | under 1% |
| Olmos Park | 8 mi | 65% | 0% |
| Alamo Heights | 9 mi | 43% | 0% |
| Grey Forest | 9 mi | 56% | 0% |
Sources: USDA SSURGO (August 5, 2026) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · Census ACS 2020-2024. Methods · Data status