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Sun Valley, Texas
Inside Sun Valley's city limits, shrink-swell clay limits houses without basements on 28% of mapped land. A shallow water table limits basements on 90%, the highest of 7 cities in Lamar County.
That clay share is below Lamar County's 66%. FEMA's flood data list 10 flood losses since 2016 in ZIP code 75462 overlapping the city.
Data as of October 13, 2026 · sources · in Lamar County
expansive clay: shrink-swell limits slab homes
high water table: limits basements
flood losses since 2016 in 1 overlapping ZIP
Foundation repair in Sun Valley
Foundation repair in Sun Valley: shrink-swell clay limits slab homes on 28% of Sun Valley's mapped land.
| 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 Sun Valley city limits
| Expansive clay (limits slab homes) | 27.7% |
| High water table (limits basements) | 90.1% |
| Septic fields very limited | 95.6% |
| Clay swell (LEP, by area) | 7.3% |
| High-swell land (LEP 6%+) | 90.1% |
| Mapped soil | 101 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Freestone | 45% | 73% |
| Derly | 22% | n/a |
| Hicota | 17% | n/a |
| Raino | 6% | n/a |
| Annona | 5% | n/a |
What the numbers mean here
Clay swell averages a linear extensibility of 7.3% by land area here, and 90% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 28% of the mapped land.
Clay shrinks as it dries: 100% of Lamar County is in drought on the latest map, and 28% of Sun Valley's mapped land has shrink-swell clay.
On 90% of Sun Valley's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
USDA rates 96% of the land very limited for septic absorption fields.
Drought in Lamar County
100% of Lamar 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 Sun Valley. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 75462 | 100% | 10 | $51,469 |
Homes
Sun Valley has fewer than 100 housing units in the ACS 2020-2024 estimates, too few for reliable shares.
Nearby cities
Sources: USDA SSURGO (August 5, 2026) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026). Methods · Data status