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Coupland, Texas
Inside Coupland's city limits, shrink-swell clay limits houses without basements on 81% of mapped land, the 5th-highest of 14 cities in Williamson County. A shallow water table limits basements on 1%, the highest of 14 cities in Williamson County.
That clay share is above Williamson County's 60%. FEMA's flood data list 6 flood losses since 2016 in the 2 ZIP codes overlapping the city. Of its 180 homes, 47% were built before 1980; the median dates from 1982.
Data as of October 13, 2026 · sources · in Williamson 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 Coupland
Foundation repair in Coupland: shrink-swell clay limits slab homes on 81% of Coupland's mapped land, more than in 87% of Texas cities.
About 100 of Coupland's 180 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 Coupland city limits
| Expansive clay (limits slab homes) | 81.2% |
| High water table (limits basements) | 0.6% |
| Septic fields very limited | 82.0% |
| Clay swell (LEP, by area) | 12.0% |
| High-swell land (LEP 6%+) | 80.6% |
| Mapped soil | 1,248 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Heiden | 46% | 80% |
| Houston Black | 18% | 91% |
| Branyon | 16% | 92% |
| Ferris | 9% | n/a |
| Altoga | 2% | n/a |
| Burleson | 2% | 84% |
What the numbers mean here
Clay swell averages a linear extensibility of 12.0% by land area here, and 81% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 81% of the mapped land.
Clay shrinks as it dries: 100% of Williamson County is in drought on the latest map, and 81% of Coupland's mapped land has shrink-swell clay.
USDA rates 82% of the land very limited for septic absorption fields.
Drought in Williamson County
100% of Williamson 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 Coupland. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 78615 | 78% | 0 | $0 |
| 76574 | 22% | 6 | $345,460 |
Homes in Coupland
| Housing units | 180 |
| Median year built | 1982 |
| Built before 1980 | 47% |
| Built 2000 or later | 33% |
| Owner-occupied | 84% |
| Median value, owner-occupied | $230,900 |
| Single-family detached | 71% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Elgin | 7 mi | 83% | 4% |
| Taylor | 8 mi | 81% | under 1% |
| Thrall | 11 mi | 84% | under 1% |
| Hutto | 11 mi | 70% | under 1% |
| Manor | 12 mi | 84% | 1% |
| Pflugerville | 12 mi | 66% | under 1% |
| Thorndale | 15 mi | 88% | 26% |
| Round Rock | 17 mi | 56% | under 1% |
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