Kirby, Texas
Inside Kirby's city limits, shrink-swell clay limits houses without basements on 86% of mapped land, the highest of 24 cities in Bexar County. A shallow water table limits basements on 0%.
That clay share is above Bexar County's 51%. FEMA's flood data list 10 flood losses since 2016 in ZIP code 78219 overlapping the city. Of its 3,046 homes, 60% 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 1 overlapping ZIP
of homes built before 1980
Foundation repair in Kirby
Foundation repair in Kirby: shrink-swell clay limits slab homes on 86% of Kirby's mapped land, more than in 94% of Texas cities.
About 2,200 of Kirby's 3,046 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 Kirby city limits
| Expansive clay (limits slab homes) | 86.1% |
| High water table (limits basements) | 0.0% |
| Septic fields very limited | 86.1% |
| Clay swell (LEP, by area) | 12.6% |
| High-swell land (LEP 6%+) | 86.1% |
| Mapped soil | 1,277 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Branyon | 67% | 92% |
| Houston Black | 14% | 91% |
| Tinn | 7% | n/a |
| Lewisville | 4% | n/a |
| Burleson | 4% | 84% |
| Frio | 3% | n/a |
What the numbers mean here
Clay swell averages a linear extensibility of 12.6% by land area here, and 86% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 86% of the mapped land.
Clay shrinks as it dries: 79.6% of Bexar County is in drought on the latest map, and 86% of Kirby's mapped land has shrink-swell clay.
USDA rates 86% 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 Kirby. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 78219 | over 99% | 10 | $25,047 |
Homes in Kirby
| Housing units | 3,046 |
| Median year built | 1978 |
| Built before 1980 | 60% |
| Built 2000 or later | 11% |
| Owner-occupied | 66% |
| Median value, owner-occupied | $165,500 |
| Single-family detached | 73% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Windcrest | 4 mi | 81% | 0% |
| Terrell Hills | 4 mi | 74% | 0% |
| Alamo Heights | 5 mi | 43% | 0% |
| China Grove | 5 mi | 60% | 0% |
| Converse | 6 mi | 85% | 0% |
| Olmos Park | 6 mi | 65% | 0% |
| Live Oak | 7 mi | 46% | 0% |
| Universal City | 8 mi | 63% | 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