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Martindale, Texas
Inside Martindale's city limits, shrink-swell clay limits houses without basements on 70% of mapped land, the 3rd-highest of 3 cities in Caldwell County. A shallow water table limits basements on under 1%.
That clay share is above Caldwell County's 59%. FEMA's flood data list 3 flood losses since 2016 in ZIP code 78655 overlapping the city. Of its 443 homes, 38% were built before 1980; the median dates from 1989.
Data as of October 13, 2026 · sources · in Caldwell 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 Martindale
Foundation repair in Martindale: shrink-swell clay limits slab homes on 70% of Martindale's mapped land, more than in 75% of Texas cities.
About 300 of Martindale's 443 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 Martindale city limits
| Expansive clay (limits slab homes) | 70.3% |
| High water table (limits basements) | 0.3% |
| Septic fields very limited | 85.9% |
| Clay swell (LEP, by area) | 8.0% |
| High-swell land (LEP 6%+) | 70.3% |
| Mapped soil | 1,337 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Lewisville | 48% | n/a |
| Houston Black | 11% | 91% |
| Queeny | 10% | n/a |
| Branyon | 10% | 92% |
| Heiden | 5% | 80% |
| Tinn | 4% | n/a |
What the numbers mean here
Clay swell averages a linear extensibility of 8.0% by land area here, and 70% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 70% of the mapped land.
Clay shrinks as it dries: 100% of Caldwell County is in drought on the latest map, and 70% of Martindale's mapped land has shrink-swell clay.
USDA rates 86% of the land very limited for septic absorption fields.
Drought in Caldwell County
100% of Caldwell 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 Martindale. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 78655 | 100% | 3 | $0 |
Homes in Martindale
| Housing units | 443 |
| Median year built | 1989 |
| Built before 1980 | 38% |
| Built 2000 or later | 35% |
| Owner-occupied | 78% |
| Median value, owner-occupied | $326,300 |
| Single-family detached | 65% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Staples | 6 mi | 83% | under 1% |
| San Marcos | 6 mi | 56% | under 1% |
| Uhland | 9 mi | 82% | under 1% |
| Lockhart | 10 mi | 79% | under 1% |
| Kyle | 11 mi | 51% | under 1% |
| Niederwald | 11 mi | 84% | 1% |
| Kingsbury | 14 mi | 35% | 12% |
| Mountain City | 14 mi | 17% | 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