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Dimmitt, Texas
Inside Dimmitt's city limits, shrink-swell clay limits houses without basements on 90% of mapped land, the 2nd-highest of 3 cities in Castro County. A shallow water table limits basements on 7%, the highest of 3 cities in Castro County.
That clay share is above Castro County's 82%. FEMA's flood data list no flood losses since 2016 in ZIP code 79027 overlapping the city. Of its 1,684 homes, 75% were built before 1980; the median dates from 1964.
Data as of October 13, 2026 · sources · in Castro 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 Dimmitt
Foundation repair in Dimmitt: shrink-swell clay limits slab homes on 90% of Dimmitt's mapped land, more than in 97% of Texas cities.
About 1,300 of Dimmitt's 1,684 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 Dimmitt city limits
| Expansive clay (limits slab homes) | 90.1% |
| High water table (limits basements) | 6.9% |
| Septic fields very limited | 83.4% |
| Clay swell (LEP, by area) | 6.2% |
| High-swell land (LEP 6%+) | 82.5% |
| Mapped soil | 2,084 acres |
What the numbers mean here
Clay swell averages a linear extensibility of 6.2% by land area here, and 82% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 90% of the mapped land.
Clay shrinks as it dries: 1.7% of Castro County is in drought on the latest map, and 90% of Dimmitt's mapped land has shrink-swell clay.
USDA rates 83% of the land very limited for septic absorption fields.
Drought in Castro County
1.7% of Castro 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 Dimmitt. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 79027 | 100% | 0 | $0 |
Homes in Dimmitt
| Housing units | 1,684 |
| Median year built | 1964 |
| Built before 1980 | 75% |
| Built 2000 or later | 4% |
| Owner-occupied | 55% |
| Median value, owner-occupied | $85,100 |
| Single-family detached | 75% |
Nearby cities
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