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South Houston, Texas
Inside South Houston's city limits, shrink-swell clay limits houses without basements on 53% of mapped land, higher than 60% of Texas cities. A shallow water table limits basements on 6%.
That clay share is above Harris County's 25%. USDA doesn't rate the 42% of mapped land classed as urban land, so these shares are floors. FEMA's flood data list 439 flood losses since 2016 in ZIP code 77587 overlapping the city. Of its 5,487 homes, 69% were built before 1980; the median dates from 1969.
Data as of October 13, 2026 · sources · in Harris 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 South Houston
Foundation repair in South Houston: shrink-swell clay limits slab homes on 53% of South Houston's mapped land, more than in 60% of Texas cities.
About 3,800 of South Houston's 5,487 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 South Houston city limits
| Expansive clay (limits slab homes) | 53.5% |
| High water table (limits basements) | 5.8% |
| Septic fields very limited | 54.2% |
| Clay swell (LEP, by area) | 13.0% |
| High-swell land (LEP 6%+) | 53.5% |
| Urban land, not rated | 41.6% |
| Mapped soil | 1,958 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Lake Charles | 52% | 97% |
| Bernard | 3% | 43% |
| Bacliff | 2% | n/a |
| Verland | 1% | n/a |
| Edna | 0% | n/a |
| Cieno | 0% | n/a |
What the numbers mean here
Clay swell averages a linear extensibility of 13.0% by land area here, and 53% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 53% of the mapped land.
Clay shrinks as it dries: 82.9% of Harris County is in drought on the latest map, and 53% of South Houston's mapped land has shrink-swell clay.
USDA rates 54% of the land very limited for septic absorption fields.
Drought in Harris County
82.9% of Harris 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 South Houston. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 77587 | 100% | 439 | $27.5 million |
Homes in South Houston
| Housing units | 5,487 |
| Median year built | 1969 |
| Built before 1980 | 69% |
| Built 2000 or later | 15% |
| Owner-occupied | 55% |
| Median value, owner-occupied | $189,300 |
| Single-family detached | 69% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Pasadena | 5 mi | 53% | 37% |
| Galena Park | 6 mi | 67% | 59% |
| Deer Park | 7 mi | 58% | 74% |
| Brookside Village | 7 mi | 69% | 56% |
| Jacinto City | 7 mi | 55% | 23% |
| Pearland | 9 mi | 70% | 36% |
| Friendswood | 11 mi | 74% | 49% |
| La Porte | 11 mi | 74% | 39% |
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