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Kemah, Texas
Inside Kemah's city limits, shrink-swell clay limits houses without basements on 20% of mapped land. A shallow water table limits basements on 93%, the 2nd-highest of 13 cities in Galveston County.
That clay share is close to Galveston County's 23%. FEMA's flood data list 332 flood losses since 2016 in ZIP code 77565 overlapping the city. Of its 1,019 homes, 27% were built before 1980; the median dates from 1997.
Data as of October 13, 2026 · sources · in Galveston 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 Kemah
Foundation repair in Kemah: shrink-swell clay limits slab homes on 20% of Kemah's mapped land.
About 600 of Kemah's 1,019 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 Kemah city limits
| Expansive clay (limits slab homes) | 19.7% |
| High water table (limits basements) | 93.1% |
| Septic fields very limited | 80.9% |
| Clay swell (LEP, by area) | 4.8% |
| High-swell land (LEP 6%+) | 19.7% |
| Urban land, not rated | 1.4% |
| Mapped soil | 1,218 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Mocarey | 23% | n/a |
| Bernard | 16% | 43% |
| Verland | 14% | n/a |
| Leton | 12% | n/a |
| Morey | 9% | n/a |
| Algoa | 8% | n/a |
What the numbers mean here
Clay swell averages a linear extensibility of 4.8% by land area here, and 20% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 20% of the mapped land.
Clay shrinks as it dries: 100% of Galveston County is in drought on the latest map, and 20% of Kemah's mapped land has shrink-swell clay.
On 93% of Kemah's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
USDA rates 81% of the land very limited for septic absorption fields.
Drought in Galveston County
100% of Galveston 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 Kemah. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 77565 | 99% | 332 | $8.6 million |
Homes in Kemah
| Housing units | 1,019 |
| Median year built | 1997 |
| Built before 1980 | 27% |
| Built 2000 or later | 44% |
| Owner-occupied | 54% |
| Median value, owner-occupied | $281,100 |
| Single-family detached | 62% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Clear Lake Shores | 1 mi | 16% | 57% |
| El Lago | 3 mi | 47% | 41% |
| Taylor Lake Village | 3 mi | 41% | 41% |
| Nassau Bay | 4 mi | 31% | 30% |
| Seabrook | 5 mi | 13% | 15% |
| Webster | 6 mi | 56% | 26% |
| Dickinson | 6 mi | 66% | 74% |
| League City | 6 mi | 42% | 71% |
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