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Richwood, Texas
Inside Richwood's city limits, shrink-swell clay limits houses without basements on 78% of mapped land, the 2nd-highest of 24 cities in Brazoria County. A shallow water table limits basements on 6%.
That clay share is above Brazoria County's 64%. FEMA's flood data list 1,422 flood losses since 2016 in the 2 ZIP codes overlapping the city. Of its 2,080 homes, 42% were built before 1980; the median dates from 1984.
Data as of October 13, 2026 · sources · in Brazoria County
expansive clay: shrink-swell limits slab homes
high water table: limits basements
flood losses since 2016 in 2 overlapping ZIPs
of homes built before 1980
Foundation repair in Richwood
Foundation repair in Richwood: shrink-swell clay limits slab homes on 78% of Richwood's mapped land, more than in 83% of Texas cities.
About 1,300 of Richwood's 2,080 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 Richwood city limits
| Expansive clay (limits slab homes) | 78.3% |
| High water table (limits basements) | 6.0% |
| Septic fields very limited | 78.3% |
| Clay swell (LEP, by area) | 17.0% |
| High-swell land (LEP 6%+) | 78.3% |
| Mapped soil | 3,047 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Pledger | 55% | n/a |
| Brazoria | 26% | n/a |
| Asa | 8% | 0% |
| Churnabog | 6% | n/a |
| Norwood | 3% | n/a |
| Lake Charles | 1% | 97% |
What the numbers mean here
Clay swell averages a linear extensibility of 17.0% by land area here, and 78% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 78% of the mapped land.
Clay shrinks as it dries: 100% of Brazoria County is in drought on the latest map, and 78% of Richwood's mapped land has shrink-swell clay.
USDA rates 78% of the land very limited for septic absorption fields.
Drought in Brazoria County
100% of Brazoria 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 Richwood. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 77531 | 59% | 257 | $25.5 million |
| 77515 | 36% | 1,165 | $87.5 million |
Homes in Richwood
| Housing units | 2,080 |
| Median year built | 1984 |
| Built before 1980 | 42% |
| Built 2000 or later | 33% |
| Owner-occupied | 54% |
| Median value, owner-occupied | $249,600 |
| Single-family detached | 63% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Clute | 3 mi | 47% | 28% |
| Lake Jackson | 3 mi | 67% | 15% |
| Oyster Creek | 6 mi | 48% | 27% |
| Jones Creek | 7 mi | 5% | 1% |
| Angleton | 8 mi | 64% | 65% |
| Bailey's Prairie | 8 mi | 57% | 13% |
| Freeport | 9 mi | 49% | 75% |
| Brazoria | 10 mi | 28% | under 1% |
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