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Dorchester, Texas
Inside Dorchester's city limits, shrink-swell clay limits houses without basements on 73% of mapped land, higher than 77% of Texas cities. A shallow water table limits basements on under 1%.
That clay share is above Grayson County's 60%. FEMA's flood data list 42 flood losses since 2016 in the 2 ZIP codes overlapping the city.
Data as of October 13, 2026 · sources · in Grayson County
expansive clay: shrink-swell limits slab homes
high water table: limits basements
flood losses since 2016 in 2 overlapping ZIPs
Foundation repair in Dorchester
Foundation repair in Dorchester: shrink-swell clay limits slab homes on 73% of Dorchester's mapped land, more than in 77% of Texas cities.
| 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 Dorchester city limits
| Expansive clay (limits slab homes) | 73.3% |
| High water table (limits basements) | 0.5% |
| Septic fields very limited | 94.8% |
| Clay swell (LEP, by area) | 9.2% |
| High-swell land (LEP 6%+) | 71.0% |
| Mapped soil | 967 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Fairlie | 41% | 70% |
| Houston Black | 24% | 91% |
| Wilson | 4% | 88% |
| Austin | 2% | 93% |
| Stephen | 2% | n/a |
| Whitewright | 1% | n/a |
What the numbers mean here
Clay swell averages a linear extensibility of 9.2% by land area here, and 71% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 73% of the mapped land.
Clay shrinks as it dries: 100% of Grayson County is in drought on the latest map, and 73% of Dorchester's mapped land has shrink-swell clay.
USDA rates 95% of the land very limited for septic absorption fields.
Drought in Grayson County
100% of Grayson 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 Dorchester. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 75459 | 80% | 3 | $8,585 |
| 75092 | 20% | 39 | $1.5 million |
Homes
Dorchester has fewer than 100 housing units in the ACS 2020-2024 estimates, too few for reliable shares.
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Howe | 5 mi | 77% | 2% |
| Southmayd | 6 mi | 82% | 3% |
| Sherman | 8 mi | 61% | 3% |
| Van Alstyne | 10 mi | 78% | under 1% |
| Gunter | 11 mi | 84% | 6% |
| Knollwood | 12 mi | 76% | 0% |
| Tom Bean | 12 mi | 40% | under 1% |
| Collinsville | 13 mi | 40% | 0% |
Sources: USDA SSURGO (August 5, 2026) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026). Methods · Data status