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Richardson, Texas
Inside Richardson's city limits, shrink-swell clay limits houses without basements on 52% of mapped land, higher than 59% of Texas cities. A shallow water table limits basements on under 1%.
That clay share is close to Dallas County's 51%. FEMA's flood data list 6 flood losses since 2016 in the 3 ZIP codes overlapping the city. Of its 47,960 homes, 44% were built before 1980; the median dates from 1986.
Data as of November 3, 2026 · sources · in Dallas County
expansive clay: shrink-swell limits slab homes
high water table: limits basements
flood losses since 2016 in 3 overlapping ZIPs
of homes built before 1980
Foundation repair in Richardson
Foundation repair in Richardson: shrink-swell clay limits slab homes on 52% of Richardson's mapped land, more than in 59% of Texas cities.
About 26,000 of Richardson's 47,960 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 Richardson city limits
| Expansive clay (limits slab homes) | 52.0% |
| High water table (limits basements) | 0.1% |
| Septic fields very limited | 85.0% |
| Clay swell (LEP, by area) | 10.4% |
| High-swell land (LEP 6%+) | 50.2% |
| Urban land, not rated | 19.8% |
| Mapped soil | 18,353 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Houston Black | 36% | 91% |
| Austin | 18% | 93% |
| Eddy | 4% | 0% |
| Heiden | 3% | 80% |
| Lewisville | 3% | n/a |
| Stephen | 2% | n/a |
What the numbers mean here
Clay swell averages a linear extensibility of 10.4% by land area here, and 50% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 52% of the mapped land.
Clay shrinks as it dries: 100% of Dallas County is in drought on the latest map, and 52% of Richardson's mapped land has shrink-swell clay.
USDA rates 85% of the land very limited for septic absorption fields.
Richardson covers 28.6 square miles of land and counts 47,960 housing units, about 1,679 per square mile.
51% of Richardson's occupied homes are owner-occupied, and the median owner-occupied home is valued at $431,400; 31% of all homes in the city date from 2000 or later.
The largest soil series under Richardson is Houston Black, on 36% of the mapped land, followed by Austin at 18%.
USDA's soil survey maps 18,353 acres inside Richardson's city limits.
Drought in Dallas County
100% of Dallas County is in drought (D1 or worse) on the November 3, 2026 map. County detail.
Flood losses by ZIP code
FEMA flood records since 2016 in the ZIP codes that overlap Richardson. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 75080 | 40% | 3 | $28,753 |
| 75081 | 31% | 0 | $0 |
| 75082 | 29% | 3 | $39,039 |
Homes in Richardson
| Housing units | 47,960 |
| Median year built | 1986 |
| Built before 1980 | 44% |
| Built 2000 or later | 31% |
| Owner-occupied | 51% |
| Median value, owner-occupied | $431,400 |
| Single-family detached | 54% |
Nearby cities
Sources: USDA SSURGO (August 5, 2026) · US Drought Monitor (November 3, 2026) · FEMA NFIP v3 (September 9, 2026) · Census ACS 2020-2024. Methods · Data status