HomeSoil seriesHouston Black

Houston Black soil series

Houston Black soils cover 1,414,933 mapped acres, almost all of them in Texas. USDA rates shrink-swell a limit for houses without basements on 91% of that land, and a shallow water table a limit for basements on 0%.

It is the leading soil series by area in 88 of the counties and cities on this site, including Collin County, TX; Rockwall County, TX; Ellis County, TX.

SSURGO survey versions to August 5, 2026 · series description revised 2017-08

91%

of its land: shrink-swell limits houses without basements

0%

of its land: a shallow water table limits basements

12%

median highest linear extensibility (6% and up is high)

54%

median highest clay content in the top 150 cm

USDA's description

The Houston Black series consists of very deep, moderately well drained, very slowly permeable soils that formed in clayey residuum derived from calcareous mudstone of Cretaceous Age. These nearly level to moderately sloping soils occur on interfluves and side slopes on upland ridges and plains on dissected plains. Slopes are mainly 1 to 3 percent but range from 0 to 8 percent. Mean annual precipitation is about 889 mm (35 in) and the mean annual air temperature is about 20.6 degrees C (69 degrees F).

Vertic features, from the same description: "slickensides at a depth of 61 to 203 cm (24 to 80 in) depth."

Source: USDA NRCS series description (OSD) for Houston Black, revised 2017-08. Read it.

Engineering properties

Mapped area (SSURGO)1,414,933 acres
Shrink-swell limits houses without basements91.2%
Shallow water table limits basements0.0%
Very limited for septic absorption fields91.2%
Most common drainage classModerately well drained
Most common hydrologic soil groupD
Taxonomic classFine, smectitic, thermic Udic Haplusterts
Type locationTravis County, Texas

Where Houston Black is mapped

StateMapped acres
Texas1,414,933

Places where Houston Black leads

Counties and cities where Houston Black covers more mapped land than any other series.

PlaceShare of mapped land
Mobile City, TX82%
Barry, TX76%
Itasca, TX75%
Nevada, TX71%
Malone, TX70%
Rogers, TX69%
Converse, TX68%
Palmer, TX68%
Murphy, TX68%
Bardwell, TX66%
Talty, TX65%
Forney, TX64%
Mart, TX63%
Lavon, TX63%
Fate, TX59%
Princeton, TX59%
Santa Clara, TX57%
Frost, TX57%
Italy, TX56%
St. Paul, TX55%
Creedmoor, TX55%
Manor, TX55%
Plano, TX54%
Buckholts, TX53%
Parker, TX52%
McLendon-Chisholm, TX52%
Mertens, TX52%
Crandall, TX51%
Anna, TX51%
Allen, TX51%
Moody, TX50%
Pecan Hill, TX49%
Celeste, TX49%
Lucas, TX48%
Lowry Crossing, TX47%
Uhland, TX46%
Hebron, TX45%
Melissa, TX44%
Weston, TX44%
Pflugerville, TX44%
Rockwall, TX44%
Heath, TX43%
Farmersville, TX43%
Ferris, TX42%
Celina, TX41%
McKinney, TX40%
Roxton, TX40%
Blue Ridge, TX40%
Sachse, TX40%
Mustang Ridge, TX39%
Collin County, TX39%
Prosper, TX37%
Rowlett, TX37%
Niederwald, TX37%
Lott, TX36%
Richardson, TX36%
Rockwall County, TX35%
Waxahachie, TX34%
Frisco, TX34%
Universal City, TX33%
Emhouse, TX32%
Lancaster, TX32%
Fairview, TX30%
Windcrest, TX29%
Wilmer, TX29%
Royse City, TX27%
Mesquite, TX26%
Robinson, TX26%
Farmers Branch, TX25%
Hutchins, TX24%
Hillsboro, TX23%
Wylie, TX22%
University Park, TX22%
Schertz, TX21%
Golinda, TX21%
Garland, TX20%
Leon Valley, TX19%
Ellis County, TX19%
Temple, TX18%
Hill County, TX15%
San Marcos, TX15%
Carrollton, TX13%
Dallas County, TX12%
Grand Prairie, TX12%
Bell County, TX11%
Arlington, TX10%
Lamar County, TX8%
Dallas, TX8%

Sources

Shares and properties: USDA NRCS SSURGO via Soil Data Access, weighted by each component's share of its map units. Description: the USDA NRCS series description. How we count.