Travis County, Texas
The most common soil here is Brackett, on about 16% of the land: a paragravelly clay loam, firm and a little sticky. Houston Black and Eckrant come next.
About 70% of the land drains well.
USDA rates 92% of the land very limited for a standard septic drain field, and 82% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 5% of the land floods occasionally or more, and bedrock lies within 40 inches under 53% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Travis County, Texas, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is D (very slow infiltration, high runoff). The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Travis County, Texas. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Brackett-Rock outcrop complex, 1 to 12 percent slopes | 110K | Well drained | D | Very limited | Very limited |
| Houston Black clay, 1 to 3 percent slopes | 71K | Moderately well drained | D | Very limited | Very limited |
| Brackett-Rock outcrop-Real complex, 8 to 30 percent slopes | 57K | Well drained | D | Very limited | Very limited |
| Eckrant very stony clay, 5 to 18 percent slopes | 35K | Well drained | D | Very limited | Very limited |
| Eckrant and Speck soils, 0 to 2 percent slopes | 26K | Well drained | D | Very limited | Very limited |
| Houston Black clay, 3 to 5 percent slopes, moderately eroded | 23K | Moderately well drained | D | Very limited | Very limited |
| Volente silty clay loam, 1 to 8 percent slopes | 20K | Well drained | C | Somewhat limited | Very limited |
| Water | 20K | D | Not rated | Not rated | |
| Tinn clay, 0 to 1 percent slopes, frequently flooded | 16K | Moderately well drained | D | Very limited | Very limited |
| Heiden clay, 3 to 5 percent slopes, eroded | 16K | Well drained | D | Very limited | Very limited |
| Ferris-Heiden complex, 8 to 20 percent slopes, severely eroded | 15K | Well drained | D | Very limited | Very limited |
| Eckrant-Rock outcrop complex, 18 to 50 percent slopes | 14K | Well drained | D | Very limited | Very limited |
| Speck clay loam, moist, 1 to 5 percent slopes, stony | 13K | Well drained | D | Very limited | Very limited |
| Heiden clay, 5 to 8 percent slopes, eroded | 13K | Well drained | D | Very limited | Very limited |
| Urban land, Austin, and Whitewright soils, 1 to 8 percent slopes | 10K | Well drained | D | Not limited | Very limited |
| Houston Black soils and Urban land, 0 to 8 percent slopes | 8K | Moderately well drained | D | Very limited | Very limited |
| Austin-Urban land complex, 2 to 5 percent slopes | 8K | Well drained | D | Somewhat limited | Very limited |
| Houston Black gravelly clay, 2 to 8 percent slopes, moderately eroded | 8K | Moderately well drained | D | Very limited | Very limited |
| Austin silty clay, 2 to 5 percent slopes, moderately eroded | 7K | Well drained | D | Somewhat limited | Very limited |
| Houston Black clay, 0 to 1 percent slopes | 7K | Moderately well drained | D | Very limited | Very limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 82% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 92% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.