Travis County, Texas
The dominant drainage class is Well drained and the dominant hydrologic group is D (very slow infiltration, high runoff). 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.
| 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 |
What This Means
Building & Foundations
About 86% 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 96% 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.