Gillespie 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 Gillespie County, Texas.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Tarrant soils, 1 to 8 percent slopes | 151K | Well drained | D | Very limited | Very limited |
| Purves soils, 1 to 8 percent slopes | 79K | Well drained | D | Very limited | Very limited |
| Tarrant-Rock outcrop complex, 8 to 40 percent slopes | 42K | Well drained | D | Very limited | Very limited |
| Tarpley clay, 1 to 8 percent slopes, stony | 40K | Well drained | D | Very limited | Very limited |
| Boerne and Oakalla soils, channeled, frequently flooded | 26K | Well drained | A | Very limited | Very limited |
| Doss silty clay, 1 to 5 percent slopes | 25K | Well drained | D | Very limited | Very limited |
| Oakalla silty clay loam, 0 to 2 percent slopes, occasionally flooded | 25K | Well drained | B | Very limited | Very limited |
| Brackett-Tarrant association, hilly | 23K | Well drained | D | Very limited | Very limited |
| Heaton loamy fine sand | 20K | Well drained | B | Not limited | Somewhat limited |
| Luckenbach clay loam, 0 to 3 percent slopes | 19K | Well drained | C | Somewhat limited | Very limited |
| Brackett soils, hilly | 15K | Well drained | D | Very limited | Very limited |
| Pedernales fine sandy loam, 1 to 3 percent slopes | 14K | Well drained | C | Somewhat limited | Very limited |
| Pedernales fine sandy loam, 3 to 5 percent slopes | 13K | Well drained | C | Somewhat limited | Very limited |
| Denton silty clay, dry, 1 to 3 percent slopes | 12K | Well drained | C | Somewhat limited | Very limited |
| Krum silty clay, 3 to 5 percent slopes | 12K | Well drained | C | Very limited | Very limited |
| Brackett soils, 1 to 8 percent slopes | 11K | Well drained | D | Very limited | Very limited |
| Hensley loam, 3 to 8 percent slopes | 11K | Well drained | D | Very limited | Very limited |
| Denton silty clay, 3 to 5 percent slopes | 11K | Well drained | D | Very limited | Very limited |
| Keese-Rock outcrop complex, 8 to 35 percent slopes, stony | 10K | Well drained | D | Very limited | Very limited |
| Topia clay, 0 to 3 percent slopes | 10K | 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.