Dallas County, Texas
The dominant drainage class is Moderately 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 Dallas County, Texas.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Houston Black-Urban land complex, 0 to 4 percent slopes | 65K | Moderately well drained | D | Very limited | Very limited |
| Houston Black clay, 1 to 3 percent slopes | 30K | Moderately well drained | D | Very limited | Very limited |
| Trinity clay, 0 to 1 percent slopes, frequently flooded | 27K | Moderately well drained | D | Very limited | Very limited |
| Ferris-Heiden complex, 5 to 12 percent slopes | 25K | Well drained | D | Very limited | Very limited |
| Water | 19K | D | Not rated | Not rated | |
| Austin-Urban land complex, 0 to 2 percent slopes | 19K | Well drained | C | Somewhat limited | Very limited |
| Austin silty clay, 1 to 3 percent slopes | 16K | Well drained | D | Somewhat limited | Very limited |
| Stephen-Urban land complex, 1 to 4 percent slopes | 16K | Well drained | D | Very limited | Very limited |
| Trinity clay, 0 to 1 percent slopes, occasionally flooded | 15K | Moderately well drained | D | Very limited | Very limited |
| Heiden clay, 2 to 5 percent slopes, moderately eroded | 15K | Well drained | D | Very limited | Very limited |
| Trinity-Urban land complex, 0 to 1 percent slopes, occasionally flooded | 15K | Moderately well drained | D | Very limited | Very limited |
| Urban land | 14K | D | Not limited | Very limited | |
| Branyon clay, 0 to 1 percent slopes | 14K | Moderately well drained | D | Very limited | Very limited |
| Dalco-Urban land complex, 0 to 3 percent slopes | 14K | Moderately well drained | D | Very limited | Very limited |
| Austin-Urban land complex, 2 to 5 percent slopes | 13K | Well drained | D | Somewhat limited | Very limited |
| Eddy-Stephen complex, 1 to 5 percent slopes | 12K | Well drained | D | Very limited | Very limited |
| Arents, loamy, hilly, rarely flooded | 12K | Well drained | A | Very limited | Very limited |
| Frio silty clay, 0 to 1 percent slopes, frequently flooded | 10K | Well drained | C | Very limited | Very limited |
| Wilson-Urban land complex, 0 to 2 percent slopes | 10K | Moderately well drained | D | Very limited | Very limited |
| Lewisville-Urban land complex, 0 to 4 percent slopes | 10K | Well drained | B | Very limited | Somewhat limited |
What This Means
Building & Foundations
About 78% 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
Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.