Johnson 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 Johnson County, Texas.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Aledo-Bolar association, 1 to 8 percent slopes | 70K | Well drained | D | Very limited | Very limited |
| Heiden clay, 1 to 3 percent slopes | 53K | Well drained | D | Very limited | Very limited |
| Crosstell fine sandy loam, 3 to 8 percent slopes | 47K | Moderately well drained | D | Very limited | Very limited |
| Sanger clay, 1 to 3 percent slopes | 34K | Well drained | D | Very limited | Very limited |
| Crosstell fine sandy loam, 1 to 3 percent slopes | 23K | Moderately well drained | D | Very limited | Very limited |
| Ponder clay loam, 1 to 3 percent slopes | 16K | Moderately well drained | C | Very limited | Very limited |
| Rader fine sandy loam, 0 to 3 percent slopes | 15K | Moderately well drained | B | Somewhat limited | Very limited |
| Ferris-Heiden complex, 2 to 5 percent slopes | 13K | Well drained | D | Very limited | Very limited |
| Bolar clay loam, 3 to 8 percent slopes | 13K | Well drained | C | Somewhat limited | Very limited |
| Slidell clay, 1 to 3 percent slopes | 13K | Moderately well drained | D | Very limited | Very limited |
| Bolar-Aledo complex, 3 to 20 percent slopes | 9K | Well drained | D | Very limited | Very limited |
| Frio silty clay, 0 to 1 percent slopes, occasionally flooded | 9K | Well drained | C | Very limited | Very limited |
| Bolar clay loam, 1 to 3 percent slopes | 8K | Well drained | C | Very limited | Very limited |
| Gasil fine sandy loam, 1 to 3 percent slopes | 8K | Well drained | B | Not limited | Somewhat limited |
| Brackett-Rock outcrop complex, 5 to 30 percent slopes | 7K | Well drained | D | Very limited | Very limited |
| Navo clay loam, 2 to 5 percent slopes | 7K | Moderately well drained | D | Very limited | Very limited |
| Lindale clay loam, 1 to 3 percent slopes | 7K | Well drained | C | Somewhat limited | Very limited |
| Gasil fine sandy loam, 3 to 8 percent slopes | 7K | Well drained | B | Not limited | Somewhat limited |
| Sanger clay, 3 to 5 percent slopes | 6K | Well drained | D | Very limited | Very limited |
| Houston Black clay, 1 to 3 percent slopes | 6K | 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, 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
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.