Jerome County and Part of Twin Falls County, Idaho
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 Jerome County and Part of Twin Falls County, Idaho.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Sluka silt loam, 1 to 4 percent slopes | 96K | Well drained | C | Somewhat limited | Very limited |
| Portneuf silt loam, 0 to 2 percent slopes | 77K | Well drained | C | Not limited | Very limited |
| Chuska gravelly loam, 2 to 12 percent slopes | 69K | Well drained | D | Very limited | Very limited |
| Rock outcrop-Banbury-Paulville complex, 2 to 6 percent slopes | 55K | Well drained | D | Very limited | Very limited |
| Chiara silt loam, 1 to 8 percent slopes | 54K | Well drained | D | Not limited | Very limited |
| Portneuf silt loam, 2 to 4 percent slopes | 52K | Well drained | C | Not limited | Very limited |
| Roseworth silt loam, 1 to 8 percent slopes | 51K | Well drained | D | Very limited | Very limited |
| Power-McCain complex, 1 to 6 percent slopes | 46K | Well drained | C | Not limited | Very limited |
| Brose-Amboat complex, 2 to 20 percent slopes | 41K | Well drained | D | Very limited | Very limited |
| Colthorp cobbly silt loam, 1 to 4 percent slopes | 40K | Well drained | D | Very limited | Very limited |
| Minveno silt loam, 2 to 8 percent slopes | 40K | Well drained | D | Very limited | Very limited |
| Power-Owinza-Rock outcrop complex, 1 to 8 percent slopes | 35K | Well drained | D | Not limited | Somewhat limited |
| Purdam silt loam, 1 to 4 percent slopes | 27K | Well drained | C | Very limited | Very limited |
| Keman very gravelly loam, 2 to 35 percent slopes | 27K | Well drained | B | Very limited | Very limited |
| Lud silt loam, 2 to 10 percent slopes | 26K | Well drained | D | Very limited | Very limited |
| Rock outcrop-Xerorthents complex, very steep | 25K | D | Very limited | Very limited | |
| Bahem silt loam, 1 to 4 percent slopes | 25K | Well drained | B | Not limited | Somewhat limited |
| Chuska very stony loam, 2 to 12 percent slopes | 24K | Well drained | D | Very limited | Very limited |
| Barrymore-Starbuck complex, 1 to 4 percent slopes | 24K | Well drained | C | Very limited | Very limited |
| Paulville-Idow complex, 1 to 4 percent slopes | 24K | Well drained | C | Not limited | Very limited |
What This Means
Building & Foundations
About 52% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes. 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.