Jerome County and Part of Twin Falls County, Idaho
The most common soil here is Portneuf, on about 9% of the land: a silt loam, smooth, like flour. Sluka and Chuska come next.
About 96% of the land drains well.
USDA rates 90% of the land very limited for a standard septic drain field, and 52% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: bedrock lies within 40 inches under 32% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Jerome County and Part of Twin Falls County, Idaho, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is D (very slow infiltration, high runoff). The most common soil order is Aridisols — dry-climate soils with limited organic matter and often calcium carbonate accumulation. 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. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| 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 |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
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 90% 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.