Jefferson 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 Jefferson County, Idaho.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Terreton silty clay loam | 52K | Well drained | D | Very limited | Very limited |
| Aecet, very stony surface-Rock outcrop-Bereniceton complex | 46K | Well drained | C | Very limited | Very limited |
| Grassy Butte-Rock outcrop complex | 31K | Somewhat excessively drained | A | Somewhat limited | Very limited |
| Malm-Rock outcrop complex | 30K | Well drained | D | Very limited | Very limited |
| Pancheri silt loam, 2 to 4 percent slopes | 27K | Well drained | B | Not limited | Very limited |
| Terreton-Zwiefel complex | 27K | Well drained | D | Very limited | Very limited |
| Mathon-Rock outcrop-Modkin complex | 24K | Well drained | A | Very limited | Very limited |
| Bereniceton-Rock outcrop-Aecet complex | 16K | Well drained | C | Somewhat limited | Very limited |
| Bondranch-Rock outcrop complex | 16K | Well drained | D | Very limited | Very limited |
| Matheson-Malm loams | 15K | Well drained | A | Somewhat limited | Somewhat limited |
| Bereniceton-Terreton-Aecet complex | 14K | Well drained | C | Very limited | Very limited |
| Tan gravelly loam, 0 to 1 percent slopes | 14K | Well drained | C | Not limited | Very limited |
| Pancheri silt loam, 4 to 8 percent slopes | 13K | Well drained | B | Not limited | Very limited |
| Pancheri silt loam, 0 to 2 percent slopes | 13K | Well drained | B | Not limited | Very limited |
| Terreton loamy sand | 12K | Well drained | C | Very limited | Very limited |
| Blackfoot silt loam, drained | 12K | Moderately well drained | B | Somewhat limited | Somewhat limited |
| Grassy Butte sand, 2 to 20 percent slopes | 12K | Somewhat excessively drained | A | Somewhat limited | Very limited |
| Xeric Torrifluvents | 11K | Excessively drained | A | Very limited | Very limited |
| Matheson loamy sand, 2 to 8 percent slopes | 10K | Well drained | A | Not limited | Not limited |
| Diston loamy sand, 0 to 4 percent slopes | 10K | Somewhat excessively drained | A | Not limited | Very limited |
What This Means
Building & Foundations
About 57% of soils are rated "very limited" for dwellings with basements. Specific challenges include flood-prone areas. 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
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.