Asotin County Area, Washington (Asotin and Garfield Counties)
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 Asotin County Area, Washington (Asotin and Garfield Counties).
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Gwinly-Mallory very stony silt loams, 30 to 70 percent slopes | 20K | Well drained | D | Very limited | Very limited |
| Lickskillet-Schuelke very stony loams, 30 to 70 percent slopes | 20K | Well drained | D | Very limited | Very limited |
| Bolicker-Asotin silt loams, 40 to 90 percent slopes | 18K | Well drained | A | Very limited | Very limited |
| Laufer-Thiessen-Rock outcrop complex, 40 to 90 percent slopes | 17K | Well drained | D | Very limited | Very limited |
| Weissenfels-Nims silt loams, 3 to 8 percent slopes | 17K | Moderately well drained | D | Very limited | Very limited |
| Lickskillet-Schuelke-Rock outcrop complex, 40 to 90 percent slopes | 15K | Well drained | D | Very limited | Very limited |
| Gwinly-Mallory-Rock outcrop complex, 40 to 90 percent slopes | 13K | Well drained | D | Very limited | Very limited |
| Laufer-Thiessen complex, 30 to 70 percent slopes | 11K | Well drained | D | Very limited | Very limited |
| Laufer-Rockly-Rock outcrop complex, 60 to 120 percent slopes | 9K | Well drained | D | Very limited | Very limited |
| Lawyer-Gwinly complex, 40 to 90 percent slopes | 9K | Well drained | C | Very limited | Very limited |
| Matheny-Linville-Laufer complex, 40 to 90 percent slopes | 9K | Well drained | B | Very limited | Very limited |
| Neconda silty clay loam, 3 to 6 percent slopes | 7K | Well drained | D | Very limited | Very limited |
| Sweitberg silty clay loam, 3 to 8 percent slopes | 6K | Well drained | D | Very limited | Very limited |
| Nims silt loam, 3 to 8 percent slopes | 6K | Well drained | C | Very limited | Very limited |
| Pataha-Neissenberg silt loams, 3 to 8 percent slopes | 5K | Well drained | C | Very limited | Very limited |
| Harlow-Snell-Harlow variant complex, 3 to 30 percent slopes | 5K | Well drained | D | Very limited | Very limited |
| Cloverland silt loam, very deep, 3 to 8 percent slopes | 5K | Moderately well drained | C | Very limited | Very limited |
| Tolo silt loam, 3 to 30 percent slopes | 5K | Well drained | C | Very limited | Very limited |
| Mallory-Rock outcrop complex, 40 to 90 percent slopes | 4K | Well drained | D | Very limited | Very limited |
| Lickskillet-Schuelke very stony loams, 3 to 30 percent slopes | 4K | Well drained | D | Very limited | Very limited |
What This Means
Building & Foundations
About 100% 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 100% 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.