Fall River County, South Dakota
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 Fall River County, South Dakota.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Pierre silty clay, 6 to 25 percent slopes | 195K | Well drained | D | Very limited | Very limited |
| Pierre clay, 2 to 6 percent slopes | 114K | Well drained | D | Very limited | Very limited |
| Hisle-Slickspots complex, 0 to 6 percent slopes | 48K | Well drained | D | Very limited | Very limited |
| Minnequa-Midway silty clay loams, 6 to 25 percent slopes | 37K | Well drained | D | Very limited | Very limited |
| Mathias-Rockoa-Rock outcrop complex, 25 to 60 percent slopes, stony | 33K | Well drained | B | Very limited | Very limited |
| Minnequa silt loam, 2 to 6 percent slopes | 30K | Well drained | C | Somewhat limited | Very limited |
| Butche-Boneek, dry complex, 3 to 15 percent slopes | 28K | Excessively drained | D | Very limited | Very limited |
| Shingle-Penrose-Rock outcrop complex, 15 to 40 percent slopes | 27K | Well drained | D | Very limited | Very limited |
| Kyle clay, 2 to 6 percent slopes | 26K | Well drained | D | Very limited | Very limited |
| Rock outcrop-Mathias-Butche complex, 30 to 75 percent slopes, very stony | 26K | Excessively drained | D | Very limited | Very limited |
| Samsil clay, 15 to 40 percent slopes | 26K | Well drained | D | Very limited | Very limited |
| Savo silt loam, 2 to 6 percent slopes | 25K | Well drained | C | Somewhat limited | Very limited |
| Grummit-Snomo clays, 3 to 15 percent slopes | 25K | Well drained | D | Very limited | Very limited |
| Mathias, very stony-Samsil-Rock outcrop complex, 15 to 30 percent slopes | 25K | Well drained | D | Very limited | Very limited |
| Kyle clay, 0 to 2 percent slopes | 23K | Well drained | D | Very limited | Very limited |
| Pierre-Grummit clays, 6 to 25 percent slopes | 22K | Well drained | D | Very limited | Very limited |
| Lohmiller silty clay loam | 21K | Well drained | C | Very limited | Very limited |
| Arvada loam, 0 to 3 percent slopes | 19K | Well drained | D | Somewhat limited | Not limited |
| Norka silt loam, 2 to 6 percent slopes | 19K | Well drained | B | Somewhat limited | Somewhat limited |
| Ascalon fine sandy loam, 0 to 6 percent slopes | 17K | Well drained | B | Not limited | Not limited |
What This Means
Building & Foundations
About 86% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. 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.