Oglala Lakota County Area, 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 Oglala Lakota County Area, South Dakota.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Oglala-Canyon loams, 9 to 25 percent slopes | 141K | Well drained | B | Very limited | Very limited |
| Canyon-Rock outcrop association, 18 to 40 percent slopes | 117K | Well drained | D | Very limited | Very limited |
| Canyon-Oglala loams, 18 to 40 percent slopes | 72K | Well drained | D | Very limited | Very limited |
| Pierre silty clay, 6 to 25 percent slopes | 55K | Well drained | D | Very limited | Very limited |
| Badland-Denby-Interior complex, 0 to 90 percent slopes | 48K | Well drained | Very limited | Very limited | |
| Lohmiller silty clay loam, channeled, 0 to 2 percent slopes | 42K | Well drained | C | Very limited | Very limited |
| Keith-Colby silt loams, 9 to 12 percent slopes | 41K | Well drained | B | Somewhat limited | Somewhat limited |
| Epping-Kadoka silt loams, 9 to 18 percent slopes | 36K | Well drained | D | Very limited | Very limited |
| Badland | 35K | Excessively drained | D | Very limited | Very limited |
| Rosebud-Canyon loams, 5 to 9 percent slopes | 31K | Well drained | C | Somewhat limited | Very limited |
| Valentine sand, 3 to 30 percent slopes | 30K | Excessively drained | A | Very limited | Very limited |
| Denby silty clay, 0 to 3 percent slopes | 28K | Well drained | C | Somewhat limited | Very limited |
| Keith-Colby silt loams, 12 to 25 percent slopes | 27K | Well drained | B | Very limited | Very limited |
| Anselmo-Valentine complex, 5 to 20 percent slopes | 26K | Well drained | A | Somewhat limited | Very limited |
| Keith silt loam, 0 to 3 percent slopes | 26K | Well drained | B | Not limited | Somewhat limited |
| Interior silt loam, 0 to 3 percent slopes | 24K | Well drained | B | Very limited | Very limited |
| Pierre clay, 3 to 9 percent slopes | 23K | Well drained | D | Very limited | Very limited |
| Wortman-Wanblee silt loams, 0 to 6 percent slopes | 21K | Well drained | D | Somewhat limited | Very limited |
| Rosebud-Keith silt loams, 3 to 9 percent slopes | 20K | Well drained | C | Somewhat limited | Very limited |
| Epping-Badland complex, 3 to 60 percent slopes | 19K | Somewhat excessively drained | D | Very limited | Very limited |
What This Means
Building & Foundations
About 77% 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.