Roberts County, South Dakota
The dominant drainage class is Well drained and the dominant hydrologic group is C (slow infiltration, moderate 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 Roberts County, South Dakota.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Forman-Aastad complex, 1 to 4 percent slopes | 87K | Well drained | C | Somewhat limited | Very limited |
| Peever clay loam, 2 to 6 percent slopes | 50K | Well drained | C | Somewhat limited | Very limited |
| Peever clay loam, 0 to 2 percent slopes | 34K | Well drained | C | Somewhat limited | Very limited |
| Heimdal-Svea loams, 2 to 6 percent slopes | 33K | Well drained | B | Not limited | Somewhat limited |
| Esmond-Heimdal-Sisseton complex, 2 to 6 percent slopes | 27K | Well drained | B | Not limited | Somewhat limited |
| Water | 20K | Not rated | Not rated | ||
| Forman-Aastad loams, 9 to 15 percent slopes | 19K | Well drained | C | Somewhat limited | Very limited |
| Forman-Buse stony complex, 9 to 40 percent slopes | 18K | Well drained | C | Very limited | Very limited |
| Peever-Tonka complex | 18K | Well drained | C | Very limited | Very limited |
| Southam silty clay loam, 0 to 1 percent slopes | 17K | Very poorly drained | C/D | Very limited | Very limited |
| Forman-Aastad loams, 6 to 9 percent slopes | 16K | Well drained | C | Somewhat limited | Very limited |
| Hamerly-Tonka complex, 0 to 3 percent slopes | 14K | Somewhat poorly drained | C | Somewhat limited | Very limited |
| Hamerly-Vallers loams, 2 to 4 percent slopes | 13K | Somewhat poorly drained | C | Somewhat limited | Very limited |
| Forman-Buse complex, 6 to 12 percent slopes, moderately eroded | 13K | Well drained | C | Somewhat limited | Very limited |
| Heimdal-Svea loams, 0 to 2 percent slopes | 12K | Well drained | B | Not limited | Somewhat limited |
| Poinsett-Waubay silty clay loams, 0 to 2 percent slopes | 12K | Well drained | C | Somewhat limited | Very limited |
| Forman-Buse loams, 15 to 25 percent slopes | 12K | Well drained | C | Very limited | Very limited |
| LaDelle silt loam | 12K | Moderately well drained | B | Very limited | Very limited |
| Playmoor silty clay loam | 10K | Poorly drained | B/D | Very limited | Very limited |
| Lamoure silty clay loam, 0 to 2 percent slopes, frequently flooded | 10K | Poorly drained | C/D | Very limited | Very limited |
What This Means
Building & Foundations
About 21% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 79% 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.