Walworth County, South Dakota
The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). 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 Walworth County, South Dakota.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Highmore silt loam, cool, 2 to 6 percent slopes | 63K | Well drained | B | Somewhat limited | Somewhat limited |
| Highmore-Eakin silt loams, cool, 2 to 6 percent slopes | 28K | Well drained | B | Somewhat limited | Somewhat limited |
| Water | 27K | Not rated | Not rated | ||
| Mobridge silt loam, cool, 0 to 2 percent slopes | 22K | Moderately well drained | B | Somewhat limited | Somewhat limited |
| Williams-Bowbells loams, 3 to 6 percent slopes | 21K | Well drained | B | Somewhat limited | Somewhat limited |
| Highmore silt loam, cool, 0 to 2 percent slopes | 20K | Well drained | B | Somewhat limited | Somewhat limited |
| Sansarc-Opal clays, 9 to 25 percent slopes | 18K | Well drained | D | Very limited | Very limited |
| Highmore silt loam, 2 to 6 percent slopes | 17K | Well drained | C | Somewhat limited | Very limited |
| Williams-Zahl-Zahill complex, 6 to 9 percent slopes | 16K | Well drained | B | Somewhat limited | Somewhat limited |
| Opal-Sansarc silty clays, very stony, 6 to 15 percent slopes | 15K | Well drained | D | Very limited | Very limited |
| Highmore silt loam, cool, 6 to 9 percent slopes | 10K | Well drained | B | Somewhat limited | Somewhat limited |
| Opal silty clay, very stony, 3 to 9 percent slopes | 9K | Well drained | D | Very limited | Very limited |
| Highmore-Bearpaw complex, cool, 6 to 9 percent slopes | 8K | Well drained | B | Somewhat limited | Somewhat limited |
| Highmore-Bearpaw complex, cool, 2 to 6 percent slopes | 7K | Well drained | B | Somewhat limited | Somewhat limited |
| Agar silt loam, cool, 2 to 6 percent slopes | 7K | Well drained | B | Somewhat limited | Somewhat limited |
| Bearpaw-Gettys complex, cool, 6 to 15 percent slopes | 7K | Well drained | C | Somewhat limited | Somewhat limited |
| Promise clay, 3 to 6 percent slopes | 7K | Well drained | D | Very limited | Very limited |
| Zahl-Williams-Zahill complex, 6 to 9 percent slopes | 6K | Well drained | B | Somewhat limited | Somewhat limited |
| Promise clay, 0 to 3 percent slopes | 6K | Well drained | D | Very limited | Very limited |
| Gettys clay loam, cool, 9 to 40 percent slopes | 6K | Well drained | C | Very limited | Very limited |
What This Means
Building & Foundations
Most soils are generally favorable for residential construction. Standard foundations are usually viable, though site-specific evaluation is always recommended.
Septic Systems
About 23% of soils have significant septic limitations, while others are more suitable. A perc test is essential — conditions vary across the area.
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.