Haakon 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 Haakon County, South Dakota.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Ottumwa silty clay, 3 to 6 percent slopes | 112K | Well drained | C | Very limited | Very limited |
| Lakoma silty clay, 6 to 15 percent slopes | 95K | Well drained | D | Very limited | Very limited |
| Okaton-Lakoma silty clays, 15 to 40 percent slopes | 64K | Well drained | D | Very limited | Very limited |
| Samsil clay, 15 to 45 percent slopes | 54K | Well drained | D | Very limited | Very limited |
| Ottumwa-Lakoma complex, 3 to 6 percent slopes | 53K | Well drained | D | Very limited | Very limited |
| Ottumwa-Lakoma silty clays, 6 to 9 percent slopes | 43K | Well drained | D | Very limited | Very limited |
| Ree loam, 0 to 3 percent slopes | 43K | Well drained | C | Somewhat limited | Very limited |
| Pierre-Samsil clays, 15 to 25 percent slopes | 37K | Well drained | D | Very limited | Very limited |
| Lakoma silty clay, 6 to 9 percent slopes | 33K | Well drained | D | Very limited | Very limited |
| Razor-Midway complex, 6 to 15 percent slopes | 32K | Well drained | D | Very limited | Very limited |
| Pierre clay, 6 to 15 percent slopes | 30K | Well drained | D | Very limited | Very limited |
| Schamber-Samsil complex, 6 to 60 percent slopes | 29K | Well drained | A | Very limited | Very limited |
| Ottumwa silty clay, 0 to 3 percent slopes | 27K | Well drained | C | Very limited | Very limited |
| Lakoma-Vivian complex, 9 to 25 percent slopes | 27K | Well drained | D | Very limited | Very limited |
| Ottumwa-Capa complex, 0 to 3 percent slopes | 25K | Well drained | C | Very limited | Very limited |
| Opal-Promise clays, 6 to 9 percent slopes | 22K | Well drained | D | Very limited | Very limited |
| Opal-Sansarc clays, 6 to 15 percent slopes | 20K | Well drained | D | Very limited | Very limited |
| Samsil-Rock outcrop complex, 9 to 60 percent slopes | 20K | Well drained | D | Very limited | Very limited |
| Kirley-Ottumwa complex, 3 to 6 percent slopes | 19K | Well drained | D | Very limited | Very limited |
| Ottumwa-Razor silty clays, 6 to 9 percent slopes | 18K | Well drained | C | Very limited | Very limited |
What This Means
Building & Foundations
About 94% 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.