Clay 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 Clay County, South Dakota.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Egan-Chancellor-Davison complex, 0 to 3 percent slopes | 25K | Well drained | C | Somewhat limited | Very limited |
| Egan-Ethan-Trent complex, 1 to 6 percent slopes | 19K | Well drained | C | Somewhat limited | Very limited |
| Egan-Clarno-Chancellor complex, 0 to 3 percent slopes | 17K | Well drained | C | Somewhat limited | Very limited |
| Luton silty clay, 0 to 2 percent slopes, rarely flooded | 16K | Poorly drained | D | Very limited | Very limited |
| Egan-Clarno-Trent complex, 0 to 2 percent slopes | 13K | Well drained | C | Somewhat limited | Very limited |
| Davison-Tetonka-Egan complex, 0 to 3 percent slopes | 11K | Moderately well drained | C | Somewhat limited | Very limited |
| Egan-Clarno-Tetonka complex, 0 to 2 percent slopes | 10K | Well drained | C | Somewhat limited | Very limited |
| Egan-Trent silty clay loams, 0 to 2 percent slopes | 10K | Well drained | C | Somewhat limited | Very limited |
| Blencoe silty clay, 0 to 2 percent slopes, clayey substratum | 10K | Somewhat poorly drained | C | Very limited | Very limited |
| Egan-Ethan-Tetonka complex, 0 to 6 percent slopes | 7K | Well drained | C | Somewhat limited | Very limited |
| Wakonda-Wentworth-Whitewood complex, 0 to 2 percent slopes | 7K | Moderately well drained | C | Very limited | Very limited |
| Egan-Clarno-Trent complex, 1 to 6 percent slopes | 6K | Well drained | C | Somewhat limited | Very limited |
| Baltic silty clay loam, 0 to 2 percent slopes, occasionally flooded | 5K | Poorly drained | C/D | Very limited | Very limited |
| Trent-Tetonka-Wakonda complex, 0 to 3 percent slopes | 4K | Moderately well drained | B | Very limited | Very limited |
| Owego silty clay, 0 to 2 percent slopes | 4K | Poorly drained | D | Very limited | Very limited |
| Egan-Trent-Chancellor silty clay loams, 0 to 2 percent slopes | 4K | Well drained | C | Somewhat limited | Very limited |
| Wentworth-Trent complex, 0 to 2 percent slopes | 3K | Well drained | C | Somewhat limited | Very limited |
| Blyburg silt loam, 0 to 2 percent slopes | 3K | Well drained | B | Very limited | Somewhat limited |
| Onawa silty clay, 0 to 2 percent slopes | 3K | Somewhat poorly drained | C | Very limited | Very limited |
| Albaton silty clay, 0 to 2 percent slopes | 3K | Poorly drained | D | Very limited | Very limited |
What This Means
Building & Foundations
About 30% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 98% 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
Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.