Douglas 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 Douglas County, South Dakota.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Eakin-Ethan complex, 2 to 6 percent slopes | 53K | Well drained | C | Not limited | Very limited |
| Clarno-Ethan-Bonilla loams, 1 to 6 percent slopes | 32K | Well drained | B | Not limited | Very limited |
| Highmore-Walke silt loams, 0 to 2 percent slopes | 28K | Well drained | C | Somewhat limited | Very limited |
| Clarno-Bonilla loams, 0 to 2 percent slopes | 17K | Well drained | B | Not limited | Very limited |
| Onita-Tetonka silt loams | 15K | Moderately well drained | C | Somewhat limited | Very limited |
| Highmore silt loam, 0 to 2 percent slopes | 15K | Well drained | C | Somewhat limited | Very limited |
| Tetonka silt loam, 0 to 1 percent slopes | 14K | Poorly drained | C/D | Very limited | Very limited |
| Clarno-Ethan-Prosper loams, 0 to 3 percent slopes | 10K | Well drained | C | Somewhat limited | Very limited |
| Prosper-Tetonka complex | 9K | Moderately well drained | B | Somewhat limited | Very limited |
| Eakin-Ethan complex, 0 to 3 percent slopes | 8K | Well drained | C | Not limited | Very limited |
| DeGrey-Walke silt loams, 0 to 2 percent slopes | 8K | Moderately well drained | D | Somewhat limited | Not limited |
| Eakin-Ethan complex, 6 to 9 percent slopes | 7K | Well drained | C | Not limited | Very limited |
| Houdek-Stickney complex, 0 to 2 percent slopes | 7K | Well drained | C | Somewhat limited | Very limited |
| Highmore silt loam, 2 to 6 percent slopes | 6K | Well drained | C | Somewhat limited | Very limited |
| Homme-Onita silty clay loams, 0 to 2 percent slopes | 6K | Well drained | C | Somewhat limited | Very limited |
| Clarno-Ethan-Bonilla loams, 2 to 9 percent slopes | 4K | Well drained | B | Not limited | Very limited |
| Bon loam, channeled, 0 to 2 percent slopes, frequently flooded | 4K | Moderately well drained | C | Very limited | Very limited |
| Worthing silty clay loam, 0 to 1 percent slopes | 4K | Very poorly drained | C/D | Very limited | Very limited |
| Delmont-Enet loams, 0 to 2 percent slopes | 3K | Somewhat excessively drained | B | Not limited | Very limited |
| Hoven silt loam, 0 to 1 percent slopes | 3K | Poorly drained | D | 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 96% 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.