Aurora County, South Dakota
The most common soil here is Houdek, on about 28% of the land: a loam, a balanced mix that crumbles in your hand. Dudley and Ethan come next.
About 74% of the land drains well, and 16% stays wet for long stretches; groundwater comes within two feet of the surface under 18% of it.
USDA rates 94% of the land very limited for a standard septic drain field, and 20% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 3% of the land floods occasionally or more.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Aurora County, South Dakota, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. 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 Aurora County, South Dakota. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Houdek-Dudley complex, 0 to 2 percent slopes | 104K | Well drained | C | Somewhat limited | Very limited |
| Houdek-Ethan loams, 2 to 6 percent slopes | 48K | Well drained | C | Somewhat limited | Very limited |
| Houdek-Prosper loams, 0 to 2 percent slopes | 37K | Well drained | C | Somewhat limited | Very limited |
| Hoven-Plankinton silt loams | 25K | Poorly drained | D | Very limited | Very limited |
| Dudley-Jerauld silt loams, 0 to 2 percent slopes | 23K | Moderately well drained | D | Somewhat limited | Not limited |
| Houdek-Dudley complex, 2 to 6 percent slopes | 19K | Well drained | C | Somewhat limited | Very limited |
| Clarno-Bonilla loams, 0 to 2 percent slopes | 18K | Well drained | B | Not limited | Very limited |
| Houdek-Ethan loams, 6 to 9 percent slopes | 16K | Well drained | C | Somewhat limited | Very limited |
| Plankinton-Prosper complex | 14K | Poorly drained | C/D | Very limited | Very limited |
| Beadle-Jerauld-Dudley complex, 0 to 6 percent slopes | 14K | Well drained | C | Somewhat limited | Very limited |
| Delmont-Enet loams, 2 to 6 percent slopes | 10K | Somewhat excessively drained | B | Not limited | Very limited |
| Highmore-Mobridge silt loams, 0 to 2 percent slopes | 10K | Well drained | C | Somewhat limited | Very limited |
| Eakin-Ethan complex, 2 to 6 percent slopes | 10K | Well drained | C | Not limited | Very limited |
| DeGrey-Onita silt loams, 0 to 2 percent slopes | 9K | Moderately well drained | C | Very limited | Very limited |
| Hoven silt loam, 0 to 1 percent slopes | 9K | Poorly drained | D | Very limited | Very limited |
| Clarno loam, 2 to 6 percent slopes | 8K | Well drained | B | Not limited | Very limited |
| Durrstein silt loam | 7K | Poorly drained | C/D | Very limited | Very limited |
| Eakin-DeGrey silt loams, 0 to 2 percent slopes | 6K | Well drained | C | Not limited | Very limited |
| Bon loam, channeled, 0 to 2 percent slopes, frequently flooded | 6K | Moderately well drained | C | Very limited | Very limited |
| Houdek-Hoven complex, 0 to 3 percent slopes | 6K | Well drained | C | Somewhat limited | Very limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
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 94% 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.