Day County, South Dakota
The most common soil here is Forman, on about 15% of the land: a clay loam, firm and a little sticky. Buse and Aastad come next.
About 73% of the land drains well, and 21% stays wet for long stretches; groundwater comes within two feet of the surface under 21% of it.
USDA rates 96% of the land very limited for a standard septic drain field, and 31% 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 Day 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 Day 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 |
|---|---|---|---|---|---|
| Forman-Buse-Aastad loams, 1 to 6 percent slopes | 105K | Well drained | C | Somewhat limited | Very limited |
| Forman-Buse-Aastad loams, 2 to 9 percent slopes | 101K | Well drained | C | Somewhat limited | Very limited |
| Buse-Barnes loams, 9 to 20 percent slopes | 48K | Well drained | C | Very limited | Very limited |
| Southam silty clay loam, 0 to 1 percent slopes | 43K | Very poorly drained | C/D | Very limited | Very limited |
| Kranzburg-Brookings silt loams, 0 to 2 percent slopes | 32K | Well drained | C | Somewhat limited | Very limited |
| Water | 24K | Not rated | Not rated | ||
| Oldham silty clay loam | 21K | Very poorly drained | C/D | Very limited | Very limited |
| Parnell silty clay loam | 19K | Very poorly drained | C/D | Very limited | Very limited |
| Poinsett-Rusklyn-Waubay silty clay loams, 1 to 6 percent slopes | 18K | Well drained | C | Somewhat limited | Very limited |
| Kranzburg-Forman complex, 2 to 6 percent slopes | 18K | Well drained | C | Somewhat limited | Very limited |
| Renshaw-Sioux complex, 2 to 6 percent slopes | 17K | Somewhat excessively drained | B | Not limited | Very limited |
| Poinsett-Waubay silty clay loams, 1 to 6 percent slopes | 13K | Well drained | C | Somewhat limited | Very limited |
| Kranzburg-Brookings-Buse complex, 0 to 6 percent slopes | 12K | Well drained | C | Somewhat limited | Very limited |
| Forman-Aastad loams, 1 to 6 percent slopes | 10K | Well drained | C | Somewhat limited | Very limited |
| Kranzburg-Buse-Waubay complex, 1 to 6 percent slopes | 10K | Well drained | C | Somewhat limited | Very limited |
| Renshaw-Fordville loams, 2 to 6 percent slopes | 10K | Somewhat excessively drained | B | Not limited | Very limited |
| Forman-Buse-Aastad loams, 1 to 6 percent slopes | 9K | Well drained | C | Somewhat limited | Very limited |
| Hamerly-Parnell complex | 8K | Somewhat poorly drained | C | Somewhat limited | Very limited |
| Sioux-Renshaw complex, coteau, 9 to 15 percent slopes | 8K | Excessively drained | B | Somewhat limited | Very limited |
| Buse-Barnes loams, 9 to 40 percent slopes, very stony | 7K | Well drained | C | Very 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
About 31% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
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
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.