Sanborn County, South Dakota
The most common soil here is Clarno, on about 18% of the land: a loam, a balanced mix that crumbles in your hand. Tetonka and Houdek come next.
About 54% of the land drains well, and 30% stays wet for long stretches; groundwater comes within two feet of the surface under 24% of it.
USDA rates 98% of the land very limited for a standard septic drain field, and 28% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 4% 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 Sanborn 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 B (moderate infiltration). 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 Sanborn 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 |
|---|---|---|---|---|---|
| Clarno-Bonilla loams, 0 to 2 percent slopes | 36K | Well drained | B | Not limited | Very limited |
| Clarno-Bonilla loams, 1 to 6 percent slopes | 26K | Well drained | B | Not limited | Very limited |
| Clarno-Ethan-Bonilla loams, 1 to 6 percent slopes | 26K | Well drained | B | Not limited | Very limited |
| Houdek-Stickney complex, 0 to 2 percent slopes | 22K | Well drained | C | Somewhat limited | Very limited |
| Tetonka silt loam, 0 to 1 percent slopes | 22K | Poorly drained | C/D | Very limited | Very limited |
| Tetonka-Davison-Clarno complex, 0 to 2 percent slopes | 16K | Poorly drained | C/D | Somewhat limited | Very limited |
| Carthage-Hand fine sandy loams, 2 to 6 percent slopes | 15K | Moderately well drained | C | Not limited | Very limited |
| Hand-Ethan loams, 2 to 6 percent slopes | 14K | Well drained | B | Not limited | Very limited |
| Durrstein silt loam | 14K | Poorly drained | C/D | Very limited | Very limited |
| Ethan-Clarno loams, 6 to 9 percent slopes | 12K | Well drained | C | Not limited | Very limited |
| Houdek-Dudley complex, 2 to 6 percent slopes | 9K | Well drained | C | Somewhat limited | Very limited |
| Carthage-Clarno fine sandy loams, 0 to 2 percent slopes | 9K | Moderately well drained | C | Somewhat limited | Very limited |
| Worthing silty clay loam, ponded, 0 to 1 percent slopes | 8K | Very poorly drained | C/D | Very limited | Very limited |
| Shue-Davison loamy fine sands | 8K | Somewhat poorly drained | A | Very limited | Very limited |
| Clarno-Dudley complex, 2 to 6 percent slopes | 7K | Well drained | B | Somewhat limited | Very limited |
| Houdek-Prosper loams, 0 to 2 percent slopes | 7K | Well drained | C | Somewhat limited | Very limited |
| Elsmere loamy fine sand, loamy substratum | 6K | Somewhat poorly drained | A | Very limited | Very limited |
| Forestburg-Ethan loamy fine sands, 2 to 6 percent slopes | 6K | Moderately well drained | A | Somewhat limited | Very limited |
| Houdek-Prosper loams, 1 to 6 percent slopes | 5K | Well drained | C | Somewhat limited | Very limited |
| Houdek-Ethan loams, 2 to 6 percent slopes | 5K | 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
About 28% 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.