Riley County, Kansas
The most common soil here is Clime, on about 17% of the land: a silty clay, smooth and very sticky when wet. Wymore and Irwin come next.
About 53% of the land drains well.
USDA rates 96% of the land very limited for a standard septic drain field, and 76% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 9% of the land floods occasionally or more, and bedrock lies within 40 inches under 32% of it.
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 Riley County, Kansas, 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 D (very slow infiltration, high 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 Riley County, Kansas. 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 |
|---|---|---|---|---|---|
| Clime-Sogn complex, 3 to 20 percent slopes | 77K | Well drained | D | Somewhat limited | Very limited |
| Wymore silty clay loam, 1 to 3 percent slopes, eroded | 41K | Moderately well drained | D | Very limited | Very limited |
| Benfield-Florence complex, 5 to 30 percent slopes | 31K | Well drained | D | Very limited | Very limited |
| Irwin silty clay loam, 3 to 7 percent slopes, eroded | 28K | Moderately well drained | D | Very limited | Very limited |
| Irwin silty clay loam, 3 to 7 percent slopes | 19K | Moderately well drained | D | Very limited | Very limited |
| Clime silty clay loam, 20 to 40 percent slopes, very stony | 18K | Well drained | D | Very limited | Very limited |
| Dwight-Irwin complex, 1 to 3 percent slopes | 17K | Moderately well drained | D | Very limited | Very limited |
| Dwight-Irwin complex, 1 to 3 percent slopes, eroded | 13K | Moderately well drained | D | Very limited | Very limited |
| Wymore silty clay loam, 1 to 3 percent slopes | 13K | Moderately well drained | D | Very limited | Very limited |
| Ivan and Kennebec silt loams, occasionally flooded | 12K | Well drained | C | Very limited | Very limited |
| Reading silt loam, rarely flooded | 11K | Well drained | C | Very limited | Very limited |
| Wymore-Kennebec complex, 0 to 17 percent slopes | 9K | Moderately well drained | D | Very limited | Very limited |
| Ivan silt loam, channeled | 8K | Well drained | B | Very limited | Very limited |
| Tully silty clay loam, 3 to 7 percent slopes, eroded | 8K | Well drained | C | Very limited | Very limited |
| Crete silty clay loam, 1 to 3 percent slopes | 8K | Moderately well drained | C | Very limited | Very limited |
| Water | 8K | Not rated | Not rated | ||
| Tully silty clay loam, 3 to 7 percent slopes | 7K | Well drained | C | Very limited | Very limited |
| Reading silt loam, 1 to 3 percent slopes | 6K | Well drained | C | Very limited | Very limited |
| Smolan silt loam, 1 to 3 percent slopes | 4K | Moderately well drained | C | Very limited | Very limited |
| Wymore silty clay loam, 3 to 6 percent slopes, eroded | 3K | Moderately well drained | D | 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 76% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
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.