Clayton County, Iowa
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 Clayton County, Iowa.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Fayette silt loam, 9 to 14 percent slopes, moderately eroded | 69K | Well drained | C | Somewhat limited | Very limited |
| Fayette silt loam, 14 to 18 percent slopes, moderately eroded | 39K | Well drained | C | Very limited | Very limited |
| Rock outcrop-Nordness complex, 25 to 60 percent slopes | 38K | Well drained | Very limited | Very limited | |
| Nordness silt loam, 14 to 25 percent slopes | 29K | Well drained | D | Very limited | Very limited |
| Downs silt loam, 5 to 9 percent slopes, moderately eroded | 29K | Well drained | C | Somewhat limited | Very limited |
| Downs silt loam, 9 to 14 percent slopes, moderately eroded | 26K | Well drained | C | Somewhat limited | Very limited |
| Fayette silt loam, 5 to 9 percent slopes, moderately eroded | 24K | Well drained | C | Somewhat limited | Very limited |
| Fayette-Dubuque silt loams, 18 to 30 percent slopes | 13K | Well drained | C | Very limited | Very limited |
| Fayette silt loam, 14 to 18 percent slopes | 12K | Well drained | C | Very limited | Very limited |
| Fayette silt loam, 5 to 9 percent slopes | 11K | Well drained | C | Somewhat limited | Very limited |
| Water | 11K | Not rated | Not rated | ||
| Fayette silt loam, 18 to 25 percent slopes | 11K | Well drained | C | Very limited | Very limited |
| Dubuque silt loam, 14 to 18 percent slopes, moderately eroded | 9K | Well drained | C | Very limited | Very limited |
| Fayette silt loam, 9 to 14 percent slopes | 9K | Well drained | C | Somewhat limited | Very limited |
| Dorchester silt loam, 0 to 2 percent slopes | 9K | Moderately well drained | B | Very limited | Very limited |
| Otter-Worthen silt loams, 1 to 4 percent slopes | 9K | Poorly drained | B/D | Very limited | Very limited |
| Dorchester-Volney complex, 1 to 5 percent slopes | 8K | Moderately well drained | B | Very limited | Very limited |
| Downs silt loam, 2 to 6 percent slopes | 8K | Well drained | C | Somewhat limited | Very limited |
| Fayette silt loam, 18 to 25 percent slopes, moderately eroded | 7K | Well drained | C | Very limited | Very limited |
| Caneek silt loam, 0 to 2 percent slopes | 6K | Poorly drained | B/D | Very limited | Very limited |
What This Means
Building & Foundations
About 50% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 97% 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.