Dubuque 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 Dubuque County, Iowa.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Fayette silt loam, 9 to 14 percent slopes, moderately eroded | 48K | Well drained | C | Somewhat limited | Very limited |
| Downs silt loam, 5 to 9 percent slopes, moderately eroded | 28K | Well drained | C | Somewhat limited | Very limited |
| Downs silt loam, 9 to 14 percent slopes, moderately eroded | 27K | Well drained | C | Somewhat limited | Very limited |
| Fayette silt loam, 5 to 9 percent slopes, moderately eroded | 22K | Well drained | C | Somewhat limited | Very limited |
| Nordness-Rock outcrop complex, 18 to 60 percent slopes | 21K | Well drained | D | Very limited | Very limited |
| Nordness silt loam, 18 to 35 percent slopes | 15K | Well drained | D | Very limited | Very limited |
| Arenzville-Chaseburg complex, 1 to 5 percent slopes | 13K | Moderately well drained | B | Very limited | Very limited |
| Rozetta-Eleroy silt loams, 9 to 14 percent slopes, moderately eroded | 12K | Moderately well drained | B | Somewhat limited | Somewhat limited |
| Rozetta-Eleroy silt loams, 14 to 18 percent slopes, moderately eroded | 9K | Moderately well drained | B | Very limited | Very limited |
| Fayette silt loam, 9 to 14 percent slopes | 9K | Well drained | C | Somewhat limited | Very limited |
| Fayette silt loam, 14 to 18 percent slopes, moderately eroded | 7K | Well drained | C | Very limited | Very limited |
| Tama silt loam, driftless, 5 to 9 percent slopes | 7K | Well drained | C | Somewhat limited | Very limited |
| Newvienna silt loam, 9 to 14 percent slopes, moderately eroded | 6K | Moderately well drained | B | Somewhat limited | Somewhat limited |
| Schapville silt loam, 18 to 30 percent slopes | 6K | Moderately well drained | C | Very limited | Very limited |
| Nordness silt loam, 9 to 18 percent slopes | 6K | Well drained | D | Very limited | Very limited |
| Fayette silt loam, 18 to 25 percent slopes | 6K | Well drained | C | Very limited | Very limited |
| Water | 6K | Not rated | Not rated | ||
| Chaseburg silt loam, moderately well drained, 0 to 2 percent slopes | 5K | Moderately well drained | B | Very limited | Very limited |
| Arenzville silt loam, 0 to 3 percent slopes, occasionally flooded | 5K | Moderately well drained | B | Very limited | Very limited |
| Fayette silt loam, 5 to 9 percent slopes | 4K | Well drained | C | Somewhat limited | Very limited |
What This Means
Building & Foundations
About 35% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 90% 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.