Carroll 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 Carroll County, Iowa.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Colo-Judson silty clay loams, 0 to 5 percent slopes, occasionally flooded | 40K | Poorly drained | C/D | Very limited | Very limited |
| Clarion loam, Bemis moraine, 2 to 6 percent slopes | 28K | Well drained | B | Somewhat limited | Somewhat limited |
| Nicollet loam, 1 to 3 percent slopes | 28K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Marshall silty clay loam, 5 to 9 percent slopes, eroded | 26K | Well drained | C | Somewhat limited | Very limited |
| Marshall silty clay loam, 2 to 5 percent slopes, eroded | 20K | Well drained | C | Somewhat limited | Very limited |
| Marshall silty clay loam, 9 to 14 percent slopes, eroded | 20K | Well drained | C | Somewhat limited | Very limited |
| Clarion loam, Bemis moraine, 6 to 10 percent slopes, moderately eroded | 18K | Well drained | B | Somewhat limited | Somewhat limited |
| Exira silty clay loam, 5 to 9 percent slopes, eroded | 18K | Well drained | C | Somewhat limited | Very limited |
| Exira silty clay loam, 9 to 14 percent slopes, eroded | 18K | Well drained | C | Somewhat limited | Very limited |
| Webster clay loam, Bemis moraine, 0 to 2 percent slopes | 17K | Poorly drained | C/D | Very limited | Very limited |
| Canisteo clay loam, Bemis moraine, 0 to 2 percent slopes | 14K | Poorly drained | C/D | Very limited | Very limited |
| Marshall silty clay loam, 2 to 5 percent slopes | 10K | Well drained | C | Somewhat limited | Very limited |
| Colo silt loam, deep loess, 0 to 2 percent slopes, overwash, occasionally flooded | 9K | Poorly drained | C/D | Very limited | Very limited |
| Clarion loam, Bemis moraine, 2 to 6 percent slopes, moderately eroded | 9K | Well drained | B | Somewhat limited | Somewhat limited |
| Ackmore silt loam, 0 to 2 percent slopes, occasionally flooded | 6K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Calco silty clay loam, 0 to 2 percent slopes, occasionaly flooded | 5K | Poorly drained | C/D | Very limited | Very limited |
| Coland clay loam, 0 to 2 percent slopes, occasionally flooded | 5K | Poorly drained | C/D | Very limited | Very limited |
| Colo silty clay loam, deep loess, 0 to 2 percent slopes, occasionally flooded | 5K | Poorly drained | C/D | Very limited | Very limited |
| Okoboji silty clay loam, 0 to 1 percent slopes | 4K | Very poorly drained | C/D | Very limited | Very limited |
| Coland-Spillville complex, 2 to 5 percent slopes | 4K | Poorly drained | C/D | Very limited | Very limited |
What This Means
Building & Foundations
About 45% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 82% 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.