Madison County, Iowa
The dominant drainage class is Moderately 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 Madison County, Iowa.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Sharpsburg silty clay loam, 2 to 5 percent slopes | 37K | Moderately well drained | C | Somewhat limited | Very limited |
| Sharpsburg silty clay loam, 5 to 9 percent slopes, eroded | 31K | Moderately well drained | C | Somewhat limited | Very limited |
| Ladoga silt loam, dissected till plain, 5 to 9 percent slopes, eroded | 23K | Moderately well drained | C | Very limited | Very limited |
| Macksburg silty clay loam, 0 to 2 percent slopes | 21K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Lamoni clay loam, 9 to 14 percent slopes, eroded | 18K | Somewhat poorly drained | D | Very limited | Very limited |
| Gara loam, dissected till plain, 14 to 18 percent slopes, eroded | 15K | Well drained | C | Very limited | Very limited |
| Gara loam, dissected till plain, 18 to 25 percent slopes, eroded | 14K | Well drained | C | Very limited | Very limited |
| Colo, frequently flooded-Ely silty clay loams, gullied, 2 to 5 percent slopes | 14K | Poorly drained | C/D | Very limited | Very limited |
| Zook silty clay loam, 0 to 2 percent slopes, occasionally flooded | 9K | Poorly drained | D | Very limited | Very limited |
| Shelby-Lamoni complex, 9 to 14 percent slopes, eroded | 9K | Well drained | D | Very limited | Very limited |
| Macksburg silty clay loam, 2 to 5 percent slopes | 9K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Shelby-Lamoni complex, 14 to 18 percent slopes, eroded | 8K | Well drained | C | Very limited | Very limited |
| Ladoga silt loam, 9 to 14 percent slopes, eroded | 8K | Moderately well drained | C | Very limited | Very limited |
| Sharpsburg silty clay loam, 5 to 9 percent slopes | 8K | Moderately well drained | C | Somewhat limited | Very limited |
| Colo, occasionally flooded-Ely silty clay loams, dissected till plain, 2 to 5 percent slopes | 7K | Poorly drained | C/D | Very limited | Very limited |
| Shelby clay loam, dissected till plain, 14 to 18 percent slopes, eroded | 7K | Well drained | C | Very limited | Very limited |
| Ladoga silt loam, 2 to 5 percent slopes | 7K | Moderately well drained | C | Very limited | Very limited |
| Steep rock land | 6K | Not rated | Not rated | ||
| Clinton silt loam, 5 to 9 percent slopes, eroded | 5K | Moderately well drained | C | Somewhat limited | Very limited |
| Winterset silty clay loam, 0 to 2 percent slopes | 4K | Poorly drained | D | Very limited | Very limited |
What This Means
Building & Foundations
About 66% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
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.