Union 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 Union County, Iowa.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Colo, occasionally flooded-Ely silty clay loams, dissected till plain, 2 to 5 percent slopes | 31K | Poorly drained | C/D | Very limited | Very limited |
| Sharpsburg silty clay loam, 2 to 5 percent slopes | 26K | Moderately well drained | C | Somewhat limited | Very limited |
| Nira-Sharpsburg silty clay loams, 5 to 9 percent slopes | 23K | Moderately well drained | C | Very limited | Very limited |
| Shelby clay loam, dissected till plain, 9 to 14 percent slopes, eroded | 11K | Well drained | C | Somewhat limited | Very limited |
| Shelby-Adair clay loams, dissected till plain, 9 to 14 percent slopes, eroded | 11K | Well drained | C | Somewhat limited | Very limited |
| Clarinda silty clay loam, 5 to 9 percent slopes, moderately eroded | 9K | Poorly drained | D | Very limited | Very limited |
| Clearfield silty clay loam, dissected till plain, 5 to 9 percent slopes | 7K | Poorly drained | C/D | Very limited | Very limited |
| Macksburg silty clay loam, 0 to 2 percent slopes | 6K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Sharpsburg silty clay loam, 5 to 9 percent slopes | 6K | Moderately well drained | C | Somewhat limited | Very limited |
| Nodaway-Vesser silt loams, 2 to 5 percent slopes | 6K | Moderately well drained | B | Very limited | Very limited |
| Clarinda silty clay loam, 5 to 9 percent slopes | 6K | Poorly drained | D | Very limited | Very limited |
| Ladoga silt loam, dissected till plain, 5 to 9 percent slopes | 5K | Moderately well drained | C | Very limited | Very limited |
| Arispe silty clay loam, 5 to 9 percent slopes | 5K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Pershing silt loam, 5 to 9 percent slopes | 5K | Somewhat poorly drained | D | Very limited | Very limited |
| Water | 4K | Not rated | Not rated | ||
| Dockery-Quiver silt loams, 0 to 2 percent slopes, occasionally flooded | 4K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Nodaway silt loam, heavy till, 0 to 2 percent slopes, occasionally flooded | 4K | Moderately well drained | B | Very limited | Very limited |
| Adair clay loam, dissected till plain, 5 to 9 percent slopes, eroded | 4K | Somewhat poorly drained | D | Very limited | Very limited |
| Grundy silty clay loam, 2 to 5 percent slopes | 3K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Macksburg silty clay loam, 2 to 5 percent slopes | 3K | Somewhat poorly drained | C/D | Very limited | Very limited |
What This Means
Building & Foundations
About 67% of soils are rated "very limited" for dwellings with basements. Specific challenges include 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.