Washington 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 Washington County, Iowa.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Mahaska silty clay loam, 0 to 2 percent slopes | 31K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Taintor silty clay loam, 0 to 2 percent slopes | 24K | Poorly drained | D | Very limited | Very limited |
| Otley silty clay loam, 2 to 5 percent slopes | 18K | Moderately well drained | C | Very limited | Very limited |
| Clinton silt loam, 5 to 9 percent slopes, eroded | 15K | Moderately well drained | C | Somewhat limited | Very limited |
| Nira silty clay loam, 2 to 5 percent slopes | 13K | Moderately well drained | C | Very limited | Very limited |
| Otley silty clay loam, 5 to 9 percent slopes, eroded | 12K | Moderately well drained | C | Very limited | Very limited |
| Ladoga silt loam, 5 to 9 percent slopes, eroded | 10K | Moderately well drained | C | Somewhat limited | Very limited |
| Kalona silty clay loam, 0 to 2 percent slopes | 10K | Poorly drained | C/D | Very limited | Very limited |
| Ladoga silt loam, 2 to 5 percent slopes | 10K | Moderately well drained | C | Somewhat limited | Very limited |
| Clinton silt loam, 9 to 14 percent slopes, eroded | 10K | Moderately well drained | C | Somewhat limited | Very limited |
| Colo-Zook silty clay loams, 0 to 3 percent slopes | 9K | Poorly drained | C/D | Very limited | Very limited |
| Clinton silt loam, 2 to 5 percent slopes | 9K | Moderately well drained | C | Somewhat limited | Very limited |
| Nodaway silt loam, shallow loess, 0 to 2 percent slopes, occasionally flooded | 8K | Moderately well drained | B | Very limited | Very limited |
| Clinton silty clay loam, 9 to 14 percent slopes, severely eroded | 7K | Moderately well drained | C | Somewhat limited | Very limited |
| Givin silt loam, 0 to 2 percent slopes | 5K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Ackmore-Nodaway silt loams, 2 to 5 percent slopes | 5K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Hedrick silt loam, 5 to 9 percent slopes, moderately eroded | 5K | Moderately well drained | C | Very limited | Very limited |
| Lawson silt loam, 0 to 2 percent slopes, occasionally flooded | 5K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Gara-Armstrong complex, 9 to 14 percent slopes, moderately eroded | 4K | Well drained | C | Somewhat limited | Very limited |
| Tuskeego silt loam, 0 to 2 percent slopes | 4K | Poorly drained | C/D | Very limited | Very limited |
What This Means
Building & Foundations
About 69% 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 100% 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.