Story County, Iowa
The dominant drainage class is Poorly drained and the dominant hydrologic group is C/D (varies with drainage). 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 Story County, Iowa.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Clarion loam, Bemis moraine, 2 to 6 percent slopes | 74K | Well drained | B | Somewhat limited | Somewhat limited |
| Webster clay loam, Bemis moraine, 0 to 2 percent slopes | 59K | Poorly drained | C/D | Very limited | Very limited |
| Nicollet loam, 1 to 3 percent slopes | 46K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Canisteo clay loam, Bemis moraine, 0 to 2 percent slopes | 29K | Poorly drained | C/D | Very limited | Very limited |
| Clarion loam, Bemis moraine, 6 to 10 percent slopes, moderately eroded | 16K | Well drained | B | Somewhat limited | Somewhat limited |
| Harps clay loam, Bemis moraine, 0 to 2 percent slopes | 12K | Poorly drained | C/D | Very limited | Very limited |
| Coland clay loam, 0 to 2 percent slopes, occasionally flooded | 11K | Poorly drained | C/D | Very limited | Very limited |
| Clarion loam, 2 to 6 percent slopes | 10K | Moderately well drained | C | Somewhat limited | Very limited |
| Webster clay loam, 0 to 2 percent slopes | 7K | Poorly drained | C/D | Very limited | Very limited |
| Kossuth silty clay loam, 0 to 2 percent slopes | 6K | Poorly drained | C/D | Very limited | Very limited |
| Spillville loam, 0 to 2 percent slopes, occasionally flooded | 5K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Nicollet clay loam, 1 to 3 percent slopes | 5K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Okoboji silty clay loam, 0 to 1 percent slopes | 5K | Very poorly drained | C/D | Very limited | Very limited |
| Canisteo clay loam, 0 to 2 percent slopes | 5K | Poorly drained | C/D | Very limited | Very limited |
| Coland-Terril complex, 1 to 5 percent slopes | 4K | Poorly drained | C/D | Very limited | Very limited |
| Clarion-Storden complex, Bemis moraine, 6 to 10 percent slopes, moderately eroded | 3K | Well drained | B | Somewhat limited | Somewhat limited |
| Spillville-Coland complex, channeled, 0 to 2 percent slopes | 3K | Moderately well drained | B/D | Very limited | Very limited |
| Zook silty clay loam, 0 to 2 percent slopes, occasionally flooded | 3K | Poorly drained | C/D | Very limited | Very limited |
| Terril loam, 2 to 6 percent slopes | 2K | Well drained | B | Somewhat limited | Very limited |
| Hayden-Storden loams, 25 to 50 percent slopes | 2K | Well drained | B | Very limited | Very limited |
What This Means
Building & Foundations
About 65% 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 70% of soils are rated "very limited" for septic absorption fields. Poorly drained soils can't absorb septic effluent effectively. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Many soils hold water for extended periods. Raised beds are highly recommended to improve drainage for vegetables. Well-adapted native plants and water-loving species will do best in natural conditions.