Story County, Iowa
The most common soil here is Clarion, on about 27% of the land: a loam, a balanced mix that crumbles in your hand. Webster and Nicollet come next.
About 36% of the land drains well, and 58% stays wet for long stretches; groundwater comes within two feet of the surface under 59% of it.
USDA rates 70% of the land very limited for a standard septic drain field, and 62% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 8% of the land floods occasionally or more.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Story County, Iowa, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Poorly drained and the dominant hydrologic group is C/D (varies with drainage). The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. 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. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| 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 |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 62% 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.