Black Hawk County, Iowa
The most common soil here is Kenyon, on about 11% of the land: a loam, a balanced mix that crumbles in your hand. Clyde and Marquis come next.
About 20% of the land drains well, and 50% stays wet for long stretches; groundwater comes within two feet of the surface under 50% of it.
USDA rates 95% of the land very limited for a standard septic drain field, and 58% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 12% 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 Black Hawk 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 Black Hawk 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 |
|---|---|---|---|---|---|
| Clyde-Floyd complex, 1 to 4 percent slopes | 32K | Poorly drained | C/D | Very limited | Very limited |
| Kenyon loam, 2 to 5 percent slopes | 29K | Moderately well drained | C | Somewhat limited | Very limited |
| Marquis loam, 2 to 5 percent slopes | 24K | Moderately well drained | C | Very limited | Very limited |
| Readlyn silt loam, 1 to 3 percent slopes | 18K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Dinsdale silty clay loam, 2 to 5 percent slopes | 18K | Moderately well drained | C | Somewhat limited | Very limited |
| Spillville-Coland-Shandep complex, 0 to 2 percent slopes, frequently flooded | 17K | Poorly drained | C/D | Very limited | Very limited |
| Clyde silty clay loam, 0 to 3 percent slopes | 12K | Poorly drained | C/D | Very limited | Very limited |
| Klinger silty clay loam, 1 to 4 percent slopes | 11K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Marshan clay loam, 0 to 2 percent slopes, rarely flooded | 9K | Poorly drained | C/D | Very limited | Very limited |
| Tripoli clay loam, 0 to 2 percent slopes | 9K | Poorly drained | C/D | Very limited | Very limited |
| Sawmill silty clay loam, shallow loess, 0 to 2 percent slopes, occasionally flooded | 9K | Poorly drained | C/D | Very limited | Very limited |
| Sparta loamy sand, 2 to 5 percent slopes | 8K | Excessively drained | A | Not limited | Very limited |
| Saude loam, 0 to 2 percent slopes | 7K | Well drained | B | Not limited | Very limited |
| Maxfield silty clay loam, 0 to 2 percent slopes | 7K | Poorly drained | C/D | Very limited | Very limited |
| Dinsmore silty clay loam, 2 to 5 percent slopes | 6K | Moderately well drained | C | Somewhat limited | Very limited |
| Finchford-Urban land complex, 0 to 2 percent slopes | 6K | Excessively drained | A | Not limited | Very limited |
| Colo-Ely complex, 0 to 5 percent slopes | 6K | Poorly drained | C/D | Very limited | Very limited |
| Coland-Spillville complex, 0 to 2 percent slopes, occasionally flooded | 6K | Poorly drained | C/D | Very limited | Very limited |
| Flagler sandy loam, 0 to 2 percent slopes | 5K | Somewhat excessively drained | A | Not limited | Very limited |
| Waukee loam, 0 to 2 percent slopes | 5K | Well drained | B | Not 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 58% 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 95% 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.