Warren County, Iowa
The most common soil here is Sharpsburg, on about 12% of the land: a silty clay loam, smooth and slightly sticky. Ladoga and Gara come next.
About 20% of the land drains well, and 46% stays wet for long stretches; groundwater comes within two feet of the surface under 51% of it.
USDA rates 99% of the land very limited for a standard septic drain field, and 72% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 20% of the land floods occasionally or more, and bedrock lies within 40 inches under 2% of it.
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 Warren 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 Somewhat poorly drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). The most common soil order is Alfisols — moderately leached forest soils with a clay-enriched subsoil. 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 Warren 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 |
|---|---|---|---|---|---|
| Sharpsburg silty clay loam, 5 to 9 percent slopes, eroded | 22K | Moderately well drained | C | Somewhat limited | Very limited |
| Ladoga silt loam, dissected till plain, 5 to 9 percent slopes, eroded | 19K | Moderately well drained | C | Very limited | Very limited |
| Zook silty clay loam, 0 to 2 percent slopes, occasionally flooded | 19K | Poorly drained | D | Very limited | Very limited |
| Sharpsburg silty clay loam, 2 to 5 percent slopes | 18K | Moderately well drained | C | Somewhat limited | Very limited |
| Lamoni silty clay loam, 9 to 14 percent slopes, eroded | 12K | Somewhat poorly drained | D | Very limited | Very limited |
| Gullied land-Ely-Colo, occasionally flooded, complex, 2 to 5 percent slopes | 10K | Well drained | B | Not rated | Very limited |
| Gara loam, dissected till plain, 14 to 18 percent slopes, eroded | 8K | Well drained | C | Very limited | Very limited |
| Armstrong-Gara loams, 14 to 18 percent slopes, moderately eroded | 8K | Somewhat poorly drained | D | Very limited | Very limited |
| Colo silty clay loam, dissected till plain, 2 to 5 percent slopes, occasionally flooded | 8K | Poorly drained | C/D | Very limited | Very limited |
| Armstrong-Gara loams, 9 to 14 percent slopes, moderately eroded | 7K | Somewhat poorly drained | D | Very limited | Very limited |
| Grundy silty clay loam, 2 to 5 percent slopes | 7K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Macksburg silty clay loam, 2 to 5 percent slopes | 7K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Macksburg silty clay loam, 0 to 2 percent slopes | 7K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Gara loam, dissected till plain, 18 to 25 percent slopes, eroded | 7K | Well drained | C | Very limited | Very limited |
| Arispe silty clay loam, 5 to 9 percent slopes, moderately eroded | 6K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Dockery-Quiver silt loams, 0 to 2 percent slopes, occasionally flooded | 6K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Munterville silt loam, 18 to 35 percent slopes | 6K | Moderately well drained | D | Very limited | Very limited |
| Colo, occasionally flooded-Ely silty clay loams, dissected till plain, 2 to 5 percent slopes | 6K | Poorly drained | C/D | Very limited | Very limited |
| Shelby-Adair clay loams, dissected till plain, 9 to 14 percent slopes, eroded | 6K | Well drained | C | Somewhat limited | Very limited |
| Pershing silt loam, 5 to 9 percent slopes, moderately eroded | 5K | Somewhat poorly drained | D | 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 72% 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 99% 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.