Rock County, Wisconsin
The most common soil here is Kidder, on about 10% of the land: a silt loam, smooth, like flour. Plano and Warsaw come next.
About 73% of the land drains well, and 21% stays wet for long stretches; groundwater comes within two feet of the surface under 18% of it.
USDA rates 88% of the land very limited for a standard septic drain field, and 35% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 10% of the land floods occasionally or more, and bedrock lies within 40 inches under 11% 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 Rock County, Wisconsin, 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 Well drained and the dominant hydrologic group is B (moderate infiltration). 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 Rock County, Wisconsin. 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 |
|---|---|---|---|---|---|
| Plano silt loam, gravelly substratum, 0 to 2 percent slopes | 38K | Well drained | B | Somewhat limited | Very limited |
| Kidder silt loam, 2 to 6 percent slopes, eroded | 20K | Well drained | B | Somewhat limited | Very limited |
| Kidder silt loam, 6 to 12 percent slopes, eroded | 18K | Well drained | B | Somewhat limited | Very limited |
| Warsaw silt loam, 0 to 2 percent slopes | 17K | Well drained | B | Somewhat limited | Very limited |
| Sebewa silt loam, 0 to 2 percent slopes | 14K | Poorly drained | B/D | Very limited | Very limited |
| Dresden silt loam, 2 to 6 percent slopes | 14K | Well drained | B | Not limited | Very limited |
| Mahalasville silt loam | 14K | Very poorly drained | B/D | Very limited | Very limited |
| Edmund loam, 6 to 12 percent slopes, eroded | 12K | Well drained | D | Very limited | Very limited |
| St. Charles silt loam, 2 to 6 percent slopes | 11K | Well drained | B | Somewhat limited | Very limited |
| Warsaw silt loam, 2 to 6 percent slopes | 10K | Well drained | B | Somewhat limited | Very limited |
| Durand silt loam, 2 to 6 percent slopes, eroded | 9K | Well drained | B | Somewhat limited | Somewhat limited |
| Elburn silt loam, 0 to 3 percent slopes | 9K | Somewhat poorly drained | C | Very limited | Very limited |
| Pecatonica silt loam, 2 to 6 percent slopes, eroded | 9K | Moderately well drained | B | Somewhat limited | Very limited |
| Ogle silt loam, 2 to 6 percent slopes | 8K | Well drained | B | Somewhat limited | Somewhat limited |
| Rockton loam, 2 to 6 percent slopes | 7K | Well drained | C | Very limited | Very limited |
| Plano silt loam, gravelly substratum, 2 to 6 percent slopes | 7K | Well drained | B | Somewhat limited | Very limited |
| Kane loam, 0 to 3 percent slopes | 7K | Somewhat poorly drained | B | Somewhat limited | Very limited |
| Dresden silt loam, 6 to 12 percent slopes, eroded | 6K | Well drained | B | Somewhat limited | Very limited |
| Plano silt loam, till substratum, 2 to 6 percent slopes | 6K | Well drained | B | Somewhat limited | Very limited |
| Griswold loam, 2 to 6 percent slopes, eroded | 6K | 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 35% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 88% 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.