Sauk County, Wisconsin
The most common soil here is La Farge, on about 9% of the land: a silt loam, smooth, like flour. Valton and Norden come next.
About 72% of the land drains well, and 16% stays wet for long stretches; groundwater comes within two feet of the surface under 13% 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: 11% of the land floods occasionally or more, and bedrock lies within 40 inches under 34% 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 Sauk 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 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 Sauk 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 |
|---|---|---|---|---|---|
| La Farge silt loam, 12 to 20 percent slopes, eroded | 31K | Well drained | C | Very limited | Very limited |
| Dorerton, very stony-Elbaville complex, 30 to 60 percent slopes | 30K | Well drained | B | Very limited | Very limited |
| Valton silt loam, 6 to 12 percent slopes, moderately eroded | 23K | Well drained | C | Somewhat limited | Very limited |
| Valton silt loam, 12 to 20 percent slopes, moderately eroded | 19K | Well drained | C | Very limited | Very limited |
| Norden loam, 20 to 30 percent slopes | 17K | Well drained | C | Very limited | Very limited |
| Ettrick silt loam, 0 to 2 percent slopes, frequently flooded | 15K | Poorly drained | C/D | Very limited | Very limited |
| La Farge silt loam, 20 to 30 percent slopes | 12K | Well drained | C | Very limited | Very limited |
| La Farge silt loam, 6 to 12 percent slopes, eroded | 12K | Well drained | C | Somewhat limited | Very limited |
| Baraboo stony silt loam, 2 to 12 percent slopes | 12K | Moderately well drained | C | Very limited | Very limited |
| Valton silt loam, 2 to 6 percent slopes, moderately eroded | 11K | Well drained | C | Somewhat limited | Very limited |
| Gaphill-Rockbluff complex, 30 to 60 percent slopes | 11K | Well drained | A | Very limited | Very limited |
| Algansee-Kalmarville complex, river valleys, 0 to 3 percent slopes, frequently flooded | 9K | Somewhat poorly drained | A/D | Very limited | Very limited |
| Dickinson sandy loam, 1 to 6 percent slopes | 9K | Somewhat excessively drained | A | Not limited | Very limited |
| Curran silt loam, 0 to 3 percent slopes, rarely flooded | 9K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Norden silt loam, 30 to 45 percent slopes | 9K | Well drained | C | Very limited | Very limited |
| Seaton silt loam, driftless valley, 6 to 12 percent slopes, moderately eroded | 9K | Well drained | B | Somewhat limited | Somewhat limited |
| Water | 9K | Not rated | Not rated | ||
| Gotham loamy sand, 2 to 6 percent slopes | 9K | Somewhat excessively drained | A | Not limited | Very limited |
| Baraboo stony silt loam, 12 to 30 percent slopes | 8K | Moderately well drained | C | Very limited | Very limited |
| Hixton silt loam, 12 to 20 percent slopes, moderately eroded | 8K | Well drained | C | 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 58% 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 95% 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
Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.