Central Sierra Foothills Area, California, Parts of Calaveras and Tuolumne Counties
The most common soil here is Loafercreek, on about 11% of the land: a gravelly loam, a balanced mix that crumbles in your hand. Nedsgulch and Bonanza come next.
About 93% of the land drains well; groundwater comes within two feet of the surface under 4% of it.
USDA rates 95% of the land very limited for a standard septic drain field, and 88% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: bedrock lies within 40 inches under 84% 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 Central Sierra Foothills Area, California, Parts of Calaveras and Tuolumne Counties, 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 Central Sierra Foothills Area, California, Parts of Calaveras and Tuolumne Counties. 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 |
|---|---|---|---|---|---|
| Bonanza-Loafercreek complex, 3 to 15 percent slopes | 44K | Well drained | D | Very limited | Very limited |
| Bonanza-Loafercreek-Gopheridge complex, 15 to 30 percent slopes | 43K | Well drained | C | Very limited | Very limited |
| Loafercreek-Gopheridge complex, 15 to 30 percent slopes | 39K | Well drained | C | Very limited | Very limited |
| Nedsgulch-Wallyhill-Arpatutu complex, 30 to 60 percent slopes | 36K | Well drained | C | Very limited | Very limited |
| Water | 35K | D | Not rated | Not rated | |
| Loafercreek-Gopheridge complex, 30 to 60 percent slopes | 28K | Well drained | C | Very limited | Very limited |
| Loafercreek-Bonanza complex, 3 to 15 percent slopes | 26K | Well drained | C | Very limited | Very limited |
| Nedsgulch-Wallyhill-Arpatutu complex, 15 to 30 percent slopes | 24K | Well drained | C | Very limited | Very limited |
| Copperopolis-Whiterock complex, 3 to 15 percent slopes, rocky | 23K | Well drained | D | Very limited | Very limited |
| Nedsgulch-Arpatutu complex, 30 to 60 percent slopes | 23K | Well drained | C | Very limited | Very limited |
| Aquic Haploxeralfs, rarely flooded and occasionally ponded-Loafercreek-Dunstone complex, 1 to 12 percent slopes | 20K | Well drained | D | Very limited | Very limited |
| Millvilla-Luckymine complex, 15 to 30 percent slopes | 18K | Well drained | C | Very limited | Very limited |
| Amador sandy loam, 2 to 15 percent slopes | 17K | Well drained | D | Very limited | Very limited |
| Nedsgulch-Sites complex, 15 to 30 percent slopes | 16K | Well drained | C | Very limited | Very limited |
| Wardsferry-Millvilla complex, 30 to 60 percent slopes | 16K | Well drained | C | Very limited | Very limited |
| Musick-Hotaw complex, 8 to 30 percent slopes | 14K | Well drained | C | Very limited | Very limited |
| Gardellones-Gopheridge-Motherlode complex, 30 to 60 percent slopes | 13K | Well drained | C | Very limited | Very limited |
| Copperopolis-Whiterock complex, 15 to 30 percent slopes, rocky | 13K | Well drained | D | Very limited | Very limited |
| Sanguinetti-Moccasinhill-Deerflat complex, 60 to 90 percent slopes, cool | 13K | Well drained | C | Very limited | Very limited |
| Copperopolis-Whiterock complex, 2 to 8 percent slopes, rocky | 12K | Well 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 88% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes. 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.