Amador Area, California
The dominant drainage class is Well drained and the dominant hydrologic group is D (very slow infiltration, high runoff). 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 Amador Area, California.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Auburn very rocky silt loam, 3 to 31 percent slopes | 23K | Well drained | D | Very limited | Very limited |
| Mariposa very rocky loam, 31 to 51 percent slopes | 12K | Well drained | C | Very limited | Very limited |
| Exchequer very rocky silt loam, 31 to 51 percent slopes | 12K | Somewhat excessively drained | D | Very limited | Very limited |
| Exchequer and Auburn very rocky loams, 3 to 31 percent slopes | 10K | Well drained | D | Very limited | Very limited |
| Rock land | 10K | Excessively drained | D | Very limited | Very limited |
| Firebrick-Mokelumne complex, 2 to 30 percent slopes | 9K | Well drained | D | Very limited | Very limited |
| Josephine very rocky loam, 16 to 51 percent slopes | 8K | Well drained | C | Very limited | Very limited |
| Auburn silt loam, 0 to 31 percent slopes | 7K | Well drained | D | Very limited | Very limited |
| Exchequer and Auburn very rocky loams, 31 to 51 percent slopes | 6K | Somewhat excessively drained | D | Very limited | Very limited |
| Amador sandy loam, 2 to 15 percent slopes | 6K | Well drained | D | Very limited | Very limited |
| Red Bluff-Mokelumne complex, 3 to 15 percent slopes | 6K | Well drained | C | Not limited | Very limited |
| Exchequer very rocky silt loam, 3 to 31 percent slopes | 6K | Somewhat excessively drained | D | Very limited | Very limited |
| Auburn very rocky silt loam, 31 to 51 percent slopes | 6K | Well drained | D | Very limited | Very limited |
| Mariposa very rocky loam, 51 to 85 percent slopes | 6K | Well drained | D | Very limited | Very limited |
| Cohasset very cobbly loam, 16 to 51 percent slopes | 5K | Well drained | B | Very limited | Very limited |
| Water | 5K | D | Not rated | Not rated | |
| Sites very rocky loam, 16 to 51 percent slopes | 4K | Well drained | C | Very limited | Very limited |
| Argonaut very rocky loam, 3 to 31 percent slopes | 4K | Moderately well drained | D | Very limited | Very limited |
| Mariposa-Sites complex, 16 to 51 percent slopes | 4K | Well drained | C | Very limited | Very limited |
| Mined land-Anthraltic Xerorthents complex, 1 to 15 percent slopes | 4K | Not rated | Not rated |
What This Means
Building & Foundations
About 90% 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 94% 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.