El Dorado 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 El Dorado Area, California.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Auburn very rocky silt loam, 2 to 30 percent slopes | 63K | Well drained | D | Very limited | Very limited |
| Mariposa very rocky silt loam, 3 to 50 percent slopes | 33K | Well drained | C | Very limited | Very limited |
| Auburn very rocky silt loam, 30 to 50 percent slopes | 29K | Well drained | D | Very limited | Very limited |
| Mariposa very rocky silt loam, 50 to 70 percent slopes | 25K | Well drained | C | Very limited | Very limited |
| Mariposa-Josephine very rocky loams, 15 to 50 percent slopes | 21K | Well drained | C | Very limited | Very limited |
| Serpentine rock land | 18K | Very limited | Very limited | ||
| Auburn silt loam, 2 to 30 percent slopes | 16K | Well drained | D | Very limited | Very limited |
| Josephine silt loam, 15 to 30 percent slopes | 12K | Well drained | B | Very limited | Very limited |
| Metamorphic rock land | 12K | Very limited | Very limited | ||
| Josephine very rocky silt loam, 9 to 50 percent slopes | 11K | Well drained | B | Very limited | Very limited |
| Josephine very rocky loam, 15 to 50 percent slopes | 11K | Well drained | B | Very limited | Very limited |
| Water | 10K | D | Not rated | Not rated | |
| Boomer very rocky loam, 30 to 50 percent slopes | 10K | Well drained | C | Very limited | Very limited |
| Rescue extremely stony sandy loam, 3 to 50 percent slopes, eroded | 10K | Well drained | C | Very limited | Very limited |
| McCarthy cobbly loam, 9 to 50 percent slopes | 9K | Well drained | B | Very limited | Very limited |
| Placer diggings | 9K | Very limited | Very limited | ||
| Maymen very rocky loam, 15 to 70 percent slopes | 9K | Excessively drained | D | Very limited | Very limited |
| Cohasset cobbly loam, 15 to 50 percent slopes | 8K | Well drained | B | Very limited | Very limited |
| Auburn extremely rocky silt loam, 3 to 70 percent slopes | 8K | Well drained | D | Very limited | Very limited |
| Holland very rocky coarse sandy loam, 15 to 50 percent slopes | 7K | Well drained | B | Very limited | Very limited |
What This Means
Building & Foundations
About 96% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 96% 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.