El Dorado Area, California

Survey Area CA624• California

The dominant drainage class is Well drained and the dominant hydrologic group is D (very slow infiltration, high 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 El Dorado Area, California. 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
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

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.

Alfisols

Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.

Ultisols

Strongly weathered clay soils of the Southeast. Acidic and naturally low in nutrients. Clay subsoil can slow drainage.

Inceptisols

Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.

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.