Sierra Valley Area, California, Parts of Sierra, Plumas, and Lassen Counties

Survey Area CA614• California

The dominant drainage class is Well drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. 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 Sierra Valley Area, California, Parts of Sierra, Plumas, and Lassen 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
Ramelli clay	14K	Poorly drained	C/D	Very limited	Very limited
Galeppi loamy coarse sand, 5 to 30 percent slopes	8K	Well drained	C	Very limited	Very limited
Balman-Ramelli complex, 0 to 2 percent slopes	8K	Somewhat poorly drained	C	Not limited	Very limited
Basic rock land	6K	Excessively drained		Very limited	Very limited
Acidic rock land	6K	Excessively drained		Very limited	Very limited
Dotta sandy loam, 2 to 9 percent slopes	6K	Well drained	C	Somewhat limited	Very limited
Loyalton fine sandy loam	5K	Moderately well drained	D	Not limited	Very limited
Trosi very stony sandy loam, 2 to 15 percent slopes	5K	Well drained	D	Very limited	Very limited
Beckwourth loamy coarse sand	5K	Somewhat poorly drained	B	Very limited	Very limited
Beckwourth-Loyalton complex, saline-alkali, 0 to 2 percent slopes	5K	Somewhat poorly drained	B	Very limited	Very limited
Galeppi sandy loam, 8 to 15 percent slopes	4K	Well drained	C	Somewhat limited	Very limited
Martineck very stony sandy loam, 2 to 30 percent slopes	4K	Well drained	D	Very limited	Very limited
Pasquetti mucky silty clay	4K	Poorly drained	D	Very limited	Very limited
James Canyon silt loam, 0 to 2 percent slopes	4K	Poorly drained	B/D	Very limited	Very limited
Ormsby loamy coarse sand, 0 to 2 percent slopes	4K	Somewhat poorly drained	A	Very limited	Very limited
Coolbrith silt loam, 0 to 2 percent slopes	4K	Somewhat poorly drained	C	Somewhat limited	Very limited
Rough broken land	4K	Excessively drained	D	Very limited	Very limited
Calpine-Lovejoy complex, 0 to 5 percent slopes, eroded	4K	Well drained	A	Not limited	Not limited
Portola cobbly coarse sandy loam, 30 to 50 percent slopes	3K	Well drained	A	Very limited	Very limited
Franktown-Aldi-Rock outcrop complex, 30 to 75 percent slopes	3K	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.

Mollisols

Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.

Entisols

Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.

Alfisols

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

Inceptisols

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

What This Means

Building & Foundations

About 70% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas, 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.