Glenn County, California

Survey Area CA021• 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 Inceptisols — young soils with minimal horizon development but more than Entisols. 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 Glenn County, 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
Sheetiron gravelly loam, 30 to 50 percent slopes, MLRA 5	51K	Well drained	C	Very limited	Very limited
Maymen gravelly loam, schist bedrock, 30 to 65 percent slopes	51K	Somewhat excessively drained	D	Very limited	Very limited
Sehorn-Millsholm association, 15 to 50 percent slopes, MLRA 15	38K	Well drained	D	Very limited	Very limited
Tehama silt loam, 0 to 3 percent slopes, MLRA 17	31K	Well drained	C	Somewhat limited	Very limited
Hillgate loam, 0 to 2 percent slopes, MLRA 17	23K	Well drained	C	Somewhat limited	Very limited
Zamora silty clay loam, 0 to 3 percent slopes, MLRA 17	22K	Well drained	C	Very limited	Very limited
Sheetiron gravelly loam, shallow, 30 to 50 percent slopes	20K	Well drained	D	Very limited	Very limited
Myers clay, 0 to 1 percent slopes, MLRA 17	19K	Moderately well drained	D	Very limited	Very limited
Arbuckle gravelly loam, 0 to 2 percent slopes, MLRA 17	17K	Well drained	B	Not limited	Somewhat limited
Wyo silt loam	16K	Well drained	B	Not limited	Somewhat limited
Newville gravelly loam, 10 to 40 percent slopes, MLRA 17	14K	Well drained	C	Very limited	Very limited
Marvin silty clay loam, 0 to 2 percent slopes	13K	Somewhat poorly drained	D	Very limited	Very limited
Henneke stony clay loam, 30 to 65 percent slopes	12K	Well drained	C	Very limited	Very limited
Capay clay, 0 to 4 percent slopes, MLRA 17	11K	Somewhat poorly drained	C	Very limited	Very limited
Landlow clay	9K	Somewhat poorly drained	D	Very limited	Very limited
Nacimiento clay, 15 to 30 percent slopes	9K	Well drained	C	Very limited	Very limited
Marvin silty clay loam, slightly saline-alkali, 0 to 1 percent slopes	8K	Somewhat poorly drained	D	Very limited	Very limited
Newville-Gullied land complex, 8 to 30 percent slopes	8K	Well drained	D	Somewhat limited	Very limited
Colluvial land, sedimentary rocks	8K			Very limited	Very limited
Willows clay, dense subsoil, slightly saline-alkali	8K	Poorly 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.

Inceptisols

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

Alfisols

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

Entisols

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

Vertisols

High-clay soils that shrink and swell dramatically. Fertile but challenging for foundations and septic systems.

Mollisols

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

What This Means

Building & Foundations

About 75% 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 91% 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.