Skagit County Area, Washington

Survey Area WA657• Washington

The dominant drainage class is Moderately well drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). The most common soil order is Andisols — soils formed in volcanic ash, very light and porous. 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 Skagit County Area, Washington. 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
Skagit silt loam	26K	Poorly drained	B/D	Very limited	Very limited
Kindy gravelly silt loam, 30 to 65 percent slopes	16K	Moderately well drained	C	Very limited	Very limited
Sumas silt loam	15K	Poorly drained	C	Very limited	Very limited
Andic Xerochrepts-Rock outcrop complex, 65 to 90 percent slopes	14K	Well drained	B	Very limited	Very limited
Wollard-Springsteen complex, 30 to 65 percent slopes	14K	Moderately well drained	C	Very limited	Very limited
Barneston gravelly ashy loam, 0 to 8 percent slopes	13K	Somewhat excessively drained	A	Not limited	Very limited
Field silt loam, protected	12K	Moderately well drained	B	Somewhat limited	Very limited
Vanzandt very gravelly loam, 15 to 30 percent slopes	11K	Moderately well drained	C	Very limited	Very limited
Vanzandt very gravelly loam, 0 to 15 percent slopes	11K	Moderately well drained	C	Very limited	Very limited
Rinker very channery loam, 30 to 65 percent slopes	10K	Well drained	C	Very limited	Very limited
Dystric Xerorthents, 50 to 80 percent slopes	10K	Excessively drained	A	Very limited	Very limited
Montborne-Rinker complex, 30 to 65 percent slopes	10K	Moderately well drained	C	Very limited	Very limited
Andic Cryochrepts-Rock outcrop complex, 65 to 90 percent slopes	9K	Well drained	A	Very limited	Very limited
Vanzandt very gravelly loam, 30 to 65 percent slopes	9K	Moderately well drained	C	Very limited	Very limited
Mt. Vernon very fine sandy loam	9K	Moderately well drained	C	Very limited	Very limited
Diobsud-Crinker complex, 30 to 65 percent slopes	9K	Moderately well drained	C	Very limited	Very limited
Bow gravelly loam, 0 to 3 percent slopes	9K	Somewhat poorly drained	C/D	Very limited	Very limited
Montborne very gravelly loam, 30 to 65 percent slopes	8K	Moderately well drained	C	Very limited	Very limited
Montborne very gravelly silt loam, 3 to 30 percent slopes	8K	Moderately well drained	C	Very limited	Very limited
Pilchuck loamy sand	8K	Excessively drained	A	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.

Andisols

Volcanic ash soils — light, porous, and fertile. Excellent drainage, but low density can complicate foundations.

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.

Spodosols

Acidic forest soils with a leached layer. Common under conifers. Often have drainage issues from a compacted subsoil layer.

What This Means

Building & Foundations

About 89% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.

Septic Systems

About 100% 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.