Willamette National Forest, Oregon

Survey Area OR657• Oregon

The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low 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 Willamette National Forest, Oregon. 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
Separation medial fine sandy loam, 2 to 15 percent slopes, moist	56K	Well drained	B	Not limited	Somewhat limited
Coolcamp-Menagerie gravelly medial silt loams, 45 to 90 percent slopes	55K	Well drained	A	Very limited	Very limited
Patjens medial fine sandy loam, 2 to 30 percent slopes	54K	Well drained	A	Very limited	Very limited
Menagerie-Ramcreek complex, 0 to 30 percent slopes	49K	Well drained	B	Very limited	Very limited
Separation medial fine sandy loam, 2 to 15 percent slopes	48K	Well drained	B	Not limited	Somewhat limited
Dorena-Mooseridge complex, 0 to 30 percent slopes	43K	Well drained	D	Very limited	Very limited
Uppersoda gravelly medial loam, 30 to 75 percent slopes, south-facing, warm	43K	Well drained	A	Very limited	Very limited
Battleax very gravelly medial loam, 30 to 75 percent slopes, cold	37K	Well drained	A	Very limited	Very limited
Kinney-Mooseridge complex, low precipitation, 0 to 30 percent slopes	36K	Well drained	B	Very limited	Very limited
Dutchoven-Kinney complex, 45 to 90 percent slopes, south-facing	35K	Well drained	A	Very limited	Very limited
Soapgrass medial loam, 2 to 30 percent slopes	35K	Well drained	A	Not limited	Very limited
Illahee, high precipitation-Browder complex, 45 to 90 percent slopes, south-facing	35K	Well drained	A	Very limited	Very limited
Dutchoven-Kinney complex, 45 to 90 percent slopes	32K	Well drained	A	Very limited	Very limited
Bohemia-Westfir, low precipitation, gravelly loams, 45 to 90 percent slopes	32K	Well drained	A	Very limited	Very limited
Browder-Ramcreek complex, 0 to 30 percent slopes, low precipitation	30K	Well drained	B	Very limited	Very limited
Singe, moist-Zing, taxadjunct gravelly loams, 0 to 30 percent slopes	29K	Well drained	B	Very limited	Very limited
Singe-Vena, dry, gravelly loams, 45 to 90 percent slopes, south-facing	27K	Well drained	B	Very limited	Very limited
Chucksney medial loam, 30 to 75 percent slopes, south-facing	27K	Well drained	A	Very limited	Very limited
Soapgrass medial loam, 30 to 75 percent slopes, low precipitation	27K	Well drained	A	Very limited	Very limited
Waldor loamy coarse sand, 0 to 8 percent slopes	24K	Moderately well drained	B/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.

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.

Spodosols

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

Histosols

Organic peat and muck soils formed in wetlands. Very poor for building (compressible) and septic. Often in regulated wetlands.

What This Means

Building & Foundations

About 81% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes. A geotechnical assessment is recommended before building.

Septic Systems

About 86% 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.