Chugach Mountains - Eagle River Area, Alaska

Survey Area AK771• Alaska

The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low runoff). The most common soil order is Spodosols — acidic forest soils with a distinctive leached layer, common under conifers. 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 Chugach Mountains - Eagle River Area, Alaska. 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
Cook Inlet Mountains-Boreal Alpine-Mountains	240K	Well drained		Very limited	Very limited
Cook Inlet Mountains-Boreal Alpine-Barren Mountains	117K			Very limited	Very limited
Cook Inlet Mountains-Boreal Upland and Lowland-Valleys	33K	Well drained	A	Very limited	Very limited
Cook Inlet Lowlands-Boreal Water, Saline	5K			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.

Spodosols

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

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.

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 100% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, 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.