Alaska Peninsula - Iliamna and Bristol Bay Lowlands Area, Alaska

Survey Area AK715• Alaska

The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). The most common soil order is Gelisols — permafrost soils found in very cold climates. 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 Alaska Peninsula - Iliamna and Bristol Bay Lowlands 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
Bristol Bay-Northern Alaska Peninsula Lowlands-Maritime Upland-Glaciated Plains, Ash Influenced	1.3M	Very poorly drained	B	Very limited	Very limited
Bristol Bay-Northern Alaska Peninsula Lowlands-Boreal and Northwest Maritimel-Glaciated Plains, Ash Influenced	1.2M	Well drained	A	Not limited	Very limited
Bristol Bay-Northern Alaska Peninsula Lowlands-Maritime Water, Fresh	599K			Not limited	Not limited
Southern Alaska Peninsula Mountains-Maritime Upland-Rounded Mountains	549K	Well drained	B	Very limited	Very limited
Bristol Bay-Northern Alaska Peninsula Lowlands-Maritime Upland-Glaciated Plains and Peatlands	378K	Very poorly drained	B/D	Very limited	Very limited
Bristol Bay-Northern Alaska Peninsula Lowlands-Maritime Water, Saline	295K			Not limited	Not limited
Bristol Bay-Northern Alaska Peninsula Lowlands-Maritime Lowlands-Coastal Plains, Low	213K	Very poorly drained	B/D	Very limited	Very limited
Southern Alaska Peninsula Mountains-Maritime Water, Saline	208K			Not rated	Not rated
Southern Alaska Peninsula Mountains-Maritime Upland-Glaciated Plains and Hills	198K	Well drained	B	Very limited	Very limited
Southern Alaska Peninsula Mountains-Maritime Alpine-Barren Mountains	96K			Very limited	Very limited
Bristol Bay-Northern Alaska Peninsula Lowlands-Maritime Upland-Glaciated Plains and Hills	92K	Very poorly drained	B/D	Very limited	Very limited
Cook Inlet Lowlands-Boreal Water, Saline	85K			Very limited	Very limited
Bristol Bay-Northern Alaska Peninsula Lowlands-Maritime Upland and Lowland-Glaciated Valleys	83K	Well drained	B	Very limited	Very limited
Cook Inlet Mountains-Boreal Upland and Subalpine-Mountains	65K	Well drained	B	Very limited	Very limited
Cook Inlet Mountains-Boreal Alpine-Mountains	45K	Well drained		Very limited	Very limited
Bristol Bay-Northern Alaska Peninsula Lowlands-Maritime Upland-Glaciated Rounded Mountains	36K	Well drained	A/D	Very limited	Very limited
Southern Alaska Peninsula Mountains-Maritime Upland-Volcanic Mountains and Lowland-Flood Plains and Stream Terraces	35K	Somewhat excessively drained	B	Not limited	Very limited
Interior Alaska Mountains-Boreal Subalpine and Alpine-Rounded Mountains, Ash Influenced	27K	Well drained	C	Very limited	Very limited
Interior Alaska Mountains-Boreal Upland and Subalpine-Glaciated Plains and Hills, Ash Influenced	20K	Well drained	B	Somewhat limited	Very limited
Southern Alaska Peninsula Mountains-Maritime Lowland-Coastal Plains	16K	Very 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.

Gelisols

Permafrost soils. Extremely challenging for construction and septic. Found almost exclusively in Alaska.

Inceptisols

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

Entisols

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

Andisols

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

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 56% 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 80% 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.