Tanana and Chatanika River Area, Alaska

Survey Area AK793• Alaska

The dominant drainage class is Very poorly drained and the dominant hydrologic group is A/D (varies with drainage). 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 Tanana and Chatanika 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
Interior Alaska Lowlands-Boreal Lowland-High Flood Plains and Terraces, Wet	433K	Very poorly drained	A/D	Very limited	Very limited
Interior Alaska Lowlands-Boreal Lowland-Flood Plains and Terraces	171K	Poorly drained	B	Very limited	Very limited
Interior Alaska Highlands-Boreal Lowland-Flood Plains and Terraces	43K	Poorly drained	D	Very limited	Very limited
Interior Alaska Lowlands-Boreal Upland-Eolian Plains, Sand Hills, and Dunes	32K	Somewhat excessively drained	D	Very limited	Very limited
Interior Alaska Lowlands-Boreal Lowland-Fan Terraces and Stream Terraces	22K	Poorly drained	D	Very limited	Very limited
Interior Alaska Lowlands-Boreal Water, Fresh	16K			Not limited	Not limited
Interior Alaska Lowlands-Boreal Upland-Loess Plains and Hills	14K	Poorly drained	D	Very limited	Very limited
Interior Alaska Lowlands-Boreal Lowland-Flood Plains and Terraces, High Elevation	10K	Poorly drained	D	Very limited	Very limited
Interior Alaska Highlands-Boreal Upland and Lowland-Mountain Valleys	9K	Poorly drained	D	Very limited	Very limited
Interior Alaska Highlands-Boreal Upland-Rounded Mountains, Acid	5K	Well drained	A	Very limited	Very limited
Interior Alaska Highlands-Boreal Upland-Hills and Plains	3K	Poorly drained	D	Very limited	Very limited
Interior Alaska Highlands-Boreal Upland and Subalpine-Rounded Mountains	1K	Well drained	B	Not limited	Very limited
Interior Alaska Highlands-Boreal Upland and Alpine-Rugged Mountains	191	Well drained	A	Very limited	Very limited
Interior Alaska Highlands-Boreal Upland-Hills and Plains, Acid	69	Well 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.

Spodosols

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

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.

What This Means

Building & Foundations

About 97% 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 97% of soils are rated "very limited" for septic absorption fields. Poorly drained soils can't absorb septic effluent effectively. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.

Gardening & Agriculture

Many soils hold water for extended periods. Raised beds are highly recommended to improve drainage for vegetables. Well-adapted native plants and water-loving species will do best in natural conditions.