Soil survey area

Yukon Delta National Wildlife Refuge - Western Part Area, Alaska

Survey Area AK703• Alaska

The short version

The most common soil here is E40-maritime tussock-scrub-silty frozen slopes, on about 18% of the land. E40-maritime dwarf scrub-gravelly colluvial slopes and E38-maritime silty dwarf scrub-lichen frozen coastal plains come next.

About 30% of the land drains well, and 69% stays wet for long stretches; groundwater comes within two feet of the surface under 99% of it.

USDA rates 99% of the land very limited for a standard septic drain field, and 99% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

Worth knowing: 16% of the land floods occasionally or more, and bedrock lies within 40 inches under 27% of it.

Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.

The biggest mapped areas

The dominant drainage class is Very poorly drained and the dominant hydrologic group is B/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 Yukon Delta National Wildlife Refuge - Western Part 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
Nulato Hills-Southern Seward Peninsula Highlands-Maritime Upland-Plains and Hills, Silty	989K	Very poorly drained	B/D	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Maritime Upland-Rounded Mountains	829K	Well drained	A	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Boreal Upland and Maritime Upland-Hills and Plains, Gravelly	398K	Poorly drained	D	Very limited	Very limited
Yukon-Kuskokwim Coastal Plain-Maritime Lowland-Flood Plains and Terraces	301K	Very poorly drained	B/D	Very limited	Very limited
Yukon-Kuskokwim Coastal Plain-Maritime Lowland-Coastal Plains, High	233K	Poorly drained	D	Very limited	Very limited
Yukon-Kuskokwim Coastal Plain-Maritime Lowland-Plains	90K	Well drained	D	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Boreal Lowland-Flood Plains and Terraces	79K	Somewhat poorly drained	B/D	Very limited	Very limited
Yukon-Kuskokwim Coastal Plain-Boreal Lowland-Flood Plains and Terraces	70K	Very poorly drained	B/D	Very limited	Very limited
Yukon-Kuskokwim Coastal Plain-Maritime Lowland-Coastal Plains, Low	55K	Very poorly drained	B/D	Very limited	Very limited
Yukon-Kuskokwim Coastal Plain-Maritime Water, Saline	33K			Not limited	Not limited
Nulato Hills-Southern Seward Peninsula Highlands-Maritime Upland-Rounded Mountains, Acid	12K	Very poorly drained	C	Very limited	Very limited
Yukon-Kuskokwim Highlands-Boreal Upland-Rounded Mountains and Hills, Acid	11K	Well drained	B	Somewhat limited	Very limited
Sikinik-Nikaat-Asulu complex, 0 to 5 percent slopes	8K	Poorly drained	D	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Boreal Upland and Maritime Upland-Rounded Mountains	3K	Well drained	B	Very limited	Very limited
Sikinik-Ugruk-Ukpik association, 0 to 4 percent slopes	3K	Poorly drained	D	Very limited	Very limited
Sikinik-Runkelscreek association, 0 to 4 percent slopes	3K	Poorly drained	D	Very limited	Very limited
Sikinik-Akpik, very stony surface-Ugruk complex, 0 to 6 percent slopes	3K	Poorly drained	D	Very limited	Very limited
Nikaat-Willowcreek association, 0 to 7 percent slopes	710	Poorly drained	B/D	Very limited	Very limited
Apun-Ukpik association, 0 to 5 percent slopes	30	Poorly drained	D	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Boreal Upland and Maritime Upland-Rounded Mountains, Acid	17	Well drained	C	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.

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 99% 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 99% 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.