Seward Peninsula and Nulato Hills Area, Alaska

Survey Area AK733• Alaska

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 Inceptisols — young soils with minimal horizon development but more than Entisols. 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 Seward Peninsula and Nulato Hills 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
Seward Peninsula Highlands-Arctic Upland-Loess Plains	1.2M	Very poorly drained	B/D	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Maritime Water, Saline	1.2M			Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Maritime Upland-Rounded Mountains, Acid	1.1M	Very poorly drained	C	Very limited	Very limited
Seward Peninsula Highlands-Arctic Upland-Hills and Plains, Gravelly	977K	Very poorly drained	D	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Maritime Upland-Plains and Hills, Silty	853K	Very poorly drained	B/D	Very limited	Very limited
Seward Peninsula Highlands-Arctic Upland-Rounded Mountains, Calcareous	621K			Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Boreal Upland and Maritime Upland-Glaciated Mountains	323K	Poorly drained	D	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Maritime Upland-Rounded Mountains	223K	Well drained	A	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Maritime Lowland-Coastal Plains	185K	Very poorly drained	B/D	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Maritime Upland-Plains and Hills, Gravelly	177K	Very poorly drained	D	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Boreal Upland and Maritime Upland-Rounded Mountains	165K	Well drained	B	Very limited	Very limited
Seward Peninsula Highlands-Arctic Lowland-Flood Plains and Terraces	148K	Poorly drained	D	Very limited	Very limited
Seward Peninsula Highlands-Arctic Upland-Rounded Mountains, Acid	146K	Moderately well drained	C	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Maritime Lowland-Flood Plains and Terraces	136K	Somewhat poorly drained	B/D	Very limited	Very limited
Northern Seward Peninsula-Selawik Lowlands-Arctic Uplands-Plains, Silty	133K	Very poorly drained	B/D	Very limited	Very limited
Seward Peninsula Highlands-Arctic Upland-Rounded Mountains	91K	Well drained	B	Very limited	Very limited
Nulato Hills-Southern Seward Peninsula Highlands-Boreal Upland and Maritime Upland-Rounded Mountains, Acid	90K	Well drained	C	Very limited	Very limited
Yukon-Kuskokwim Coastal Plain-Maritime Lowland-Plains	86K	Well drained	D	Very limited	Very limited
Northern Seward Peninsula-Selawik Lowlands-Water, Saline	83K			Very limited	Very limited
Seward Peninsula Highlands-Arctic Upland-Coastal Plains	69K	Very poorly drained	C/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.

Inceptisols

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

Gelisols

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

Mollisols

Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.

What This Means

Building & Foundations

About 100% 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 100% 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.