Chugach National Forest - Prince William Sound Area, Alaska
The most common soil here is E20-maritime forest-loamy colluvial slopes, shallow, on about 9% of the land. E20-maritime sedge-scrub-organic depressions and E20-maritime forest-organic slopes come next.
About 0% of the land drains well, and 55% stays wet for long stretches; groundwater comes within two feet of the surface under 64% of it.
USDA rates 77% of the land very limited for a standard septic drain field, and 77% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 11% of the land floods occasionally or more, and bedrock lies within 40 inches under 74% 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 A/D (varies with drainage). The most common soil order is Histosols — organic soils (peat/muck) formed in wetlands. 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 National Forest - Prince William Sound 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 |
|---|---|---|---|---|---|
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Upland and Subalpine-Rounded Mountains | 952K | Very poorly drained | A/D | Very limited | Very limited |
| Southern Alaska Coastal Mountains-Maritime Alpine-Barren Mountains | 741K | Not rated | Not rated | ||
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Lowland-Coastal Plains, Deltas and Mud Flats | 408K | Very poorly drained | B/D | Very limited | Very limited |
| Southern Alaska Coastal Mountains-Maritime Subalpine and Alpine-Mountains | 363K | Very limited | Very limited | ||
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Subalpine and Alpine-Rounded Mountains | 282K | Very limited | Very limited | ||
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Upland-Glaciated Plains and Peatlands | 159K | Very poorly drained | A/D | Very limited | Very limited |
| Southern Alaska Coastal Mountains-Maritime Lowland-Flood Plains and Terraces | 93K | Very poorly drained | A/D | Very limited | Very limited |
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Upland-Glaciofluvial Plains and Beaches | 85K | Poorly drained | B/D | Very limited | Very limited |
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Water, Saline | 60K | Very limited | Very limited | ||
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Upland-Glaciated Hills and Plains | 44K | Very poorly drained | A/D | Very limited | Very limited |
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Upland-Hills, Recently Glaciated | 24K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Southern Alaska Coastal Mountains-Maritime Upland-Hills, Recently Glaciated | 3K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Southern Alaska Coastal Mountains-Maritime Upland-Mountains | 906 | Moderately well drained | B/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.
What This Means
Building & Foundations
About 77% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 77% 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.