Aleutian Islands - Unalaska and Andreanof Islands Area, Alaska
The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low runoff). 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 Aleutian Islands - Unalaska and Andreanof Islands Area, Alaska.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Aleutian Islands-Western Alaska Peninsula-Maritime Upland-Rounded Mountains and Hills | 1.0M | Well drained | A | Very limited | Very limited |
| Aleutian Islands-Western Alaska Peninsula-Maritime Upland-Lower Mountain Slopes, Volcanic | 486K | Well drained | A | Very limited | Very limited |
| Aleutian Islands-Western Alaska Peninsula-Maritime Upland-Barren Mountains | 461K | Very limited | Very limited | ||
| Aleutian Islands-Western Alaska Peninsula-Maritime Upland-Glaciated Plains | 424K | Well drained | A | Very limited | Very limited |
| Aleutian Islands-Western Alaska Peninsula-Maritime Water, Saline | 2K | Very limited | Very limited |
What This Means
Building & Foundations
About 100% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 100% 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.