Alaska Range - Tordrillo Mountains and Happy River 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 Alaska Range - Tordrillo Mountains and Happy River Area, Alaska.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Cook Inlet Mountains-Boreal Alpine-Barren Mountains | 1.1M | Very limited | Very limited | ||
| Interior Alaska Mountains-Boreal Alpine-Barren Mountains | 658K | Very limited | Very limited | ||
| Cook Inlet Mountains-Boreal Subalpine and Alpine-Mountains, Acid | 436K | Well drained | A | Very limited | Very limited |
| Cook Inlet Mountains-Boreal Subalpine and Alpine-Rounded Mountains | 399K | Well drained | A | Very limited | Very limited |
| Interior Alaska Mountains-Boreal Alpine-Mountain Valleys | 291K | Well drained | B | Very limited | Very limited |
| Interior Alaska Mountains-Boreal Alpine-Mountain Valleys, Ash Influenced | 141K | Very limited | Very limited | ||
| Cook Inlet Mountains-Boreal Upland and Lowland-Valleys | 107K | Well drained | A | Very limited | Very limited |
| Interior Alaska Mountains-Boreal Alpine-Rugged Mountains | 63K | Well drained | B | Very limited | Very limited |
| Cook Inlet Lowlands-Boreal Upland-Till Plains | 42K | Very poorly drained | B/D | Very limited | Very limited |
| Cook Inlet Mountains-Boreal Alpine-Mountains | 40K | Well drained | Very limited | Very limited | |
| Interior Alaska Mountains-Boreal Upland and Subalpine-Mountain Valleys, Ash Influenced | 39K | Well drained | B | Very limited | Very limited |
| Interior Alaska Mountains-Boreal Upland and Lowland-Mountain Valleys | 36K | Well drained | B | Very limited | Very limited |
| Cook Inlet Lowlands-Boreal Lowland-Flood Plains and Terraces, Wet | 22K | Very poorly drained | B/D | Very limited | Very limited |
| Cook Inlet Mountains-Boreal Water, Fresh | 19K | Not limited | Not limited | ||
| Interior Alaska Mountains-Boreal Upland and Subalpine-Glaciated Plains and Hills, Ash Influenced | 18K | Well drained | B | Somewhat limited | Very limited |
| Cook Inlet Lowlands-Boreal Lowland-Flood Plains, Terraces, and Fans | 11K | Very limited | Very limited | ||
| Interior Alaska Mountains-Boreal Subalpine and Alpine-Rounded Mountains, Ash Influenced | 3K | Well drained | C | Very limited | Very limited |
What This Means
Building & Foundations
About 98% 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 99% 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.