Upper Tanana Area, Alaska
The dominant drainage class is Very poorly drained and the dominant hydrologic group is D (very slow infiltration, high 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 Upper Tanana Area, Alaska.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Tanana silt loam, 0 to 3 percent slopes | 31K | Poorly drained | D | Very limited | Very limited |
| Goldstream and Histosols, 0 to 3 percent slopes | 24K | Very poorly drained | D | Very limited | Very limited |
| Goldstream peat, 0 to 3 percent slopes | 20K | Very poorly drained | D | Very limited | Very limited |
| Water | 15K | Not rated | Not rated | ||
| Jarvis-Stratify complex, 0 to 7 percent slopes | 11K | Well drained | B | Very limited | Very limited |
| Steese-Ester association, 12 to 45 percent slopes | 10K | Well drained | B | Very limited | Very limited |
| Koyukuk silt loam, 3 to 7 percent slopes | 10K | Well drained | B | Not limited | Very limited |
| Goldstream-Tanana complex, 0 to 3 percent slopes | 8K | Very poorly drained | D | Very limited | Very limited |
| Stratify and Riverwash, 0 to 3 percent slopes | 6K | Moderately well drained | C | Very limited | Very limited |
| Riverwash | 6K | Not rated | Not rated | ||
| Salchaket-Riverwash association, 0 to 3 percent slopes | 5K | Well drained | B | Very limited | Very limited |
| Nenana silt loam, 3 to 7 percent slopes | 5K | Well drained | B | Not limited | Very limited |
| Nenana silt loam, 0 to 3 percent slopes | 5K | Well drained | B | Not limited | Very limited |
| Minchumina peat, 3 to 7 percent slopes | 4K | Well drained | D | Very limited | Very limited |
| Goldstream peat, 3 to 7 percent slopes | 4K | Very poorly drained | D | Very limited | Very limited |
| Ester-Steese association, 7 to 12 percent slopes | 3K | Very poorly drained | D | Very limited | Very limited |
| Tanana, moderately wet-Goldstream complex, 0 to 3 percent slopes | 3K | Somewhat poorly drained | C | Very limited | Very limited |
| Nenana silt loam, 12 to 45 percent slopes | 3K | Well drained | B | Very limited | Very limited |
| Goodpaster variant-Goldstream complex, 0 to 3 percent slopes | 3K | Poorly drained | D | Very limited | Very limited |
| Goldstream peat, 7 to 12 percent slopes | 2K | Very poorly drained | D | Very limited | Very limited |
What This Means
Building & Foundations
About 77% 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 88% 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.