Matanuska-Susitna Valley 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 Matanuska-Susitna Valley Area, Alaska.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Histosols | 335K | Very poorly drained | D | Very limited | Very limited |
| Cryaquepts, depressional, 0 to 7 percent slopes | 91K | Very poorly drained | D | Very limited | Very limited |
| Water | 90K | Not rated | Not rated | ||
| Rock outcrop-Cryumbrepts association, extremely steep | 58K | Well drained | D | Very limited | Very limited |
| Nancy silt loam, 0 to 3 percent slopes | 53K | Well drained | B | Not limited | Very limited |
| Talkeetna, warm, and Talkeetna, thick surface soils, 15 to 45 percent slopes | 47K | Well drained | B | Very limited | Very limited |
| Tokositna, undulating-Chunilna complex | 44K | Well drained | B | Not limited | Somewhat limited |
| Tokositna, hilly-Chunilna complex | 42K | Well drained | B | Very limited | Very limited |
| Typic Cryaquents, 0 to 2 percent slopes | 42K | Very poorly drained | D | Very limited | Very limited |
| Nancy silt loam, sloping and moderately steep | 41K | Well drained | B | Not limited | Very limited |
| Cryods and Cryaquepts, cool, 0 to 35 percent slopes | 41K | Very poorly drained | B | Very limited | Very limited |
| Susivar-Moose River complex, 0 to 2 percent slopes | 40K | Somewhat poorly drained | C | Very limited | Very limited |
| Typic Cryaquents, coastal, 0 to 2 percent slopes | 34K | Very poorly drained | D | Very limited | Very limited |
| Cryods, low elevation, and Cryochrepts, 30 to 70 percent slopes | 33K | Well drained | B | Very limited | Very limited |
| Cryods, 35 to 90 percent slopes | 31K | Well drained | B | Very limited | Very limited |
| Benka silt loam, 0 to 3 percent slopes | 30K | Well drained | B | Not limited | Very limited |
| Talkeetna, low elevation-Deneka, low elevation association, steep and moderately steep | 28K | Well drained | B | Very limited | Very limited |
| Talkeetna, warm-Talkeetna, thick surface complex, hilly | 25K | Well drained | B | Very limited | Very limited |
| Kashwitna silt loam, 0 to 3 percent slopes | 25K | Well drained | B | Not limited | Very limited |
| Susivar and Niklavar fine sandy loams | 25K | Somewhat poorly drained | C | Very limited | Very limited |
What This Means
Building & Foundations
About 75% 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.