Chatham Area, Alaska
The dominant drainage class is Very poorly drained and the dominant hydrologic group is A/D (varies with drainage). 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 Chatham Area, Alaska.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Water, Saline | 1.1M | Not rated | Not rated | ||
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Upland and Subalpine-Rounded Mountains | 761K | Very poorly drained | A/D | Very limited | Very limited |
| Rock outcrop and Lithic Cryorthents | 601K | Very limited | Very limited | ||
| Southern Alaska Coastal Mountains-Maritime Alpine-Barren Mountains | 551K | Not rated | Not rated | ||
| Glaciers | 347K | Not rated | Not rated | ||
| Southern Alaska Coastal Mountains-Maritime Subalpine and Alpine-Mountains | 268K | Very limited | Very limited | ||
| Typic Humicryept and Lithic Cryorthent soils, 76 to 140 percent slopes | 260K | Moderately well drained | A | Very limited | Very limited |
| Tolstoi and Kaikli soils, alpine, 76 to 120 percent slopes | 173K | Moderately well drained | D | Very limited | Very limited |
| Southern Alaska Coastal Mountains-Maritime Upland-Mountains | 101K | Moderately well drained | B/D | Very limited | Very limited |
| Lithic Cryorthent-Entic Cryumbrept association, 76 to 140 percent slopes | 101K | Somewhat poorly drained | D | Very limited | Very limited |
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Upland-Glaciated Hills and Plains | 100K | Very poorly drained | A/D | Very limited | Very limited |
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Subalpine and Alpine-Rounded Mountains | 100K | Very limited | Very limited | ||
| Water | 90K | Not rated | Not rated | ||
| Entic Cryumbrepts-Tolstoi-Kupreanof association, 76 to 140 percent slopes | 86K | Moderately well drained | A | Very limited | Very limited |
| Lithic Cryosaprists, Alpine, and Rock outcrop soils, 0 to 35 percent slopes | 85K | Very poorly drained | D | Very limited | Very limited |
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Upland and Subalpine-Rounded Mountains, Ash Infuenced | 83K | Moderately well drained | D | Very limited | Very limited |
| Tolstoi and Kaikli soils, subalpine, 36 to 55 percent slopes | 64K | Moderately well drained | D | Very limited | Very limited |
| Kina-Kasiana association, sloping lowlands, 6 to 35 percent slopes | 60K | Very poorly drained | D | Very limited | Very limited |
| Entic Cryumbrepts, McGilvery, and Rock outcrop soils, ravines, 76 to 140 percent slopes | 49K | Moderately well drained | A | Very limited | Very limited |
| Alexander Archipelago-Gulf of Alaska Coast-Maritime Upland and Lowland-Mountain Valley Bottoms | 46K | Moderately well drained | B/D | Very limited | Very limited |
What This Means
Building & Foundations
About 58% 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 58% 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.