Seward Area, Alaska
The most common soil here is Exit, on about 7% of the land. Callisto and Aialik come next.
About 46% of the land drains well, and 5% stays wet for long stretches; groundwater comes within two feet of the surface under 23% of it.
USDA rates 75% of the land very limited for a standard septic drain field, and 75% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 11% of the land floods occasionally or more, and bedrock lies within 40 inches under 48% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). The most common soil order is Entisols — young soils with little profile development, often on floodplains or steep slopes. 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 Seward Area, Alaska. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Water, saline | 17K | Not rated | Not rated | ||
| Rock outcrop-Aialik-Snow complex, 10 to 100 percent slopes | 17K | Very limited | Very limited | ||
| Exit-Ski association, 20 to 90 percent slopes | 10K | Well drained | B | Very limited | Very limited |
| Callisto-Caines association, 20 to 80 percent slopes | 9K | Well drained | A | Very limited | Very limited |
| Andacher-PorcupineGlacier complex, 20 to 65 percent slopes | 3K | Well drained | A | Very limited | Very limited |
| Iron-Spruce complex, 0 to 3 percent slopes | 3K | Well drained | B | Very limited | Very limited |
| Army-Spruce complex, 0 to 8 percent slopes | 3K | Well drained | B | Very limited | Very limited |
| Moose-PorcupineGlacier complex, 30 to 80 percent slopes | 2K | Well drained | C | Very limited | Very limited |
| Moose-Hive-Andacher complex, 0 to 60 percent slopes | 2K | Well drained | C | Very limited | Very limited |
| Riverwash-Sandspit complex, 0 to 3 percent slopes | 2K | Poorly drained | Very limited | Very limited | |
| Marys-Riverwash association, 1 to 12 percent slopes | 1K | Well drained | B | Very limited | Very limited |
| Rugged-Rubble land-Rock outcrop association, 20 to 100 percent slopes | 977 | Very limited | Very limited | ||
| Humpy-Squab complex, 0 to 2 percent slopes | 956 | Poorly drained | B/D | Very limited | Very limited |
| Blying-Ascension association, 2 to 35 percent slopes | 729 | Well drained | D | Very limited | Very limited |
| Water, lakes and ponds | 528 | Not rated | Not rated | ||
| Urban land, flood plains, 0 to 12 percent slopes | 439 | Not rated | Not rated | ||
| Riverwash-Water complex, 2 to 7 percent slopes | 274 | Poorly drained | Very limited | Very limited | |
| Urban land, alluvial fans, 0 to 15 percent slopes | 257 | Not rated | Not rated | ||
| Bulldog-Resurrection-Tidal flats complex, 0 to 10 percent slopes | 239 | Poorly drained | B/D | Very limited | Very limited |
| Humpy-Water complex, 0 to 2 percent slopes | 201 | Very poorly drained | B/D | Very limited | Very limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 75% 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 75% 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.