Greater Delta Area, Alaska
The most common soil here is 29-Nenana, on about 8% of the land. 29-Salchaket and 29-Gerstle come next.
About 59% of the land drains well, and 19% stays wet for long stretches; groundwater comes within two feet of the surface under 52% of it.
USDA rates 86% of the land very limited for a standard septic drain field, and 69% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 8% of the land floods occasionally or more, and bedrock lies within 40 inches under 12% 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 Inceptisols — young soils with minimal horizon development but more than Entisols. 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 Greater Delta 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-Riverwash complex | 44K | Not rated | Not rated | ||
| Nenana silt loam, 0 to 3 percent slope | 37K | Well drained | B | Not limited | Very limited |
| Gerstle-Moosehead complex, 0 to 3 percent slopes | 30K | Well drained | B | Very limited | Very limited |
| Salchaket very fine sandy loam | 19K | Well drained | B | Very limited | Very limited |
| Tanacross, occasionally flooded-Histels association | 16K | Poorly drained | D | Very limited | Very limited |
| Lupine-Jarvis complex | 11K | Well drained | B | Very limited | Very limited |
| Chatanika-Goldstream complex, 0 to 5 percent slopes | 11K | Poorly drained | D | Very limited | Very limited |
| Jarvis-Salchaket complex | 11K | Well drained | B | Very limited | Very limited |
| Lupine family-Beales complex, 3 to 12 percent slopes | 10K | Well drained | B | Not limited | Very limited |
| Nenana-Donnelly complex, 0 to 3 percent slopes | 9K | Well drained | B | Not limited | Very limited |
| Koyukuk-Audrey family complex | 8K | Well drained | B | Very limited | Very limited |
| Lupine very fine sandy loam | 8K | Well drained | B | Very limited | Very limited |
| Saulich-Chatanika complex, 3 to 7 percent slopes | 7K | Very poorly drained | D | Very limited | Very limited |
| Tanana silt loam | 7K | Poorly drained | D | Very limited | Very limited |
| Southpaw-Butchlake complex, 0 to 12 percent slopes | 7K | Well drained | B | Not limited | Very limited |
| Interior Alaska Lowlands, Water | 7K | Not rated | Not rated | ||
| Steese silt loam, 12 to 20 percent slopes | 7K | Well drained | B | Very limited | Very limited |
| Fairbanks silt loams, gullied, 7 to 70 percent slopes | 7K | Well drained | B | Somewhat limited | Somewhat limited |
| Gerstle-Tanana complex | 7K | Well drained | B | Very limited | Very limited |
| Gerstle-Tanacross families complex, 0 to 4 percent slopes | 6K | Moderately well drained | B | 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 69% of soils are rated "very limited" for dwellings with basements. Specific challenges include poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 86% 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
Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.