Alsea Area, Oregon
The most common soil here is Bohannon, on about 46% of the land: a gravelly medial loam, a balanced mix that crumbles in your hand. Slickrock and Preacher come next.
About 97% of the land drains well.
USDA rates 94% of the land very limited for a standard septic drain field, and 91% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 3% of the land floods occasionally or more, and bedrock lies within 40 inches under 61% 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 soils you're most likely standing on
The biggest named soils in Alsea Area, Oregon, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
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 Alsea Area, Oregon. 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 |
|---|---|---|---|---|---|
| Bohannon gravelly loam, dissected, 50 to 90 percent slopes | 40K | Well drained | B | Very limited | Very limited |
| Bohannon-Slickrock gravelly loams, dissected, 37 to 50 percent slopes | 19K | Well drained | B | Very limited | Very limited |
| Slickrock gravelly loam, 25 to 37 percent slopes | 13K | Well drained | B | Very limited | Very limited |
| Bohannon gravelly loam, dissected, 37 to 50 percent slopes | 11K | Well drained | B | Very limited | Very limited |
| Bohannon-Slickrock gravelly loams, 35 to 50 percent slopes | 7K | Well drained | B | Very limited | Very limited |
| Slickrock gravelly loam, dissected, 25 to 37 percent slopes | 6K | Well drained | B | Very limited | Very limited |
| Bohannon gravelly loam, 50 to 75 percent slopes | 6K | Well drained | B | Very limited | Very limited |
| Bohannon gravelly loam, 35 to 50 percent slopes | 6K | Well drained | B | Very limited | Very limited |
| Preacher clay loam, ridge, 0 to 25 percent slopes | 5K | Well drained | B | Somewhat limited | Very limited |
| Slickrock gravelly loam, dissected, 37 to 50 percent slopes | 4K | Well drained | B | Very limited | Very limited |
| Nehalem silt loam | 3K | Well drained | B | Very limited | Very limited |
| Slickrock gravelly loam, 37 to 50 percent slopes | 3K | Well drained | B | Very limited | Very limited |
| Colluvial and Alluvial land | 3K | Well drained | B | Somewhat limited | Somewhat limited |
| Bohannon-Slickrock gravelly loams, dissected, 25 to 37 percent slopes | 3K | Well drained | B | Very limited | Very limited |
| Bohannon gravelly loam, ridge, 25 to 37 percent slopes | 3K | Well drained | B | Very limited | Very limited |
| Bohannon loam, ridge, 5 to 25 percent slopes | 3K | Well drained | B | Very limited | Very limited |
| Water | 3K | Not rated | Not rated | ||
| Bohannon-Slickrock gravelly loams, 25 to 35 percent slopes | 2K | Well drained | B | Very limited | Very limited |
| Bohannon-Slickrock gravelly loams, dissected, 50 to 75 percent slopes | 2K | Well drained | B | Very limited | Very limited |
| Klickitat gravelly clay loam, dissected, 50 to 85 percent slopes | 2K | 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 91% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 94% 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.