Clatsop County, Oregon
The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). 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 Clatsop County, Oregon.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Rinearson silt loam, 30 to 60 percent slopes | 46K | Well drained | B | Very limited | Very limited |
| Water | 43K | Not rated | Not rated | ||
| Templeton-Ecola silt loams, 30 to 60 percent slopes | 39K | Well drained | B | Very limited | Very limited |
| Klootchie-Necanicum complex, 30 to 60 percent slopes | 37K | Well drained | B | Very limited | Very limited |
| Skipanon gravelly medial silt loam, 30 to 60 percent slopes | 33K | Well drained | B | Very limited | Very limited |
| Skipanon gravelly medial silt loam, 3 to 30 percent slopes | 28K | Well drained | B | Very limited | Very limited |
| Rinearson silt loam, 3 to 30 percent slopes | 20K | Well drained | B | Very limited | Very limited |
| Caterl-Laderly complex, 30 to 60 percent slopes | 18K | Well drained | B | Very limited | Very limited |
| Templeton medial silt loam, 3 to 30 percent slopes | 16K | Well drained | B | Very limited | Very limited |
| Klootchie silt loam, 3 to 30 percent slopes | 15K | Well drained | B | Very limited | Very limited |
| Scaponia-Braun silt loams, 30 to 60 percent slopes | 14K | Well drained | B | Very limited | Very limited |
| Necanicum-Ascar complex, 30 to 60 percent slopes | 13K | Well drained | B | Very limited | Very limited |
| Laderly-Rock outcrop complex, 60 to 90 percent slopes | 11K | Well drained | B | Very limited | Very limited |
| Hemcross-Klistan complex, 30 to 60 percent slopes | 11K | Well drained | B | Very limited | Very limited |
| Svensen medial loam, 30 to 60 percent slopes | 10K | Well drained | A | Very limited | Very limited |
| Coquille-Clatsop complex, protected, 0 to 1 percent slopes | 10K | Very poorly drained | C/D | Very limited | Very limited |
| Murtip-Caterl complex, 30 to 60 percent slopes | 9K | Well drained | B | Very limited | Very limited |
| Coquille-Clatsop complex, 0 to 1 percent slopes | 8K | Very poorly drained | C/D | Very limited | Very limited |
| Necanicum-Ascar complex, 60 to 90 percent slopes | 7K | Well drained | B | Very limited | Very limited |
| Caterl-Laderly complex, 3 to 30 percent slopes | 7K | Well drained | B | Very limited | Very limited |
What This Means
Building & Foundations
About 89% 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 89% 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.