Linn County Area, Oregon
The dominant drainage class is Well drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). 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 Linn County Area, Oregon.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Dayton silt loam | 58K | Poorly drained | D | Very limited | Very limited |
| Honeygrove silty clay loam, 12 to 25 percent slopes | 32K | Well drained | C | Very limited | Very limited |
| Harrington-Klickitat complex, 50 to 75 percent south slopes | 31K | Well drained | B | Very limited | Very limited |
| Woodburn silt loam, 0 to 3 percent slopes | 29K | Moderately well drained | C | Very limited | Very limited |
| Amity silt loam | 26K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Bashaw silty clay | 25K | Poorly drained | D | Very limited | Very limited |
| Harrington-Klickitat complex, 50 to 75 percent north slopes | 17K | Well drained | B | Very limited | Very limited |
| Keel gravelly silt loam, 45 to 75 percent slopes | 17K | Well drained | C | Very limited | Very limited |
| Holcomb silt loam | 17K | Somewhat poorly drained | D | Very limited | Very limited |
| Honeygrove silty clay loam, 25 to 50 percent south slopes | 16K | Well drained | C | Very limited | Very limited |
| Coburg silty clay loam | 15K | Moderately well drained | C | Very limited | Very limited |
| Water | 14K | Not rated | Not rated | ||
| Newberg fine sandy loam | 14K | Well drained | A | Very limited | Very limited |
| Blachly clay loam, 3 to 30 percent slopes | 12K | Well drained | C | Very limited | Very limited |
| Malabon silty clay loam | 12K | Well drained | C | Somewhat limited | Very limited |
| Keel gravelly silt loam, 25 to 45 percent slopes | 11K | Well drained | C | Very limited | Very limited |
| Nekia silty clay loam, 2 to 12 percent slopes | 11K | Well drained | C | Very limited | Very limited |
| Chehalis silty clay loam | 11K | Well drained | B | Very limited | Very limited |
| Concord silt loam | 11K | Poorly drained | C/D | Very limited | Very limited |
| Kinney-Klickitat complex, 50 to 70 percent south slopes | 11K | Well drained | B | Very limited | Very limited |
What This Means
Building & Foundations
About 93% 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 96% 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.