Benton County, 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 Benton County, Oregon.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Price-MacDunn-Ritner complex, 30 to 60 percent slopes | 23K | Well drained | C | Very limited | Very limited |
| Jory-Gelderman complex, 12 to 30 percent slopes | 20K | Well drained | C | Very limited | Very limited |
| Honeygrove-Peavine complex, 3 to 30 percent slopes | 15K | Well drained | C | Somewhat limited | Very limited |
| Preacher-Bohannon-Slickrock complex, 35 to 60 percent slopes | 15K | Well drained | B | Very limited | Very limited |
| Apt-McDuff complex, 5 to 30 percent slopes | 13K | Well drained | C | Somewhat limited | Very limited |
| Dayton silt loam, 0 to 2 percent slopes | 12K | Poorly drained | D | Very limited | Very limited |
| Dixonville-Gellatly complex, 12 to 30 percent slopes | 11K | Well drained | D | Very limited | Very limited |
| Bohannon-Preacher complex, 30 to 60 percent slopes | 11K | Well drained | C | Very limited | Very limited |
| Chehalis silty clay loam, 0 to 3 percent slopes | 11K | Well drained | B | Very limited | Very limited |
| Waldo silty clay loam, 0 to 3 percent slopes | 9K | Poorly drained | C/D | Very limited | Very limited |
| Digger-Remote-Umpcoos complex, 30 to 60 percent slopes | 8K | Well drained | C | Very limited | Very limited |
| Woodburn silt loam, 0 to 3 percent slopes | 8K | Moderately well drained | C | Very limited | Very limited |
| Jory silty clay loam, sedimentary bedrock, 12 to 20 percent slopes | 8K | Well drained | C | Very limited | Very limited |
| Bellpine-Jory complex, 30 to 60 percent slopes | 7K | Well drained | C | Very limited | Very limited |
| Apt-McDuff complex, 30 to 50 percent slopes | 7K | Well drained | C | Very limited | Very limited |
| Preacher-Bohannon complex, 5 to 35 percent slopes | 7K | Well drained | B | Somewhat limited | Somewhat limited |
| Bellpine-Jory complex, 12 to 20 percent slopes | 6K | Well drained | C | Very limited | Very limited |
| Slickrock gravelly medial loam, 3 to 25 percent slopes | 6K | Well drained | B | Somewhat limited | Somewhat limited |
| Honeygrove-Peavine complex, 30 to 60 percent slopes | 6K | Well drained | C | Very limited | Very limited |
| Amity silt loam, 0 to 3 percent slopes | 6K | Somewhat poorly drained | C/D | Very limited | Very limited |
What This Means
Building & Foundations
About 80% 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 93% 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.