Grays Harbor County Area, Pacific and Wahkiakum Counties, Washington
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 Grays Harbor County Area, Pacific and Wahkiakum Counties, Washington.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Zenker silt loam, 30 to 65 percent slopes | 86K | Well drained | B | Very limited | Very limited |
| Elochoman silt loam, 8 to 30 percent slopes | 86K | Well drained | B | Very limited | Very limited |
| Lytell silt loam, 30 to 65 percent slopes | 80K | Well drained | B | Very limited | Very limited |
| Lytell silt loam, 8 to 30 percent slopes | 67K | Well drained | B | Very limited | Very limited |
| Ocosta silty clay loam | 44K | Poorly drained | D | Very limited | Very limited |
| Water | 44K | Not rated | Not rated | ||
| Bunker silt loam, 30 to 65 percent slopes | 43K | Well drained | B | Very limited | Very limited |
| Hoquiam silt loam, 8 to 30 percent slopes | 39K | Well drained | B | Very limited | Very limited |
| Knappton silt loam, 30 to 65 percent slopes | 37K | Well drained | B | Very limited | Very limited |
| Le Bar silt loam, 8 to 30 percent slopes | 36K | Well drained | B | Very limited | Very limited |
| Palix silt loam, 30 to 65 percent slopes | 36K | Well drained | B | Very limited | Very limited |
| Zenker silt loam, 65 to 90 percent slopes | 35K | Well drained | B | Very limited | Very limited |
| Buckpeak silt loam, 30 to 65 percent slopes | 32K | Well drained | B | Very limited | Very limited |
| Astoria silt loam, 8 to 30 percent slopes | 27K | Well drained | B | Very limited | Very limited |
| Grehalem silt loam | 26K | Well drained | B | Very limited | Very limited |
| Elochoman silt loam, 30 to 65 percent slopes | 26K | Well drained | B | Very limited | Very limited |
| Calawah silt loam, 1 to 8 percent slopes | 25K | Well drained | B | Not limited | Somewhat limited |
| Bunker silt loam, 5 to 30 percent slopes | 25K | Well drained | B | Very limited | Very limited |
| Mopang silt loam, 5 to 30 percent slopes | 24K | Well drained | B | Very limited | Very limited |
| Willapa silt loam, 8 to 30 percent slopes | 24K | Moderately well drained | C | Very limited | Very limited |
What This Means
Building & Foundations
About 91% 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 91% 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.