Olympic National Forest Area, Washington (Parts of Clallam, Grays Harbor, Jefferson, and Mason Counties)
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 Olympic National Forest Area, Washington (Parts of Clallam, Grays Harbor, Jefferson, and Mason Counties).
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Rock outcrop-Rubble land complex, 15 to 100 percent slopes | 40K | Very limited | Very limited | ||
| Skookumcreek-Bonjonpass-Mountscott complex, 0 to 100 percent slopes | 17K | Well drained | A | Very limited | Very limited |
| Waketickeh-Fricaba complex, 60 to 100 percent south slopes | 13K | Well drained | D | Very limited | Very limited |
| Fricaba-Waketickeh-Duckabush complex, 60 to 90 percent south slopes | 11K | Well drained | B | Very limited | Very limited |
| Rock outcrop-Haplocryands association, glacial trough, 60 to 100 percent slopes | 11K | Very limited | Very limited | ||
| Sawpeak-Walkinshaw-McGravey complex, 60 to 90 percent north slopes | 10K | Well drained | B | Very limited | Very limited |
| Larsencreek-Elklake-Eatoncreek complex, 60 to 100 percent north slopes | 9K | Well drained | B | Very limited | Very limited |
| Aristine-Brokenfinger complex, 30 to 60 percent north slopes | 9K | Moderately well drained | C/D | Very limited | Very limited |
| Fricaba-Waketickeh-Duckabush complex, low precipitation, 60 to 90 percent south slopes | 9K | Well drained | B | Very limited | Very limited |
| Sorethumb-Blackjack complex, 50 to 100 percent south slopes | 9K | Well drained | C | Very limited | Very limited |
| Hapludands and Dystrudepts soils, 50 to 90 percent slopes | 9K | Well drained | A | Very limited | Very limited |
| Sappho-Edenvalley-Pysht complex, 40 to 80 percent north slopes | 9K | Well drained | C | Very limited | Very limited |
| McKinnon-Flatbottom-Lizardlake complex, 60 to 100 percent south slopes | 9K | Well drained | B | Very limited | Very limited |
| Tunnelcreek-Juandefuca-Pennycreek complex, 60 to 90 percent south slopes | 8K | Well drained | B | Very limited | Very limited |
| Solleks-Kestner complex, 15 to 50 percent slopes | 8K | Well drained | C | Very limited | Very limited |
| Mudcreek gravelly loam, 5 to 20 percent slopes | 8K | Moderately well drained | C/D | Very limited | Very limited |
| Tylerpeak-Bungalow-Mueller complex, 60 to 90 percent north slopes | 8K | Well drained | B | Very limited | Very limited |
| Quinault-Murhut complex, 60 to 100 percent north slopes | 8K | Well drained | D | Very limited | Very limited |
| Edenvalley-Sappho-Pysht complex, 15 to 40 percent slopes | 8K | Well drained | C | Very limited | Very limited |
| Rock outcrop-Haplocryands-Rubble land association, cirque headwalls, 60 to 100 percent slopes | 8K | Very limited | Very limited |
What This Means
Building & Foundations
About 100% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes. A geotechnical assessment is recommended before building.
Septic Systems
About 100% 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.