Olympic National Park, Washington
The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low 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 Olympic National Park, Washington.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Skookumcreek-Bonjonpass-Mountscott complex, 0 to 100 percent slopes | 216K | Well drained | A | Very limited | Very limited |
| Mountmystery-Ignarcreek-Lakedilly complex, 15 to 100 percent slopes | 72K | Well drained | A | Very limited | Very limited |
| Hungrycreek-Nonamecreek-Lakedilly complex, 15 to 100 percent slopes | 65K | Well drained | A | Very limited | Very limited |
| Mountdeception-Irely complex, 35 to 100 percent slopes | 60K | Well drained | A | Very limited | Very limited |
| Rock outcrop-Rubble land complex, 15 to 100 percent slopes | 50K | Very limited | Very limited | ||
| Bonjonpass-Skookumcreek-Lapoetcreek complex, 0 to 65 percent slopes | 47K | Well drained | A | Very limited | Very limited |
| Sentinelpeak gravelly loam, 35 to 100 percent slopes | 43K | Well drained | A | Very limited | Very limited |
| Jolleycreek-Saghalie complex, 0 to 60 percent slopes | 33K | Well drained | A | Very limited | Very limited |
| Grandpass-Marmotlake-Allincreek,dry complex, 40 to 100 percent slopes | 31K | Well drained | A | Very limited | Very limited |
| Lollah-Hungrycreek-Allincreek complex, 15 to 100 percent slopes | 26K | Well drained | A | Very limited | Very limited |
| Catpeak-Allincreek-Rubble land complex, 0 to 100 percent slopes | 23K | Well drained | D | Very limited | Very limited |
| Sunnybrook-Mountscott complex, 0 to 100 percent slopes | 21K | Well drained | A | Very limited | Very limited |
| Mountstone-Mountfromme,cool,dry complex, 40 to 100 percent slopes | 20K | Well drained | A | Very limited | Very limited |
| Catpeak-Allincreek-Hungrycreek complex, 0 to 60 percent slopes | 19K | Well drained | A | Very limited | Very limited |
| Allincreek,dry-Rubble land complex, 0 to 100 percent slopes | 15K | Well drained | D | Very limited | Very limited |
| Mountmeany-Marymere complex, 0 to 10 percent slopes | 14K | Well drained | A | Very limited | Very limited |
| Water | 13K | Not rated | Not rated | ||
| Hatana-Cragcreek complex, 0 to 10 percent slopes | 13K | Well drained | A | Very limited | Very limited |
| Palix-Ozette complex, 5 to 25 percent slopes | 12K | Well drained | B | Very limited | Very limited |
| Sentinelpeak gravelly loam, 15 to 60 percent slopes | 11K | Well drained | A | Very limited | Very limited |
What This Means
Building & Foundations
About 98% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 98% 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.