Island County, Washington
The dominant drainage class is Somewhat excessively 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 Island County, Washington.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Elwha-Zylstra-Morancreek, cool, complex, 2 to 12 percent slopes | 19K | Moderately well drained | B/D | Very limited | Very limited |
| Everett-Alderwood complex, 3 to 15 percent slopes | 13K | Somewhat excessively drained | A | Somewhat limited | Very limited |
| Indianola-Uselessbay complex, 5 to 30 percent slopes | 11K | Somewhat excessively drained | A | Very limited | Very limited |
| Everett-Alderwood complex, 15 to 40 percent slopes | 7K | Moderately well drained | A | Very limited | Very limited |
| Mitchellbay gravelly sandy loam, cool, 2 to 10 percent slopes | 7K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Utsalady-Uselessbay complex, 2 to 12 percent slopes | 6K | Well drained | A | Somewhat limited | Very limited |
| Indianola loamy sand, 3 to 15 percent slopes | 6K | Somewhat excessively drained | A | Not limited | Very limited |
| Uselessbay-Utsalady complex, 0 to 10 percent slopes | 6K | Moderately well drained | A/D | Very limited | Very limited |
| Everett-Alderwood complex, 0 to 5 percent slopes | 5K | Somewhat excessively drained | A | Not limited | Very limited |
| Aquic Dystroxerepts-Oxyaquic Xerorthents complex, 15 to 70 percent slopes | 3K | Somewhat poorly drained | A/D | Very limited | Very limited |
| Beaches-Endoaquents, tidal-Xerorthents association, 0 to 5 percent slopes | 3K | Very limited | Very limited | ||
| Zylstra-Frostad complex, 0 to 8 percent slopes | 3K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Sholander, cool-Spieden complex, 0 to 5 percent slopes | 3K | Poorly drained | C/D | Very limited | Very limited |
| Everett sandy loam, 15 to 40 percent slopes | 2K | Somewhat excessively drained | A | Very limited | Very limited |
| Sucia loamy sand, cool, 2 to 10 percent slopes | 2K | Moderately well drained | A/D | Very limited | Very limited |
| Indianola loamy sandy, dry, 0 to 5 percent slopes | 2K | Somewhat excessively drained | A | Not limited | Very limited |
| Coveland loam, cool, 0 to 5 percent slopes | 2K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Hoypus sandy loam, 0 to 3 percent slopes | 2K | Somewhat excessively drained | A | Not limited | Very limited |
| Sholander, cool-Limepoint complex, 0 to 8 percent slopes | 2K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Zylstra-Alderwood complex, 3 to 30 percent slopes | 2K | Somewhat poorly drained | C/D | Very limited | Very limited |
What This Means
Building & Foundations
About 67% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas, sandy or gravelly soils with low bearing capacity. A geotechnical assessment is recommended before building.
Septic Systems
About 100% of soils are rated "very limited" for septic absorption fields. The well-drained soils may actually drain too fast for standard leach fields, allowing effluent to reach groundwater. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Soils tend to drain very quickly, meaning nutrients and water don't stick around long. Raised beds with amended soil, drip irrigation, and heavy mulching will give the best results. Compost is your best friend here — it improves water retention dramatically.