Whatcom County Area, Washington
The dominant drainage class is Moderately 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 Whatcom County Area, Washington.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Whatcom-Labounty silt loams, 0 to 8 percent slopes | 13K | Moderately well drained | C | Very limited | Very limited |
| Whatcom silt loam, 3 to 8 percent slopes | 11K | Moderately well drained | C | Very limited | Very limited |
| Edmonds-Woodlyn loams, 0 to 2 percent slopes | 10K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Hale silt loam, drained, 0 to 2 percent slopes | 10K | Somewhat poorly drained | C | Somewhat limited | Very limited |
| Andic Xerochrepts, 60 to 90 percent slopes | 10K | Well drained | C | Very limited | Very limited |
| Lynden sandy loam, 0 to 3 percent slopes | 10K | Well drained | A | Not limited | Very limited |
| Tromp loam, 0 to 2 percent slopes | 9K | Moderately well drained | C | Very limited | Very limited |
| Shuksan-Kulshan-Rock outcrop complex, 50 to 80 percent slopes | 9K | Moderately well drained | C | Very limited | Very limited |
| Pangborn muck, drained, 0 to 2 percent slopes | 8K | Very poorly drained | C | Very limited | Very limited |
| Squalicum gravelly loam, 15 to 30 percent slopes | 7K | Moderately well drained | B | Very limited | Very limited |
| Briscot silt loam, drained, 0 to 2 percent slopes | 7K | Poorly drained | C | Very limited | Very limited |
| Whatcom silt loam, 8 to 15 percent slopes | 7K | Moderately well drained | C | Very limited | Very limited |
| Oakes very gravelly loam, 30 to 60 percent slopes | 7K | Well drained | B | Very limited | Very limited |
| Whitehorn silt loam, 0 to 2 percent slopes | 6K | Poorly drained | C/D | Very limited | Very limited |
| Andic Xerochrepts-Rock outcrop complex, 60 to 90 percent slopes | 6K | Well drained | C | Very limited | Very limited |
| Winston silt loam, 0 to 3 percent slopes | 6K | Well drained | B | Not limited | Very limited |
| Andic Xerochrepts, cool-Rock outcrop complex, 60 to 90 percent slopes | 6K | Well drained | B | Very limited | Very limited |
| Nati loam, 30 to 60 percent slopes | 6K | Well drained | C | Very limited | Very limited |
| Squalicum gravelly loam, 5 to 15 percent slopes | 6K | Moderately well drained | B | Somewhat limited | Very limited |
| Whatcom silt loam, 0 to 3 percent slopes | 6K | Moderately well drained | C | Very limited | Very limited |
What This Means
Building & Foundations
About 80% 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 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.