Jefferson County Area, Washington
The most common soil here is Hoko, on about 12% of the land: a gravelly medial silt loam, smooth, like flour. Dimal and Solleks come next.
About 55% of the land drains well, and 5% stays wet for long stretches; groundwater comes within two feet of the surface under 24% of it.
USDA rates 96% of the land very limited for a standard septic drain field, and 91% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 4% of the land floods occasionally or more, and bedrock lies within 40 inches under 17% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Jefferson County Area, Washington, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Moderately well drained and the dominant hydrologic group is B (moderate infiltration). The most common soil order is Inceptisols — young soils with minimal horizon development but more than Entisols. 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 Jefferson County Area, Washington. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Dimal very flaggy silty clay loam, 50 to 90 percent slopes | 49K | Somewhat excessively drained | D | Very limited | Very limited |
| Solleks channery silty clay loam, 30 to 50 percent slopes | 32K | Well drained | B | Very limited | Very limited |
| Hoko gravelly silt loam, 0 to 15 percent slopes | 25K | Moderately well drained | C | Very limited | Very limited |
| Hoko-Snahopish association, hilly | 17K | Moderately well drained | C | Very limited | Very limited |
| Alderwood gravelly sandy loam, 0 to 15 percent slopes | 16K | Moderately well drained | B | Very limited | Very limited |
| Skookumcreek-Bonjonpass-Mountscott complex, 0 to 100 percent slopes | 15K | Well drained | A | Very limited | Very limited |
| Klone-Hoko association, moderately steep | 15K | Well drained | B | Very limited | Very limited |
| Sinclair gravelly sandy loam, 0 to 15 percent slopes | 13K | Moderately well drained | B | Very limited | Very limited |
| Calawah silt loam, 0 to 8 percent slopes | 12K | Moderately well drained | B | Not limited | Somewhat limited |
| Mountdeception-Irely complex, 35 to 100 percent slopes | 11K | Well drained | A | Very limited | Very limited |
| Willapa-Calawah complex, 15 to 45 percent slopes | 9K | Moderately well drained | B/D | Very limited | Very limited |
| Clallam gravelly sandy loam, 0 to 15 percent slopes | 9K | Well drained | D | Very limited | Very limited |
| Alderwood gravelly sandy loam, 15 to 30 percent slopes | 7K | Moderately well drained | B | Very limited | Very limited |
| Snahopish silty clay loam, 0 to 30 percent slopes | 6K | Well drained | B | Very limited | Very limited |
| Alderwood gravelly loam, 0 to 15 percent slopes | 6K | Moderately well drained | B | Very limited | Very limited |
| Sinclair gravelly sandy loam, 15 to 30 percent slopes | 6K | Moderately well drained | B | Very limited | Very limited |
| Jolleycreek-Saghalie complex, 0 to 60 percent slopes | 6K | Well drained | A | Very limited | Very limited |
| Itswoot very cobbly silt loam, 0 to 30 percent slopes | 5K | Well drained | C | Very limited | Very limited |
| Hoko-Tealwhit association, gently rolling | 5K | Moderately well drained | C | Very limited | Very limited |
| Dabob very gravelly sandy loam, 0 to 15 percent slopes | 5K | Moderately well drained | B | Very limited | Very limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 91% 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 96% 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.