Humboldt and Del Norte Area, California
The dominant drainage class is 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 Humboldt and Del Norte Area, California.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Bagaul-Burroin-Redtop complex, 15 to 50 percent slopes | 53K | Well drained | C | Very limited | Very limited |
| Slidecreek-Lackscreek-Coppercreek complex, 50 to 75 percent slopes | 36K | Well drained | C | Very limited | Very limited |
| Coppercreek-Slidecreek-Tectah complex, 30 to 50 percent slopes | 27K | Well drained | C | Very limited | Very limited |
| Hullygully-Burroin complex, 50 to 75 percent slopes | 24K | Well drained | C | Very limited | Very limited |
| Sasquatch-Sisterrocks-Ladybird complex, 30 to 50 percent | 22K | Well drained | C | Very limited | Very limited |
| Darkwoods-Firmountain-Oakside complex, 50 to 75 percent slopes | 20K | Well drained | C | Very limited | Very limited |
| Sisterrocks-Sasquatch-Footstep complex, 50 to 75 percent | 19K | Well drained | C | Very limited | Very limited |
| Sidehill-Oakside-Darkwoods complex, 50 to 100 percent slopes | 19K | Well drained | C | Very limited | Very limited |
| Scaath-Rockysaddle-Wiregrass complex, 50 to 75 percent slopes | 15K | Well drained | C | Very limited | Very limited |
| Burgsblock-Coolyork-Tannin complex, 30 to 50 percent slopes | 13K | Well drained | C | Very limited | Very limited |
| Coppercreek-Slidecreek-Lackscreek complex, 30 to 50 percent slopes | 13K | Well drained | C | Very limited | Very limited |
| Mooncreek-Tossup-Noisy complex, 15 to 50 percent slopes | 13K | Well drained | C | Very limited | Very limited |
| Mooncreek-Noisy-Sidehill complex, 30 to 75 percent slopes | 13K | Well drained | C | Very limited | Very limited |
| Darkwoods-Firmountain-Oakside complex, 75 to 110 percent slopes | 12K | Well drained | C | Very limited | Very limited |
| Burroin-Redtop complex, 9 to 30 percent slopes | 12K | Well drained | C | Very limited | Very limited |
| Tectah-Coppercreek-Trailhead complex, 0 to 30 percent slopes | 10K | Well drained | C | Somewhat limited | Very limited |
| Wiregrass-Rockysaddle-Peacock complex, 30 to 50 percent slopes | 9K | Well drained | C | Very limited | Very limited |
| Darkwoods-Firmountain-Redtop complex, 30 to 50 percent slopes | 9K | Well drained | B | Very limited | Very limited |
| Coppercreek-Ahpah-Lackscreek complex, 30 to 50 percent slopes | 8K | Well drained | C | Very limited | Very limited |
| Coppercreek-Tectah-Slidecreek complex, 9 to 30 percent slopes | 8K | Well drained | C | Very limited | Very limited |
What This Means
Building & Foundations
About 97% 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.