Mendocino National Forest 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 Mendocino National Forest Area, California.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Colluvial land, 60 to 75 percent slopes | 35K | Excessively drained | Not rated | Not rated | |
| Sheetiron very gravelly loam, 30 to 50 percent slopes | 32K | Well drained | C | Very limited | Very limited |
| Sheetiron very gravelly loam, 50 to 75 percent slopes | 31K | Well drained | C | Very limited | Very limited |
| Sheetiron-Rock outcrop complex, 10 to 50 percent slopes | 27K | Well drained | C | Very limited | Very limited |
| Yollabolly very rocky loam, 30 to 65 percent slopes, low ffd | 24K | Well drained | D | Very limited | Very limited |
| Madonna complex, 10 to 50 percent slopes | 23K | Well drained | C | Very limited | Very limited |
| Rock land, mixed rocks | 17K | Excessively drained | Not rated | Not rated | |
| Los Osos-Yorkville complex, 10 to 50 percent slopes | 15K | Well drained | D | Very limited | Very limited |
| Madonna gravelly loam, 30 to 50 percent slopes, rocky | 13K | Well drained | C | Very limited | Very limited |
| Yollabolly-Rock outcrop complex, 50 to 75 percent slopes | 12K | Excessively drained | D | Very limited | Very limited |
| Tyson very gravelly loam, 30 to 50 percent slopes, rocky | 8K | Well drained | C | Very limited | Very limited |
| Maymen gravelly loam, 30 to 50 percent slopes | 8K | Somewhat excessively drained | D | Very limited | Very limited |
| Landslides, active, 20 to 65 percent slopes | 8K | Not rated | Not rated | ||
| Landslides, inactive, 10 to 50 percent slopes complex | 6K | Not rated | Not rated | ||
| Tyson-Rock outcrop complex, 10 to 50 percent slopes | 6K | Well drained | C | Very limited | Very limited |
| Etsel very gravelly loam, 50 to 75 percent slopes, rocky | 3K | Somewhat excessively drained | D | Very limited | Very limited |
| Shortyork-Yorkville-Witherell complex, 30 to 50 percent slopes, MLRA 5 | 3K | Well drained | C | Very limited | Very limited |
| Masterson very gravelly loam, 10 to 40 percent slopes, eroded | 3K | Well drained | C | Very limited | Very limited |
| Etsel-Rock outcrop, sedimentary complex, 30 to 75 percent slopes | 2K | Somewhat excessively drained | D | Very limited | Very limited |
| Masterson very gravelly loam, 10 to 40 percent slopes | 2K | Well drained | C | Very limited | Very limited |
What This Means
Building & Foundations
About 76% 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 76% 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.