Mendocino County, Eastern Part and Southwestern Part of Trinity County, California

Survey Area CA687 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 County, Eastern Part and Southwestern Part of Trinity County, California.

Soil Map UnitAcresDrainageHydro GroupDwellingsSeptic
Yorkville-Yorktree-Ashokawna complex, 30 to 50 percent slopes, MLRA 5 59K Well drainedDVery limitedVery limited
Yorkville-Ashokawna Witherell complex, 30 to 50 percent slopes, MLRA 5 59K Moderately well drainedCVery limitedVery limited
Sanhedrin-Kekawaka-Speaker complex, 30 to 50 percent slopes 53K Well drainedCVery limitedVery limited
Yorktree-Hopland-Woodin complex, 30 to 50 percent slopes 42K Well drainedCVery limitedVery limited
Casabonne-Wohly loams, 30 to 50 percent slopes 40K Well drainedCVery limitedVery limited
Shortyork-Yorkville-Witherell complex, 30 to 50 percent slopes, MLRA 5 36K Well drainedCVery limitedVery limited
Hopland-Sanhedrin-Kekawaka complex, 30 to 50 percent slopes 31K Well drainedCVery limitedVery limited
Maymen-Woodin-Etsel complex, 50 to 75 percent slopes 31K Somewhat excessively drainedDVery limitedVery limited
Hopland-Witherell-Ashokawna complex, 30 to 50 percent slopes, MLRA 5 30K Well drainedCVery limitedVery limited
Maymen-Etsel-Snook complex, 30 to 75 percent slopes, high ffd 29K Somewhat excessively drainedDVery limitedVery limited
Yorktree-Yorkville loams, 30 to 50 percent slopes 28K Well drainedCVery limitedVery limited
Maymen-Etsel-Snook complex, 30 to 75 percent slopes, low ffd 18K Somewhat excessively drainedDVery limitedVery limited
Area not surveyed, access denied 18K Not ratedNot rated
Casabonne-Wohly-Pardaloe complex, 50 to 75 percent slopes, low ffd 17K Well drainedCVery limitedVery limited
Pardaloe-Woodin complex, 50 to 75 percent slopes, low ffd 16K Well drainedBVery limitedVery limited
Bearwallow-Hellman-Witherell complex, 30 to 50 percent slopes 14K Well drainedCVery limitedVery limited
Yorktree-Hopland-Woodin complex, 50 to 75 percent slopes 14K Well drainedCVery limitedVery limited
Dingman-Beaughton complex, 5 to 50 percent slopes 14K Well drainedDVery limitedVery limited
Maymen-Etsel-Mayacama complex, 30 to 75 percent slopes 14K Somewhat excessively drainedDVery limitedVery limited
Shortyork-Yorkville-Witherell complex, 15 to 30 percent slopes, MLRA 5 13K Well drainedCVery limitedVery limited

What This Means

Building & Foundations

About 96% 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.

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