Sierra National Forest Area Parts of Fresno, California
The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low 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 Sierra National Forest Area Parts of Fresno, California.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Holland-Chaix families complex, 35 to 65 percent slopes | 35K | Well drained | B | Very limited | Very limited |
| Holland-Chawanakee families complex, 35 to 65 percent slopes | 32K | Well drained | B | Very limited | Very limited |
| Holland family, 35 to 65 percent slopes | 31K | Well drained | B | Very limited | Very limited |
| Rock outcrop-Lithic Xeropsamments complex, 15 to 45 percent slopes | 28K | Excessively drained | D | Very limited | Very limited |
| Cagwin family-Lithic Xeropsamments-Rock outcrop complex, 15 to 45 percent slopes | 27K | Well drained | A | Very limited | Very limited |
| Rock outcrop-Lithic Xeropsamments complex, 45 to 85 percent slopes | 26K | Excessively drained | D | Very limited | Very limited |
| Sirretta family and Umpa family, wet, 2 to 25 percent slopes | 24K | Somewhat excessively drained | A | Somewhat limited | Very limited |
| Holland family, 5 to 35 percent slopes | 23K | Well drained | B | Very limited | Very limited |
| Chawanakee family-Rock outcrop complex, 35 to 65 percent slopes | 22K | Somewhat excessively drained | D | Very limited | Very limited |
| Wilderness Area | 22K | Not rated | Not rated | ||
| Rock outcrop | 20K | Excessively drained | D | Not rated | Not rated |
| Coarsegold-Auberry families association, 35 to 65 percent slopes | 20K | Well drained | C | Very limited | Very limited |
| Chaix family, deep, 5 to 45 percent slopes | 19K | Well drained | A | Very limited | Very limited |
| Holland-Chaix families complex, 5 to 35 percent slopes | 19K | Well drained | B | Very limited | Very limited |
| Cagwin family, 25 to 60 percent slopes | 19K | Well drained | A | Very limited | Very limited |
| Stecum family-Rock outcrop complex, 5 to 45 percent slopes | 19K | Excessively drained | A | Very limited | Very limited |
| Entic Cryumbrepts-Rock outcrop complex, 15 to 55 percent slopes | 18K | Somewhat excessively drained | A | Very limited | Very limited |
| Ledford family-Entic Xerumbrepts-Rock outcrop association, 10 to 45 percent slopes | 18K | Well drained | A | Very limited | Very limited |
| Cagwin family-Lithic Xeropsamments-Rock outcrop complex, 45 to 65 percent slopes | 18K | Well drained | A | Very limited | Very limited |
| Shaver family, 35 to 65 percent slopes | 17K | Well drained | A | Very limited | Very limited |
What This Means
Building & Foundations
About 85% 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 90% 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.