San Bernardino National Forest Area, California
The dominant drainage class is Somewhat excessively drained and the dominant hydrologic group is D (very slow infiltration, high 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 San Bernardino National Forest Area, California.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Trigo family-Lithic Xerorthents, warm complex, 50 to 75 percent slopes | 74K | Somewhat excessively drained | D | Very limited | Very limited |
| Rock outcrop, 30 to 100 percent slopes | 41K | Excessively drained | D | Very limited | Very limited |
| Springdale family-Lithic Xerorthents association, dry, 50 to 75 percent slopes | 31K | Somewhat excessively drained | A | Very limited | Very limited |
| Wapi-Pacifico families, dry-Rock outcrop complex, 50 to 75 percent slopes | 29K | Somewhat excessively drained | D | Very limited | Very limited |
| Wapi-Pacifico families, dry-Rock outcrop complex, 30 to 50 percent slopes | 28K | Somewhat excessively drained | D | Very limited | Very limited |
| Lithic Xerorthents-Rock outcrop complex, 50 to 100 percent slopes | 28K | Excessively drained | D | Very limited | Very limited |
| Lithic Xerorthents, warm-Rock outcrop complex, 50 to 100 percent slopes | 27K | Excessively drained | D | Very limited | Very limited |
| Lithic Xerorthents-Springdale family-Rubble land association, 50 to 100 percent slopes | 26K | Excessively drained | D | Very limited | Very limited |
| Wapi-Pacifico families-Rock outcrop complex, 50 to 75 percent slopes | 23K | Somewhat excessively drained | D | Very limited | Very limited |
| Pacifico-Wapi families complex, 30 to 50 percent slopes | 23K | Somewhat excessively drained | D | Very limited | Very limited |
| Wapi-Pacifico families, dry-Rock outcrop complex, 15 to 30 percent slopes | 21K | Somewhat excessively drained | D | Very limited | Very limited |
| Lithic Xerorthents, cool-Rock outcrop complex, 50 to 100 percent slopes | 20K | Excessively drained | D | Very limited | Very limited |
| Wapal family-Lithic Xerorthents, cool association, 50 to 75 percent slopes | 18K | Somewhat excessively drained | A | Very limited | Very limited |
| Typic Xerorthents, warm-Typic Haploxeralfs-Badland complex, 30 to 100 percent slopes | 17K | Somewhat excessively drained | B | Very limited | Very limited |
| Trigo family-Lithic Xerorthents, warm complex, 30 to 50 percent slopes | 17K | Somewhat excessively drained | D | Very limited | Very limited |
| Olete-Goulding families-Rubble land association, 50 to 100 percent slopes | 16K | Well drained | Very limited | Very limited | |
| Osito-Modesto families association, 30 to 50 percent slopes | 16K | Well drained | D | Very limited | Very limited |
| Morical-Wind River families complex, 30 to 50 percent slopes | 15K | Well drained | C | Very limited | Very limited |
| Pacifico-Preston families complex, 30 to 50 percent slopes | 15K | Somewhat excessively drained | D | Very limited | Very limited |
| Morical-Wind River families complex, 15 to 30 percent slopes | 15K | Well drained | C | Very limited | Very limited |
What This Means
Building & Foundations
About 100% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, sandy or gravelly soils with low bearing capacity. A geotechnical assessment is recommended before building.
Septic Systems
About 100% of soils are rated "very limited" for septic absorption fields. The well-drained soils may actually drain too fast for standard leach fields, allowing effluent to reach groundwater. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Soils tend to drain very quickly, meaning nutrients and water don't stick around long. Raised beds with amended soil, drip irrigation, and heavy mulching will give the best results. Compost is your best friend here — it improves water retention dramatically.