San Mateo County, Eastern Part, and San Francisco County, California
The dominant drainage class is Well 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 Mateo County, Eastern Part, and San Francisco County, California.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Water | 105K | D | Not rated | Not rated | |
| Urban land-Orthents, reclaimed complex, 0 to 2 percent slopes | 18K | D | Not limited | Not limited | |
| Alambique-McGarvey complex, 30 to 75 percent slopes | 13K | Well drained | C | Very limited | Very limited |
| Urban land | 13K | D | Not limited | Not limited | |
| Orthents, cut and fill-Urban land complex, 5 to 75 percent slopes | 12K | Well drained | Very limited | Very limited | |
| Urban land-Orthents, cut and fill complex, 0 to 5 percent slopes | 10K | D | Not limited | Not limited | |
| Urban land-Orthents, cut and fill complex, 5 to 75 percent slopes | 9K | D | Very limited | Very limited | |
| Barnabe-Candlestick complex, 30 to 75 percent slopes | 8K | Well drained | D | Very limited | Very limited |
| Urban land-Orthents, smoothed complex, 5 to 50 percent slopes | 8K | D | Very limited | Very limited | |
| Urban land-Sirdrak complex, 2 to 50 percent slopes | 6K | D | Very limited | Very limited | |
| Botella-Urban land complex, 0 to 5 percent slopes | 6K | C | Somewhat limited | Very limited | |
| Los Gatos loam, 30 to 75 percent slopes, MLRA 15 | 6K | Well drained | C | Very limited | Very limited |
| Candlestick-Kron-Buriburi complex, 30 to 75 percent slo pes | 5K | Well drained | C | Very limited | Very limited |
| Orthents, cut and fill, 0 to 15 percent slopes | 5K | Well drained | Not limited | Not limited | |
| Fagan loam, 15 to 50 percent slopes | 4K | Well drained | C | Very limited | Very limited |
| Novato clay, 0 to 1 percent slopes ponded | 3K | Very poorly drained | C/D | Very limited | Very limited |
| Reyes clay, 0 to 1 percent slopes | 3K | Somewhat poorly drained | C | Very limited | Very limited |
| Scarper-Miramar complex, 30 to 75 percent slopes | 2K | Well drained | B | Very limited | Very limited |
| Accelerator-Fagan-Urban land complex, 5 to 15 percent s lopes | 2K | Well drained | C | Somewhat limited | Very limited |
| Sirdrak sand, 5 to 50 percent slopes | 2K | Somewhat excessively drained | A | Very limited | Very limited |
What This Means
Building & Foundations
About 33% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 37% of soils have significant septic limitations, while others are more suitable. A perc test is essential — conditions vary across the area.
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.