San Luis Obispo County, California, Carrizo Plain Area
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 San Luis Obispo County, California, Carrizo Plain Area.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Balcom-Nacimiento complex, 30 to 50 percent slopes | 30K | Well drained | C | Very limited | Very limited |
| Beam-Panoza-Hillbrick complex, 50 to 75 percent slopes | 27K | Well drained | D | Very limited | Very limited |
| Padres sandy loam, 2 to 9 percent slopes | 24K | Well drained | B | Not limited | Very limited |
| Seaback-Panoza-Jenks complex, 15 to 30 percent slopes | 22K | Well drained | C | Very limited | Very limited |
| Polonio clay loam, 2 to 9 percent slopes | 22K | Well drained | C | Somewhat limited | Very limited |
| Balcom-Nacimiento complex, 15 to 30 percent slopes | 21K | Well drained | C | Very limited | Very limited |
| Beam-Panoza-Hillbrick complex, 30 to 50 percent slopes | 18K | Well drained | D | Very limited | Very limited |
| Panoza-Beam complex, 15 to 30 percent slopes | 17K | Well drained | C | Very limited | Very limited |
| Arbuckle sandy loam, 30 to 50 percent slopes | 16K | Well drained | C | Very limited | Very limited |
| San Timoteo-San Andreas-Bellyspring complex, 30 to 50 percent slopes | 15K | Well drained | B | Very limited | Very limited |
| Wasioja-Polonio complex, 2 to 5 percent slopes | 15K | Well drained | C | Somewhat limited | Very limited |
| Tajea-Saltos complex, 30 to 50 percent slopes | 12K | Well drained | C | Very limited | Very limited |
| Chicote complex, 0 to 2 percent slopes | 10K | Moderately well drained | D | Very limited | Very limited |
| Kilmer-Hillbrick complex, 15 to 50 percent slopes, MLRA 15 | 10K | Well drained | C | Very limited | Very limited |
| Panoza-Beam complex, 30 to 50 percent slopes | 10K | Well drained | C | Very limited | Very limited |
| Lithic Torriorthents-Semper-Rock outcrop complex, 50 to to 75 percent slopes | 10K | Well drained | D | Very limited | Very limited |
| Kilmer-Nacimiento-Aido complex, 30 to 60 percent slopes | 9K | Well drained | C | Very limited | Very limited |
| Balcom loam, 50 to 75 percent slopes | 9K | Well drained | C | Very limited | Very limited |
| Yeguas-Pinspring complex, 0 to 2 percent slopes | 9K | Well drained | C | Not limited | Very limited |
| Yeguas-Pinspring complex, 2 to 5 percent slopes | 9K | Well drained | C | Not limited | Very limited |
What This Means
Building & Foundations
About 75% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 100% 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.