Shasta County Area, California
The most common soil here is Cohasset, on about 9% of the land: a loam, a balanced mix that crumbles in your hand. Newtown and Aiken come next.
About 93% of the land drains well; groundwater comes within two feet of the surface under 2% of it.
USDA rates 99% of the land very limited for a standard septic drain field, and 82% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 1% of the land floods occasionally or more, and bedrock lies within 40 inches under 45% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Shasta County Area, California, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). The most common soil order is Alfisols — moderately leached forest soils with a clay-enriched subsoil. 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 Shasta County Area, California. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Cohasset stony loam, 0 to 30 percent slopes | 52K | Well drained | B | Very limited | Very limited |
| Windy and McCarthy stony sandy loams, 0 to 30 percent slopes | 30K | Well drained | A | Very limited | Very limited |
| Guenoc very rocky loam, 0 to 30 percent slopes | 28K | Well drained | C | Very limited | Very limited |
| Newtown gravelly loam, 30 to 50 percent slopes, eroded | 28K | Well drained | C | Very limited | Very limited |
| Maymen very stony loam, 30 to 80 percent slopes, eroded | 25K | Somewhat excessively drained | D | Very limited | Very limited |
| Cohasset stony loam, 10 to 50 percent slopes, MLRA 22B | 25K | Well drained | C | Very limited | Very limited |
| Toomes very rocky loam, 0 to 50 percent slopes | 24K | Somewhat excessively drained | D | Very limited | Very limited |
| Toomes very stony loam, 0 to 30 percent slopes | 21K | Well drained | D | Very limited | Very limited |
| Cohasset loam, 0 to 30 percent slopes | 20K | Well drained | B | Very limited | Very limited |
| Rockland | 18K | Excessively drained | Very limited | Very limited | |
| Colluvial land | 17K | Excessively drained | Very limited | Very limited | |
| Red Bluff loam, 0 to 3 percent slopes, MLRA 17, moist | 15K | Well drained | C | Not limited | Very limited |
| Newtown gravelly loam, 15 to 30 percent slopes | 14K | Well drained | C | Very limited | Very limited |
| Windy and McCarthy very stony sandy loams, 30 to 50 percent slopes | 13K | Well drained | A | Very limited | Very limited |
| Chaix sandy loam, 50 to 70 percent | 13K | Somewhat excessively drained | B | Very limited | Very limited |
| Goulding very rocky loam, 50 to 70 percent slopes, eroded | 13K | Well drained | D | Very limited | Very limited |
| Kilarc very stony sandy clay loam, 10 to 30 percent slopes | 13K | Moderately well drained | C | Very limited | Very limited |
| Marpa gravelly loam, 50 to 75 percent slopes | 12K | Well drained | C | Very limited | Very limited |
| Millsholm gravelly loam, 30 to 50 percent slopes, MLRA 15 | 12K | Well drained | D | Very limited | Very limited |
| Aiken stony loam, 15 to 30 percent | 12K | Well drained | C | Very limited | Very limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 82% 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 99% 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.