Glenn County, California
The most common soil here is Sheetiron, on about 9% of the land: a gravelly sandy loam, gritty and crumbly. Maymen and Millsholm come next.
About 74% of the land drains well, and 15% stays wet for long stretches; groundwater comes within two feet of the surface under 3% of it.
USDA rates 94% of the land very limited for a standard septic drain field, and 79% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 6% of the land floods occasionally or more, and bedrock lies within 40 inches under 43% 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 Glenn County, 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 D (very slow infiltration, high 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 Glenn County, 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 |
|---|---|---|---|---|---|
| Sheetiron gravelly loam, 30 to 50 percent slopes, MLRA 5 | 51K | Well drained | C | Very limited | Very limited |
| Maymen gravelly loam, schist bedrock, 30 to 65 percent slopes | 51K | Somewhat excessively drained | D | Very limited | Very limited |
| Sehorn-Millsholm association, 15 to 50 percent slopes, MLRA 15 | 38K | Well drained | D | Very limited | Very limited |
| Tehama silt loam, 0 to 3 percent slopes, MLRA 17 | 31K | Well drained | C | Somewhat limited | Very limited |
| Hillgate loam, 0 to 2 percent slopes, MLRA 17 | 23K | Well drained | C | Somewhat limited | Very limited |
| Zamora silty clay loam, 0 to 3 percent slopes, MLRA 17 | 22K | Well drained | C | Very limited | Very limited |
| Sheetiron gravelly loam, shallow, 30 to 50 percent slopes | 20K | Well drained | D | Very limited | Very limited |
| Myers clay, 0 to 1 percent slopes, MLRA 17 | 19K | Moderately well drained | D | Very limited | Very limited |
| Arbuckle gravelly loam, 0 to 2 percent slopes, MLRA 17 | 17K | Well drained | B | Not limited | Somewhat limited |
| Wyo silt loam | 16K | Well drained | B | Not limited | Somewhat limited |
| Newville gravelly loam, 10 to 40 percent slopes, MLRA 17 | 14K | Well drained | C | Very limited | Very limited |
| Marvin silty clay loam, 0 to 2 percent slopes | 13K | Somewhat poorly drained | D | Very limited | Very limited |
| Henneke stony clay loam, 30 to 65 percent slopes | 12K | Well drained | C | Very limited | Very limited |
| Capay clay, 0 to 4 percent slopes, MLRA 17 | 11K | Somewhat poorly drained | C | Very limited | Very limited |
| Landlow clay | 9K | Somewhat poorly drained | D | Very limited | Very limited |
| Nacimiento clay, 15 to 30 percent slopes | 9K | Well drained | C | Very limited | Very limited |
| Marvin silty clay loam, slightly saline-alkali, 0 to 1 percent slopes | 8K | Somewhat poorly drained | D | Very limited | Very limited |
| Newville-Gullied land complex, 8 to 30 percent slopes | 8K | Well drained | D | Somewhat limited | Very limited |
| Colluvial land, sedimentary rocks | 8K | Very limited | Very limited | ||
| Willows clay, dense subsoil, slightly saline-alkali | 8K | Poorly drained | D | 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 79% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 94% 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.