Piedra Area, Colorado, Parts of Archuleta, Hinsdale, La Plata, Mineral, and Rio Grande Counties
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 Piedra Area, Colorado, Parts of Archuleta, Hinsdale, La Plata, Mineral, and Rio Grande Counties.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Dunton loam, 4 to 25 percent slopes | 66K | Well drained | C | Very limited | Very limited |
| Igneous outcrop-Cryorthents complex | 59K | D | Not rated | Not rated | |
| Carracas loam, 25 to 65 percent slopes | 54K | Well drained | D | Very limited | Very limited |
| Corta silt loam, 25 to 65 percent slopes | 44K | Well drained | C | Very limited | Very limited |
| Leal sandy loam, 25 to 65 percent slopes | 44K | Well drained | A | Very limited | Very limited |
| Igneous outcrop | 41K | D | Not rated | Not rated | |
| Chris gravelly loam, 25 to 65 percent slopes | 38K | Well drained | C | Very limited | Very limited |
| Corta silt loam, 4 to 25 percent slopes | 36K | Well drained | C | Very limited | Very limited |
| Sandstone outcrop-Ustorthents complex | 30K | D | Not rated | Not rated | |
| Chris stony loam, 25 to 65 percent slopes | 27K | Well drained | C | Very limited | Very limited |
| Pagosa loam, 4 to 25 percent slopes | 27K | Well drained | C | Very limited | Very limited |
| Grenadier loam, 25 to 65 percent slopes | 27K | Well drained | C | Very limited | Very limited |
| Hunchback clay loam, 4 to 15 percent slopes | 19K | Somewhat poorly drained | C | Very limited | Very limited |
| Nunn loam, 4 to 25 percent slopes | 17K | Well drained | C | Very limited | Very limited |
| Castelleia loam, 4 to 25 percent slopes | 16K | Well drained | C | Very limited | Very limited |
| Carracas loam, 4 to 25 percent slopes | 16K | Well drained | D | Very limited | Very limited |
| Woodrock silt loam, 25 to 65 percent slopes | 14K | Well drained | C | Very limited | Very limited |
| Hossick gravelly loam, 25 to 65 percent slopes | 13K | Well drained | C | Very limited | Very limited |
| Woodrock silt loam, 4 to 25 percent slopes | 12K | Well drained | C | Very limited | Very limited |
| Rubble land | 11K | A | Not rated | Not rated |
What This Means
Building & Foundations
About 76% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas. A geotechnical assessment is recommended before building.
Septic Systems
About 76% 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.