Costilla County Area, Colorado
The most common soil here is McGinty, on about 10% of the land: a sandy loam, gritty and crumbly. Cososa and Tolvar come next.
About 90% of the land drains well, and 5% stays wet for long stretches; groundwater comes within two feet of the surface under 2% of it.
USDA rates 68% of the land very limited for a standard septic drain field, and 55% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 4% of the land floods occasionally or more, and bedrock lies within 40 inches under 35% 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 Costilla County Area, Colorado, 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 B (moderate infiltration). The most common soil order is Aridisols — dry-climate soils with limited organic matter and often calcium carbonate accumulation. 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 Costilla County Area, Colorado. 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 |
|---|---|---|---|---|---|
| McGinty fine sandy loam, 0 to 1 percent slopes | 66K | Well drained | A | Not limited | Not limited |
| Fallriver-Rock outcrop complex, 10 to 65 percent slopes | 62K | Somewhat excessively drained | A | Very limited | Very limited |
| Cososa loamy sand, 0 to 3 percent slopes | 57K | Well drained | B | Not limited | Somewhat limited |
| Seitz-Tolvar complex, 10 to 65 percent slopes | 49K | Well drained | C | Very limited | Very limited |
| Tolvar-Laveta-Rock outcrop complex, 9 to 65 percent slopes | 36K | Well drained | B | Very limited | Very limited |
| Uracca-Culebra complex, 5 to 50 percent slopes | 35K | Well drained | B | Very limited | Very limited |
| Tolvar gravelly sandy loam, 10 to 65 percent slopes | 31K | Well drained | B | Very limited | Very limited |
| Comodore-Uracca-Rock outcrop complex, 5 to 65 percent slopes | 31K | Well drained | D | Very limited | Very limited |
| Rock outcrop-Rubble land complex, 45 to 90 percent slopes | 22K | D | Very limited | Very limited | |
| Cososa loamy sand, 3 to 9 percent slopes | 21K | Well drained | B | Not limited | Somewhat limited |
| Trinchera fine sandy loam, 3 to 9 percent slopes | 20K | Well drained | B | Not limited | Not limited |
| Travelers-Rock outcrop complex, 9 to 50 percent slopes | 19K | Well drained | D | Very limited | Very limited |
| Morval-Uracca complex, 5 to 35 percent slopes | 19K | Well drained | B | Very limited | Very limited |
| Kibin fine sandy loam, 0 to 3 percent slopes | 19K | Well drained | C | Not limited | Very limited |
| Lambe-Woodhall complex, 5 to 65 percent slopes | 18K | Well drained | B | Very limited | Very limited |
| Trinchera fine sandy loam, 1 to 3 percent slopes | 17K | Well drained | B | Not limited | Not limited |
| Vastine-Gerrard complex, 0 to 1 percent slopes | 15K | Poorly drained | C/D | Very limited | Very limited |
| Potrio gravelly silt loam, 1 to 6 percent slopes | 15K | Well drained | B | Somewhat limited | Very limited |
| Travelers-Rock outcrop complex, 1 to 9 percent slopes | 14K | Well drained | D | Very limited | Very limited |
| Grayco sandy loam, 0 to 2 percent slopes | 14K | Well drained | B | Not 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 55% 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 68% 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.