Arapahoe County, Colorado
The most common soil here is Bresser, on about 10% of the land: a sandy loam, gritty and crumbly. Nunn and Renohill come next.
About 96% of the land drains well.
USDA rates 60% of the land very limited for a standard septic drain field, and 21% 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 29% 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 Arapahoe County, 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 C (slow infiltration, moderate runoff). The most common soil order is Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. 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 Arapahoe County, 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 |
|---|---|---|---|---|---|
| Nunn-Bresser-Ascalon complex, 0 to 3 percent slopes | 51K | Well drained | B | Not limited | Very limited |
| Renohill-Buick loams, 3 to 9 percent slopes | 32K | Well drained | D | Somewhat limited | Very limited |
| Adena-Colby silt loams, 1 to 5 percent slopes | 31K | Well drained | C | Not limited | Somewhat limited |
| Bresser-Truckton sandy loams, 3 to 5 percent slopes | 29K | Well drained | B | Not limited | Somewhat limited |
| Weld-Deertrail silt loams, 0 to 3 percent slopes | 25K | Well drained | C | Not limited | Somewhat limited |
| Nunn loam, 1 to 3 percent slopes | 24K | Well drained | C | Somewhat limited | Very limited |
| Terry-Olney-Thedalund sandy loams, 5 to 20 percent slopes | 21K | Well drained | B | Somewhat limited | Very limited |
| Weld silt loam, 0 to 3 percent slopes | 20K | Well drained | C | Not limited | Somewhat limited |
| Fondis silt loam, 1 to 3 percent slopes | 17K | Well drained | C | Somewhat limited | Very limited |
| Bresser-Truckton sandy loams, 5 to 20 percent slopes | 17K | Well drained | B | Somewhat limited | Somewhat limited |
| Loamy alluvial land | 16K | Well drained | B | Very limited | Very limited |
| Renohill-Litle-Thedalund complex, 9 to 30 percent slopes | 16K | Well drained | D | Very limited | Very limited |
| Sandy alluvial land | 12K | Somewhat excessively drained | A | Very limited | Very limited |
| Fondis silt loam, 3 to 5 percent slopes | 11K | Well drained | C | Somewhat limited | Very limited |
| Litle silty clay loam, 1 to 9 percent slopes | 11K | Well drained | D | Very limited | Very limited |
| Bresser-Stapleton sandy loams, 9 to 20 percent slopes | 9K | Well drained | B | Somewhat limited | Somewhat limited |
| Fondis-Colby silt loams, 3 to 5 percent slopes | 9K | Well drained | C | Somewhat limited | Very limited |
| Baca-Thedalund loams, 3 to 9 percent slopes | 9K | Well drained | C | Not limited | Somewhat limited |
| Bresser and Truckton soil, 3 to 9 slopes, eroded | 8K | Well drained | B | Not limited | Not limited |
| Buick loam, 5 to 9 percent slopes | 8K | Well drained | C | Not limited | Somewhat 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 21% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 60% 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.