Washington County, Colorado
The most common soil here is Weld, on about 14% of the land: a silt loam, smooth, like flour. Valent and Platner come next.
About 99% of the land drains well.
USDA rates 38% of the land very limited for a standard septic drain field, and 13% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 2% of the land floods occasionally or more, and bedrock lies within 40 inches under 5% 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 Washington 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 Washington 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 |
|---|---|---|---|---|---|
| Weld silt loam, 0 to 3 percent slopes | 272K | Well drained | C | Not limited | Somewhat limited |
| Platner loam, 0 to 3 percent slopes | 176K | Well drained | C | Not limited | Somewhat limited |
| Valent sand, 3 to 9 percent slopes | 140K | Excessively drained | A | Not limited | Very limited |
| Colby-Norka loams, 5 to 9 percent slopes | 114K | Well drained | B | Not limited | Somewhat limited |
| Valent sand, rolling | 100K | Excessively drained | A | Very limited | Very limited |
| Rago silt loam, 0 to 2 percent slopes | 95K | Well drained | C | Somewhat limited | Very limited |
| Norka-Colby loams, 3 to 5 percent slopes | 73K | Well drained | B | Not limited | Somewhat limited |
| Ascalon sandy loam, 0 to 3 percent slopes | 55K | Well drained | B | Not limited | Somewhat limited |
| Haxtun loamy sand, 0 to 3 percent slopes | 50K | Well drained | C | Not limited | Very limited |
| Ascalon sandy loam, 3 to 9 percent slopes | 40K | Well drained | B | Not limited | Not limited |
| Colby loam, 6 to 15 percent slopes | 36K | Well drained | B | Somewhat limited | Somewhat limited |
| Wages-Ascalon loams, 2 to 5 percent slopes | 35K | Well drained | B | Not limited | Somewhat limited |
| Sampson loam | 33K | Well drained | B | Somewhat limited | Somewhat limited |
| Keith-Kuma complex | 29K | Well drained | C | Not limited | Very limited |
| Haxtun sandy loam, 0 to 3 percent slopes | 28K | Well drained | C | Not limited | Very limited |
| Razor-Heldt complex, 3 to 9 percent slopes | 23K | Well drained | D | Very limited | Very limited |
| Table Mountain loam | 17K | Well drained | B | Not limited | Somewhat limited |
| Wages-Ascalon loams, 5 to 9 percent slopes | 17K | Well drained | B | Not limited | Somewhat limited |
| Osgood-Valent complex | 16K | Well drained | A | Not limited | Not limited |
| Julesburg loamy sand, 0 to 3 percent slopes | 15K | Well drained | A | Not limited | Not 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
Most soils are generally favorable for residential construction. Standard foundations are usually viable, though site-specific evaluation is always recommended.
Septic Systems
About 38% of soils have significant septic limitations, while others are more suitable. A perc test is essential — conditions vary across the area.
Gardening & Agriculture
Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.