Delaware County, Oklahoma
The most common soil here is Clarksville, on about 36% of the land: a gravelly silt loam, smooth, like flour. Britwater and Doniphan come next.
About 80% of the land drains well, and 7% stays wet for long stretches; groundwater comes within two feet of the surface under 14% of it.
USDA rates 62% of the land very limited for a standard septic drain field, and 45% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 9% of the land floods occasionally or more.
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 Delaware County, Oklahoma, 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 Somewhat excessively drained and the dominant hydrologic group is B (moderate infiltration). 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 Delaware County, Oklahoma. 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 |
|---|---|---|---|---|---|
| Clarksville very gravelly silt loam, 20 to 50 percent slopes, stony | 115K | Somewhat excessively drained | B | Very limited | Very limited |
| Clarksville very gravelly silt loam, 1 to 8 percent slopes | 63K | Somewhat excessively drained | B | Not limited | Very limited |
| Clarksville very gravelly silt loam, 5 to 20 percent slopes, stony | 54K | Somewhat excessively drained | B | Somewhat limited | Somewhat limited |
| Razort gravelly loam, 0 to 3 percent slopes, occasionally flooded | 39K | Well drained | B | Very limited | Very limited |
| Water | 36K | Subaqueous | Not rated | Not rated | |
| Doniphan gravelly silt loam, 1 to 3 percent slopes | 26K | Well drained | B | Not limited | Somewhat limited |
| Britwater gravelly silt loam, 3 to 8 percent slopes | 17K | Well drained | B | Not limited | Somewhat limited |
| Doniphan-Tonti complex, 3 to 5 percent slopes | 17K | Well drained | B | Not limited | Somewhat limited |
| Macedonia silt loam, 1 to 3 percent slopes | 15K | Well drained | B | Not limited | Somewhat limited |
| Captina silt loam, 1 to 3 percent slopes | 15K | Moderately well drained | C/D | Very limited | Very limited |
| Eldorado silt loam, 1 to 3 percent slopes | 13K | Well drained | B | Not limited | Somewhat limited |
| Eldorado stony silt loam, 3 to 12 percent slopes | 9K | Well drained | C | Not limited | Very limited |
| Tonti gravelly silt loam, 1 to 3 percent slopes | 9K | Moderately well drained | D | Very limited | Very limited |
| Dennis silt loam, 1 to 3 percent slopes | 9K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Britwater silt loam, 1 to 3 percent slopes | 7K | Well drained | B | Not limited | Somewhat limited |
| Eldorado silt loam, 3 to 5 percent slopes | 7K | Well drained | C | Somewhat limited | Very limited |
| Taloka silt loam, 0 to 1 percent slopes | 6K | Somewhat poorly drained | D | Very limited | Very limited |
| Stigler silt loam, 0 to 1 percent slopes | 6K | Somewhat poorly drained | D | Very limited | Very limited |
| Jay silt loam, 1 to 3 percent slopes | 5K | Moderately well drained | C | Very limited | Very limited |
| Mayes silt loam, 0 to 1 percent slopes | 5K | 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 45% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 62% of soils are rated "very limited" for septic absorption fields. The well-drained soils may actually drain too fast for standard leach fields, allowing effluent to reach groundwater. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Soils tend to drain very quickly, meaning nutrients and water don't stick around long. Raised beds with amended soil, drip irrigation, and heavy mulching will give the best results. Compost is your best friend here — it improves water retention dramatically.