Tulsa County, Oklahoma
The most common soil here is Dennis, on about 20% of the land: a silt loam, smooth, like flour. Radley and Okemah come next.
About 27% of the land drains well, and 53% stays wet for long stretches; groundwater comes within two feet of the surface under 59% of it.
USDA rates 86% of the land very limited for a standard septic drain field, and 80% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 14% of the land floods occasionally or more, and bedrock lies within 40 inches under 24% 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 Tulsa 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 poorly drained and the dominant hydrologic group is D (very slow infiltration, high 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 Tulsa 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 |
|---|---|---|---|---|---|
| Dennis silt loam, 1 to 3 percent slopes | 28K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Okemah-Parsons-Pharoah complex, 0 to 1 percent slopes | 27K | Somewhat poorly drained | D | Very limited | Very limited |
| Dennis-Radley complex, 0 to 12 percent slopes | 25K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Dennis-Pharoah complex, 1 to 3 percent slopes | 22K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Urban land-Dennis complex, 0 to 5 percent slopes | 16K | D | Not limited | Somewhat limited | |
| Eram-Coweta complex, 5 to 15 percent slopes | 16K | Moderately well drained | D | Very limited | Very limited |
| Niotaze-Bigheart-Rock outcrop complex, 15 to 25 percent slopes, extremely stony | 15K | Somewhat poorly drained | D | Very limited | Very limited |
| Radley silt loam, 0 to 1 percent slopes, frequently flooded | 14K | Moderately well drained | B | Very limited | Very limited |
| Wynona silty clay loam, 0 to 1 percent slopes, occasionally flooded | 13K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Dennis silt loam, 3 to 5 percent slopes, eroded | 13K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Osage silty clay, 0 to 1 percent slopes, occasionally flooded | 12K | Poorly drained | D | Very limited | Very limited |
| Water | 12K | Not rated | Not rated | ||
| Niotaze-Bigheart-Rock outcrop complex, 3 to 15 percent slopes, very stony | 12K | Somewhat poorly drained | D | Very limited | Very limited |
| Choska-Severn-Urban land complex, 0 to 1 percent slopes, rarely flooded | 11K | Well drained | B | Very limited | Very limited |
| Coweta-Urban land-Eram complex, 3 to 12 percent slopes | 10K | Well drained | D | Very limited | Very limited |
| Coweta-Bates complex, 3 to 5 percent slopes | 10K | Well drained | D | Very limited | Very limited |
| Choska very fine sandy loam, 0 to 1 percent slopes, rarely flooded | 8K | Well drained | B | Very limited | Very limited |
| Dennis silt loam, 3 to 5 percent slopes | 8K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Okemah silt loam, 0 to 1 percent slopes | 8K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Severn very fine sandy loam, 0 to 3 percent slopes, rarely flooded | 6K | Well drained | B | 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 80% 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 86% of soils are rated "very limited" for septic absorption fields. Poorly drained soils can't absorb septic effluent effectively. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Many soils hold water for extended periods. Raised beds are highly recommended to improve drainage for vegetables. Well-adapted native plants and water-loving species will do best in natural conditions.