What is Dale soil and how does it affect Oklahoma foundations?

Reviewed by Preston, Oklahoma foundation repair consultant · Updated 2026-10-14

In short: Dale is a very deep, well-drained soil formed in loamy stream sediment on the flood plains of central Oklahoma. Its layers are silt loam to clay loam rather than heavy clay. Because Dale lies on flood plains, flood exposure and the variable layering of stream deposits are the key questions for a house built on it.

Where does Dale soil occur?

The USDA Natural Resources Conservation Service (NRCS) Official Series Description (OSD) places Dale in central Oklahoma and south-central Kansas, in Major Land Resource Area 80A, the Central Rolling Red Prairies ¹. It is moderately extensive ¹. The type location is in Lincoln County about 1 mile east of Harrah, at 1,070 feet elevation, and the series was established in Okfuskee County in 1940 ¹.

Dale forms on level to sloping flood plains, on slopes of 0 to 8 percent ¹. Its parent material is loamy alluvium ¹, the young stream deposits described on the Quaternary alluvium and terraces page. Within Oklahoma that ties Dale to river and creek valleys of the OKC metro and the Southwest (Lawton and Red Plains).

What are its key properties?

"Alluvium" is sediment deposited by flowing water. "Pachic" means the dark, organic-rich topsoil is unusually thick. Dale is mostly cultivated for alfalfa, small grains, grain sorghum and cotton, and native vegetation included tall and mid grasses with pecan, black walnut, bur oak and cottonwood ¹.

What do its properties mean for foundations?

Flood plain setting

The OSD describes Dale as a flood plain soil ¹. Official flood hazard maps for the National Flood Insurance Program are published through FEMA's Flood Map Service Center, which can be searched by address ⁵. Flood history for Oklahoma creeks and rivers is summarized in creeks and flood history.

Layered stream deposits

Some Dale profiles contain thin strata of loamy fine sand, fine sandy loam or very fine sandy loam below 50 inches ¹. Settlement in soft or variable alluvial layers is covered under soft soil consolidation in alluvium and wet clays.

Shrink-swell

Clayey soils swell when wet and shrink when dry ⁴. Dale's layers are loamy, and the OSD lists geographically associated series such as Brewer, Lela and McLain as having more than 35 percent clay in the control section ¹. NRCS classes linear extensibility (LEP) under 3 percent as low and 3 to 6 percent as moderate ³; the LEP for each Dale map unit is in Web Soil Survey ².

Water near the foundation

Uneven soil moisture is more damaging than uniform moisture, and leaks or poor drainage near a house can cause localized movement ⁴. Related topics: erosion, undermining and washout voids and surface drainage and grading.

How can a specific lot be checked?

• Look up the map unit and its LEP in Web Soil Survey ².
• Search the address in FEMA's Flood Map Service Center ⁵.
• Keep downspout water and sprinklers from ponding next to the foundation ⁴.

Related

• Quaternary Alluvium and Terraces
• Erosion, Creeks and Slopes
• Groundwater and Perched Water
• Soil Series - OKC Metro
• Soil Series Index