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

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

In short: Chickasha is a well-drained, fine-loamy soil that formed from weathered Permian sandstone and sits on weakly cemented sandstone 40 to 60 inches down. Its subsoil is mainly sandy clay loam with moderate permeability. Compared with Oklahoma's heavy clays, Chickasha has less clay, so drainage, erosion and fill tend to matter more than seasonal swelling.

Where does Chickasha soil occur?

According to the USDA Natural Resources Conservation Service (NRCS) Official Series Description (OSD), Chickasha occurs in Oklahoma and Texas within Major Land Resource Area 80A, the Central Rolling Red Prairies 1. The type location is in Carter County, the series was established in Washita County, and it is of moderate extent 1.

Chickasha forms on nearly level to sloping broad ridgetops and side slopes of convex hills, on slopes of 0 to 8 percent 1. Its parent rock is Permian sandstone 1, part of the Western Permian red beds and related units such as the Garber Sandstone. The series spans the South-Central (Arbuckles and Texoma) and Southwest (Lawton and Red Plains) regions.

What are its key properties?

Property Chickasha (from the OSD) 1
Classification Fine-loamy, mixed, active, thermic Udic Argiustolls
Parent material Material weathered from Permian sandstone
Depth to rock 40-60 in to weakly cemented sandstone
Drainage Well drained
Permeability Moderate
Subsoil (Bt) Sandy clay loam (range loam to clay loam)
Clay in control section 18-30%
Slopes 0-8%
Mean annual rainfall 35-41 in (typical pedon 34 in)
Mean annual temperature 59-63°F

"Fine-loamy" is a soil-taxonomy family name for soils with a loamy texture and moderate clay. Most Chickasha land is cultivated to small grains, grain sorghum, cotton and improved pasture, and native vegetation is tallgrass prairie 1.

What do its properties mean for foundations?

Moderate clay, lower shrink-swell

Clayey soils swell when they gain water and shrink when they dry, which moves shallow foundations up and down 4. Chickasha's weighted clay content of 18 to 30 percent is modest 1. NRCS measures shrink-swell as linear extensibility percent (LEP): under 3 percent is low, 3 to 6 percent moderate, 6 to 9 percent high and 9 percent or more very high 3. The rated LEP for each Chickasha map unit is listed in Web Soil Survey 2.

Sandstone within reach

Weakly cemented sandstone lies 40 to 60 inches below the surface in Chickasha 1. "Weakly cemented" means the rock grains are only loosely bound, so the rock is softer than hard sandstone. Where foundation repair involves driving piers (steel or concrete supports pushed down to firm bearing), the depth and hardness of this layer is part of what an engineer evaluates; see shale weathering and bearing strata and depth to rock from borings.

Water and erosion

Uneven soil moisture causes more damage than uniform moisture, and water or sewer leaks can cause localized foundation movement 4. Sandy and loamy soils on sloping ground are the setting described in erosion, undermining and washout voids. Downspouts that discharge well away from the house and soil graded away from the foundation keep water from concentrating at the slab edge 4.

How can a specific lot be checked?

Free, plain-English answers. It asks a few questions and walks you to the repair that fits.

Common questions

How deep is bedrock in Chickasha soil?

The official description gives a solum thickness of 40 to 60 inches over weakly cemented Permian sandstone. Depth can vary from place to place within a mapped area.

Is Chickasha soil expansive?

Chickasha is a fine-loamy soil whose subsoil is mostly sandy clay loam, with 18 to 30 percent clay in the control section. That is less clay than Oklahoma's heavy expansive clays; the rated shrink-swell for a lot is shown as linear extensibility in Web Soil Survey.

Where is Chickasha soil found?

Chickasha occurs in Oklahoma and Texas in the Central Rolling Red Prairies. Its type location is in Carter County, and the series was established in Washita County.

What drains well and what doesn't in Chickasha soil?

The soil is well drained with moderate permeability, so water moves through it at a moderate rate until it reaches the sandstone below.

Sources

  1. Official Series Description - CHICKASHA Series USDA Natural Resources Conservation Service
  2. Web Soil Survey - Home USDA Natural Resources Conservation Service
  3. Definition: Linear Extensibility Percent (LEP) UC Davis California Soil Resource Lab (from the NRCS National Soil Survey Handbook)
  4. Living With Shrink/Swell Soils: A Homeowners' Guide to Maintenance of Shallow Foundations American Society of Civil Engineers, Geo-Institute

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