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

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

In short: Pulaski is a very deep, well-drained fine sandy loam that forms on the flood plains of small creeks in central Oklahoma's Cross Timbers. It floods occasionally to frequently for very brief periods between March and October. Its sandy loam texture means flooding, water movement and erosion, not clay swelling, are the foundation issues.

What is Pulaski soil?

Pulaski is an official USDA soil series classified as "Coarse-loamy, mixed, superactive, nonacid, thermic Udic Ustifluvents" ¹. The "fluv" in its name refers to stream deposits; USDA soil terminology uses flood plains, which periodically receive fresh sediment, as the example setting for such soils ⁴. It formed in loamy alluvial sediments of Holocene (recent) age ¹.

The soil occurs on flood plains of small tributaries in the Northern Cross Timbers (MLRA 84A) of Oklahoma, Kansas and Texas and is rated as extensive ¹. Its type location is in Lincoln County, Oklahoma, about 6 miles north and 1 mile east of Chandler; the series was established in Lonoke County, Arkansas, in 1921 ¹. Mean annual precipitation is about 34 inches (range 30-40) ¹.

In Oklahoma, Pulaski areas include creek bottoms in and around the OKC Metro, on Quaternary alluvium and terraces.

What is the typical soil profile?

Source for the table: ¹. Other properties from the official description ¹:

• Flooding: occasional to frequent, very brief, March to October ¹.
• Drainage: well drained; permeability moderately rapid; runoff negligible ¹.
• Slopes: 0 to 3 percent ¹.
• Subsoil: no B horizon; the soil goes from topsoil directly into layered C material ¹.
• Vegetation: tall and midgrasses with pecan, black walnut, American elm, eastern cottonwood and tamarisk ¹.
• Depth to bedrock and water table: not stated ¹.

What does Pulaski soil mean for foundations?

Flooding

Pulaski forms on creek flood plains and floods occasionally to frequently ¹. FEMA's Flood Map Service Center provides the official Flood Insurance Rate Map panel and a printable flood map (FIRMette) for any address, and lists any later map revisions ³. See creeks and flood history and erosion, creeks and slopes.

Low clay

The USDA rates shrink-swell as linear extensibility, with under 3 percent rated low ⁵. Pulaski is coarse-loamy, fine sandy loam from top to bottom, with no clay-enriched subsoil ¹. The rated value for a specific mapped unit is in Web Soil Survey ².

Water moving through sandy soil

Moderately rapid permeability ¹ means water from floods, roof runoff or plumbing leaks moves into and through the soil readily. For how moving water can wash soil from beneath slabs and footings, see erosion, undermining and washout voids and plumbing leaks under slab.

Soft or placed layers

Layered creek sediments and any fill placed to raise a lot are covered on these pages:

• Soft soil consolidation (alluvium and wet clays)
• Fill consolidation settlement

How do you confirm the soil at a property?

Web Soil Survey shows mapped soil units and soil data for more than 95 percent of U.S. counties ².

Related

• Port soil
• Konawa soil
• Kiomatia soil
• Soil series in the OKC metro
• Soil series index