What soils cause foundation problems in southeast Oklahoma?

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

In short: Southeast Oklahoma gets the most rain in the state — about 56 inches a year in the far southeast ¹. The Ouachita Mountains bring steep slopes with shallow, rocky soils, where slope movement and runoff are key ground concerns ²³. To the south, Cretaceous shale clays can shrink and swell strongly, and Red River bottomland sands are prone to flooding ⁴⁶.

Cities covered: Idabel, Broken Bow, Hugo, Poteau and Antlers.

What is the climate like?

Oklahoma's climate grades from humid subtropical in the east to semi-arid in the west, and annual precipitation reaches about 56 inches in the far southeast ¹. USDA soil descriptions for the region list mean annual precipitation of roughly 38 to 48 inches across their mapped ranges, with mean annual temperatures of about 58 to 70 °F ⁵⁶. The Oklahoma Geological Survey notes that major Oklahoma floods frequently occur in spring and fall ². See creeks and flood history and severe weather effects.

What is the ground like?

Ouachita Mountains

The bedrock of the mountains is described on Ouachita folded rocks.

Hector soils, for example, are shallow, well drained soils formed from sandstone, with hard rock at 14 to 20 inches, on ridgetops and mountainsides with slopes from 2 to 60 percent ³. The Oklahoma Geological Survey reports that most Oklahoma landslides occur in the eastern third of the state, where wetter climate and steeper, mountainous terrain favor them ².

Cretaceous clays and sands (Gulf Coastal Plain side)

Several soils toward the Red River formed from Cretaceous rock ⁴⁵; see Cretaceous shales, clays and sandstones.

• Durant: very deep, moderately well drained clays from Cretaceous clayey shale and claystone, smectitic, with very slow permeability and cracks wider than 1 cm and deeper than 30 inches in dry periods ⁴.
• Bernow: deep, well drained sandy and loamy soils from Cretaceous sandstone, mapped in eastern Oklahoma in the Texas Claypan and Western Coastal Plain land resource areas ⁵.

Red River bottomlands

Kiomatia soils are well drained, rapidly permeable sandy alluvium on natural levees of the Red River floodplain, frequently flooded for brief periods in most years where unprotected ⁶.

Which soils are found here?

What are the common foundation problems?

• Slope creep and lateral movement on steep Ouachita hillsides.
• Crawl space moisture and wood decay in a high-rainfall climate.
• Erosion and washout voids where heavy runoff reaches foundations.
• Shrink-swell movement on Durant-type clays toward Durant.

On sloped lots, drainage guidance calls for ground next to a foundation to fall at least 6 inches within 10 feet, and notes that bare soil erodes easily and swales that are too steep can erode ⁷.

Related

• Ouachita Folded Rocks
• Erosion, Creeks and Slopes
• Slope and Erosion Stabilization
• South-Central (Arbuckles & Texoma)
• East-Central (Arkoma)