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What are foundation conditions like in Okmulgee, Oklahoma?

Reviewed by Preston ยท Updated 2026-11-12

In short: Okmulgee has a mix of ground: about 19% high shrink-swell soil, 35% moderate and 26% low 1. The soil survey also maps a water table within 2 feet of the surface at some point in the year under about 50% of it and bedrock within 40 inches under about 33% 1. Which of these a house sits on decides whether clay swell, water, rock or soft ground is the thing to watch.

What does the soil survey show for Okmulgee?

Okmulgee covers about 17 square miles 2 and had 11,322 people in the 2020 Census 2.

Measure Share of the area
High shrink-swell soil (linear extensibility 6% or more) 19% 1
Moderate shrink-swell (3% to under 6%) 35% 1
Low shrink-swell (under 3%) 26% 1
Somewhat poorly or poorly drained 37% 1
Water table within 2 feet at some time of year 50% 1
Bedrock within 40 inches (soft or hard) 33% 1
Occasional or frequent flooding 9% 1

Which soils matter most for houses in Okmulgee?

What does this mean for houses in Okmulgee?

Shallow water. A water table near the surface, often perched on tight clay or shale in winter and spring, keeps soil at slab edges and in crawl spaces wet and swollen. See groundwater and perched water, crawl space moisture and surface drainage and grading.

Shallow rock. Where bedrock is close to the surface, lots are often cut into rock on one side and built up with fill on the other, so fill settlement and slope creep matter more than clay swell, and piers can stop at very different depths across one house. See depth to rock from borings.

Flood-prone soils. Floodplain soils are layered stream deposits: softer, wetter and more variable than upland soils, and they flood. See soft soil consolidation and Quaternary alluvium and terraces.

Which soils cover Okmulgee?

Soil Share
Dennis 12.7% 1
Water 12.3% 1
Hector 8.8% 1
Bates 6.0% 1
Wrightsville 5.7% 1
Endsaw 5.0% 1
Verdigris 4.8% 1
Parsons 4.8% 1

Looking for a foundation company near Okmulgee?

Companies that serve Okmulgee can appear on the company map in the Homeowner Hub. Paid listings there are marked Sponsored; the library and the AI guide don't rank or recommend any of them.

Buying or selling a house in Okmulgee? Realtors who serve the area can be on the same map, also marked Sponsored, and for realtors covers the seller disclosure form, inspections and the sale timeline. Seeing cracks at home? Start with for homeowners.

How were these numbers measured?

We overlaid the city limits from the Census Bureau 2 on the USDA soil survey's map units 1 and added up the area of each soil. Where a map unit is a mix of soils, its area was split by the percentages the survey lists for its major soils, so shares leave out minor inclusions and do not add to 100%. Shrink-swell is rated by the linear extensibility of a soil's most expansive layer, the survey's measure of how much it changes length between wet and dry (6% or more is high). Water table, bedrock and flooding come from the survey's map-unit summaries: the shallowest water table in any month, the shallowest bedrock, and the most common flooding frequency. Bedrock here includes soft, weathered sandstone and shale that a pier can push through, so it is not the depth where piers stop. These are mapped averages, not a test of any one lot; fill, grading and the soil actually under a house can differ, which is why a site visit or soil boring still decides a repair.

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

Common questions

How much of Okmulgee has expansive clay soil?

About 19% of Okmulgee is mapped in soils rated high shrink-swell, 35% moderate and 26% low, measured inside the city limits from the USDA soil survey.

What is the most common soil in Okmulgee?

Dennis, which covers about 13% of the city. USDA describes it as very deep, somewhat poorly drained soils that formed in residuum weathered from shale of Pennsylvanian age.

Is rock shallow in Okmulgee?

Bedrock is within 40 inches of the surface under about 33% of the city, according to the USDA soil survey's map-unit data. Where rock is that shallow, piers and footings can reach it quickly, and cut-and-fill lots are common.

Does Okmulgee have high groundwater or flooding?

The soil survey maps a water table within 2 feet of the surface at some time of year under about 50% of the city, and occasional or frequent flooding on about 9%.

Sources

  1. Soil Survey Geographic Database (SSURGO), queried through Soil Data Access, November 2026 USDA Natural Resources Conservation Service
  2. TIGERweb, 2020 Census: Incorporated Places and ZIP Code Tabulation Areas U.S. Census Bureau
  3. Official Soil Series Description: DENNIS Series USDA Natural Resources Conservation Service
  4. Official Soil Series Description: HECTOR Series USDA Natural Resources Conservation Service
  5. Official Soil Series Description: BATES Series USDA Natural Resources Conservation Service
  6. Official Soil Series Description: WRIGHTSVILLE Series USDA Natural Resources Conservation Service
  7. Official Soil Series Description: ENDSAW Series USDA Natural Resources Conservation Service

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