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What are foundation conditions like in Harrah, Oklahoma?

Reviewed by Preston ยท Updated 2026-11-12

In short: Only about 6% of Harrah is mapped in high shrink-swell soil; 71% rates low 1. The soil survey also maps occasional or frequent flooding on about 12% 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 Harrah?

Harrah covers about 12 square miles 2 and had 6,245 people in the 2020 Census 2.

Measure Share of the area
High shrink-swell soil (linear extensibility 6% or more) 6% 1
Moderate shrink-swell (3% to under 6%) 3% 1
Low shrink-swell (under 3%) 71% 1
Somewhat poorly or poorly drained 6% 1
Water table within 2 feet at some time of year 8% 1
Bedrock within 40 inches (soft or hard) 30% 1
Occasional or frequent flooding 12% 1

Which soils matter most for houses in Harrah?

What does this mean for houses in Harrah?

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 Harrah?

Soil Share
Littleaxe 23.3% 1
Stephenville 14.9% 1
Harrah 14.0% 1
Urban land 6.4% 1
Darnell 6.1% 1
Tribbey 4.3% 1
Newalla 4.3% 1
Yahola 1.9% 1

ZIP codes in Harrah

ZIP 73045

Looking for a foundation company near Harrah?

Companies that serve Harrah 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 Harrah? 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 Harrah has expansive clay soil?

About 6% of Harrah is mapped in soils rated high shrink-swell, 3% moderate and 71% low, measured inside the city limits from the USDA soil survey.

What is the most common soil in Harrah?

Littleaxe, which covers about 23% of the city. USDA describes it as deep, well drained, moderately permeable soils that formed in materials weathered from weakly cemented sandstone interbedded with weakly cemented shale of Permian age.

Is rock shallow in Harrah?

Bedrock is within 40 inches of the surface under about 30% 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 Harrah 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 8% of the city, and occasional or frequent flooding on about 12%.

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: LITTLEAXE Series USDA Natural Resources Conservation Service
  4. Official Soil Series Description: STEPHENVILLE Series USDA Natural Resources Conservation Service
  5. Official Soil Series Description: HARRAH Series USDA Natural Resources Conservation Service
  6. Official Soil Series Description: DARNELL Series USDA Natural Resources Conservation Service
  7. Official Soil Series Description: TRIBBEY Series USDA Natural Resources Conservation Service

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