How much of each Wichita-area town sits on shrink-swell clay

The numbers

Andover, Augusta and El Dorado are in Butler County, Newton is in Harvey County, and Mulvane straddles Sedgwick and Sumner counties. The rest are in Sedgwick County. The full figures, including the moderate share and the notes below, are in a CSV file.

Source: USDA NRCS Web Soil Survey, Soil Survey Geographic Database for Sedgwick, Butler, Harvey and Sumner counties, survey versions August 2025, clipped to 2026 city limits from Census TIGERweb. Shares are our calculation.

What the rating means

The USDA's Natural Resources Conservation Service rates each soil by its linear extensibility: how much a moist sample shrinks, as a percentage, when it dries out. Under 3 percent is low, 3 to 6 moderate, 6 to 9 high, and 9 or more very high. Soils in the top two classes swell and shrink enough to lift, drop and crack slabs as the seasons change.

A town's figure describes the ground across the whole city, not any single lot. Soils change from one block to the next, and the ground right under a driveway or patio is often fill brought in when the house was built. The figure says how common expansive clay is in a town. The soil under a particular house can be looked up on the USDA NRCS Web Soil Survey.

What stands out

• The east and north run high. Andover, Bel Aire, Augusta and El Dorado to the east and northeast, and Newton to the north, all have more than 60 percent of their soil area in the top two classes.
• The south and west run lower. Haysville and Mulvane to the south, and Maize and Goddard to the northwest and west, are all under a quarter. Haysville's most common soils are sandy and loamy river soils rated low.
• Wichita is mixed. About 38 percent of Wichita's rated soil area is high or very high, close to the Sedgwick County figure of about 34 percent. Its most common soils range from low-rated Canadian to very-high-rated Rosehill.
• Goddard's number rests on one soil. About two thirds of Goddard's soil area is Blanket silt loam, which sits exactly on the line between moderate and high. We count it as moderate. Counted as high, Goddard would be close to 70 percent.

How we calculated it

• City limits come from the Census Bureau's TIGERweb incorporated places layer, current in 2026.
• Soil map units inside each boundary come from the USDA's Soil Survey Geographic Database, through its Soil Data Access service. Each map unit's area is split among its component soils by their listed percentages.
• Each component is rated by the highest linear extensibility of any layer starting within 60 inches of the surface.
• A soil rated exactly 6 is counted as moderate. That affects Goddard most (67 percent of its soil area), then Park City (15 percent) and Mulvane (12 percent). The CSV lists it for every town.
• Areas the survey does not rate, such as water, pits and land mapped only as urban land, are left out. That is about 21 percent of Wichita's area, mostly in its most built-up parts, and 13.5 percent of Augusta's. Every other town is under 5 percent.

Using these figures

Reporters, neighborhood associations, HOAs and anyone else are welcome to use these figures and the chart, with a link to this page. If you spot a problem with the method or the numbers, the corrections form comes to us directly.

For what shrink-swell clay does to a slab and how Wichita's weather drives it, see why concrete sinks in Wichita. Town pages with local sidewalk rules are up for Derby, Andover and Haysville.

Where we work

We take calls from across Wichita and the surrounding towns in Sedgwick, Butler and Harvey counties.

• Wichita
• Derby
• Andover
• Haysville
• Maize
• Park City
• Bel Aire
• Valley Center
• Goddard
• Mulvane
• Augusta
• El Dorado
• Newton