This region links the Brazos Valley city of Bryan with the Interstate 35 corridor cities of San Marcos, New Braunfels and Seguin, the clay country around Lockhart and the Hill Country city of Kerrville.
Lockhart and Seguin are among the highest shrink-swell ratings profiled here. San Marcos, New Braunfels and Kerrville add shallow rock: a bedrock or hardpan layer within three feet is mapped at every sampled soil unit with data. Bryan is the milder case, rating moderate.
Across the 6 South Central Texas cities profiled here, the soil survey rates shrink-swell high around 5, moderate around 1 and low around 0.