Highland Park and University Park together form the Park Cities, a 5.5-square-mile enclave completely surrounded by the city of Dallas. These affluent communities, located just 3 miles north of downtown Dallas, are known for tree-lined streets, architecturally significant homes, award-winning schools, and beautifully maintained properties—many with luxury swimming pools.

While the Park Cities represent some of the finest residential real estate in Texas, the homes here share the same geological challenge as the rest of Dallas: expansive clay soil. The soil in Dallas County is primarily composed of Houston Black-Heiden-Wilson clay, which is highly reactive to moisture changes. This clay can gain or lose up to 75% of its original volume as it absorbs water and then dries out.

The result is constant soil movement beneath pool structures. Clay swells when wet and shrinks when dry, creating a “push-pull” effect that stresses pool shells, separates plumbing connections, and damages equipment over time. According to the American Society of Civil Engineers, nearly one quarter of all homes in the U.S. have some foundation damage from these soils—and pools face the same forces.

Many pools in Highland Park and University Park are decades old, having been built alongside historic homes in the 1920s through 1960s. These mature pools have weathered countless cycles of soil expansion and contraction, making them particularly susceptible to leaks. Even newer pools in renovated properties experience stress from Dallas’ challenging soil conditions.