The ground moves here
Much of the Fort Worth–Dallas area sits on the Blackland Prairie, where the USDA's soil survey rates shrink-swell potential asvery high. These clays contain minerals that absorb water between their layers and force them apart, so the soil expands when wet and contracts when it dries. Rainfall makes that a repeating cycle rather than a one-time event: the National Weather Service records annual precipitation at DFW ranging from under 20 inches to more than 50, unevenly distributed through the year.
Gate posts, track foundations, and hinge posts are all fixed into that ground. Where a post shifts, the geometry it was set to holds no longer — which is one of several things that can put a slide gate's track out of alignment or drop a swing gate on its hinges.


