Soils here are less uniform than in Collin County
This part of Denton County sits near the boundary between the Blackland Prairie and the Eastern Cross Timbers, a narrow band of sandier soils running north to south through the county. The practical consequence is that ground conditions vary over shorter distances than they do further east. Two houses a few streets apart can sit on noticeably different soil, so foundation and buried pipe behaviour is less predictable and local experience counts for more.
