One glance at the Texas Water Development Board’s map delineating 15 flood planning regions spread out over the vastness of the state and it becomes clear: Region 11, the Guadalupe River Basin, is a very small slice.

The regions are based on watersheds, and the Guadalupe basin contains only 10 counties from Kerr County to Calhoun County on the coast. Only the southern portions of Hays and Blanco counties are included – and the whole thing is dwarfed by the Colorado/Lavaca region to th...