Land of the Underground Rain: Irrigation on the Texas High Plains, 1910-1970The scarcity of surface water which has so marked the Great Plains is even more characteristic of its subdivision, the Texas High Plains. Settlers on the plateau were forced to use pump technology to tap the vast ground water resources the underground rain beneath its flat surface. The evolution from windmills to the modern high speed irrigation pumps took place over several decades. Three phases characterized the movement toward irrigation. In the