Efficiently-utilized natural runoff should be less expensive water. He stated that Texas has already fully developed her share of Canadian River flows. Because the Canadian River flows are appropriated, Texas and New Mexico municipalities which obtain water from diminishing ground water supplies may soon need to develop additional water supplies. The Bureau of Reclamation and the Army Corps of Engineers are considering the importation of water to the Texas High Plains from the Mississippi River system. However, legal, political, or economic barriers may prevent or delay such importation.
Water harvesting is a potential source of water for arid and semiarid lands.
The farmers cleared hillsides of rock and gravel to increase runoff and conveyed it to the cultivated field at a lower elevation. These include concrete, asphaltic concrete, soil cement, sheet metal, plastic and artificial rubber sheets, asphalt, and asphalt covered with aluminum foil. Most soil treatments are designed to produce a surface completely impermeable to water. Many of the problems peculiar to each of' the treatments have been solved by these researchers. Each treatment, however, is expensive.