During 1984, an estimated 1.25 million acre feet of water were used by Texans in the care and maintenance and residential landscapes. Texas is expected to soon become the second most popular state in the U.S. with two-thirds of the population located in urban/suburban areas. With this growth, conservative estimates indicate water needs will increase 75 percent by the year 2000. Thus, conservation, reclamation and efficient use of water resources will become increasingly important.
Essentially all water used in Texas is derived from precipitation. Part of the precipitation flows into streams, ponds, lakes and reservoirs, and some of this eventually reaches the Gulf; another portion infiltrates the soil to the rooting zone of plants; a third portion percolates below the rooting zone and becomes groundwater.
Surface water sources are recharged rapidly, but groundwater reservoirs such as the Ogallala Aquifer, are recharged very slowly. The Ogallala Aquifer is slowly being exhausted in some areas of heavy pumping. The proportion of precipitation received in Texas that is returned to the atmosphere as water vapor is estimated to be 70 percent from non-irrigated land areas and 2 percent from irrigated areas. Most of this loss represents evaporation or transpiration from plant surfaces.