Quality of percolating waters

Overpumping ground water for agricultural, domestic, and industrial use has resulted in a lowering water table in many areas of California. The California Water Plan includes delivery of surface water to some of these areas to make up the water deficits and to provide water for future development. Since the amount of surface water available each year is variable, it has been proposed that in years when excess water exists, it be used to recharge the underground water supply.