Primer on Groundwater Law in the United States

One-fourth of the water consumed in the United States today is groundwater—including about one-third of the water used in the western states. Half of the people in the United States drink groundwater. Groundwater down to a depth of one-half mile is six times as much as the available surface water in the United States. Yet ground-water is not an inexhaustible resource: Current usage depends on withdrawals substantially in excess of natural recharge of the groundwater. Changes in technology and changes in demand have given the controlling law a dynamic character. The traditional legal neglect of groundwater has given way to statutory and regulatory intervention by the state and federal governments and to frequent litigation between private parties over the right to use groundwater and the responsibility to protect it. This paper summarizes the law presently applicable to groundwater in the United States.