Ground water in the United States has emerged from a quantitatively minor (though incalculably valuable) water source, whose chief role was in the settlement of primitive areas, to a major source now accounting for one-fifth to one-sixth of the Nation's total withdrawal requirements for water. With the growth in ground-water withdrawals is an accompanying growth in the realization that large-scale development of ground water is feasible only on the basis of a fuller understanding than has existed to date of the complex interrelations of the hydrologic cycle and of ground water's place in the cycle
This report outlines briefly the principles of water occurrence and describes the water situation in the United States as of 1960-61, with emphasis on the occurrence of ground water and the status of development and accompanying problems. The Nation has been divided into 10 major ground-water regions by H. E. Thomas (1952a). The report summarizes the occurrence and development of ground water in each of Thomas' regions. In a large terminal section it also describes the occurrence and development of water, again with emphasis on ground water, in each of the 50 States and in certain other areas. The main text ends with a discussion of the water situation and prospects of the Nation.
