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 (1952). 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, and of the role to be played by ground water in meeting future needs. The 10 ground-water regions, in the order listed by Thomas and followed here, are the Western Mountain Ranges, the Alluvial Basins (Thomas' Arid Basins), the Columbia Lava Plateau, the Colorado Plateaus and Wyoming Basin (Thomas' Colorado Plateau), the High Plains (Thomas' Great Plains), the Unglaciated and Glaciated Central regions, the Unglaciated and Glaciated Appalachian regions, and the Atlantic and Gulf Coastal Plain.
The Western Mountain Ranges include the northern Coast Ranges, the Cascade Range and Sierra Nevada, the isolated ranges of the Basin and Range province, and the Rocky Mountains. They are the West's precipitation-catching and water-shedding highlands, serving as the major sources of water for the vast 'have not' area surrounding them. Built largely of dense, relatively impermeable rocks, they are largely unfavorable for the occurrence of ground water. As defined, however, they include a few sizable bodies of alluvium and permeable bedrock, as well as weathered rock and fractures in unweathered rock, which absorb, store, and transmit ground water. Their relatively small water needs generally are met readily from streams, springs, or wells, and they have a large surplus of water for export to the adjacent drier lowlands. The Alluvial Basins include the alluvial lowlands of the Basin and Range province and of the southern and larger part of coastal California. As defined they include a separate area, the alluvial lowland of the Puget-Willamette trough between the Coast Ranges and the Cascade Range in Oregon and Washington. At the northwest end of the main body of the region they overlap with the Columbia Lava Plateau in an area in which block-fault mountains of volcanic rocks alternate with alluvial basins. On the southeast they overlap similarly with the Unglaciated Central region.
The Alluvial Basins include areas of water-bearing alluvium which constitute the principal residential, agricultural, and industrial sites of the Southwest. They have an enormous present water demand, and a still greater potential demand by virtue of their current rapid population growth and of the presence of fertile land in amounts greatly exceeding that which currently is irrigated or conceivably could be supplied with water. The region accounts for a large share of the Nation's existing and potential water problems. Available streamflow, which serves both as a direct source of water and as the chief source of ground-water recharge, is largely appropriated. Ground water is withdrawn on a large scale, in many parts of the region at rates far in excess of replenishment. Problems of
Additional Publication Details
USGS Numbered Series
The role of ground water in the national water situation : with state summaries based on reports by District Offices of Ground Water Branch
Water Supply Paper
U.S. Govt. Print. Off.,
xii, 1121 p. :maps (5 fold. (1 col.) in pocket) diagrs., tables ;24 cm.