Pure water is essential for human health and the functioning of many businesses, and throughout American history aqueducts have been built to supply water to agricultural areas and to large urban areas, such as New York and Los Angeles. Many dams have been constructed to prevent floods, improve the navigability of rivers for commercial transportation of goods and people, and provide power for developing cities, businesses, and farms.

Dams are barriers, usually constructed of earth, rock, masonry, steel, concrete, or combinations of these materials, that are placed across watercourses to control their flow or create reservoirs. Aqueducts are systems of channels, ditches, tunnels, and pipes constructed to transport water by gravity and with pumps from a plentiful source to a population center. Water resourcesBecause reliable sources of pure water are indispensable for many businesses, from agriculture to industries, ways of conveying water from these sources to places where it is needed have been important throughout American history. As the United States grew as a nation, its cities and industries required more and more water, so businesses and, more often, local and state governments constructed aqueducts to meet these needs.DamsAqueducts

New York State, which constructed the Erie Canal between 1817 and 1825, required eighteen aqueducts to provide efficient transportation of goods from the East to the Midwest, thus facilitating the economic development of not only New York City but also Utica, Syracuse, Rochester, and Buffalo. New York City officials were behind the Croton AqueductCroton Aqueduct, built from 1836 to 1843, to bring nearly a billion gallons of water every day from a reservoir created by a dam on the Croton River via a 40.5-mile aqueduct system through Westchester County to New York City. Though designed to satisfy the city’s water needs for centuries, the Croton Aqueduct, within several decades, proved inadequate to meet the growing water demands of people and businesses in the New York City area, and a New Croton Aqueduct had to be built, three times the size of the original system and having the world’s longest and largest tunnel. The much larger Catskill and Delaware aqueduct systems had to be built in the twentieth century because of the phenomenal growth in New York City businesses and population.

A similar pattern of population and business growth characterized the settling of the American West. One of the earliest aqueducts, a large wrought-iron pipe, supplied water to the mining town of Virginia City, Nevada, in 1873. Because of the arid conditions of the West, water was a scarce commodity that was fiercely fought over. Businessmen who speculated in land tried to discover when and where aqueducts would be built, because marginal lands would increase dramatically in value when water rights became available. A good example is the Los Angeles AqueductLos Angeles Aqueduct, completed in 1913, which brought water from the Owens Valley near the Sierra Nevada across two hundred miles of desert to southern California. Without this water, business and population growth in Los Angeles would not have been possible.

Los Angeles’s experience mirrored that of New York City. Commercial development, which involved extensive amounts of water for the irrigation of massive agricultural areas and for urban industries, outstripped the water supplies much more quickly than was initially envisioned. As a result, the California AqueductCalifornia Aqueduct, the largest in the world, was begun in 1957. These and other projects involved large dams that created reservoirs, huge pumping plants, concrete-lined open and covered channels, and subsidiary aqueducts that supplied water to such new cities as San Diego. During this time, environmentalists such as John Muir, JohnMuir and others opposed the building of dams and aqueducts, the most famous example being the Hetch-Hetchy dam and aqueduct, designed to transport water from the Sierra Nevada to San Francisco. In this and other instances, commercial and political interests prevailed, and the dams and aqueducts were built.

Besides their connections to aqueduct systems, dams were specifically involved in various businesses. During the colonial period, dams provided power for various commercial enterprises. The earliest American dam was built in 1634 to power a sawmill in South Berwick, Maine, and during the early history of the United States, from its founding until well after the U.S. Civil War, ironworkers, sawyers, and mill operators relied on waterpower to drive bellows, saws, machine tools, and looms. A dam on the Blackstone River in Rhode Island provided the power that ran the textile machinery of SamuelSlater mill Slater, which initiated the American Industrial Revolution. Much more extensive textile-manufacturing facilities were constructed and powered by the water pressure created by dams throughout New England and the northeastern United States, most notably the Lowell Mills in Massachusetts.

During the late nineteenth and throughout the twentieth century, dam construction became an important part of the economic development of the American West. In 1888, John Wesley Powell, John WesleyPowell, the renowned explorer of the Colorado River, who had authored a report on the arid regions of the West, convinced Congress to authorize a survey of Western rivers and potential reservoir sites, with a view toward developing irrigable lands for large farms. During the twentieth century many dams were built in the Western states by the federal government and private power companies to provide water for irrigation and electricity for new cities and industries. The most famous of these dams, built between 1931 and 1936 by the Bureau of Reclamation, was first known as Boulder Dam, and later as Hoover DamHoover Dam. It was located on the Colorado River between Nevada and Arizona, and it increased water supplies and electricity for neighboring regions as well as for Southern California, especially Los Angeles.

Although entrepreneurs were responsible for the early construction of aqueducts and dams, during the twentieth century, the federal government undertook the largest projects. Private electric utilities increasingly came into conflict with social and environmental progressives who wanted the federal government to take over electric-power-generating projects. This trend is well exemplified by the Tennessee Valley AuthorityTennessee Valley Authority (TVA), commissioned by Congress in 1933. This grand endeavor was intended to control floods, create electric power, deepen rivers for shipping, and accelerate a multistate region’s economic development. Because the TVA was a federal corporation, it represented a great change in government policy, provoking much controversy, especially from critics who believed that such undertakings were best left to private enterprise.

Even private enterprises could provoke controversy. When, in 1962, Consolidated Edison Company and Central Hudson Gas and Electric revealed plans to construct the world’s largest hydroelectric plant near Storm King Mountain on the Hudson River to alleviate New York’s chronic electricity shortages, several environmental groups banded together to stop the project, which, in a landmark class-action lawsuit, they succeeded in accomplishing. Those in favor of Environment;waterdams and aqueducts, especially business interests, emphasize their necessity in helping a region’s economic progress, but those against these constructs, especially environmentalists, emphasize the damage that they do to scenic locations and wildlife. Most analysts now agree that dams and aqueducts have both costs and benefits for businesses, the environment, and people, and it will be a major task for future generations to balance these conflicting interests in ways that best serve the needs of all.

• Goldsmith, Edward, and Nicholas Hildyard. The Social and Environmental Effects of Large Dams. San Francisco, Calif.: Sierra Club Books, 1984. An analysis of the economic and social benefits of dams as well as their great environmental costs. Thirty-seven pages of notes, with many primary and secondary references, and an index.
• Hundley, Norris. The Great Thirst: Californians and Water–A History. Rev. ed. Berkeley: University of California Press, 2001. Update of the story of how feuds over the control and use of water shaped the economic history of California. Notes, bibliography, and index.
• Lowry, William R. Dam Politics: Restoring America’s Rivers. Washington, D.C.: Georgetown University Press, 2003. This analysis of how water marketing and public policy have influenced decisions about dam building and dam removal reveals the significance of dams to America’s urban and rural regions. Bibliography and index.
• Reisner, Marc. Cadillac Desert: The American West and Its Disappearing Water. New York: Penguin Books, 1987. This book, honored as one of the most notable nonfiction works in the twentieth century, is a revisionist account of the settling of the West, as due not to rugged individualists but to the creation of an expensive and environmentally detrimental “hydraulic society.” Index.
• Schnitter, Nicholas J. A History of Dams: The Useful Pyramids. Rotterdam, The Netherlands: A. A. Balkema, 1994. The story of dams, their construction and uses, from antiquity to the present, with a focus on changing engineering practices. Illustrated with photos, graphs, and tables.

Colorado River water

Construction industry

Erie Canal

Irrigated farming

Mississippi and Missouri Rivers

Public utilities

Tennessee Valley Authority

Water resources