But Mulholland's vision soon reached further, and in 1905 citizens approved a $1.5 billion bond issue that brought his revolutionary plan into being. Work soon began on an aqueduct that would bring the city clear, clean water from the Owens River in the eastern Sierra Nevada, more than 230 miles to the north. Under Mulholland's direction, some 5,000 workers toiled on the project, which was deemed one of the most difficult engineering challenges yet undertaken in America. When it was completed, within the original schedule and budget, commentators marveled at how Mulholland had managed to build the thing so that the water flowed all the way by the power of gravity alone. At a lavish dedication ceremony on November 5, 1913, water finally began to flow. Letting his actions speak for him, Mulholland made one of the shortest speeches on record: "There it is. Take it!"
Los Angeles took what Mulholland had provided, but still the thirst grew. Indeed, throughout the 20th century communities in the American West took dramatic steps to get themselves more water. Most notable is undoubtedly the combined building of the Hoover Dam and the Colorado River Aqueduct in the 1930s and early 1940s. The dam was the essence of multipurposefulness. It created a vast reservoir that could help protect against drought, it allowed for better management of the Colorado River's flow and controlled dangerous flooding, and it provided a great new source of hydroelectric power. The aqueduct brought the bountiful supply of the Colorado nearly 250 miles over and through deserts and mountains to more than 130 communities in Southern California, including the burgeoning metropolis of Los Angeles. Other major aqueduct projects in the state included the California Aqueduct, supplying the rich agricultural lands of the Sacramento and San Joaquin valleys. The unparalleled growth of the entire region quite simply would have been impossible without such efforts. Los Angeles took what Mulholland had provided, but still the thirst grew. Indeed, throughout the 20th century communities in the American West took dramatic steps to get themselves more water. Most notable is undoubtedly the combined building of the Hoover Dam and the Colorado River Aqueduct in the 1930s and early 1940s. The dam was the essence of multipurposefulness. It created a vast reservoir that could help protect against drought, it allowed for better management of the Colorado River's flow and controlled dangerous flooding, and it provided a great new source of hydroelectric power. The aqueduct brought the bountiful supply of the Colorado nearly 250 miles over and through deserts and mountains to more than 130 communities in Southern California, including the burgeoning metropolis of Los Angeles. Other major aqueduct projects in the state included the California Aqueduct, supplying the rich agricultural lands of the Sacramento and San Joaquin valleys. The unparalleled growth of the entire region quite simply would have been impossible without such efforts.
The American West set the model Egypt building of the Aswan High Dam in the 1960s created the third-largest reservoir in the world, tamed the disastrous annual flooding of the Nile, and provided controlled irrigation for more than a million acres of arid land. Built a few miles upriver from the original Aswan Dam (built by the British between 1898 and 1902), the Aswan High Dam was a gargantuan project involving its share of engineering challenges as well as the relocation of thousands of people and some of Egypt's most famous ancient monuments. Spanning nearly two miles, the dam increased Egypt's cultivable land by 30 percent The American West set the model Egypt building of the Aswan High Dam in the 1960s created the third-largest reservoir in the world, tamed the disastrous annual flooding of the Nile, and provided controlled irrigation for more than a million acres of arid land. Built a few miles upriver from the original Aswan Dam (built by the British between 1898 and 1902), the Aswan High Dam was a gargantuan project involving its share of engineering challenges as well as the relocation of thousands of people and some of Egypt's most famous ancient monuments. Spanning nearly two miles, the dam increased Egypt's cultivable land by 30 percentin many cases, they don't have the water to work with in the first place. desalination —the treatment of seawater to make it drinkable. desalination is now a viable process, and more than 7,500 desalination plants are in operation around the world, the vast majority of them in the desert countries of the Middle East. Two main (but costly) processes are used to desalinate seawater. - reverse osmosis, involves forcing the water through permeable membranes made of special plastics that let pure water through but filter out salts and any other minerals or contaminants.
- distillation, in which the water is heated until it evaporates, then condensed, a process that separates out any dissolved minerals.
For a shockingly high proportion of the world's population, clean water is still the rarest of commodities. By some estimates, more than two billion people on the planet have inadequate supplies of safe drinking water. In the developing world, more than 400 children die every hour from those old, deadly scourges—cholera, typhoid, and dysentery.
smaller-scale solutions. A case in point is a relatively simple device invented by Ashok Gadgil, an Indian-born research scientist working at the Lawrence Berkeley National Laboratory in California. When a new strain of cholera killed more than 10,000 people in southeastern India and neighboring countries in 1992 and 1993, Gadgil and a graduate student assistant worked to find an effective method for purifying water that wouldn't require the cost-prohibitive infrastructure of treatment plants.
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