Certain irrigation practices degrade soil quality and reduce agricultural productivity. More than 20 % of all freshwater fish species are now threatened or endangered because dams and water withdrawals have destroyed the free-flowing river ecosystems where they thrive. Tens of millions of people have been forced to move from their homes - often with little warning or compensation - to make way for the reservoirs behind dams. The consequences of our water policies extend beyond jeopardising human health. Preventable water-related diseases kill an estimated 10,000 to 20,000 children every day, and the latest evidence suggests that we are falling behind in efforts to solve these problems. As the United Nations report on access to water reiterated in November 2001, more than one billion people lack access to clean drinking water some two and a half billion do not have adequate sanitation services. Yet there is a dark side to this picture: despite our progress, half of the world’s population still suffers, with water services inferior to those available to the ancient Greeks and Romans. Nearly one fifth of all the electricity generated worldwide is produced by turbines spun by the power of falling water. Food production has kept pace with soaring populations mainly because of the expansion of artificial irrigation systems that make possible the growth of 40 % of the world’s food. Unprecedented construction of tens of thousands of monumental engineering projects designed to control floods, protect clean water supplies, and provide water for irrigation and hydropower brought great benefits to hundreds of millions of people. At the height of the Roman Empire, nine major systems, with an innovative layout of pipes and well-built sewers, supplied the occupants of Rome with as much water per person as is provided in many parts of the industrial world today.ĭuring the industrial revolution and population explosion of the 19th and 20th centuries, the demand for water rose dramatically. As towns gradually expanded, water was brought from increasingly remote sources, leading to sophisticated engineering efforts such as dams and aqueducts. The history of human civilisation is entwined with the history of the ways we have learned to manipulate water resources. ![]() A - A description of ancient water supplies
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