| Fresh Water Supplies At Risk, Part 1: Surface Water |
| Saturday, 02 July 2011 | John Potter | Article |
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Although water covers 70% of our planet’s surface, nearly all of it is difficult to use or access. According to the US Geological Survey 97 percent of Earth's water exists in the oceans as saltwater, 2.061% is frozen in glaciers and icecaps, 0.903% is underground, and 0.027% is part of the atmosphere or in plants and animals (including us). This leaves just 0.009 percent as surface water in lakes, streams, rivers and the like. Put another way, of the 1% of Earth's liquid and potable H2O, almost all is locked away far underground. Even so, we have enough to meet our present needs. This may not always be the case. As our population increases, so do our requirements. We also continue to pollute our available fresh water at an alarming rate and use much of the rest inefficiently. The greatest human demands upon fresh water are for household, industrial and agricultural purposes, with 87% going to agriculture alone, mostly for food, animals and irrigation. Unfortunately, a good deal of irrigation water never even reaches the intended crops thanks to antiquated technologies. Most of the water we use is from surface sources like rivers and lakes, followed by shallow underground resources (in Florida, for example, 90% of drinking water is groundwater). Water from both above and below ground is susceptible to pollution and overuse. When we contaminate water, we essentially remove it from the cycle. It either becomes useless because we recognize it as contaminated or we are doomed to consume it anyhow (possibly repeatedly). Overuse of water damages our environment, risks lowering water quality and removes large amounts from the replenishment cycle at any given time. Right now, we use about 30% of the world's accessible renewable water supply, but if we continue to consume the same amount per person, we will be using 70% by 2025. Thanks to diversion for agriculture, virtually no water from the Colorado River reaches its mouth. Other rivers suffering from overuse include the Rio Grande, San Joaquin and Ipswich, all of which are spent before reaching the sea. The resulting loss of downstream water has had a devastating impact on the ecology and the economies of the affected areas, as well as cheapening landscape aesthetics. Water can be conserved inside the home by using more water-efficient appliances and adjusting usage habits; conservation outside the home may be accomplished by xerascaping (techniques to reduce or eliminate the need for supplemental irrigation), watering lawns very early or late in the day or not at all, and using carwashes that recycle their water supplies. In agriculture, farmers can employ better and more advanced irrigation techniques to ensure that the right amount of water gets to the right crops with minimum waste. In manufacturing, as well as in agriculture and the home, tighter regulations that demand better use of water resources not only help the environment, but also spur innovation in green technologies. Well-written regulations, by removing financial disincentives, can provide a level playing field for businesses that would like to be more ecologically conscious. Water is essential to our survival. Although it is plentiful on our planet, less than 0.01% is potable and accessible—and we waste or pollute much of that. Although population growth is causing our demand for water to increase, there are winning strategies we can employ. Better water management, use regulations and new technologies that achieve the same goals using less resources, can leave us with sufficient water to cook, clean, manufacture and farm into the foreseeable future. Without these stategies, however, we will be forced to accept an ever-expanding percentage of our freshwater resources as a contaminated loss, which would not bode well for our species or our planet. See other parts of this series: Part 2 | Part 3 | Part 4 Additional resources:
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The water on this planet is finite. Even so, although we use it, we never lose it. Rather, water cycles through the environment and returns to us. In one simplified example, when a droplet of rain falls, it runs along the ground into a river that carries it to the sea. There it eventually evaporates into the atmosphere and becomes rain again. Along the way, that droplet may have been drunk by an animal or taken in by the roots of a tree, but in the end it moves through the same basic cycle again and again. Although we cannot remove water from this cycle, we can redistribute it so that an area has more or less. We also have the capacity to pollute it to such a degree that it is unusable or even poisonous. 
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