How to save water at home, in business, and on the field.
 | Bedouin women plant seedlings on a farm nearby the Gaza Strip in southern Israel. Some 70 percent of all water used worldwide is swallowed up by agriculture (Photo: Reuters) |
Agriculture
Seventy percent of all water taken from rivers and groundwater is swallowed up by agriculture, 20 percent is taken by industry, and the remaining 10 percent goes on domestic usage, according to the OECD. Consequently, some of the most immediate and largest improvements in water management can and will be made in the fields, particularly in developing countries where existing irrigation systems are wasteful.
"Smallholder farmers possess the greatest unexploited potential to directly influence land and water use management," argues the IWMI. Simple water management techniques would help them conserve water.
One such "crop-per-drop" improvement is drip-irrigation, which distributes water to crops more precisely and reliably than conventional systems. Instead of using huge sprinklers or channels, water goes directly to the plant through a network of small pipes, drippers, or micro sprinklers. Often these systems are fed by treadle pumps that can extract water from up to seven meters down using only leg power.
Another is the revival of small-scale rainwater harvesting. In the arid Indian state of Rajasthan, the restoration of traditional water-harvesting structures has allowed farmers to gain a second cropping season and reduce groundwater pumping.
Conservation tillage, which disturbs the soil as little as possible to avoid soil moisture loss, is another technique practiced widely in South and North America. Extensive ploughing leads to erosion that drains the soil of its nutrients and pollutes rivers and lakes.
"These techniques hold under-exploited potential for quickly lifting the greatest number of people out of poverty and for increasing water productivity, especially in Sub-Saharan Africa and parts of Asia," says the IWMI.
 | Picture Gallery (click to start)Billions of people depend on water from a handful of major rivers. Find out more about the world's most important rivers |
Industry
As consumer of one fifth of the world's water - for cooling, heating, and as a product ingredient - industry also has a huge part to play in advancing water management techniques. The most egregious misuse of water in the industrial world occurs when factories use fresh water for industrial uses when wastewater would do the job just as well. Put another way, recycling water is the biggest contribution that industry can make to water preservation.
One recycling method would be to eliminate single-pass cooling, whereby water is circulated once through a piece of equipment and then discarded. Single-pass systems can use as much as 40 times more water than a cooling tower reusing water, calculates the U.S. Environmental Protection Agency (EPA).
The EPA itself upgraded one of its facilities with a "re-circulated chilled water loop" making 80 percent water savings in the process. By installing a closed-looped, re-circulated cooling water system, an aluminium rolling mill can cut its water consumption by 93 per cent, according to aluminium manufacturer Alcan.
At Home
Domestic water management, meanwhile can be improved primarily by making every drop count, preferably twice, thrice, or even ten times by using recycled water. Water recycled can be used for fighting fires, washing cars, flushing toilets, and watering the garden.
In urban areas, this requires two sets of piping: one for drinking water and another for recycled water - termed "dual reticulation." For years, Tokyo city authorities have encouraged the fitting of new office blocks and apartments with dual reticulation. It is only practical in new buildings, but with the world population expanding rapidly and the construction industry booming, there is enormous scope for water savings.
If nothing changes, water supply problems will result in a grim equation. According to the Swiss Agency for Development and Co-operation, by 2025, two out of three people in the world will suffer from water shortages - they will simply not have enough water to waste.
Water Management Part 1: Sharing the Source of Life
editor: James Tulloch
Publishing date: March 19, 2008
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Comment Policy
water and climate change
The coran is saying: life is related to water We hope that water mismaanagement will not conduct to an end life of some futue generations!! KARIM TUNISIA