|It may seem curious to celebrate a tiny piece of rubber, smaller than a US quarter, found in bathroom taps and kitchen faucets around the globe. But the humble washer is one of a range of low-tech devices with a big part to play in reducing losses of water, that most fundamental natural resource on which all life depends.
A leaky tap, dripping every second, may seem like a drop in the ocean, but it wastes well over 4 litres a day. Over a month, a seriously leaking tap can lose as much as 10,500 litres.
UNEPs International Environmental Technology Centre in Osaka, Japan, is compiling a database of water-saving tips, technologies and policies drawn from both the developed and developing world, including small island states.
Dual flush lavatories, in which either 10 or 5 litres are used depending on need, can save up to 15 litres a day. They may only be affordable in more developed nations. But bricks, milk jugs filled with pebbles, or similar toilet displacement devices as they are euphemistically called cost little and, when placed in a conventional lavatorys water tank, can cut the flush by some 4 litres.
Showers account for some 20 per cent of a households total in-door water use in a country like the United States. Installing low-flow showerheads has been calculated to save a family of four 80,000 litres of water a year.
As much as 600 litres can be saved when washing a car by turning off the hose between rinses, while washing it on the lawn, rather than the driveway, can save water needed to keep the grass green.
Some Pacific and Caribbean islands such as Kiribati, Nauru, Saint Lucia and the Bahamas have dual supply systems. Drinking water comes through one pipe while another brings in saltwater for the lavatory.
Rainwater harvesting is underutilized, but has huge potential in both the developing and developed worlds. The Ryogoku Kokugikan Sumo-wrestling arena in Sumida City, Japan, collects rainwater on its 8,400 square metre roof for lavatory flushing and air conditioning.
In China, 17 provinces have installed between 5 million and 6 million rainwater harvesting tanks supplying an estimated 15 million people with drinking water as well as providing back-up irrigation for over a million hectares of farmland. In some Nigerian homes, broad-leaved trees collect rainwater which then runs down a bamboo gutter into a pot.
Real conservation efforts are needed in agriculture, which uses up to 70 per cent of freshwater and wastes much of it. Simple and cheap drip technologies, using underground pipes, can dramatically reduce losses by such factors as evaporation. Indian researchers have claimed water savings of 60 per cent.
The database also cites case studies from countries, including developing ones, where water metering has been tried and leak detection adopted to reduce huge losses from water supply networks. Water consumption was cut by 43 per cent in Honiara, Solomon Islands, after the introduction of meters. In Malta, losses from pipes were cut from 55 per cent to 25 per cent following a leak detection programme.
In Chile, laws have encouraged a water market involving tradable and transferable rights. As a result, its farmers shift during droughts from growing water-intensive crops such as corn and oilseeds, to higher value ones, which need less water, like fruits and vegetables.
This years slogan for World Environment Day is Water: Two Billion People are Dying for It!. It is incumbent on the 4 billion who are not, to renew their respect for water by valuing every drop
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Contents | Editorial K. Toepfer | World Environment Day | Water is life | The water century | Taking it at the flood | Renewing the commitment | Waterless cities | Keeping pollution at bay | People | At a glance | Changing agenda | Nor any drop to drink | Bridging troubled waters | Books & products | Getting there | Sinking fast | Waste not | Water the poors priority | Atomic power