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If we had a richer language than English,
we would probably have several words for water. Recognizing
the huge differences between various 'kinds' of H2O in terms
of potential environmental, economic and social implications,
we might conduct our discussions more rationally and with
some degree of perspective. Useful distinctions lie in the
prices, and the quantities, involved.
Drinking water is a very special substance;
we cannot live without it, and no one should have to try to.
It is truly priceless, and every living being should have
a inalienable right to the quantity they need (something less
than 5 litres per day) of clean drinking water. The quantity
needed to supply this much to all the world's people would
be about 30 million m3 per day, i.e. one billion m3, or one
km 3, per year. Although this sounds like a lot, global water
use for all purposes is now estimated to be approaching 5,000
km3 per year, so drinking water represents less than one fiftieth
of 1% of the total !
Bottled water is, in the Western world at
least, something quite different. It is a commodity not unlike
wine, except that, where wine is concerned, the stuff in the
bottle has real value. Where bottled water is concerned, what
we pay for is packaging, transport, advertising, and the profits
expected by firms all down the distribution chain. Recent
prices at a local supermarket ranged from $150 to $2,500 per
m3. The number of people in the world able and willing to
pay these prices is probably well under 60 million. If each
consumed 2 litres a day, this would amount to 120,000 m3/day,
or about 50 mcm/yr - about one thousandth part of 1% of global
water use!
For irrigation water, prices are low, normally
under 10¢ / m3, and they have to be, because irrigated crops
need a great deal of water. The quantities involved are huge,
amounting to over 60% of global water use. This critical price-quantity
relationship is absolutely central to an understanding of
the problem, because it is about the real global 'demand'
for water. When someone states that 'demand' exists for any
amount of water for a specific purpose, the response in future
must be: "Demand at what price?" At under 10¢/m3, the world
uses more than 3,000 km3 per year of water for irrigation.
At $1.00/m3 or more, 99% of the world's dry-region farmers
would go straight out of business - widespread famine would
be the result.
Bulk water is also a term increasingly heard
in the debate on water policy, but again used without clarity.
Whether it is hundreds of m3 in an ocean-going tanker, or
thousands of m3 per hour moving down a huge canal, its distinctive
characteristics are that:
• it is being transported,
a long way, to serve some human purpose;
• it is not
in containers small enough to be carried around by people;
• it is also; typically,
sufficiently expensive to make its use, except
for the highest-valued purposes, uneconomic.
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