Seminary Journal 2008 (August) - Virginia Theological Seminary

purposes, such as fi lling the taps in
our homes.
What about poorer countries? There
will still be a case for large reservoirs
in some parts of the world. At a World
Water Forum, held in Mexico City
last year, engineers, politicians, and
fi nanciers from round the world called
for investment in more large dams to
meet growing demand for water.
But there are serious questions about
how much dams can do. What is the
point of more dams when the rivers
are already drying up? A global study
published last week showed that a
quarter of the world’s population
already lives in river basins where
the water is already fully allocated or
over-allocated. New developments in
these areas will only take water from
some users and give it to others.
What else? Well, moving water from
one river system to another—from wet
areas to dry areas—is possible. But it
is very expensive—both to build and
in pumping costs. China is currently
spending $60 billion on a series of vast
canals to pump water from the wet
south to the arid north. India is talking
about trucking water from the great
monsoon rivers of the north, like the
Ganges, to the dry south and west. But
the price tag for construction alone is
a cool $200 billion. Australians discuss
massive canals or pipes to bring water
south from the monsoon lands of the
north. Even Britain from time to time
considers building a national water
grid to connect the wet northwest to
the dry southeast.
All this could be good business for
engineers, but I suspect will rarely be
the answer for consumers. The Austra-
lian schemes being discussed currently
work out to be more costly than
desalinated seawater. Farmers could
never afford their product.
But we do need some answers, and
soon. Economists estimate that by
2025, with current water use patterns
and growing population, water scarcity
will be cutting global food production
by 350 million tons a year. That is
rather more than the current U.S. grain
harvest, and the equivalent of a loaf of
bread every week for every person on
the planet. For hundreds of millions of
people, that disappearing loaf may be
the only one they get.
One other thing: If the world gets
into growing biofuels to reduce our
reliance on oil and cut greenhouse gas
emissions—say by converting a quarter
of its fuels to biofuel—that would
effectively double our water demand
for crops.
I think two things need to happen.
First, we need to get better at catching
the rain where it falls and before it
disperses. We need a modern version
of the old water butt catching rainfall
off the roof for use in the garden. It’s
not rocket science.
In researching my book, I visited villages
across India and China where they
are doing just this—reviving ancient
methods of capturing the rain as it falls,
and pouring it down their wells.
Secondly, there needs to be a massive
revolution in the way we use water.
Most homes can make big savings. So
can most water companies, by reducing
leaks. In most of the world’s cities,
between a quarter and a half of the
water put into distributions networks
never reaches customers because it
leaks away.
Similarly, we need to reduce the vast
losses from evaporation at reservoirs.
Did you know, for instance, that more
water evaporates from behind the
High Aswan Dam on the Nile in Egypt
than is delivered to homes and factories
throughout Britain in a year?
And much, much more urban waste
water should be recycled to make
clean drinking water. Some people
have an antipathy to this. The yuck
factor. But in London we have been
doing it for decades. We are drinking
water excreted by the people of Swindon
and Oxford and Reading and
all down the Thames. The fact that
they put it back into the river briefl y
before we take it out again doesn’t
alter the fact.
Most industries can use water much
more effi ciently. The biggest savings
globally, however, have to be in
agricultural irrigation, the biggest
user of water, especially in the driest
countries. Tens of millions of farmers
worldwide still irrigate their crops
by fl ooding their fi elds. Most of the
water evaporates and little, in practice,
reaches the plants. But cheap, modern
systems of drip irrigation—delivering
water drop by drop close to the crop
roots—can cut water demand by 40 or
50 percent or even, in some soils, 70 or
80 percent.
The simple truth is that, to protect our
rivers and ensure water supplies in
the future, we have to use less water.
The days of seeing the stuff as a free
resource, available in unlimited quantities
as of right, must surely be over.
64 VIRGINIA SEMINARY JOURNAL AUGUST 2007