Running Short On Water?
We're using up Earth's resources faster than nature replenishes
them. And Canada has less fresh water than we think, says
research scientist JOHN SPRAGUE
June 28, 2002
Globe and Mail Print Edition, Page A19
Most Canadians think this country is rich in water --
that we have "more than a fifth of the world's freshwater
supply." If we knew the facts, we might make different
decisions about the protection and commercial exploitation
of this resource -- especially as we head into another
hot summer of drought and boil-water alerts, and even
more especially as we consider new research published
yesterday in the peer-reviewed journal, Proceedings of
the National Academy of Sciences, reporting that it takes
the planet 15 months to regenerate the resources (such
as water) that humanity uses up in a year.
What does this mean in terms of freshwater supplies?
Recent data from the Washington-based World Resources
Institute put Canada in fifth place among nations. The
three big players in national water supplies are Brazil,
with 12.7 per cent of the world's renewable supply, Russia
with 10.2 per cent and China with 8.3 per cent. Canada's
annual renewable volume of fresh water is just 6.4 per
cent of the world's total. The United States, with 5.8
per cent, is very close behind.
We seem to keep overestimating our supply because the
volume in all the lakes of North America is approximately
one-fifth of the fresh water sitting in lakes all over
the world. But water sitting in a lake is totally different
from renewable supply. We cannot consume a lake unless
we plan to dry it up. Supply is what falls from the sky
and runs off through lakes and rivers as it moves to the
sea. Some of the water moves underground and replenishes
aquifers that can be tapped by wells. The moving flows
are renewed every year, and count as the water supply.
Think of water sitting in lakes and aquifers as a capital
resource, money that can be spent only once. The rivers
running into and out of a lake represent interest and
dividends that can be used every year for an indefinite
time. Or suppose I have a swimming pool full of water
in my back yard, and you have only a barrel full.
This information says nothing about our water supplies.
What counts is the flow when we turn on our taps. If our
taps produce at the same rate, then we have equal supplies.
If my tap only dribbles and yours gushes, then you have
the better supply. If I use the water in my swimming pool
for baths and watering the garden, it will only last a
few weeks or months. The net result is that I can no longer
swim in the pool, but my tap still dribbles.
It is the same with our giant lakes; we can use them
to boat and fish and swim, but cannot consume their standing
water. Current complaints about low water levels in the
Great Lakes indicate why that is not an option. The size
of the lake (or swimming pool) is of no consequence in
the long term.
Indeed, lakes are not as big as might be thought; in
only three and a half years, the runoff in the world's
rivers equals the amount sitting in all the lakes. Exactly
the same principles apply to aquifers, and to the consequences
if we deplete them faster than they are renewed.
The World Resources Institute defines renewable fresh
water as "salt-free water that is fully replaced in
any given year through rain and snow that falls on continents
and islands and flows through rivers and streams to the
So misleading statements, such as "Canada has one
of the most abundant supplies of fresh water in the world,
exceeding the volume of U.S. water resources by a factor
of 10," cannot help but influence the outlook of the
average citizen about the merits of exporting water. It
also influences political decisions, because our leaders
apparently believe the same myth. David Anderson, Canada's
Minister of the Environment, was heard on CBC Radio not
too long ago to say, "Although Canada has the world's
largest supply of fresh water . . ."
It's distressing to hear our leaders talk about Canada's
huge reserves -- and to hear Americans talk openly about
joint exploitation of them. It's particularly distressing
to see such statements from our leaders because government
technical experts know the real situation.
The Web site of Environment Canada (http://www.ec.gc.ca/water)
distinguishes between static volumes of lakes and the
renewable supply; Environment Canada assigns us about
9 per cent of the world's share, a good estimate except
that it is based on 1970s data.
The up-to-date numbers come from the publication World
Resources 2000-2001 (produced co-operatively by the
World Resources Institute, the UN development and environment
Programs, and the World Bank). Until 1999, Canada ranked
as No. 3 nation for renewable water supply, but China
and Indonesia were close behind. New data for water flowing
out of China moved it up to No. 3; Indonesia has also
moved up and now Canada is in fifth place.
Let's also bear in mind that about 60 per cent of Canadian
yearly water flow goes north into the Arctic, according
to Environment Canada's Web site. That water is largely
unavailable for use in the southern part of the country,
where most of us live, work and farm. The supply in southern
Canada would only be about 2.6 per cent of the world's
This is the number that should spring to the minds of
Canadians when contemplating our water resources, rather
than some mythical large portion. It has an entirely different
influence on thoughts about sharing with neighbours.
If Canada has a comfortable total supply of water, it
should be used creatively within the country. General
A.G.L. Mc- Naughton -- a wartime leader, he became chairman
of the Canadian Section, International Joint Commission
on Boundary Waters -- noted this as long ago as 1965,
when he told the Montreal Canadian Club: "All of our
water can be translated into growth somewhere. Let it
take place in Canada." Let's remember this as we consider
the latest information about the nothing less than rapacious
human consumption of the Earth's resources. Supply is
John B. Sprague is a former research scientist with
the federal Department of Fisheries, and a retired academic
now living on Saltspring Island, B.C. One of his early
publications was, for a third of a century, the world's
most frequently cited paper in limnology (fresh-water