ON a daily basis we hear the following two statements repeated in relation to water in Australia: 1. That Australia is the driest inhabited continent on earth; and 2. That water is very scarce in Australia and we must take immediate action to conserve it. It is time we took a closer look at these assumed facts.
If we convert the average annual rainfall into megalitres and do the same for the other continents, then yes, Australia does receive the least precipitation of all of the inhabited continents. This is exemplified by comparing some average runoff data. Of all of the rain that falls on Australia about 11% finds its way to the sea via our river system, which on average amounts to 290 million megalitres per year from mainland Australia. Another 50million megalitres runs to the sea from Tasmania. By comparison the Mississippi river alone in USA averages a discharge of 560 million megalitres annually – almost double all of the rivers from mainland Australia. The Yangtze Kiang in China discharges 690 million megalitres annually and the Amazon in Brazil nearly ten times that amount.
So, yes, Australia does have meager water supplies compared to the other continents, but these figures lack relevance unless we consider two other vital factors. Australia is the smallest continent and much more importantly we have a miniscule population in comparison to other continents and countries.
If we look at a comparison of water availability per head of population, which is much more relevant, we get a dramatically different picture. Water per person from annual precipitation from various countries:
Australia: 130 megalitres
Brazil: 121 megalitres
United States 29 megalitres
China: 11 megalitres
Japan: 5.9 megalitres.
United Kingdom: 2.6 megalitres.
Leaving aside ground water for now, Australia has another source of water. Because most of our cities and towns were originally built on river estuaries, for obvious reasons and because no thought was given to the collection of runoff from roofing and pavement, most of our storm water runs into the sea. While the quantum of this is not known, estimates of around 40 million megalitres annually are considered reasonable.
So, how much water do we need?
For each Australia household to have all the water we need to live what we consider to be the Australian lifestyle. That is, have a garden with lawn on which we wash the car when we feel like it, have a pool for the kids and generally not have to be concerned about water. We need 110,000, litres per person per year. That includes all domestic use, Council and industrial use, but does not include Agriculture and Mining. Therefore for every 9 people in Australia we need 1 megalitre of water per year.
Let us assume that with some rational planning we did the following:
A. Collected and recycled just 5% of urban runoff = 2M megalitres
B. New dams to collect just 5% of river runoff = 14 M megalitres.
Total 16 million megalitres = sufficient for 144 million people.
So, Australia is not short of water, but incredibly short of practical planning and intelligent use of this resource.
Radical environmentalism has distorted our capacity to make rational decisions on how we harvest and recycle this resource in the interests of all Australians.
Let us look at this from an extraterrestrial viewpoint.
If there were intelligent aliens orbiting the earth and looking down on Australia, they would certainly recognize that a large part of our continent is dry and a rugged place to live. But they would also note that the coastal strip from Adelaide to Cairns was sparsely populated with beautiful clean cities and towns, enjoying a wonderful lifestyle. All built on river and creek estuaries.
They would note that while these rivers did not have huge mountain catchments like other continents, they nonetheless had mostly pristine catchments that delivered regular stream flows.
They would also observe over time that the streams that served this naturally wonderful area in which to live, regularly had excess flows and on an irregular basis carried huge floods to the sea.
They would then learn from our media that these beautiful cities and towns were regularly short of water.
They could only conclude that the people who lived in this wonderful part of the world. Lacked basic intelligence! They could not reasonably come to any other conclusion.
Should you think this is a harsh criticism, let me give you an example from my home area on our wonderful coastal strip at Coffs Harbour.
Since arriving here in 2002 most of the towns both north and south of Coffs Harbour have had water restrictions. Coffs Harbour uses approximately 5,500 megalitres of water per year.
Since our arrival in this wonderful part of the world, the Bellinger River (a small river, average discharge 240,000 megs/year.) has been in flood three times. In March 2006 a flood in this river was flowing over the top of the bridge at Bellingen at the rate of 72.000 megalitres per day, sufficient flow if harvested to keep Coffs Harbour in water for 13 years.
This is just one small example of the water harvesting opportunities that can be shared with hydro electricity generation in Australia on many streams.
It needs to be shouted from the rafters and repeated over and over, that in the Australian environment, correctly sited, properly engineered and sensibly managed dams and water storages are never other than a plus for the environment.
There is no environmental downside.
Properly managed water storages, augment stream flow in drought, they do not deplete flows. Water saved from flood flows is there for mankind to use to best advantage, for the environment, for community consumption, for hydro power, for agriculture and fishing and for leisure activities.
Water is not scarce, it is perpetual.
Australia is not short of water, but we are short on practical planning and the intelligent use of a basic resource.
Coffs Harbour, New South Wales