19 August 2012
“We consider ourselves the canary in the coal mine for climate change-induced changes to water supply systems.” Ross Young, executive director, Water Services Association of Australia
We live in the only period in history where water can be moved around in quantity by means other than gravity. While water is falling from the sky, it’s free; the moment it hits the ground it has a value and that value is directly proportional to the effort required to get it to where it’s needed to sustain life. If water cannot be made available where we want to live, then the choice is simple: move or die. Large numbers of people can only function in towns and cities as a single entity if sufficient water can be delivered to them on a regular and reliable basis.
If each of us had to make our own arrangements to collect our daily water needs and dispose of our own wastes, then healthy communal living much above the village level would be impossible. Water is heavy stuff to move around: 1 litre of it weighs 1kg. Try carrying 25 litres 5 miles back from a well to a family of thirsty children and water becomes very precious indeed. This is energy used to move water, at first hand, with no input other than human muscle. With that kind of work outlay, there’s little time left to build a city.
We recognize that our developed civilization is energy driven, but to a great extent that energy has been put to use pumping our water systems.
We need 2 litres of clean water every day to stay alive, the human body is 70% water, and losing 1% of it brings on acute thirst. A loss of 10% will cause death if it is not replaced quickly. Our digestive systems are adapted to use meat, fish or vegetables for food, but clean water intake is non negotiable.
We have created an alternative lifestyle of cleanliness and food safety that needs vast amounts of water. Our food delivery and waste systems demand a daily input of 2000 litres of water to supply the food eaten by each of us and dispose of the waste. That’s 500 times more liquid than we take in directly. The modern city is exactly like the human body; it cannot survive without the means to pump clean water in and wastes out. If we can’t find the means to maintain that input-output, then our towns and cities, just like our bodies, will slip back 500 years to a medieval condition: dirty and disease ridden and subject to every unpleasantness that nature can devise.
Our water supply is much more than turning on a tap and drinking the stuff.