Water sustainability not all it`s cracked up to be

Sustainability may not be all it’s cracked up to be. That is the message in a recent paper by a hydrogeologist at Reading University . Michael Price argues that most human advances have been non-sustainable in the long term and that when we talk of ‘sustainable use’ we must define the period over which the use is planned or implemented.

Price identifies three major challenges currently facing Britain and the world. The first is that the climate, and with it the supply of water, is becoming less predictable. Since 1975 Great Britain has suffered four droughts, each of which has been estimated to have a return period of more than 200 years. In 2000-1, parts of England experienced some of the worst instances of flooding on record. Global climate models predict that we can expect more droughts and more periods of heavy rainfall accompanied by increased occurrences of flooding.

The second challenge is that the global demand for fresh water will increase, as population increases and the standard of living improves. It has been argued that in Britain we can counter this increased demand by metering water and making it more expensive. However, consumption of water per head of population in Britain is below that of many other developed countries where domestic water is metered. The stark truth is that demand for water is almost directly related to prosperity – as disposable income increases, water use increases.

The third fact is that concern for the environment has increased and is likely to go on increasing. This too is a reflection of increased prosperity and – for at least some of the population – increased leisure time to spend enjoying the countryside and thinking about environmental issues. Price accepts the need for some form of sustainable approach to water use to protect the environment, but concludes that

1. Sustainability should not be seen as an end in itself. Most human advances have not been sustainable in the long term; rather, mankind has advanced by a series of unsustainable developments.
2. It follows that when we talk of sustainability, we should define the time period over which we are measuring sustainability
3. Resources traditionally have been exploited by the first people to need them and to have the technology to use them.
4. Although bad planning decisions play a part, environmental problems are usually the result of a conflict of legitimate interests rather than deliberate lack of concern for environmental well being.
5. The best ways to ensure sustainable use of water are to re-use water after abstraction and to reduce irrigated agriculture wherever possible in favour of rain-fed agriculture. The first essentially means some form of re-use of sewage effluent and will require a change in public attitude; Price argues that it is pointless to treat sewage to very high standards only to pipe it out to sea. The second will require a change in economic approach that is outside the control of hydrologists and water engineers.
6. Finally, and perhaps most importantly, we should remember that a water environment that was sustainable under one climatic regime may become unsustainable if – or when – the climate changes. Water tables will rise and fall and stream networks expand and shrink depending on the amounts of recharge. If the changes are short-term fluctuations, groundwater storage will be important in helping to ameliorate the effects on both the environment and water supplies. If the climatic changes are long-term trends, then no amount of planning or legislation will prevent the resulting changes to the environment.