A personal take on the future of the water sector by Prof Paul Younger FREng, holder of the Rankine Chair of Engineering at the University of Glasgow.

In the 20^th Century, the management of water was largely conducted in isolation from the that of other natural resources. If you worked in the water industry, you had a pretty clear idea of where the boundaries of your business lay. As the decades of the 21^st Century become plural, however, those boundaries are becoming increasingly fuzzy.

The connectivity between water and land-use, water and carbon, and water and energy are expanding the remit of water managers in the direction of integrated land and water resources management, and towards concerted initiatives to recover and use energy within the processes of water and wastewater management.

There are huge areas of unfinished business, however. It is now clear that the ambition of the UN Millennium Development Goals on sanitation provision will not be met until at least the middle of this century at current rates of progress. Similarly, as populations grow, and existing populations become more affluent, the predominant use of water – for agriculture – also looks set to expand inexorably.

Yet improving the efficiency of sanitation and agricultural water use remain minority topics in most current research agendas – and definitely a “poor relation” compared to research on climate change, for instance. Nevertheless, we would do well to heed the centrality of water to the climate change agenda too, as even cities in the humid global North add carbon-intensive desalination processes to their water management asset registers.

People cannot survive without water, so water provision will ultimately trump any other political priority. Hence there is a pressing need to restore water to pole position in debates about human futures. Can we turn the depressing alternation of droughts and floods to our advantage by dramatically expanding the use of Aquifer Storage and Recovery, for instance? Can we find new ways of desalinating water that use far less energy? Can we find cost-effective ways to make water – as a vast reservoir of hydrogen – the raw material of choice for the future development of transport fuels?

As a committed optimist, I have to say I believe we can – but we had better start in earnest right away if the 21^st Century is to turn out more happily for humankind and ecosystems than the previous few centuries did.

Prof Paul Younger FREng holds the Rankine Chair of Engineering at the University of Glasgow. His new book, Water: All That Matters (Hodder & Stoughton) is just out. More information at: www.allthatmattersbooks.com