Proposition for a national water bank

The director of the National Centre for Groundwater Research and Training, Professor Craig Simmons, has proposed the development of a national water bank - a vast monitored network of ‘underground dams’ to help Australia avoid water shortages for centuries to come.

“The Australian Government has recognised the vital importance of having enough water to underpin our national economic future and anticipated population growth, and has set up a Ministerial Working Group to oversee it,” said Professor Simmons. “Our proposal for a national water bank is intended to contribute to this process.

“Groundwater accounts for 95% of Australia’s available fresh water. It is a vital reserve for agriculture, mining, manufacturing and urban use, and supports industry worth $34 billion. If we look after it, it will look after us - for all our foreseeable future.”

Professor Simmons said a national water bank would help by ensuring the nation’s aquifers were recharged during times of plentiful rainfall and then monitoring the water balance of both surface and underground water to ensure adequate future supplies for industry, cities and the environment.

“Underground dams have two big advantages over surface dams - first, they lose little of their water to evaporation and second, they are cheaper to build,” he said. “Instead of vast earthworks and flooded valleys, you just need a few pumps or soaks to inject water at the right time into carefully researched aquifers. That water can then generally be recovered at need.”

The storage ability of a national water bank lies in relatively lower cost items like infiltration ponds, injection bores, computer models and sensors rather than in costly earthworks and concrete associated with major dams and reservoirs costing hundreds of millions of dollars.

Furthermore, said Professor Simmons, if the amount of water being stored and discharged from an aquifer is known, it can always be managed sustainably. “It is vital we better understand our national groundwater storage capacity, its recharge rates and the potential for us to augment and top up our aquifers with artificial recharge,” he said.

The fifth report of the Intergovernmental Panel on Climate Change (IPCC), released last month, warned that rainfall in south-eastern Australia could decline by up to 40% and in south-western Australia by as much as 70% over the coming three to four decades. This will lead to massive reductions of water flowing in surface rivers and streams. This will be accompanied by increases in evaporation due to warmer days and the prospect of more frequent, fiercer droughts - interspersed by episodes of more intense rainfall and flooding.

According to Professor Simmons, the report “emphasises the need to stock up on water as soon as possible - rather than waiting for our groundwater reserves to become depleted by the next big drought”. He added that a national water bank can outlast many existing projects and structures by centuries and can potentially benefit the whole continent, not just particular regions.

“All we need to do to achieve this is invest wisely in the necessary science, technology and management skills. Water science and training are not high-cost items, relative to other activities like building huge dams or ports. They represent a form of infrastructure that lasts for generations and only needs topping up, not repair. They pay off immediately in water savings and help keep water prices low for everyone. They provide insurance against drought, climate change and the loss of water-dependent industries, towns and landscapes. They can reduce the economic and social costs of drought greatly.”

Professor Simmons added that the opportunity to build a national water bank will put Australia in the front rank of the world’s wise water managers at a time of looming global water scarcity, leading to major new knowledge exports in water management and technology. “So it will create jobs and exports as well as preserve our most precious resource - fresh water.”

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