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Banking water underground for our future

Australia should prepare now for dry times ahead by “banking” its water underground. This means storing surplus water underground during wet periods and bringing it up for use during dry times. Water storage…

Storing surplus water underground will ease the hard times during drought. Tim J Keegan/Flickr

Australia should prepare now for dry times ahead by “banking” its water underground. This means storing surplus water underground during wet periods and bringing it up for use during dry times. Water storage and banking are the missing links in Australian water reform.

Historically Australians rely on large surface reservoirs to provide water for agriculture and cities, and encourage farmers to harvest and store water in farm dams. This strategy is not sufficient to cope with drought and increasing climate variability as demand for food and water grows. Underground water banking can help ensure that there is enough water for both irrigation and the environment when drought hits.

The benefits

Water banking has several advantages.

First, it augments the natural processes of water storage in the landscape, avoiding evaporative losses. In the Murray-Darling Basin up to 3000 gigalitres (GL or billion litres) of water a year evaporates from surface water storages.

Second, it helps to recharge aquifers during wet years, thus ensuring that rivers continue to receive flows of water from aquifers during dry times. It can also assist environmental water managers by allowing them to synchronise supply with specific environmental watering requirements.

Third, water banking helps communities adjust to climate variability and uncertainty, and enables irrigators to receive additional water during droughts.

Fourth, it can help to increase Australian agricultural exports. Water banking expertise and technology could also be a valuable new export industry in its own right.

What’s happening currently

We are already storing about 45GL of water underground in the Burdekin region of Queensland every year for use in agriculture and horticulture. Significant quantities of recycled stormwater and wastewater are being stored and used around Adelaide. In Orange County, California they store around 300 GL a year – enough for the annual household use of 2.3 million people. One water bank in California has held up to 800 GL for its members. The known capacity of aquifers to store additional water below Perth, Adelaide and Melbourne could meet the needs of 2.5 million people per year– and may be far larger.

The argument that there is no spare surface water to store underground, ignores hundreds of gigalitres per year in dam spills and floodwater, recycled stormwater and wastewater. This “spare” water can be stored by channelling water to sand or gravel beds where it can filter down into the aquifer. When infiltration is blocked by rock or clay injection drills can be used.

On the face of it storing water underground and extracting it costs more than storing it on the surface – but this fails to account for the high engineering and environmental costs of dams and reservoirs. Also surface storages lose a third or more per year due to evaporation, and this cost is rarely acknowledged. If we choose not to make water users pay the full cost of surface storage, including evaporative losses, there is a case for public intervention to reduce the cost of aquifer storage for users.

Where to from here

While this needs national leadership, the concept of water banking can be implemented at grassroots level by Landcare and catchment management groups, even by individuals, as well as by larger organisations and agencies.

It is important that water banking is consistent with national water management principles and guidelines, and that the broader impacts are assessed. Every decision to bank water underground needs to be based on careful analysis of local needs. It is important to ensure that aquifer structures are not damaged and that water quality is maintained. In some cases water quality may even benefit from increased groundwater storage.

Good management of groundwater banks also requires some changes to current water management practises. When Australians deposit water in an underground water bank they generally do not retain legal ownership rights, or have any guarantee that they can recover their water. These rights and guarantees need to be established. There are restrictions on how much water entitlement can be carried over from one year to another. This prevents Australians from saving enough water to buffer them against the next drought. Extended carryover could be developed, with rules to prevent excessive withdrawals from aquifers during droughts.

The Murray-Darling Basin Plan is a major step forward in planning the future use of surface water and groundwater. The basin plan provides a platform for the development of coordinated surface water and groundwater plans and water banks at regional scale. Meanwhile communities can start their own water banking initiatives.

We bank money so it is there when we need it. We stockpile many other things, like grain or minerals, so there is always a reliable supply on hand. Why should water be any different? We should start banking our water now – before another major drought arrives.

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27 Comments sorted by

  1. Michael McCarthy

    ARC Future Fellow at University of Melbourne

    Hi Andrew,

    That is an interesting piece. To some extent, aren't we already withdrawing from the water bank by using existing aquifers (e.g., Great Artesian Basin)? You are suggesting that we should make some deposits too.

    You only hint at the economics. What are the likely costs in areas where water banking might be possible and valuable (e.g., Murray-Darling irrigation or city water supply)? How do these compare with, for example, direct use of excess water such as residential and industrial rainwater tanks?

    1. Andrew Ross

      Research Fellow at Australian National University

      In reply to Michael McCarthy

      Michael and others

      The financial and economic viability of water banking is an important but under researched question.

      Water banking involves storing water in an aquifer and recovering it. There are relatively few published studies of financial and economic viability of aquifer storage and recovery (ASR).

      It is difficult to give any general estimate for the cost of ASR because there is so much variation between different locations with different hydrogeological features requiring…

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  2. Kim Peart

    Researcher & Writer

    I hold concern for the future quality of groundwater at present, as a consequence of fracking for gas.

    A certain level of energy would also be needed to "bank" the water.

    I wonder if as a nation we aught invest our resource bonanza in the construction of solar power stations in space, to directly access the unlimited energy-well of our star.

    With unlimited stellar energy, we would be able to extract excess carbon from the air and sea, winning back a safe Earth ~ and also be able to reprocess…

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    1. Nev Norton


      In reply to Kim Peart

      Kim, I keep reading about this stellar energy in just about every post you put up, I'm really fascinated how this is going to work, because for the life of me I can't figure out how you would realistically achieve it.
      What orbit height?
      transmission, AC or Zero length DC links?
      How are you going to keep possibly a hundred tonnes of transformers or converters in orbit and keep it there considering the forces that will be acting on the cable/s
      How are you going to service that equipment?

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    2. Kim Peart

      Researcher & Writer

      In reply to Kim Peart

      Nev Norton ~

      Space based solar power (SBSP) was first proposed by Dr Peter Glaser in 1968 and championed by Professor Gerard K. O'Neill with his space development vision ('The High Frontier' ~ 1977), of which he wrote, "If this development comes to pass, we will find ourselves here on Earth with a clean energy source, and we will further improve our environment by saving, each year, over a billion tons of fossil fuels,” (p.162).

      We could have avoided the carbon crisis, by making the transition…

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    3. Kim Peart

      Researcher & Writer

      In reply to Kim Peart

      Michael Shand ~

      In the longer-term, the potential to supply all Earth's energy needs from ground based solar power generation would be quite high, especially with systems like that developed in Spain, were energy is stored in molten salt.

      This would be especially so if much industry were located in space, where the energy of our star is so abundant. It is hard to imagine a power source that will expand to the orbit of the Earth over the next five billion years.

      Our immediate challenge on…

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    4. Jonathan Maddox

      Software Engineer

      In reply to Kim Peart


      Space-based solar power involves no cables, rather a microwave beam.

      The concept has fascinated people for 70 years, having first been suggested in print by Isaac Asimov as early as 1941. NASA engineer Geoffrey Landis has contributed much of the concrete analysis of potential implementations.

      There is a company called Solaren which hoped to get a working 200MW system into orbit and operational, providing power to the Californian grid, as soon as 2016. They seem to have gone quiet in the last 12 months though, and today their website seems to be no more than a splash page.

    5. Kim Peart

      Researcher & Writer

      In reply to Kim Peart

      Jonathan Maddox ~

      Much appreciated alert to Isaac Asimov's 1941 imagineering of space based solar power.

      No I wonder why Asimov wasn't awarded the patent, as this went to Dr Peter Glaser in 1973.

      Quite a neat 2008 article in The Economist ~

  3. Steve Davis

    Brian Surgeon

    I have just returned from a few weeks in central New South Wales and seeing the amount of water from The Great Artesian basin pouring out of bores was disturbing.

    There are several tourist bore baths at places like Pilliga and Burren Junction which have been "limited" but it is still an incredible waste, despite bringing some income to these towns.

    One agricultural bore in particular at a property call Youendah ( pours at least 200 litres per minute (at a conservative…

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    1. Kim Peart

      Researcher & Writer

      In reply to Steve Davis

      Steve Davis ~

      I fear that unless we strike out with a major new energy option, our groundwater will be condemned to contamination through fracking.

      Because of the unlimited energy supply from the Sun that can be accessed through space based solar power, which can also be used to extract excess carbon from the biosphere to win back a safe Earth, I suggest stellar energy, which is the source of all the fossil fuel on Earth in the first place.

      Kim Peart

  4. Ewen Peel


    Good article that looks at a different concept.
    Not sure about the economics of it, although i would think that if solar pumps were used to access the underground water then it might add up.
    Earthworks above ground and the other looses incurred with above ground storage certainly would add up, so it might be feasible.

    Certainly as mentioned below the issue of fracking for gas production could put an end to the whole idea, and from an Agricultural point of view i am not hearing many good outcomes for the underground water and the users of it.
    Selling the concept of a large unseen pool of water to invest in will be challenging.

  5. Dianna Arthur
    Dianna Arthur is a Friend of The Conversation.


    Excellent article.

    I have been banging on for years about storing rainfall rather than watch it carry litter and detritus out to sea.

    The methods of storage can range from the small home garden tank, through to industrial size tanks placed under building at commencement from construction.

    Also allowing our natural aquifers to refill, would bode well for the future and provide a significant reason to rethink hydraulic fracturing for gas.

    We actually do have the finance and technical ability, what we lack are government and business leaders with vision.

  6. Christopher G. Baker

    Research Analyst, Centre for International Security Studies at University of Sydney

    Thanks for the article Andrew. It's nice to see some forward thinking in regards to groundwater extraction. Water will undoubtedly be one of the biggest concerns for mankind as a whole in the coming decades and in many countries, especially in Asia, it is already a pressing concern with millions of lives at stake.

    I must admit that I am really disappointed that you failed to engage with the fracking debate. I understand the desire to appear non-political or non-controversial, but this issue concerns…

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  7. John Davidson

    Retired engineer

    Newcastle NSW uses the Grahamstown scheme to recharge the Tomago sand beds - a major source of Newcastle's water supply. (Has been doing it for over 50 years.)
    Newman in WA uses a small dam to recharge the aquifer it draws all its (and the mines) water from. Before the recharge system was installed the aquifer would have run out of water. Has been doing it for over 20 years.
    You usually need a source of clean water, an accessible aquifer and a small holding dam to hold the water long enough to get into the aquifer.
    A civil engineer explained to me once that politicians prefer dams and open water channels because they provide better photo ops. What politician is going to worry about evaporation losses when the alternative is photo op losses?

    1. John Davidson

      Retired engineer

      In reply to John Davidson

      Mark Amey: Thanks for the correction. I had always understood that the Grahamstown dam was part of the Tomago recharge system.

      I am right about Newman. I arrived there just after the recharge system was built

  8. Daniel Boon

    logged in via Facebook

    yes ... more water, to water down the fracking chemicals currently allowed / facilitated by government ...

  9. David Collett

    logged in via Twitter

    It would be constructive to follow this up with an article from some engineers/scientists who could outline what is involved physically to create re-charge points for the naturally occurring underground aquifers, then a discussion/outline of the costs involved and land owners will be able to make up their own mind whether it's the right decision for them.

    The changes to the rules seem straightforward enough.

  10. Lincoln Fung


    Apart from its economnics, how realistic is it to have sufficiently large underground water stoarge spaces in areas where rainwater is also sufficient for doing it?

    1. Eddy Schmid


      In reply to Andrew Hastings

      Andrew, it is true, what you have posted. However, do you honestly believe that such a process will go even half way to replace the aquifer replenishing locations we have had along the metropolitan coast line in the series of freshwater lakes that collect the run off from rains and gradually allow the replenishment of underground aquifers via these areas, which have over the last thirty years been INFILLED and housing established upon them, thereby destroying forever a natural replenishing resource…

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  11. Eddy Schmid


    Very timely and thought provoking article.
    However, it must not be taken without consideration to Australia's love affair with mining.
    I live in W.A. and am very familiar with our underground aquifers and their capacities to store water.
    However, that capacity relies on the FACT that the sub strata is NOT DISTURBED in any way.
    Yet, we see our state Govt has given approval for fracking operations to commence and are currently being undertaken as we write.
    The claim made by our Govt, that such…

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  12. Muhammad Arshad

    logged in via LinkedIn

    Andrew, rightly mention that economics of groundwater banking (Aquifer storage and recovery) is complex. A set of local hydrogeological and climatic condition dictate the cost across localities, mainly depending on recharge rates, aquifer type, water source, water quality and method of treatment being used. Most important is the selection of recharge method. ASR/well injection system requires treated water near to the drinking water quality standard to avoid any risk of contaminating native groundwater. This cost of water capture and stabilization i-e temporary storage before injection makes the ASR approach less attractive than the simpler pond infiltration system. In fact the right choice of aquifer recharge method can be a tool to overcome high cost. A combination of more than one method suiting to the local hydrogeological conditions can bring the cost down and maximise utility of water banking.

  13. Dean Ashby

    Company Owner at Ezestore Storage Sydney

    Working in the storage industry of a while before venturing on my own, has sparked a great deal of interest in me of news about anything concerning storage. I have read news about latest developments in storage facilities, on what could be done to maximize space within the business in order to deliver cheap storage without having to sacrifice the quality of service, and the like. Now with this underground water storage, it is rather amazing to find out and read more about the technology behind this to make it possible. I am sure that it will be amazing to follow thru the development of this, and hopefully such will happen in my lifetime, and that it will be affordable for the generations to come.

  14. Cameron John Robertson

    Storage Company Owner at Supercheap Storage Northern Beaches

    Surplus water storage is a very smart move indeed. When the sea levels are high, they should take advantage of it fully. This way, even during low sea levels, the issue of drought can be tackled easily without the need for extra costs especially when resources are going to be really expensive when the volume available is low. Surplus water storage will also mean that water can be made available anytime it is needed without the need to go to extreme means.