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As El Niño bites, it’s time to take stock of our water

17 mile regulator - a computer controlled flume gate - on the East Goulburn Main Channel Water. ©Rubicon Water, Author provided

As El Niño bites, it’s time to take stock of our water

17 mile regulator - a computer controlled flume gate - on the East Goulburn Main Channel Water. ©Rubicon Water, Author provided

With El Niño upon us and the prospect of water scarcity ahead, how well positioned are we to make accurate and timely decisions about water resources?

Our last water crisis, still a vivid memory for many Australians, was the Millennium Drought, which was extreme by any measure.

Protracted and widespread water shortages saw farm dams empty, rivers run dry, and lakes acidify as streamflow dwindled. Treasury estimated that agricultural output fell by 24%, rural exports by fell by 26%, agricultural income plummeted by 46% and 100,000 people in farm-related employment were left without work. Controversy surged through the media as opinion divided about what to do.

At the peak of the water security crisis, amid dire warnings that water supplies could run dry, former Prime Minister John Howard called a water summit of Murray–Darling Basin Premiers on Melbourne Cup Day 2006 to discuss emergency measures.

Soon after, on Australia Day 2007, he announced the 10-point, A$10 billion National Plan for Water Security, announcing a raft of water reform initiatives and asserting that “you cannot manage what you cannot measure”.

Water is big business

Almost 30% of Australia’s economic activity comes from water-sensitive industries. Water trade worth A$1.3–2.6 billion annually supports irrigated agriculture worth A$13 billion. Water entitlements (or rights) amount to around 30,000 gigalitres (GL) nationally, and have been valued in excess of A$30 billion.

Water infrastructure is valued at A$162 billion and with the Millennium Drought, construction increased sharply in the scramble to build desalination plants, interconnecting pipelines and to modernise inefficient irrigation infrastructure, as the following graph shows.

Water infrastructure engineering construction – adjusted by chain volume index to remove the effect of price changes (ABS 2014 Cat. No.8762.0) Bureau of Meteorology

Desalination plants at cities are now capable of producing between 15% and 60% of daily needs as shown in the graph below.

Desalination plant capacity, and as a proportion of total urban supply (2012-14) Bureau of Meteorology

Efficient use of water and capital becomes even more important with Australia’s four largest cities projected to increase by 43% or 6.4 million people between 2011 and 2031.

Taking stock of Australia’s water

The Bureau of Meteorology was tasked by the National Plan for Water Security to provide water data necessary for good decision-making by governments and industry.

Since 2008 the the Bureau has been collaborating with the water sector and curating water data from over 200 providers in Australia, bringing data from the back office into the public domain. This includes more than 4 billion observations – a vast amount of data.

As competition for water resources intensifies, it is more important than ever to account for how water is managed, in a transparent and rigorous way. This is a key objective of the Intergovernmental Agreement on a National Water Initiative.

The Bureau has now produced six annual National Water Accounts – accounting for up to 85% of the water across the country in ten nationally significant catchments.

Across the nation, water use decreased by 21% of use in 2012-13. The Murray-Darling Basin accounted for 80% of water used in these regions, primarily for irrigated agriculture which used 57% of all water in Australia in 2013-14. Perth and Adelaide relied heavily on desalinated water for almost 40% of urban supply, an increase of more than 30% from 2012-13.

We also collect data on the status of 310 reservoirs, representing over 95% of water held in public water storages.

Water storage in the three largest dams in the Murray-Darling Basin – Dartmouth, Eildon and Hume – all dropped 30% or more in the last 12 months. A fall in volume of 25% also occurred in Adelaide’s dams. Perth dam levels remain low at below 24%, down 9% from the same time last year.

For the first time last year the Bureau produced the urban national performance report comparing 78 urban water utilities across Australia. It is now produced by the Bureau jointly with state and territory governments and the Water Services Association of Australia.

With drier and hotter conditions in 2013-14, the median volume of water supplied increased 3% to 185 kilolitres per property. There’s also been a 2% increase in the median annual residential water bill, but a decrease in complaints.

Even in dry times, flooding rains can be a problem at local scales. The Bureau collects data on rainfall intensity, frequency and duration that are vital for informing design of drains, gutters, bridges and small dams worth millions of dollars. The data has recently been updated with 30 years’ more data at 2,300 extra sites.

Hydrologic reference stations provide high-quality, long-term data on streamflow at 222 sites unaffected by development or landuse. These reveal decreasing streamflow at 35% of the sites surveyed, with 4% of sites in northern Australia increasing as shown in the following figure. You can also find 7-day and seasonal streamflow forecasts, and access streamflow data for more than 3,500 sites across Australia at Water Data Online.

Streamflow trends at 222 Hydrologic Reference Stations having at least 30 years of high quality records. Bureau of Meteorology

The Bureau also compiles groundwater information from more than more than 800,000 groundwater bores. Licensed entitlements and ecosystems that depend on groundwater have also been mapped and are often used for assessing development proposals.

Location of more than 800,000 groundwater bores around Australia. Bureau of Meteorology

While there is much less volume of groundwater issued as an entitlement than from rivers and streams (7,000 GL compared to 25,800 GL), it’s the only source of water for many regions and can provide a crucial reserve during drought. For example, in 2007 Greater Geelong’s water supplies plummeted to 14% and groundwater provided up to 70% of the city’s drinking water.

We’ve also created a national database for climate resilient water sources. An initial stocktake of desalination and recycling plants revealed over 480 plants. Just 360 of these plants – those larger than 50 megalitres – manufactured 442 GL, more than Melbourne’s annual water use in 2012-13. Details of plants can be found at the Bureau’s Climate Resilient Water Sources portal.

With many inland water storages again quite low, public receptiveness to alternative water sources (such as recycled water) may be increasing, as suggested by a recent survey of water consumers by the Australian Water Association.

Are we better prepared?

Since the Millennium Drought, Australia’s water security posture has been considerably hardened. City water supplies have been augmented with climate-resilient sources and many novel water conservation measures have been locked in.

In the bush, irrigation systems have been modernised, water trading systems have been enhanced and environmental water reserves have been established.

Still, we cannot drought proof this expansive continent. Australia’s rainfall is too variable and climate change is making it even more so. There will be another water security crisis and it will again be difficult and expensive to deal with.

Australia’s new water information capability now enables us to understand where we have come from and where we are at; evaluate how we are tracking; anticipate the future, and think through how we can do better.