Water buybacks from the Murray-Darling Basin will reopen by voluntary tender from March 23 for irrigators to sell their permanent water entitlements to the Australian government.
The announcement marks a renewed effort to return environmental water to the basin after buybacks were capped in 2015 in favour of irrigation and on-farm efficiency programs. These were deemed insufficient in a 2022 review.
Australia’s biggest river system
The Murray-Darling Basin covers much of south-eastern Australia, including parts of four States – NSW, Qld, SA and Victoria – and the ACT.
The basin is home to 2.3 million people, supports 7300 irrigated agriculture businesses, and contributes $22 billion to the Australian economy.
It also sustains 16 internationally significant wetlands, 35 endangered species and 120 different species of waterbirds.
The Water Act 2007 legislated more water be allocated for the environment. Yet, while some progress has been made, the expected volumes have fallen short.
A decade of neglect
The Water Act 2007 established the Murray-Darling Basin Authority and set out requirements for a Murray-Darling Basin Plan that would ensure “environmentally sustainable levels of water extraction” and “protect, restore and provide for the environment of the Basin”.
After considerable debate over how much environmental water was needed, the $13 billion plan was released in 2012, promising 3,200 gigalitres of water to the environment each year.
This would be achieved by the government buying back water allocated to extractors (such as irrigators) and retaining it in the river.
The plan aimed to immediately return 2750GL of water back to rivers, wetlands and groundwater systems, and flagged another 450GL to deliver “enhanced environmental outcomes” by mid-2024.
In 2013, a Water for the Environment Special Account (WESA) was established to fund the extra 450GL.
In 2015, irrigators opposing any buybacks were successful in having buybacks capped. The Government’s new plan would now achieve the water savings through spending on irrigation efficiencies instead.
In 2018, serious doubt was cast on the value of infrastructure efficiencies by five professors of water economics, who wrote that “economics evidence … does not support the claim that water entitlement buybacks must be precluded to achieve neutral or improved socio-economic outcomes”.
Also in Cosmos: Want water for the Murray-Darling Basin? Don’t ask a zombie
Nonetheless, two amendments to the plan were made the same year, in line with the Murray-Darling Basin Authority’s 2016 Northern Basin Review and the Basin Plan’s Sustainable Diversion Limit Adjustment Mechanism.
The adjustments were made “to achieve environmental outcomes required through the Basin Plan with less water (resulting in) more water available for productive use without impacting the environment.”
The result was the targets being watered down yet again in a deal to have governments commit to the 450GL, but only if “no socioeconomic harm is done to river communities”.
The changes contravened modelling already published in 2013 in the Australian Journal of Agricultural and Resource Economics, showing water buybacks to be more efficient than infrastructure upgrades.
Meanwhile, the basin itself was drying out.
Research published in Nature in 2021, showed climate change and higher temperatures led to river flows declining over time, further exacerbating the effects of the over-extraction of water.
What’s happening now?
Alongside evidence that water use efficiencies were not working, reviews of the WESA were undertaken in 2019 and 2022.
The 2022 WESA Second Review revealed only 2.6GL of the 450GL had actually been delivered.
As for the main target, now 2075GL, there remained a “gap” or shortfall of 49.2GL of missing water between the revised target and the amount so far recovered.
With buybacks reinstated, the Australian government now aims to recover the 2,075GL of water for the environment by 30 June 2024.
The buyback aims to recover 46GL of surface water and 3.2GL of groundwater from seven catchments across the basin.
A Strategic Water Purchasing Framework sets out the Australian Government’s plan to buy water in six of these catchments in Queensland and New South Wales, while still hoping to identify 4.9GL of water in ACT catchments.
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