Why we need it
The Murray-Darling Basin (MDB) is Australia's most valuable agricultural region, is of great importance to First Peoples and provides very large environmental, tourism, cultural, and social values. The decade-long Millennium Drought had negative impacts on the environment, communities and agriculture. Research shows the environment suffered a disproportionate impact with: losses of native fish populations; declining waterbird populations and poor bird-breeding events; loss of vegetation, especially in floodplain forests and wetlands; and high salt concentration at the end of the system from low stream flows in parts of the Basin. Responses by the Australian government included:
A $10 billion package (later increased to some $13 billion) in January 2007, of which some $6 billion was allocated to modernise irrigation infrastructure and significantly improve the health of the rivers and wetlands of the Basin.
The Water Act (2007) that has as its key objects: 1) 3d(i) to ensure the return to environmentally sustainable levels of extraction for water resources that are over-allocated or overused; and 2) 3d(ii) to protect, restore and provide for the ecological values and ecosystem services of the MDB.
A Basin Plan (enacted in November 2012) with its key objective to achieve Sustainable Diversions Limits (SDL) by reducing surface water diversions by an equivalent to, on average, 2,750 GL/year by 1 July 2019 while noting that CSIRO concluded that increases in actual Basin stream flows of 3,000 GL/year would be insufficient to meet South Australia’s environmental water requirements.
Current State of the Basin
It is more than five years since the Basin Plan was enacted and $6 billion has been spent on water recovery. Much more could have been achieved for far less because subsidising infrastructure to acquire water for the environment is, based on Australian government data, 2.5 times more expensive than buying water entitlements directly, and might be much more expensive after accounting for reductions in return flows. Little evidence exists that key objects of the Water Act (2007) have been realised or key socio-cultural values been adequately supported because:
While there has been some localised recovery, there is very little evidence of Basin-wide environmental improvements since 2011. The 2017 State of the Environment Report, supported by other evidence, gives a ‘poor’ assessment grade of inland water flows and “longer-term downwards trends in flows seen in nearly 50% of stations,” while ecological processes and key species populations are ‘very poor’ with a deteriorating trend.
There is no observable relationship between volumes of water acquired by the Australian government for the environment and stream flows at the Murray Mouth over the period 2007-08 to 2016-17 and, for many of the water recovery infrastructure projects, no scientific evidence that they have increased stream flows.
Given recent dredging at the Murray Mouth, the Australian government’s Basin environmental watering plan objective to keep the Murray Mouth open to the sea 90% of the time will almost certainly not be achieved.
Actual (net) increases in stream flows are much less than the approximate 2,000 GL of water entitlements already acquired by the Australian government as a result of several factors including: i) reduced recoverable return flows from increased irrigation efficiency that have not been properly measured or fully accounted for; ii) double-counting by the Australian government of water allocated to water entitlements, but not previously fully used by irrigators; and iii) water theft.
A December 2017 draft determination by the Murray-Darling Basin Authority to diminish the volume of surface water to be acquired as water entitlements for the environment by 22% to 2,145 GL/year by 1 July 2019. Instead of acquiring water entitlements for the environment equal to 2,750GL/year, 36 water supply projects are planned that will reduce this volume by 605GL/year, of which 25 do not satisfy Basin Plan requirements.