The real environmental water figures

By Jan Beer

There are too many misconceptions about the Murray-Darling Basin and water sharing within it.

We have seen constant pedalling of false information, on top of the acknowledged poor initial benchmarking, which has led to a Basin Plan that is not delivering the social, economic and environmental outcomes that were promised.

To adequately assess and implement an effective plan we need to improve our understanding of some basics around water availability and distribution.

The long-term average rainfall (1895-2009) across the Murray-Darling Basin is about 500,000 gigalitres per year (GL/yr). Because Australia is the driest inhabited continent on earth, with a flat, arid landscape and extremely low river gradients, 94 per cent of this rainfall is either lost through evaporation, transpiration, recharges to groundwater through seepage or is used by the natural environment.

The six per cent (32,800GL/year) on average that we are left with,  is surface water which flows into creeks, streams and rivers and is available to sustain the Basin, its people and the environment. (NB: This does not include groundwater.)

Of this six per cent remaining surface water flows, on average 19,100GL stays in the environment and is used for natural flows and all manner of environmental watering programs.

The remaining annual average 13,700GL/yr of surface water inflows used for all consumptive use is at the heart of arguments regarding the recovery of further amounts of water for the environment.

The MDB Plan is close to achieving its target recovery of 2,750GL ( including the 605GL Sustainable Diversion Limits Adjustment Mechanism projects) meaning the amount of water available on average each year to the environment will be 21,850GL or 67 per cent of all total basin surface water inflows. The remaining 33 per cent (10,873GL) is the maximum finite surface water volume available for all human, urban, irrigation, agricultural and industrial use.

It should also be recognised that in above average rainfall years the environmental benefits are naturally increased, while the consumptive pool essentially remains fixed.

Under the Basin Plan, the Murray Darling Basin Authority (MDBA), assessed how much water was being extracted, using 2009 as the baseline year, which happened to be 12 years into the Millennium Drought. On this basis it was decided that a further 2750GL would be taken from the consumptive pool of 13,700GL and given to the Commonwealth Environmental Water Holder. The MDBA stated this was an environmentally, socially and economically acceptable amount and that 10,873GL/y was the long term average environmentally sustainable level of take that could be extracted annually from the Basin for all consumptive use and called it the sustainable diversion limit.

However, at the very last minute, then South Australian Premier Jay Weatherill threatened the Federal Government with High Court action if it did not extract a further 450GL from the consumptive pool  to bring the total environmental portion to 3,200GL/yr. If this further water is extracted from the consumptive pool then the environmental pool would total 68 per cent of all available water in the basin.

We all want a healthy environment, but let’s see some common sense prevail. The MDBA Basin Evaluation Report 2017 states there has been a huge reduction in employment and population in regional communities. For example, the Wakool community has seen a net reduction of 34.5 per cent of water available for production, with a subsequent decrease in its agricultural workforce between 2001-2016 of 61.5 per cent.

With many reports documenting the severe social and economic impacts and hardships that have been incurred by the rapid extraction of water from the irrigation industry, it is clear there must be no further acquisition of water and the MDBA must undertake the following investigations:

  1. There must be a detailed assessment of actual ecological outcomes, environmental benefits and disbenefits.
  2. It must be discerned if the water already in the environmental pool (21,850GL) is sufficient to achieve the Basin Plan objectives.
  3. Demonstrate that the water already acquired can actually be delivered downstream to the Lower Lakes, Murray Mouth and Coorong within the legislative requirement of no adverse social or economic impacts, such as substantial flooding of private property.
  4. Review the MDBA’s initial environmental objectives for the end of system, such as the technical possibility of providing enough water to keep the Murray Mouth open 95 per cent of time without dredging.

It should also be understood that the 10,873 GL/yr that is left for all consumptive use, be it rural, urban, human, industry or irrigation, has to sustain 3.5 million Australians – 2.1 million people living within the Basin and directly reliant on its water resources and another 1.3 million outside it who also depend on supply from the Basin. The population reliant on the basin water resources is constantly increasing with the use of major pipeline systems including some to towns, cities and communities well outside the basin region, for example Broken Hill, Melbourne and Adelaide.

The Murray Darling Basin is known as our nation’s food bowl and is our most important agricultural region with 40 per cent of our farms producing agricultural and food products valued at $22 billion and over 50 per cent of our nation’s irrigated produce.

The gross value of the basin’s agricultural production is 39 per cent of the national value, producing food and fibre for the domestic and overseas market as well as providing the raw materials for most of the manufacturing activity within the Basin and for many processing companies outside the Basin.

It is simply unsatisfactory and totally inadequate for the MDBA to complete a Basin Evaluation Report, confirm that the plan is “on track” and will be delivered “in full and on time” when its strategies have so obviously created immense hardship in regional communities, caused irrigation districts to lose such large quantities of water that they are on the brink of collapse, but then have no idea if the large volumes of water accumulated for the environment can actually be delivered downstream to the Lower Lakes, Murray Mouth and Coorong under the legislative requirements.

It is time the Federal Government, which charged the MDBA with the responsibility of ‘enforcing’ the Basin Plan, demand that the Authority be accountable in delivering a “triple bottom line” plan and show clear justification of its strategies. We have yet to see this happen.

  • Jan Beer is spokesperson for the Upper Goulburn River Catchment Association.

For further information and interviews Jan Beer – Upper Goulburn River Catchment Association, phone 0407 144 777 or email [email protected];

Jan Beer, “Cheviot Hills”, Yea, Vic. 3717

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