The release by the Murray-Darling Basin Authority of its draft Plan to restore and sustainably manage the basin should be a cause for celebration. Sadly, the poor translation of science into policy and political compromises will leave the rivers' ecosystems and the people who depend on their health increasingly vulnerable to desiccation.
Extensive parts of the rivers, lakes, billabongs, and floodplain forests of the basin have been severely degraded by decades of excessive diversion of water for human use. The past decade of drought accelerated the loss of tens of thousands of hectares of flood plain forests, saw salt accumulate and some wetland sediments generate sulphuric acid. We now need to add more water to restore these wetlands. However a particularly egregious decision of the state and federal ministers will see implementation of this plan delayed to 2019-2024.
Rivers and other wetlands need water to be healthy. The authority's own Guide to the Basin Plan suggested in 2010 that as much as 7600 gigalitres (GL) needs to be reallocated from agriculture to meet Australia's obligations under the Ramsar Convention on Wetlands to maintain the ''ecological character'' of key habitats. However this plan would allocate less water for the environment than was proposed in the guide, reallocating just 2800GL a year (about a quarter of diverted water) compared to the 3-4000GL a year proposed last year. Of great concern is the continual loss of water to largely unregulated uses (such as forestry plantations, farm dams and gas extraction), which would only be ''identified'' by 2017.
Even this reduced environmental water allocation is under review in 2015 and may be lowered by the authority following ''environmental works and measures''. Environmental works and measures are engineered structures like weirs, levees and canals that would spread smaller water volumes over larger areas of wetlands. They are more risky for the environment in a number of respects. To be effective this infrastructure relies on good management every year for ever. Yet time and again state governments have demonstrated that they cannot be trusted to implement their water agreements for the environment, for instance when Victoria and NSW suspended water sharing plans during the last drought. In ''running the river harder'', there is less capacity to withstand management errors or unexpected droughts or climate change.
This infrastructure fragments the riverine environment, causing damage like blocking fish passage and drying out some wetlands. Indeed, the infrastructure built for the previous program, The Living Murray, waters less than 40per cent of the target sites and so effectively abandons 60per cent of these wetlands. Further, by pooling water on isolated floodplain wetlands there comes the risk of degrading soil and water quality by increasing salinity levels.
The proposal to reallocate only 3per cent of diverted waters to the environment over a 10-year period to ameliorate losses expected with climate change is particularly risky. The authority appears to have mistakenly interpreted CSIRO's ''median'' forecast of 12per cent less surface water availability from 1990-2030 to mean that this is the most likely impact of climate change. This fails to adequately manage the risks from possible and known catastrophic changes; for instance, CSIRO ''extreme dry'' scenario of 24per cent less water or the reduction of inflows into the river system by 63per cent during the peak of the last drought.
Restoring the health of the rivers is not a case of agriculture versus the environment. A healthy river is needed to deliver basic benefits for people, including flushing salt out to sea, maintaining drinking water for Adelaide, restoring fish stocks and growing floodplain pastures for livestock. Indeed, research at the Australian National University shows that the irrigation industry is not as sensitive to reductions in water availability as they say. In the drought years of 2000-01 to 2007-08, for instance, water diversions for agriculture fell by about 70per cent yet the gross value of irrigated agricultural production in nominal terms declined by less than 1per cent thanks to water trading and more efficient water use. Less than a third of farmers in the basin irrigate and they produce 5.4per cent of the gross regional product.
The amount of money for repairing the basin should not be a problem. The Federal Government's current allocation of $5.8 billion to subsidise rebuilding the irrigation industry's old infrastructure should be reallocated to increase the existing $3.1 billion fund for voluntary purchases of water rights and to a diverse array of regional economic development projects. While returning more water to rivers will always help the environment to some extent, this draft plan is a case of too little (2800GL a year) and too late (2019-2024).