Displaying items by tag: fish kill
We have all been shocked by the mass killing of fish in the Menindee Lakes and other areas in January, the loss of wildlife and the poor water quality and quantity for communities along the Darling River. Murray Cod and other native species believed to be up to 100 years old that have survived numerous droughts have not survived this one. The politicians are blaming the drought but the causes of the severe degradation of the Darling River go back a long way stemming from the over exploitation of the water and the lack of political will to solve the problem.
The Murray-Darling Basin covers a massive area of southeast Australia inland from the Great Dividing Range, from southern Queensland through to the mouth of the Murray in South Australia (see map).
Water extraction for irrigation commenced late in the 19th century along the Murray River with the creation of schemes by the Caffey brothers near Mildura and Samuel McCaughey in the Murrumbidgee Valley. Regulation of the Murray River system was one of the first issues addressed after Federation.
With a severe drought in the late 1960s, environmental impacts were starting to emerge as water quality had deteriorated and salinity was apparent. From the 1970s state governments undertook initiatives to manage water diversions including the definition of water entitlements, development of water markets and salinity management, but there was no interest in the fundamental issue of too much water being used.
By 1995, in response to increasing evidence of deterioration of the Basin’s river system including a massive blue-green algae outbreak in 1991–92, the Murray–Darling Basin Ministerial Council directed that a water audit be prepared to investigate the current levels of water use and potential increases across the Basin if infrastructure was developed so that all available entitlements were taken up.
The audit showed that between 1988-89 and 1992-93 the average total diversion from the Basin was 10,780 GL/year. Of this amount, over 95% was diverted for irrigation.
The report modelled the hypothetical flows of water at the mouth of the Murray. With no diversions drought conditions would have occurred in 1 in 20 years, but with the current level of diversions drought conditions would occur in 60% of years, and under full development it would occur in 3 out of 4 years.
This graph shows the massive increase in the water used for irrigation and agriculture as revealed in the audit report. It showed that growth even in the previous 8 years had been 8%, mostly in the north for cotton growing. Not only that, there was the potential under the current management regime for usage to grow by a further 14.5% if the infrastructure capacity were installed. However use of the full entitlements would reduce the overall security of the system for individual irrigators because the levels of reserves in storages would be reduced. The full entitlements equated to diversion of 12,344 GL per year.
Environmental Impact of Current Extractions
The 1995 audit reported that the changes to the natural flow regime from the current water diversions and extractions had had a significant impact on river health. There was a reduction in the areas of healthy wetland, native fish numbers had declined in response to the reduction in flow triggers for spawning and salinity levels had risen. Algal blooms had increased in frequency in line with more periods of low flow leading to increased water temperatures and nutrient levels. The fish kills occur when the temperature changes and the algae die off and the bacteria increase reduces oxygen levels available to fish and other aquatic life.
First Plan to Control Extractions, the Cap
In 1995, the Murray–Darling Basin Ministerial Council introduced the Murray–Darling Basin Cap on Surface Water Diversions (the Cap):
to protect and enhance the riverine environment and protect the rights of existing water users.
The Cap introduced long-term average limits on how much water could be taken from rivers in 24 designated river valleys. The total Cap was 12,100 GL per year based on possible extractions in the 1993-94 year under infrastructure then available with some adjustment for the development of new diversions outside the main states of NSW and Victoria. This total extraction each year was to be adjusted to allow for actual rainfall. With the Cap in place, new developments were allowed, provided that the water for them was obtained by improving water use efficiency or by purchasing water from existing developments.
The Cap made water in the Basin a more valuable resource as it gave entitlements to its diversion more value and saw increased trade in these entitlements. The Cap was meant as an emergency measure to prevent further disasters while a long-term policy was worked out. Nearly 25 years later, it is still in effect.
The Cap is too High
The millennium drought from the late 1990s to 2010 in much of the Basin highlighted the need for continuing reform. Too much water was still being used and the environment was suffering.
In 2007, Prime Minister John Howard announced a $10b plan to improve water efficiency and to address over-allocation of water. The Water Act was passed that set up the Murray–Darling Basin Authority (MDBA) with the purpose of developing the Basin Plan. The Act’s primary objective is:
to bring water extractions back to sustainable levels in order to protect, restore and provide for the ecological values and ecosystem services of the Murray–Darling Basin
The Act should give effect to Australia’s international agreements such as the Ramsar wetlands. The ultimate source of conflict in implementation of the Act was the provision that management should optimise economic, social and environmental outcomes.
Contents of the Plan
In October 2010, as part of the preparation of the Basin Plan, the MDBA produced a report for discussion entitled Guide to the Proposed Basin Plan. The scientific evidence described in the report stated that achieving an ecologically sustainable level of take would require the recovery of between 3,856 GL ± 20% (high uncertainty of success) and 6,983 GL ± 10% (low uncertainty of success) of surface water from the current baseline development level of consumptive use of 13,623 GL. 10,900 GL of this baseline development level was extracted for irrigation and the remainder was run off stored in on farm dams.
The irrigation communities objected violently to the idea that their allocations could be reduced by so much. The MDBA and politicians buckled and in 2012, the Basin Plan passed by parliament was for a water recovery target of only 2,750 GL (by June 2019), with a program to recover an additional 450 GL of water (by 2024) to benefit South Australia through ‘efficiency measures’ (reducing water losses via infrastructure improvements rather than buying back entitlements), bringing the total to 3,200 GL.
What about Climate Change?
In preparing the Plan in 2010 the MDBA also asked CSIRO to prepare a report modelling water availability in the Murray–Darling Basin including a projection of the effects of climate change.
The assessments for climate change scenarios were made for the median model at 2030 and for the ‘dry extreme’ and ‘wet extreme’. The median projection was of a 10% reduction in Basin-wide water availability with a range of –27% (dry extreme) to +9% (wet extreme).
So not only was the Plan the bare minimum with great risk of not achieving the necessary improvement in environmental flows, there was no allowance for adjustment for the impacts of rainfall reduction from climate change.
Unwinding of Water Recovery Targets since 2012
As has become apparent the Basin Plan is too little, too late. To make matters worse the state and federal governments have been fudging the implementation of the Plan that was always going to require dedication and strict administration.
There are several instances of improper governance and attempts to water down (pun, sorry!) the Plan. A few are outlined below.
In July 2017 ABC’s Four Corners aired a story of water theft and lack of proper oversight allowed by the NSW government. Some prosecutions followed but the administration has been laissez faire.
The Four Corners report prompted the South Australia government to hold a Royal Commission. The report just released condemns the MDBA and governments for maladministration of the Water Act and calls for a separation of management and compliance.
A series of policy changes since 2012 are threatening to further undermine the possibility satisfying the objectives of the Basin Plan. The Australian government intends to amend the Basin Plan by increasing surface water extraction limits for irrigation by 70 GL in the northern Basin. After NSW and Victoria threatened to abandon the Plan water extraction limits in the southern Darling Basin were increased by 605 GL on the basis of 36 projects that improve water efficiency but so far the MDBA has failed to demonstrate that they will achieve genuine water saving. Progress in getting the extra 405 GL to South Australia seems non-existent. Water buy-backs have been halted in favour of these so-called efficiency projects.
The Menindee Lakes fish kill is another story relating to a plan to change the water flow and reduce evaporation, too complicated to explain here but another example of mismanagement. Read a report on this from the Australian Institute.
The federal and state government ministers responsible for the success of the Act have actively undermined the Plan.
Fish Strategy Killed Off
Another concerning demonstration of disregard for science is the treatment of the Native Fish Strategy. This was developed in 2001 and lays out a plan for helping the Basin’s fish communities to recover. The MDBA produced a report in 2009 showing fish stocks were at 10% of pre-European levels (0% in some parts) and the objective of the strategy was to bring this back to 60% over 50 years. It was visionary and forward-thinking – contributed to by a multitude of scientists, managers, indigenous groups and Basin communities.
But direct funding ceased in 2012 when NSW pulled out 60% of its funding. Since then, implementation of its recommendations has been opportunistic and without central coordination. Science ignored again!
Even before the Plan is due to be fully implemented it has been shown to be totally inadequate. Taxpayers that have already paid billions of dollars for water buybacks now have to bear the cost of river rehabilitation, clean up of fish kills and assistance to river communities. The politicians must have the fortitude to strengthen the water take restrictions. We hope the recent events will convince the sceptics and vested interests that stronger action is needed for the common good.