Murray-Darling Basin dry inflow contingency planning
Overview report to First Ministers
- Murray-Darling Basin dry inflow contingency planning: overview report to First Ministers (PDF - 150 KB)
- Frequently asked questions (PDF 98 KB)
About the publication
by the Prime Minister and
Premiers of New South Wales, Victoria and South Australia
Water contingency planning in the southern Murray-Darling Basin
At the Summit on the Murray-Darling Basin on 7 November 2006, the Prime Minister and the premiers of New South Wales, Victoria and South Australia asked officials to examine contingency planning to secure urban water supplies during 2007-08.
The December 2006 Contingency Planning Report highlighted the extent of record low inflows into the Murray-Darling Basin in 2006 and recommended a series of measures that would secure domestic water supply for communities relying on basin water, should dry conditions persist in 2007-08. The recommendations of the original report were agreed by the Acting Prime Minister, the Hon Mark Vaile MP, and the premiers of New South Wales, Victoria and South Australia.
A second report by senior officials provides an update to the contingency planning work.
Inflows in the Murray-Darling Basin have continued to set new record lows in recent months. In over 100 years of streamflow and rainfall records, the key Murray-Darling Basin headwater catchments have never been as dry as this. Whilst there has been near average rainfall in February and March 2007 and Bureau of Meteorology advises that the El Nino event is finished, catchments remain extremely dry. Dry catchments have led to inflows continuing to be low, with inflows in February and March 2007 being the lowest ever recorded.
The headwater catchments of the River Murray have received the lowest rainfall on record from January 2006 to February 2007. Due to the extremely dry condition of these headwater catchments, which normally generate half of the total inflow to the River Murray, inflows are likely to recover only slowly even if rainfall is average to above average over the next few months.
The water situation remains critical and contingency planning will need to continue through 2007-08, even if conditions improve during the highest inflow months of September and October 2007.
The situation out to May 2008 is sufficiently critical that State water sharing under the Murray-Darling Basin Agreement should be modified as a matter of urgency. It is proposed that the quantities of water currently in storage and estimated to be available in 2007-08 based on the minimum inflow scenario, be first allocated for critical human water consumption needs. This will enable core critical demand to be met most effectively. It will also ensure appropriate management of water in storages this water year by giving a greater degree of certainty to jurisdictions.
Unless there are very substantial inflows prior to mid May 2007, there will be insufficient water available to allow any allocation for irrigation (including of high security water and water carried over from 2006-07), the environment or any purpose other than urban and stock and domestic supplies for human consumption at the normal commencement of the 2007-08 irrigation season.
First Ministers have agreed to coordinate efforts to ensure farmers have access to information about water supplies and their implications for allocation decisions at critical decision making times for business planning. Further, they have agreed to keep allocation decisions under review to ensure that the impacts on the irrigation sector are minimised given the likelihood that allocations in 2007-08 will not be sufficient to avoid losses of income and assets.
One of the recommendations of the December Contingency Planning Report was that 'town-by-town' contingency planning be completed by end March 2007. This exercise is now largely complete. State resources will be available to put these plans into place should the need arise. Indeed, many towns have put in place water restrictions, sought alternative water sources (e.g. bores) or are carting water for domestic use.
Owing to the critical water situation, all outside water use for domestic purposes dependent on Murray-Darling Basin supplies should be prohibited from 1 July 2007. Industrial water users should be required to adopt stringent water saving measures and major users should be required to develop water efficiency plans incorporating industry best practice water efficiency targets from 1 July 2007.
A number of the contingency measures outlined in the December 2006 Contingency Planning Report have already been implemented. The target end of season reserve in Lake Victoria has been lowered to reduce storage evaporation losses, flows in the River Murray are being reduced to lower target minimum flows to conserve water in upstream storages and reduce evaporation, a pumping schedule has been developed to secure an additional 60 GL of water from the River Murray into storages in the Mount Lofty Ranges for Adelaide, and work on lowering off-takes in pumping stations supplying Adelaide will be progressively implemented during 2007. Contingency planning by State governments for 'at risk'
towns is now being finalised and resources will be available to put them into place should the need arise.
Work continues to be progressed on other measures that may need to be implemented if dry conditions continue through 2007-08. The South Australian Government has commenced preparations for the construction of a temporary weir near Wellington on the River Murray with a feasible site for the weir located across the neck of Lake Alexandrina, adjacent to Pomanda Island. A decision on whether to commence construction of a temporary weir will be made by the South Australian Government after June 2007. Senior officials will also continue to examine the role of Snowy Hydro Ltd, should dry conditions continue.
Certain wetlands in the southern Murray-Darling Basin system have been disconnected to reduce evaporative losses, with more wetlands identified for potential disconnection, after agreement, if dry conditions continue.
The approach taken on contingency measures is designed to manage the risks of low inflow of water into the Basin. If seasonal conditions improve then plans will be modified as the situation develops. With proper preparations, the critical demands of urban areas and towns, and other households relying on the water supply systems of the southern Murray-Darling Basin will be able to be met even in the face of another very dry year in 2007-08.
Regular reports will be published on the water availability outlook and progress on implementing measures.
20 April 2007