Managing River Murray water resources during the current dry conditions
Large parts of South Australia and the Murray-Darling Basin have been declared drought affected.
In dry years, Basin states/the ACT and the Australian Government work closely together to ensure farmers, communities and the environment all receive a share of the available water.
Water sharing plans within each state and territory help make tough decisions at a local scale and arrangements are also in place to ensure critical human water needs when drought conditions become severe.
The Murray-Darling Basin Authority determines how much water is available to be shared between the states. This is primarily based on the volumes of water held in the Southern Basin storages and minimum volumes projected to be available over the coming 12 months.
After two consecutive years of low rainfall and inflows across the Murray-Darling Basin, the volume of water in storage is at 28 per cent capacity (as at the end of March 2020). This compares to the long-term average at this time of year of 59 per cent capacity.
PIRSA is leading South Australia's drought response, working with industry, the Australian and local governments, other agencies and support services to help farm families, farm businesses and rural communities to prepare for and manage the drought conditions. DEW is leading the management of water availability and water resources operations in the River Murray.
The South Australian Government has been supporting River Murray irrigators to better prepare for the season ahead by providing early water allocation and private carryover announcements as well as tools such as flow reports and water availability projections.
How has River Murray water management improved since the Millennium Drought?
South Australia learnt from the Millennium Drought, putting us in a better position to manage water during dry times.
The water allocation plan for the River Murray has been updated and it includes rules around how water is allocated, private carryover, trading and the take and use of water.
In line with new rules in the updated water allocation plan, private carryover was announced in mid-April 2019 and mid-April 2020 because opening allocations for 2019-20 and 2020-21 years respectively were projected to be less than 50 per cent. This approach to private carryover reflects the feedback from key industry representatives during consultation on the draft River Murray water allocation plan in mid-2018.
The water allocation plan locks in a commitment to reduce Adelaide's reliance on the River Murray by 50 gigalitres in dry years, in recognition of Adelaide's access to other sources of water. Compared to the Millennium Drought, the commitment boosts irrigation allocations by 8 per cent in dry years and applies whenever irrigators are on allocations of less than 100 per cent, and once critical human water needs have been secured.
Adelaide now has access to a wider range of resources including water from the River Murray, Mount Lofty storages, Adelaide Desalination Plant, water recycling, aquifer storage and recovery and there has been a substantial increase in the number of household rainwater tanks.
South Australia may now store part of its Entitlement in upper River Murray storages for critical human water needs and private carryover in future years. However, South Australia’s stored water must not adversely affect water availability for New South Wales and Victoria.
Currency Creek, Jervois and Lake Albert pipelines have been constructed to provide an alternative supply of water for irrigators and stock and domestic users during periods of reduced water availability and quality.
The South Australian Government is working with the Murray-Darling Basin Authority and the Australian, New South Wales, Queensland, Victorian and Australian Capital Territory governments to ensure that the Basin Plan is implemented.
Environmental water from a range of sources, including that recovered under the Basin Plan, is now available to support the river and its environmentally important wetlands in South Australia.
The water market has matured significantly. Water trade allows for the movement of water among users and is an important mechanism for managing the Murray-Darling Basin's scarce water resources. In addition to local water allocation and entitlement markets, individuals can now source water from a range of water products such as interstate entitlements, forwards, entitlement leases and carryover parking.