There’s great potential to improve irrigation efficiency in the Murray Darling Basin but it needs to be holistically managed at a regional and Basin-wide level, writes Charles Sturt University (CSU) social researcher, Dr Jenifer Ticehurst.
Dr Ticehurst is a member of the Graham Centre for Agricultural Innovation and with her colleague Professor Allan Curtis has studied the adoption of irrigation efficiencies in two case studies in the Basin.
An amendment to the Murray Darling Basin Plan has been passed by the Senate, proposing additional water gains for the environment through funding water efficiency projects, rather than buying back irrigator entitlements.
As part of the Sustainable Diversion Limit Adjustment Projects program, the efficiency projects are aiming to increase the water available for the environment without any negative social or economic impacts, through altering the supply and efficient delivery of the available water.
The programs include reconfiguring the design and management of specific regional water systems, as well as on-farm works.
Policy makers should investigate the potential for on-farm adaptation before evaluating policy instruments that involve the expenditure of public funds, for example water buybacks or infrastructure upgrades.
Many farmers in the Murray Darling Basin have already improved irrigation efficiency. Along with my colleague Professor Allan Curtis I’ve been investigating water-use efficiency gains at a farm and regional scale in northern Victoria and northern NSW.
Our social research suggests that irrigators have considerable capacity to adapt to reduced entitlements or allocations through the adoption of more efficient on-farm irrigation practices.
In two case-study areas about three quarters of irrigators had already changed their irrigation practices to more efficient ones, without any specific mention of government support.
Given the already implemented, and future intention to adopt more efficient practices, irrigators in these areas will use about 10 per cent less irrigation water in the future, on top of an existing 15 per cent reduction from the already adopted practices.
Assuming that their changes have been self-funded, they can use water saved to maintain or increase production or trade, which shows a social and economic resilience to government policies that reduce their available irrigation water.
However, increasing on-farm water use efficiency may lead to less runoff or infiltration and therefore reduce return flows that contribute to downstream irrigation or environmental water.
So the impact of increased on-farm water use efficiency on return flows requires further investigation and quantification to be able to holistically manage it from a policy perspective.
Dr Ticehurst’s research is through the National Centre for Groundwater Research and Training and has been funded by the Murray Darling Basin Authority.
Dr Jenifer Ticehurst's main research interest is the sustainability of Australia's agricultural systems. She has developed models that integrate social, economic and environmental factors for decision support in natural resource management. Her work has a strong focus on the engagement and participation of clients and stakeholders. More recently she has focused on social research in rural areas studying the adoption of best land management practices such as fencing off waterways from livestock for water quality control and the adoption of water use efficient practices by irrigators in the Murray-Darling Basin.