Technological change in the Australian irrigation industry: implications for future resource management and policy development

The irrigation industry contributes significantly to the Australian economy. The irrigation sector has faced many challenges over the past decade including severe and prolonged drought, reduced water availability and ongoing reform of government water policies. At the same time, climate change and increasing climate variability are likely to increase the uncertainty of water supply. As a result, irrigated agriculture is under considerable pressure to adopt best practice methods to increase efficiency in terms of water use and productivity. Until now, investment in innovative onfarm irrigation technologies has played a significant role in accommodating the reduction in agricultural water use, by increasing water use efficiencies and contributing to increases in the value of irrigated agriculture. Additional investments are needed to increase irrigation efficiency at the field, farm and irrigation-area scales to fill the supply and demand gap and ensure robust adaptation to climate change. To help fill the investment gap, the Australian Government is meeting the challenge of water scarcity and climate change through its Water for the Future initiative. A major component of this initiative is the $5.8 billion Sustainable Rural Water Use and Infrastructure Program that is helping to upgrade irrigation infrastructure and secure long-term water supply. The conversion to pressurised systems is a valid option due to the potential increase in efficiency of pressurised systems and the subsequent water savings, but these new irrigation technologies will change the patterns of onfarm energy consumption and generate considerable greenhouse gas (GHG) emissions. If the Australian Government is successful in introducing a price on carbon, this may influence the extent to which new irrigation technologies are adopted. This study explored the trade-offs between water savings, economics, energy consumption and GHG emissions, critical elements of both Water for the Future and any future price on carbon. We developed an integrated economic framework to assess the effectiveness of different irrigation technologies used at farm level. This framework was used to evaluate trade-offs between various choices of irrigation technology adoption in terms of irrigation requirements, water savings, energy consumption and GHG emissions and the relative costs of irrigation and associated equipment. The integrated framework has three main components: hydrological modelling, energy and GHG modelling, and cost and benefit estimation, and highlights trade-offs between energy consumption (and GHG emissions) and water savings at various levels of investment. We also applied the integrated framework to farm-level case studies and irrigation transformation scenarios. It is important to realise that there is unlikely to be just one ideal choice; there may be many alternatives, any one of which might be quite appropriate, depending on the priorities set by the individual farmers and governments