Can irrigation be sustainable?

Globally, about 10 Mha of agricultural land is lost annually due to salinisation, of which about 1.5 Mha is in irrigated areas. While some climate and management aspects are common to semi-arid regions, the detailed mechanisms and options to secure ecological sustainability and economic viability may vary considerably from case to case. This paper applies a whole of system-water balance to compare irrigation in three semi-arid regions suffering from similar sustainability issues: Rechna Doab (RD), Pakistan; the Liuyuankou irrigation system (LIS), China; and Murrumbidgee irrigation area (MIA), Australia. Soil salinity, lack of adequate water resources and groundwater management are major issues in these areas. The MIA and LIS irrigation systems also suffer from soil salinity and low water-use efficiency issues. These similarities occur in spite of very different climatic and underlying hydrogeological conditions. The key data used to compare these different regions are climate and soils, available water resources and their use, as well as components of the water balance. In addition, the history of water resource development in these areas is examined to understand how salinity problems emerge in semi-arid regions and the consequences for production. Based on the efficiency parameters and the definitions of sustainability, approaches are explored to solve common environmental problems while maintaining economic viability and environmental sustainability for irrigation systems.     

Estimating potential costs and gains from an aquifer storage and recovery program in Australia

Artificial recharge of aquifer storage can provide water during drought periods, reverse falling groundwater levels and reduce water losses associated with leakage and evaporation, as compared with surface water storage. We examine the technical and economic potential of artificial storage and recovery for drought mitigation in the Murrumbidgee Region of New South Wales, Australia. Potential locations for infiltration basins and injection/recovery wells are identified according to criteria such as water availability, aquifer suitability, recharge potential, and potential to provide a usable resource. The estimated annual artificial recharge potential is 180,000 ML through a combination of injection wells and infiltration basins. The cost estimates for artificial recharge vary from AU$ 62 ML⁻¹ to AU$ 174 ML⁻¹ depending on the choice of recharge method. Underground storage capacity can be developed at less than half the cost of surface storage facilities without undesirable environmental consequences or evaporation losses. The estimated benefits of artificial storage and recovery through infiltration basins are three to seven times the costs, during low allocation years.     

Triple bottom line reporting to promote sustainability of irrigation in Australia

Irrigation development induces considerable environmental change, but the expectation has been in the past that the economic and social benefits would be greater than the environmental costs. However, public attitudes change over time from acceptance of development and exploitation to greater concern regarding environmental issues and sustainability. Recently, the irrigation industry has found it difficult to communicate to the wider populace the regional benefits of irrigation and the current activities and investment undertaken to address the environmental sustainability concerns. To address this, irrigation water supply businesses are investigating using a broader reporting structure that includes financial, environmental, and social and cultural elements. This triple bottom line, holistic approach should provide a more balanced view of water use with socio-economic benefits and environmental consequences demonstrated. It is anticipated that this approach embedded in the newly developed Irrigation Sustainability Assessment Framework will lead to a more transparent and informed debate on the sustainable use of resources between all parties.