2026/01/02 by Matthew J. Colloff, Maryanne Slattery, Jamie Pittock +1 · 1 voice
Agricultural and Biological Sciences · Engineering · Social Sciences · #Pasture and Agricultural Systems #Water resources management and optimization #Political Developments and Conflicts
paper · doi:10.1080/13241583.2026.2650962
openalex publication_date 2026/01/02 · openalex created_date 2026/04/11 · openalex updated_date 2026/06/14
Since the 1960s, irrigated cotton production has expanded considerably in the northern Murray–Darling Basin, with substantial losses to evaporation from large on-farm storages used for floodplain water harvesting. Diversion of this water negatively impacts downstream communities and ecosystems. We quantified area and capacity of 2,786 storages and 10,173 km of irrigation channels and estimated annual evaporation (1987-88 to 2023–24) using remote sensing time series and meteorological data Annual evaporation was 1,247 GL; 39% of surface water take from cotton-producing catchments. Storages in 2024 covered 94,758 ha (capacity 3,300 GL); a two-fold increase since 1995 when a cap on irrigation diversions was introduced. Storages contained water for 89% of the time and were 38-100% full for 34% of the time; longer than needed for irrigation requirements. Including evaporation, it takes 11.8 ML to grow a hectare of cotton; twice the 6–7 ML ha−1 the cotton industry estimates is applied to the crop. Evaporation is not accounted for in water policy reforms, yet we consider it is just another form of water take. Under increasing water scarcity due to climate change and irrigation diversions, there is a clear need to reduce losses. We discuss implications for water policy and options for management of evaporation on-farm.