Hotspots Assessment of Spatial Water Losses in the Off-Farm Open Channels Irrigation Supply System

Open channels are the dominant off-farm systems employed to supply irrigation water in both developed and developing countries. However, a majority of these systems are often criticised for their low conveyance efficiencies. Under the water scarce environment, improving the conveyance efficiency provides an opportunity to realise basin level water savings. To define the quantum of such opportunities, there is a need to identify the location, nature and amount of water losses (hotspots) in the off-farm open channels irrigation supply system that can be saved, in a cost-effective manner, through investments in the conveyance infrastructures. This paper presents the hotspots assessment of the off-farm open channels irrigation supply system located in New South Wales, Australia. Hotspots assessment is primarily drawn upon the public domain datasets and information available in the published literature or anecdotal evidences. The study area has a 296 km long network of open channels spanning over 96,000 ha. The results indicate that almost 50% of the water losses due to channel seepage occur at specific hotspots that cover only 1.7% of the length of the total channel network. The presented approach has a potential to help make consistent and transparent decisions for allocating irrigation infrastructure investments across different stakeholders.