9.5 Point return from irrigation scheme
The volumetric value for the line item for the 2011–12 year was 198,314 ML. The line item represents point discharge of water from irrigation schemes into surface water within the Murray–Darling Basin (MDB) region. The line item includes overflows from irrigation scheme water supply channels, discharge of used irrigation water from irrigation scheme collection systems and other irrigation scheme point discharges.
Information on point returns from irrigation schemes was provided in this line item only for Murrumbidgee and Victorian Murray river systems within the Southern Basin. There was no measured data available for the other irrigation areas particularly in the Northern Basin within the MDB region. The details of the volume shown in the above table are as follows:
- the Coleambally irrigation area within Murrumbidgee NSW water resources plan area (103,214 ML)
- the Broken Creek irrigation system (3,700 ML) and Torrumbarry system (91,400 ML) within Victorian Murray water resources plan area.
Murray–Darling Basin Authority: water audit monitoring data received from New South Wales (22 January 2013) and Victoria (21 March 2013), and stored in the HYDRO database.
Bureau of Meteorology (the Bureau).
Assumptions, limitations, caveats and approximations
The uncertainty estimate except for the returns in the Broken Creek irrigation system is +/– 5%. The uncertainty estimate for the Broken Creek irrigation system, is +/– 40%.