Evaluating the performance of bay irrigation in the GMID

Abstract

The CRC for Irrigation Futures recently undertook a project piloting use of the IrriMATE performance evaluation process in bay irrigation at a number of sites across the Goulburn Murray Irrigation District (GMID). This evaluation technique, which was developed originally for furrow irrigation, is now well accepted in the cotton industry. The project successfully demonstrated that evaluation of performance can lead to substantial realisable gains in efficiency for bay irrigation, including the 'good' irrigators. For the irrigations evaluated, application efficiencies averaged 72% and realisable gains in efficiency of 19% are possible with changed management. For most farmers this will mean application of higher flow rates and shorter irrigation times. Practically this means on-farm automation. The evaluation process provides the means to determine the preferred flow rate and irrigation time for automated systems and also the means for identifying optimum capacities for farm outlets. This latter data is of interest to scheme modernisation design, because flow rates available to irrigators through their meter outlets are often less than required for maximum performance on farm. The project identified some deficiencies in the evaluation process caused by differences in the management of bays compared to furrows, deficiencies which have now been overcome in the development of new evaluation tools.