IMPACT OF A SUSTAINED WATER USE EFFICIENCY PROGRAM IN THE BUNDABERG DISTRICT

DURING the past 15 years rainfall in the Bundaberg district has met only 45%-55% of total crop water requirements. Irrigation allocations were severely reduced during this period also making the efficient use of the water resource paramount in optimising productivity and maintaining acceptable profitability levels. This paper describes a sustained, coordinated approach adopted by sugar industry stakeholders in the Bundaberg district to improve irrigation efficiency as an effective method of alleviating declining farm productivity and profitability. Programs included investigation of factors contributing to low water use efficiency (WUE), monitoring and evaluation of irrigation practices and targeting causative factors through promotion of best management irrigation practice. A benchmarking system termed the Crop Water Index (CWI), defined as the ratio of yield to total water use, was developed at the outset to provide a practical measure of WUE for evaluation purposes and to gauge change as the program developed. Wide variation of CWI was identified within the different irrigation systems employed. Extension programs focused on developing skills and encouraging adoption of best practice WUE techniques. Additional activities established soil characteristics such as Readily Available Water content (RAW) and developed practical irrigation scheduling tools. The Queensland Government's Rural Water Use Efficiency Initiatives 1 and 2 extended further the best management practices developed using the concepts of 'how much, how often and how efficient'. Annual district WUE assessments measured CWI at 7.4 (tonnes cane/ML) at the commencement of the program in 1989. By 2004, CWI had risen to 9.7 representing an improvement of 31%. The 15 year evaluation shows that the sustained, targeted program has impacted greatly on the level of overall irrigation efficiency in the Bundaberg district.