THE DAVCO GROUNDWATER PROJECT—A GROWER INITIATED MULTIDISCIPLINARY APPROACH TO GROUNDWATER MANAGEMENT IN THE BURDEKIN DISTRICT

GROUNDWATER levels in the Burdekin Haughton Water Supply Scheme area (BHWSS) have been consistently rising at about 500 mm/annum, since the development of 40 000 ha of additional irrigation land within the Burdekin River Irrigation Area (BRIA). During 2007 Davco Farming, alarmed by the continued rise in groundwater levels, applied for and was granted, $670 000 through the Regional and Community Projects (RCP), under the Sugar Industry Reform Programme 2004, for a project titled Managed utilisation of elevated salinity groundwater to control rising water tables and improve cane yield. The primary objective of this project was to show if rising groundwater levels could be arrested by intensive pumping on the Davco Farming property. This site was seen as strategically important, since the property spans over 12 km east to west and its long axis is perpendicular to most of the groundwater flow as it moves from the upslope zones of the BRIA to the sea. These funds, along with over $1.2 million of Davco Farming monies, have been invested in resistivity studies by Charles Sturt University, additional groundwater drilling, pumping infrastructure, a network of data-logged observation bores, Dualem mapping, and the installation of lysimeters to measure deep drainage losses on a test field. The results from this work will provide other Burdekin growers with additional information on ways to deal with rising groundwater, the effects of conjunctive water use strategies on both the crop and soil characteristics, and the likely costs involved. Only 5339 ML were pumped in the 2009–2010 year. It seems likely that increased volumes of water will need to be pumped to show if the Davco groundwater project is having an influence on regional groundwater levels. Initial results suggest the increased usage of saline waters has had no negative impacts on soil structure or sugarcane yields.