TRaCK: Tropical Rivers and Coastal Knowledge

Science and knowledge that governments, communities, industries for sustainable use of Australia's tropical rivers and estuaries

Surface Water – Groundwater Interactions in the Lower Fitzroy River, Western Australia

TitleSurface Water – Groundwater Interactions in the Lower Fitzroy River, Western Australia
Publication TypeReport
Year of Publication2011
AuthorsHarrington, G, Stelfox, L, Gardner, P, Davies, P, Doble, R, Cook, PG
Date Published08/2011
InstitutionCSIRO Water for a Healthy Country National Research Flagship
Keywords4: Material Budgets

The water resources of the lower Fitzroy River catchment in the Kimberley region of north-west Western Australia are continuing to present both opportunities and impediments for future irrigation development, mining activities and municipal water supply to southern parts of the State. The recent CSIRO Northern Australia Sustainable Yields (NASY) project revealed that the groundwater and surface water resources of this catchment, and many others across northern Australia, lack the historical monitoring data and fundamental technical understanding required to undertake quantitative water assessments and therefore establish sustainable water management policies. In particular, there is a dearth of information and knowledge of groundwater controls on dry season flows in the Fitzroy River. This report presents a synthesis of preliminary research projects that have aimed at starting to address these knowledge gaps. It includes work undertaken by CSIRO as part of the Tropical Rivers and Coastal Knowledge (TRaCK) program, as well as a project in which CSIRO collaborated with WA Department of Water under the Raising National Water Standards program of the National Water Commission, and finally work undertaken by CSIRO as an extension to NASY.
The main reach of the Fitzroy River on which projects have been focussed is between Jubilee Downs Station (i.e. downstream of Fitzroy Crossing) and the eastern boundary of Liveringa Station. We have identified two major zones of groundwater discharge along this reach: the first is around the confluence of the Fitzroy River with Cunningham Anabranch, and the second is between a well-known waterfall and Yungngora Community on Noonkanbah Station. Two complex discharge mechanisms have been invoked to explain chemical and isotopic data in the context of recently revised geology for these areas.

The results demonstrate a high dependence of dry season flows in the Fitzroy River on discharge from both local and regional groundwater flow systems. It is likely that future groundwater pumping adjacent the Fitzroy River will result in a reduction to dry season flows, which in turn will have an impact on the water level of permanent pools. The distance at which future extractive industries should be placed away from the River in order to minimise impacts to dry season flows and permanent pools requires further research; however, it will be site specific—that is, it will depend upon the size and pumping regime of the proposed extraction, the hydrogeological properties of the aquifers between the river and the proposed development, and the proximity of the proposed extraction to the various groundwater discharge mechanisms identified above.