A new report more closely identifying the mechanisms that link surface water (rivers) and groundwater (aquifers) has identified the serious implications double counting has for water use and water planning.

The Impact of Groundwater Use on Australia's Rivers is the outcome of a year-long Land & Water Australia Senior Research Fellowship by Dr Richard Evans, Principal Hydrogeologist with Sinclair Knight Merz.

Land & Water Australia is one of 15 Rural Research & Development Corporations, working towards knowledge, understanding and informed debate in the sustainable use and management of natural resources.

"Groundwater and surface water are often closely linked. However, at times, we have over-estimated our total water resource by treating them as different; we have sometimes allocated the same resource twice," Dr Evans said.

"There is little doubt this has reduced the flow in our rivers and streams and contributed to the nation's present water shortage, but the extent of the problem is not accurately understood.

"Tackling the impacts of surface water and groundwater interaction requires a national approach on three fronts - technical, management and education.

"Scientists, engineers and governments of all types and persuasions need to work together with the broader community to develop improved and integrated water management plans.

"Remedies should be borne equitably by all, not just groundwater users," Dr Evans said.

The relationship between groundwater pumping and stream flow is complex, with a range of time lags depending on local and regional factors. Between the start of pumping and the impact on the stream, the lag can be days, years or centuries.
Land & Water Australia Executive Director Dr Michael Robinson said this report is an important contribution to the current focus on our precious water resources.

"Climate variability, climate change and their impact on urban, rural and farming communities are high on the public agenda and we need sound science to back up policy decisions at all levels.

"Dr Evans has provided a framework on the way forward that will help to focus further research efforts where they are needed most and help policy-makers as they review allocations and regulations affecting both surface water and groundwater," Dr Robinson said.

The internationally peer-reviewed technical report is available electronically or in hard copy through Land & Water Australia's Product Catalogue.

Download the Media Release:  Media_Release_May_22st_2007 (pdf - 41KB)

Media Enquiries: Kaaren Latham, 02 8204 3852, 0409 809 909, media@lwa.gov.au