Broken Hill Managed Aquifer Recharge
The Broken Hill Managed Aquifer Recharge (BHMAR) project was undertaken to investigate and provide recommendations for groundwater-related options to help secure Broken Hill's water supply during drought; reduce evaporation and improve water efficiency at the Menindee Lakes Storages; protect the local environment and heritage; and return up to 200 gigalitres (GL) to the Murray-Darling Basin.
The project is a key element of the Federal Government's 2007 election commitment of up to $400 million for improving the management of the Menindee Lakes area in far western New South Wales and is managed by the Australian Government Department of the Environment.
In the southern half of Australia, recent droughts and predictions of a drier future under a number of climate change scenarios have led to the search for innovative strategies to identify more secure water supplies for regional communities and industries, while also delivering environmental benefits to threatened river systems. These issues are of particular concern in the Murray-Darling Basin, where the recent Millennium Drought (late 1990's - 2010) adversely affected many communities, industries and the environment. While subsequent heavy rains and flooding associated with La Niña weather cycles broke the drought in late 2010 onwards, there is general acknowledgement that longer-term strategic solutions are needed to protect communities against future droughts and to achieve a healthier working Basin.
Beginning in 2008, the BHMAR has become the largest hydrogeological investigation project undertaken by the Australian Government in the past 30 years, and has delivered outcomes that could herald a new approach to water security in Australia by using aquifers during drought periods to reduce our dependence on surface water.
- Investigations to secure Broken Hill's water supply have identified a priority site (Jimargil) that could provide enhanced drought security for Broken Hill. There are a number of groundwater-related options at this site, all of which take a conjunctive approach to water management by combining the continued use of surface water when abundant, with groundwater extraction during drought conditions. Overall, the conjunctive management of surface water and groundwater involving managed aquifer recharge (MAR) options at the Jimargil site would provide the greatest drought security for Broken Hill.
- A shift to a reliance on groundwater-related options during drought would provide significant water quality benefits for the Darling River system and water supplies for Broken Hill and Menindee during drought periods, while enabling changes to the Menindee Lakes Storage that would provide substantial water savings. This would have significant downstream benefits in dry years.
- Investigations have also revealed potential groundwater resources beneath the Darling River floodplain at Menindee Lakes. These resources are estimated to contain a total of 2100 to 4400 gigalitres of fresh to acceptable quality groundwater in 14 discrete targets, 25 to 125 metres below ground level. This is the estimated storage of groundwater in these aquifers, and is not the amount of groundwater that can be sustainably extracted, which would be significantly smaller.
Project Reports and Data
The Summary Report (report 5) provides a synopsis of the key findings and principle recommendations for potential groundwater resources across the BHMAR study area, and possible alternative water supply options for Broken Hill. This report is supported by four accompanying scientific and technical reports (reports 1-4).
All reports are available as free digital downloads, or as a USB drive at cost-of-transfer via Client Services.
- Final Report 1: Lawrie et al. (2012a). BHMAR Project: Data acquisition, processing, analysis and interpretation methods. This report details the substantive new data investigative program undertaken as part of this project, and includes details of the data acquisition, processing analysis and interpretation methods.
- Final Report 2: Lawrie et al. (2012b). BHMAR Project: Geological and hydrogeological framework and conceptual model. This report details the results from geological, hydrogeological and hydrogeochemical investigations, and sets out 3D geological and hydrogeological frameworks and a new hydrogeological conceptual model for the area.
- Final Report 3: Lawrie et al. (2012c). BHMAR Project: Securing Broken Hill's water supply: Assessment of conjunctive water supply options involving managed aquifer recharge options at Menindee Lakes. This report details the findings of investigations into groundwater-related water supply options for Broken Hill within a 20km radius of Menindee. These options include groundwater extraction and MAR.
- Final Report 4: Lawrie et al. (2012d). BHMAR Project: Assessment of potential groundwater resources and underground storage options in the Darling Floodplain. This report details the results of investigations to identify groundwater resources and potential MAR options in the greater BHMAR project area within the Darling Floodplain.
- Final Report 5: Lawrie et al. (2012e). BHMAR Project: Assessment of conjunctive water supply options to enhance the drought security of Broken Hill, regional communities and industries - summary report. This summary report outlines the scientific findings of the BHMAR study (Phases 1-3).
Supporting data, analytical, interpretation and product generation methods are included in fifteen accompanying appendix volumes (Apps et al., 2012), and all project data and products are also available in the BHMAR project GIS (Gow et al., 2012a). The GIS (GeoCat #73825) and appendices will be made available via Client Services.
The final project reports have been reviewed internally by scientific experts within Geoscience Australia and the Commonwealth Scientific and Industrial Research Organisation (CSIRO); externally reviewed by independent consultants within Australia, as well as by an expert panel from the United States Geological Survey (USGS). The project was guided by a Steering Committee with representatives from the Australian and New South Wales state governments.