Background

The Australian Government has made a commitment to invest up to A$400 million to reduce evaporation and improve water efficiency at Menindee Lakes, secure Broken Hill's water supply, protect the local environment and heritage, and return up to 200 gigalitres of water to the environment.

Based on positive findings from earlier investigations, the Australian Government Department of the Environment, Water, Heritage and the Arts has commissioned Geoscience Australia to undertake a project to help identify options to secure Broken Hill's water supply. The Broken Hill Managed Aquifer Recharge Project (Phase 2) will test groundwater resources and aquifer storage options. This project will assist the Australian Government in determining a way forward to deliver its A$400 million commitment to Menindee Lakes.

Key components of this project are the airborne geophysical surveys to be flown in the Darling Floodplain area in New South Wales. The surveys will involve collecting airborne electromagnetic (AEM) data to help map groundwater resources and quality as well as the spatial extent of aquifers.

Phase 2

Phase 2 of the project involves acquisition of new data including:

• an AEM survey of the region to determine the characteristics of the target aquifers, e.g. size and water quality, and the nature of the confining aquitards
• a light detection and ranging (LIDAR) to support the interpretation of the AEM and help with the identification of the critical landscape elements and floodplain characteristics
• a seismic reflection survey to confirm aquitard continuity
• a program of borehole geophysics (EM and gamma logging) to calibrate and validate the AEM survey results
• drilling and pump tests to characterise the aquifers and aquitards and confirm the findings of the targets identified by the AEM survey and LIDAR
• petrophysics and laboratory analysis to confirm aquifer and aquitard properties and to assist with analysis and validation of the AEM survey
• data integration, analysis, interpretation and reporting.

What is the survey about?

Between June and November 2009 we plan to collect data using helicopters (similar to that pictured below) which suspend equipment beneath them to transmit and receive electromagnetic signals.

The helicopters will fly at approximately 60m above the ground, with the transmitter/receiver frame suspended beneath the helicopters will fly at approximately 30m above the ground.

The information collected from these surveys will help map:

• the spatial extent (in three dimensions) of groundwater resources up to a couple of hundred metres below the surface of the Darling Floodplain
• the location and extent of aquifers in the survey area.

These airborne surveys will be followed up with a program of borehole drilling and ground-based geophysical surveys to help validate the airborne survey results.

Who will be impacted?

During the survey period local residents and businesses throughout the Darling Floodplain regional community and Broken Hill township may become aware of aerial activity. In particular, anyone using light aircrafts will need to be aware of the survey activities.

How can I keep informed?

The flying phase of the Broken Hill MAR AEM survey was completed on Thursday 3 September 2009.  A total of 32 659 line km of new data were collected.  The flight path as flown is available for viewing here AEM Flight Plan [JPG 4.5MB]. Please note: After opening this image, click on it to see the full size version.

You can also contact the AEM project hotline (freecall within Australia): 1800 091 964 or email aem@ga.gov.au.