Captains Flat (Lake George) Mine
The Lake George Mine is at Captains Flat, approximately 50 kilometres south east of Canberra. The mine operated over several decades starting in the late 1880s and closing in the 1960s, producing lead, zinc, copper, pyrite, silver and gold.
Extensive rehabilitation works have been carried out since the mine closed to manage erosion, improve safety and control tailings pollution from the site. Current and ongoing issues include seepage of acid mine drainage (AMD) and heavy metal contaminants spreading from the site, with zinc being the primary contaminant of concern.
Site description
Lake George Mine covers about 100 hectares with the main mine infrastructure extending underground to a depth of 619 metres. Numerous shafts and adits were present at the surface, and structures for ore storage, processing, loading and transport remain at the site. There are 2 large mine tailings dump areas (northern and southern).
Current remediation project
Further remediation work will commence on Monday 20 November 2023 to improve safety and environmental outcomes.
The project involves treating historic mine waste and encapsulating it in a purpose-built containment cell before revegetating the site. Areas currently without vegetation will also be treated to promote vegetation growth.
Work will be carried out in stages, with strict monitoring and controls in place to ensure public safety and minimise impact on the environment.
Throughout the work, the Lake George Mine site will be closed to the public for safety reasons and fencing will be put in place in key areas.
Remediation work is expected to be complete mid-2026, weather permitting.
Should you have any questions about the remediation works please call 1300 814 609
Review of environmental factors
A Review of Environmental Factors (REF) has been prepared to assess matters affecting, or likely to effect the environment during the remediation of the Legacy Lake George Mine under the provisions of Division 5.1 of the Environmental Planning and Assessment Act 1979.
You can view the REF and supporting documents here:
- Lake George mine - Review of environmental factors (PDF, 23.89 MB)
- Lake George mine - Review of environmental factors - Appendices A-F (PDF, 31.21 MB)
- Lake George mine - Review of environmental factors - Appendices G-H (PDF, 80.29 MB)
- Lake George mine - Review of environmental factors - Appendices I-O (PDF, 14.58 MB)
- Lake George mine - Review of environmental factors - Addendum (PDF, 25.35 MB)
- Lake George mine - Review of environmental factors - Addendum - Appendix 1 (PDF, 24.83 MB)
- Lake George mine - Review of environmental factors - Addendum - Appendix 2 (PDF, 24.74 MB)
Pollution incident response management plan
A Pollution Incident Response Management Plan (PIRMP) has been developed for the project and can be viewed here:
Captains Flat lead management plan taskforce
Information on the Captains Flat taskforce or to contact a representative agency about an issue visit: https://www.nsw.gov.au/regional-nsw/captains-flat
Frequently asked questions
Q. Why is this remediation work being carried out?
A. Work is being carried out to improve safety and reduce risks to the environment. It will involve treating historic mine waste and encapsulating it in a purpose-built containment cell before revegetating the site. Areas currently without vegetation will also be treated to promote vegetation.
Q. What are the community and environmental impacts of this work?
A. Most of the scheduled work will be low to medium impact and will be delivered during stages. Strict monitoring and controls will be in place to ensure public safety and minimise impact on the environment.
Q. Will Lake George Mine be open to the public during remediation?
A. No. Throughout the work period, Lake George Mine site will be closed to the public for safety reasons. Signs and/or fencing will be put in place in key areas.
Q. Will there be traffic impacts during the work?
A. Motorists may notice a small increase in traffic on Captains Flat Road as trucks enter and exit the site from time to time. Due to the nature of the works, Old Mines Road will be temporarily closed during the day throughout the course of the remediation works. Traffic management plans will be in place to accommodate these changes.
Q. What about the heritage of the site?
A. Remediation works will also be carried out in consideration of the heritage values of the site.
Q. Who can I contact for more information?
A. For more information about this work and for general enquiries please contact 1300 814 609.
Q. Who can I contact for urgent information or to make safety or environment reports?
A. For urgent information or to make an environmental complaint report please contact 1300 814 609.
Past rehabilitation work
Initial rehabilitation works to reduce pollution were carried out between 1966 and 1968 by the NSW Department of Mines but were only partially successful.
Further, significant works were carried out in 1976, which included stabilising and capping mine waste dumps to prevent erosion and leaching, and to minimise the risk of major collapse. Work also included drainage modifications to Forsters Creek to minimise the inflow of water into the mine.
The 1976 works were primarily to protect and upgrade water quality of the Molonglo River for drinking and agricultural use, and of Lake Burley Griffin.
Since the early 1990s other significant works on various sections of the site have included:
- 1993 – erosion control works
- 2000/01 – contaminated materials removal
- 2002/03 – relocation of waste slag
- 2005/06 – erosion control/structure safety2007/08 – sediment control and de-silting
- 2009/10 – drainage mill/load out site and safety fencing2012 – erosion control at the north face of the south tailings dump
- 2013 – site safety works to rectify subsidence issues
- 2014 – dam maintenance, spillway repair and stabilisation2019 - Safety fencing delivered around Keatings Collapse area, and fence repairs to the north and south tailing dumps
Mine history and heritage value
During the mining days, Captains Flat was one of the largest towns in the southern mining region, having a considerable impact on the development and settlement of the area.
Mining operations in Captains Flat were carried out during two periods between 1882-1899 and 1937-1962. The site was closed in 1962 due to the depletion of economic grade ore.
During the second period of operation, more than 4 million tonnes of complex copper-lead-zinc ore was processed to produce approximately 243,000 tonnes of lead, 406,000 tonnes of zinc, 27,000 tonnes of copper, 7.4 million ounces of silver and 220,000 ounces of gold.
All of the workings of the mine were underground, with the lowest levels reached being 619 metres. At this level, drives (horizontal tunnels) were extended a number of times to locate the ore bodies but in 1960, the diamond drilling at the end of the drives failed to locate any ore of economic importance.
While dwarfed in size by the Broken Hill field (which was one of the largest in the world), Lake George Mine at Captains Flat was one of the largest base metal mining fields in NSW, if not Australia. The Mt Isa and Mt Lyell fields were larger but primarily produced copper.
The highly complex mineralogy of the ore body and consequently the varied and changing processing technology was a unique aspect of mining of Captains Flat.