Rehabilitation of mined land for safety and conservation purposes is becoming an important part of initial mining approvals. With this strategy comes opportunities for recreational users to access some of Australia’s most amazing landscapes.
There are almost 400 operating mineral mines across Australia and due to our country’s size, most of our land is unexplored or underexplored. Australia’s oil and gas industry has been increasing over the past 10 years, with 11 offshore oil rigs now in operation and gas mining occurring for domestic and international consumption across the country.
Australia is recognised globally as one of the world’s largest contributors of minerals, oil and gas. The resources sector is worth around $264 billion to the economy and accounting for more than 70 per cent of Australia’s exports.
Regulatory approvals for mining and exploration, which differ between states and territories, require plans to mitigate the effects mining will have on the environment and communities. Plans for the area to be made safe, stable, non-polluting and sustainable became compulsory national policy in 2010, but implementation of this agreement between Australia’s states and territories was slow to follow.
As a result, there are around 800,000 abandoned mines across Australia which have a wide range of environmental, social and economic problems associated. This can vary from unstable landforms, water pollution and economically depressed communities left behind after a mining boom.
It can also include less obvious environmental impacts as was discovered in 2010 by a natural resource management group in South Australia. This group published a study measuring fauna entrapment numbers in uncapped, abandoned mining shafts of small vertebrate species. The study found 190 reptiles from 18 species had become trapped in a disused mine shaft in a 13-month period, including the nationally vulnerable Bronzeback Legless Lizard.
Abandoned mines and concerns for public safety in Western Australia prompted the WA Government to form the Abandoned Mines Program in 2016. Mining has occurred in WA for more than 150 years and often land areas once used for mining are located in areas of public interest with significant environmental and social risks now involved.
The program started with four initial pilot projects, including the now completed Black Diamond historical abandoned mine site project near Allanson, around five kilometres west of Collie in Western Australia’s South West.
Coal mining took place at Black Diamond between the late 1940s and early 1950s. When mining finished, little rehabilitation work was performed as it was not a legal requirement back then. The pits filled with water over time to form lakes which became a popular but unmanaged recreation site, prompting concern from the local community.
In 2014, the Department of Mines and Petroleum Director General Richard Sellers highlighted the importance of consultation in the Black Diamond project.
“DMP will consult and work with stakeholders to develop a rehabilitation strategy for the Black Diamond site,” he said.
“Neighbouring landholders and the Shire of Collie will be consulted to ensure that the rehabilitation strategy and end land use meets the needs of landholders and the broader community.”
Consultation began in 2016 and a working group was formed to focus on key risks and also future land use options. This resulted in a design to reshape one of the pit walls and earthworks which began in late 2016. The issue with this area was around public safety when accessing the lake. There were also erosion management works needed on another side of the lake.
Revegetation was the final part of the work which involved native seed and tube-stock plantings, weed management and mulch being spread to stabilise topsoil and reduce erosion.
As a part of the final stages of the redevelopment, students from the Allanson Primary School and Collie-Preston MLA Mick Murray attended a seedling planting day in 2017, reinforcing the community’s involvement in the project.
Black Diamond Lake is now known as a tourist destination where swimmers, kayakers and stand-up paddle boarders frequent. There are no camping facilities and limited rubbish facilities on site, with tourists encouraged to stay nearby at Allanson or Collie.