The total area of the three huge Latrobe Valley open-cut mines, (Yallourn, Hazelwood and Loy Yang) is over 50 square kilometres. This is approximately the same area as Sydney Harbour, or, in Melbourne, the equivalent to an area encompassed by a line joining Flemington Racecourse with Williamstown, Albert Park and Studley Park. The Hazelwood Open Cut Mine alone encompasses an area which could contain the equivalent of all the land in East Melbourne, the Melbourne CBD, Southbank and Docklands, and all of Victoria Harbour. The Loy Yang Open Cut Mine has a depth of approximately 200 metres – there are only 12 buildings in Melbourne which have a height greater than 200 metres. In short, the scale of the open-cuts of the Latrobe Valley are not huge, they are gargantuan.
However, few people outside the Latrobe Valley have even the slightest appreciation of the enormous scale of the open-cuts. Even many Latrobe Valley residents are not particularly appreciative of the massive scale of the mines. Apart from limited passing glimpses of the Yallourn and Hazelwood mines from either the Princes Freeway or the Gippsland Rail Line, most people would not normally be in locations which would enable them to see the scale of even one of the open-cut mines. Consequently, important issues associated with planning, establishment, development and, ultimately, rehabilitation of the open-cut mines can all too easily miss out on the critical public and governmental attention which their scale and importance warrants due to them being “out of sight, out of mind.”
Large scale open-cut mining of brown coal has been going on in the Latrobe Valley for nearly one hundred years. However, after the alienation of huge swathes of valuable land for the purposes of open-cut mining, not even a tiny section of any of the major mined areas has been fully and finally rehabilitated to any form of productive use and returned to some form of non-mining company ownership. This is an extremely unfortunate situation.
Some substantial rehabilitation work has been done at Yallourn, the oldest of the three major mines. However, none of this area has yet been made accessible for any form of public or private use. At the Hazelwood (Morwell) Open Cut, internal dumping of overburden back into the open-cut was delayed for 43 years after the initial commencement of the open-cut. In the case of the Loy Yang Open Cut, internal dumping of overburden back into the open-cut has only recently commenced, some 15 years later than the date promised by the State Electricity Commission of Victoria when it sought approval from the Victorian Government to enable the commencement of the mine back in 1974.
In April this year, a report on mine rehabilitation was submitted to the Victorian Government by the Board of Inquiry chaired by the Honourable Justice Bernard Teague AO. The Board of Inquiry report made 19 recommendations, including:
• Increasing the rate of progressive rehabilitation;
• Immediately requiring substantial increases to the existing rehabilitation bonds and then undertaking a further review of appropriate bond levels;
• Establishing post closure trust funds;
• Advocating further relevant research including the scope for use of ground and surface waters in rehabilitation arrangements; and
• Establishing a Latrobe Valley Mine Rehabilitation Commissioner and a Latrobe Valley Mine Rehabilitation Authority.
Effective mine rehabilitation planning will need to take into account a number of crucial considerations. It is particularly important to appreciate that there is insufficient overburden to enable the complete filling of the mine voids. Similarly, it is generally accepted that there would be too little potential water inflow (from ground or surface water sources), and too much water evaporation and seepage, to enable the whole mine voids to be completely filled with water. Consequently, it is most likely that, to a greater or lesser extent, the mine voids will remain as “sunken landscapes” which are partially filled with overburden and contain some water areas.
Basic requirements for the rehabilitation of the Latrobe Valley’s gargantuan brown coal mines must include making the mines physically safe and stable. This will need to include the long-term minimisation of the risks of fire, erosion, and land movement. Effective achievement of these requirements would ensure that the mine areas do not become major environmental liabilities.
However, if rehabilitation work were only to achieve safety and stability objectives, then the former mine areas would probably become massive, worthless wastelands of no real value or benefit. Consequently, it is crucial that all the open-cuts are rehabilitated so that they become areas which have a range of valuable environmental, community and economic benefits. Given that the open-cuts will most likely remain as ‘sunken landscapes’, what beneficial uses could possibly be established there? Some of the categories and types of future beneficial uses which have been suggested include:
• Nature Conservation – such as nature reserves, wetlands, etc;
• Passive Recreation – such as parks, botanic gardens, lakes, walking or cycling tracks, hiking, camping, hot springs;
• Active Recreation – sports fields, golf courses, racing tracks, boating, fishing, adventure or fun parks, extreme sports, hang gliding;
• Agricultural – cropping, grazing, forestry, aquaculture;
• Heritage or Culture – arts performance spaces, amphitheatres, interpretative centres, display exhibition or gallery areas or facilities;
• Commercial – kiosks, restaurants;
• Waste Management – landfill, recycling, recovery and salvage;
• Water storage;
• Technology industries;
• Education, Training, Research; and
• Power Generation from non-coal sources – bioenergy, hydroelectricity, wind or solar.
There are a number of fine examples of former mine and quarry areas in various parts of the world which have been rehabilitated to become areas with considerable ongoing environmental, community and economic benefits. These include some superbly rehabilitated coal mining areas in the Rhine Valley, Germany. The Butchart Gardens on Victoria Island, Canada, were developed in a former quarry site and have become a world-famous tourist attraction. Closer to home, the much appreciated and well used Wilson Botanic Park in Berwick was also developed on a former quarry site.
There are a number of very important matters which will need to be addressed, researched and resolved in the process of Latrobe Valley mine rehabilitation planning. These include:
• Possible approaches to covering exposed coal seams;
• The likely availability, quality and usability of any water stored in the voids; and
• The range and suitability of potential uses in rehabilitated open-cuts areas including their relative environmental, social and economic benefits and disbenefits.
Unfortunately, there have been decades-long delays in the commencement of planning for, and the undertaking of, progressive mine rehabilitation – particularly involving a failure to back-fill overburden into the mine voids at Hazelwood and Loy Yang at a sufficiently early stage. This factor has the potential to seriously exacerbate the costs and difficulties of achieving effective, attractive and beneficial rehabilitation outcomes. These issues and dilemmas will now be severely tested in the coming years following the recent decision to close the Hazelwood Power Station and Open Cut.
It will be very interesting, and important, to watch closely what happens to these gargantuan spaces!
This article was originally published in Planning News, Volume 42 No. 11 (December 2016).
