The quarry will clear around 14 hectares of rainforest – including protected habitat – on an extremely steep mountainside in one of the highest rainfall areas in the country. The final quarry face will be more than 250 metres high, 500 metres wide.
When pressed about this environmental legacy Boral are quick to point to rehabilitation plans. Only an economist would agree that rehabilitation is an adequate substitute for world-heritage-quality rainforest, but that aside, residents have no faith in Boral’s rehabilitation plans because:
- effective rehabilitation is almost a physical impossibility; and
- for 35 years, Boral has ignored existing rehabilitation obligations entirely.
Extreme Physical Constraints
The constraints related to the extension of the Redlynch Quarry are so extreme that they were the subject of their own Quarry Magazine article. These constraints include the sheer steepness of the mountainside, the unique tropical environment of Cairns, and recent urban encroachment.
In 2014 Boral submitted a rehabilitation plan to Cairns Regional Council as part of a vegetation clearing application. Residents believe the plan leaves many unanswered questions, including the following.
- Boral is pursuing a ‘reconstruction’ approach, but what evidence is there that the rehabilitated landscape will approach anything like the existing rainforest cover? Will it achieve anything more than a superficial greening?
- The quarry benches and walls will be bare rock. The walls will be up to 15 metres in height. How many metres of topsoil is Boral planning to return to each bench in order to support tree heights of at least 15 metres?
- Boral are planning to use the overburden from the mountain to meet another rehabilitation obligation – filling an alluvial quarry pit – which has been outstanding since 1990. Where will Boral source soil of a suitable profile to rehabilitate the mountainside?
- Cairns receives between two and three metres of rain each year, most of it over the space of a few months. Following cyclone Jasper, Redlynch residents recorded falls of around 1.5 metres in three days and the quarry haul road was severely damaged. Does Boral realistically expect to prevent the erosion of soil, several metres deep, that has been returned to the rock benches? How?
- Can Boral guarantee that sediment from eroded rehabilitation efforts will not end up in the environmentally sensitive waterways of Currunda Creek and Freshwater Creek? Can the Cairns Regional Council vouch for this?
- Between wet seasons the Cairns climate is hot and dry and rehabilitation efforts will require water. The quarry’s previous attempts to grow a much smaller area of vegetation (a treed buffer) failed due to a lack of water. Why would things be any different this time?
A Track Record of Inaction
A condition of Boral’s 1990 approval was the rehabilitation of an existing alluvial quarry. The condition required Boral to lodge a rehabilitation plan within thirty days of receiving the permit, and commence rehabilitation within thirty days of the Council’s acceptance of the plan. Boral were required to complete rehabilitation within nine months of the council’s acceptance of the plan.
To fill the quarry in 1990 would have required around 1,000 Olympic sized swimming pools of fill. Today, in 2025, it still requires around 1,000 Olympic sized swimming pools of fill. This is despite the Cairns Regional Council re-stating the condition as part of a change to the development application in 2001.
In 2014 Boral finally put forward a plan to rehabilitate the alluvial site. It was submitted as part of the application for the mountainside extension because Boral need somewhere to dump the ‘overburden’ – that is, the rich rainforest soil built up over the millennia – as it is stripped from Mount William.
This year, thirty-five years after agreeing to the obligation, Boral finally set about rehabilitating the alluvial quarry – but there are some catches.
Thirty-five years is a long time and:
- scientists have discovered that silica dust is devastating to human health,
- the quarry is now closely bordered on two sides by residential estates; and
- it has regrown a protected ecosystem that includes cassowary habitat.
Cairns Regional Council made Boral aware of the ‘cassowary problem’ earlier this year. Residents followed up, providing overwhelming evidence of cassowaries inhabiting the area around the quarry, and to ensure all parties are aware of the related issues.
Despite this, it appears that the long-delayed ‘rehabilitation’ will go ahead as planned. In an upcoming blog post we will explore the merits of Boral using thirty-five years of non-compliance to its advantage, even though rehabilitation may no longer be appropriate. We will also put forward alternative uses for the land.
The Final Word
Boral’s past record and the physical characteristics of the location cast doubt over the rehabilitation of the new quarry. Will there be any serious attempt to deliver? Will it be timely? Or only when it contributes to “alternate end-use outcomes” in the profit and loss? Will it achieve anything more than superficial greening?
How does the community reconcile the replacement of world-leading rainforest with a rock face, 500 metres wide by 250 metres high? And what role will Cairns Regional Council play in protecting the rights of the community?
In 2023, residents asked Boral for examples of where the proposed rehabilitation approach had been used in high rainfall areas such as Cairns. Boral was unable to provide examples but assured us that “once revegetation takes place the quarry area will be almost lost to the surrounding landscape.”