Mt Owen Coal Mine: The successful case of Biodiversity Offsetting

Best practice biodiversity offset strategy coupled with the ongoing efforts in mine rehabilitation, flora and fauna management and restoration research will achieve a larger conservation area of increased biodiversity value than existed prior to mining at Mt Owen Complex, providing important habitat for threatened fauna species as well as an expanded conservation area for the community.

Open-cut mining commenced at Mt Owen in the Hunter Valley in 1993. The original 1994 approval permitted disturbance of 240 hectares of the Ravensworth State Forest (RSF), a highly significant remnant on a local and regional scale. To offset this impact, the company established a 430 hectare area of woodland adjoining the RSF, and named it the ‘New Forest’, which was planted with native tree and shrub species indigenous to the forest and surrounding area. Encouraging growth rates and survival of trees, along with the re-afforestation programme establishing key species for fauna habitat foster the movement of native fauna into the area.

View across the ‘New Forest’ area. Note progressive rehabilitation works at Mt Owen adjoining the New Forest. Source: Glencore

Later, in 2004, the company received approval for an extension to the currently approved mining area, involving the disturbance of an additional 35 hectares of RSF and 59 hectares of open woodland outside of the RSF boundary. Given that 18 threatened species were recorded within the Mt Owen project area and that the high habitat value of the RSF were at stake, Xstrata Mt Owen (formerly Hunter Valley Coal Corporation) developed a comprehensive Biodiversity Offset Strategy in close consultation with regulatory authorities, the University of New Castle (Centre for Sustainable Ecosystem Restoration) and other key stakeholders.

This strategy aims to compensate for the disturbance of vegetation communities through the conservation of 415 hectares in offset areas adjoining the RSF and New Forest, providing ‘like for like’ for habitat that will be disturbed by mining compared to habitat protected in conservation areas. In doing so, the company is recognised to be setting a new industry benchmark for biodiversity offsets, as well as securing its future as a key producer of export coal in the Hunter Valley at least until 2025.

The project’s short-term aim was to conserve existing flora and fauna in conservation areas through effective management, while establishing new areas that would provide a self-sustaining system in the long-term, whereas the long-term aim was to provide a self-sustaining flora and fauna conservation reserve with sufficient size to provide the necessary diversity, while providing corridor linkages to the larger vision for integrated landscapes in the Hunter Valley.

Since an appropriate offset is one that includes similar vegetation communities, species, habitat value and similar physiological characteristics, through the provision of ‘like for like’ habitat in terms of area (quantity) and quality immediately, there will be no time lag in the establishment of the offset. That is, the conservation management of existing established communities and habitat values of each offset would provide immediate compensation for the loss of habitat associated with the mine operations.

Further habitat in the medium to long-term will be provided by the revegetation and natural regeneration of the offset areas. Given that it is proposed to secure all of the offset areas immediately and since there will be progressive disturbance over the next years, the offsets will secure habitat in excess of that being disturbed for most of the mine life. Providing security for the offset areas in perpetuity is a commitment of the Strategy. Therefore, regardless of the term of the impact, the offsets will provide compensation for that impact.

Moreover, not only will the company ensure a substantial improvement in the ecological values of the Mt Owen mining impacted areas through the extent of woodland to be established as part of the existing and proposed offsets, but also will rehabilitate all mining areas at Mt Owen to woodland.

Progressive rehabilitation works Source: Glencore

Hence, the total area of woodland to be established at the end of the mine’s life will be 1774 hectares, comprising 430 hectares from existing offsets (New Forest), 376 from the biodiversity offset strategy and 968 hectares from mine rehabilitation, which will be comparable with the largest areas of existing remnant vegetation on the Hunter Valley floor, and will establish a core area that can be connected by corridors to other remnant woodlands on the Valley floor and ridges. Given that the 1994 approval included the disturbance of 240 hectares of RSF and the 2004 approval permitted the disturbance of additional 94 hectares of RSF and open woodland, the ratio of woodland in the existing and proposed offsets (including mine rehabilitation) compared with woodland lost because of mining, is likely to be higher than 5:1, which undoubtedly represents a net gain for the environment.

Consequently, the successful case of biodiversity offsetting at Mt Owen seems to be evident. Moreover, the company’s efforts have been recognised internationally and their progress and achievements have recently been highly commended by the Global Restoration Network of the Society of Ecosystem Restoration, International.

A potential criticism of the company is that it should not be operating in the area in the first place, as it is habitat for numerous threatened species. However, Mt Owen Mine is demonstrating, through its ongoing biodiversity monitoring, that its operations are not further compromising the status of already threatened species, evidencing that mines can go beyond compliance in the area of environmental management. Tangible results are being achieved and a five times larger woodland than the original, when mining activities began, prove it. That is certainly an enduring legacy for Mt Owen.

Wait… Let’s give it one last thought!

A ratio of 5:1 for compensation sounds great, but, how do we know that critical factors of risk, effectiveness and permanence of biodiversity gains are adequately taken into account in their biodiversity accounting framework? How does the company judge whether the disturbance of 334 hectares of mature forest is equivalent to 1774 hectares of new and rehabilitated forest that are meant to compensate for their impacts?

A novel and cutting edge paper on biodiversity offsetting measurement1 (Mining and biodiversity offsets: a transparent and science-based approach to measure ‘no-net-loss’) show that in spite of what can be seen as a ‘generous’ offset area of about 6687 forest hectares conserved to 1665 forest hectares impacted (ratio of 3:1) by Rio Tinto-QMM mining company, net-loss – properly measured – is unavoidable. Consequently, the authors warn that land-based multipliers should not be used as an indicator of predicted no-net-loss because such multipliers do not implicitly nor reliably indicate the real dimension of biodiversity in jeopardy.

Finally, while the project could have an outwardly, marvellous, and even noble goal, if an overall net gain is to be created, critical parameters such as biodiversity attributes, counterfactual scenarios, leakage risks and effectiveness need to be addressed in a larger and more transparent, science-based framework to capture the much more complex nature of biodiversity, particularly in highly biodiverse regions such as Ravensworth State Forest in the Hunter Valley.

By Joshelyn Paredes

1. Virah-Sawmy, M, Ebeling, J & Taplin, R 2014, ‘Mining and biodiversity offsets: a transparent and science-based approach to measure ‘no-net-loss’’, Journal of Environmental Management

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