Sustainability website / Case Studies 2004 / Xstrata coal / Managing biodiversity at Mount Owen coal mine

Managing biodiversity at Mount Owen coal mine

Mount Owen open-cut coal mine in New South Wales is using an extensive biodiversity offset strategy and conservation programme to mitigate the impact of its mine extension. In early 2004, Mount Owen submitted a development application to extend its approved mining area to provide for a further 21 years of mining, which requires the disturbance of an additional 35 hectares of the Ravensworth State Forest and 59 hectares of open woodland outside the forest. The application was approved in December 2004 and is subject to stringent conditions to minimise impacts on the environment and surrounding community.

Mount Owen Mine General Manager, Derek Walls said Mount Owen had developed a comprehensive biodiversity offset strategy in consultation with the Department of Infrastructure, Planning and Natural Resources, Department of Environment and Conservation (formally the National Parks and Wildlife Service) and the Mount Owen Flora and Fauna Advisory Committee.

"This strategy compensates for the disturbance of vegetation communities within the project area through the conservation of 415 hectares in offset areas adjoining the Ravensworth State Forest and our New Forest area and in the end we will create a woodland that is almost five times its original size" he said.

"The proposal includes the conservation of 100 hectares of the Central Hunter Spotted Gum/Grey Box/Ironbark Woodland Community. Consequently, the offsets provide immediate protection for a slightly greater area of woodland than the 94 hectares that would be lost through the project.

"Where accessible, open pasture land within the offset areas will be planted with native tree and shrub species indigenous to the forest and surrounding area. Measures will also be implemented to encourage natural regeneration, such as fencing and exclusion of livestock.

"Following the completion of the reforestation programme, Mount Owen proposes to secure the long-term conservation of these offset areas through a combination of measures available under its operating consent. This will expand on the existing Ravensworth State Forest and New Forest reserve and provide for an expanded conservation area."

In addition to the establishment of the offset areas, existing flora and fauna management measures will be maintained for the life of the project. These include such initiatives as the installation of additional nesting boxes for bats, use of tree debris from mining areas for mulch, ensuring domestic stock is excluded from rehabilitation and conservation zones, the continuation of Mount Owen's feral animal and weed control programme, and the construction of aquatic habitat in dams and channels. Prior to tree clearing being undertaken, which is restricted during breeding times for key species such as woodland bats and arboreal mammals, a survey will be undertaken to identify habitat trees. Habitat trees are then left for the latest possible removal to allow native fauna to disperse into adjacent woodland.

Derek said Mount Owen's original offset programme was already producing results.

"In 1995, Mount Owen started planting a new 430 hectare area of woodland adjoining the remnant Ravenswood State Forest, known as the New Forest, to offset the impacts of mining through the State Forest," he said.

"The New Forest, originally open forest with isolated mature trees, was planted with native tree and shrub species indigenous to the forest and surrounding area. We have achieved good growth and survival rates. The three-year reforestation programme has established key species for fauna habitat and encouraged the movement of native fauna into the area."

Since 1995, 145 bird species, 24 non-flying mammals, 18 bat species, 20 reptile and 15 amphibian species have been recorded in the Ravensworth State Forest or adjacent land. Eighteen threatened fauna species have been recorded, including the Green and Golden Bell Frog, Squirrel Glider, Spotted Tailed Quoll, and a number of bat and woodland bird species. The remnant area of the Ravensworth State Forest that will not be disturbed by mining contains an area of the Hunter Lowlands Redgum Forest, an endangered ecological community listed under the Threatened Species Conservation Act.

Derek said in addition to its offset programmes, Mount Owen had utilised best practice rehabilitation techniques to transform mined areas into woodland communities, supported research into rehabilitation and reforestation, and had undertaken comprehensive flora and fauna management and monitoring programmes in accordance with its revegetation and wildlife management plans.

The implementation of the plan is overseen by the Mount Owen Flora and Fauna Advisory Committee.