Mt Owen/Glendell Operations has a Biodiversity Offset Strategy in place as the primary ameliorative measure to minimise the impact of the project on flora and fauna. The Biodiversity Offset Strategy includes the protection of 415 hectares of land currently owned by Mt Owen/Glendell Operations for conservation purposes. It is proposed to promote the establishment of local forest species within offset areas to increase the habitat value of these areas. This will involve active intervention, where appropriate. All areas will be managed to enhance natural regeneration. A strategy for restoration of the biodiversity offset areas has been developed in conjunction with the University of Newcastle

The Biodiversity Offset Strategy was developed after extensive consultation with the Department of Planning and Environment, DP&E), the Office of Environment and Heritage OEH), and the Mt Owen Flora and Fauna Interagency Advisory Committee to offset the impacts of the development, including the clearing of an additional 35 hectares of Ravensworth State Forest. The Biodiversity Offset Strategy includes the protection of 100 hectares of Central Hunter Spotted Gum/Grey Box/Ironbark woodland. This provides immediate protection for a slightly greater area of woodland and riparian vegetation than is lost through the project.

The Biodiversity Offset Strategy will compliment the "New Forest" area established under the 1994 Consent. The New Forest comprises 430 hectares of formerly degraded pasture land that was actively planted with native tree and shrub species found in the adjoining Ravensworth State Forest between 1995 and 1997. The New Forest was formally incorporated into the Forest Reserve System in December 2003 and has been gazetted as part of the Ravensworth State Forest. Both the Ravensworth State Forest and the New Forest are zoned Forest Management Zone 2, which means that they are managed for conservation purposes.

The combination of the New Forest , life of mine rehabilitation, Northern Remnant of the Ravensworth State Forest and the proposed Biodiversity Offset Strategy will result in a total area of woodland approximately five times larger than the area of forest/woodland to be cleared over the approved life of mining. This total area of woodland (1774 hectares) will be comparable with the largest areas of existing remnant vegetation on the Hunter Valley floor.

Due to the much lower biodiversity value of the Glendell Mine area, biodiversity management includes maintenance of existing rehabilitation and rehabilitating disturbed areas in accordance with the approved Mining Operations Plan (MOP). There is also the opportunity to develop corridor linkages with Mt Owen conservation areas to maximise the benefits of native vegetation establishment and provide protective vegetation corridors for fauna. Glendell mine also manages the land surrounding mining in a designated habitat management zone. Areas in this zone have been planted with native trees to help restore local ecological communities.