Dawson Mine is one of three large open cut coal-mining operations. A change in mining strategy to terrace mining allowed the operation to significantly reduce the area of disturbance and enhance progressive rehabilitation. Evaluating the business case for the change showed that this resulted in a reduction in operational expenditure of more than $10/tonne. This was due to a relatively short haul distance. Even allowing for a period of 18 months where costs were slightly increased as operational changes were established, the net benefit was clear to the operation.
The success of this approach required a shift in paradigm for closure planning. The shift was based on a sound financial business case; a solid closure liability estimate; compelling visual and spatial outputs; and the work of multi-disciplinary teams to identify, plan and implement the operational changes. It also required ownership by the site leadership team and alignment of key financial goals across the site.