Water Management / Rehabilitation
The site water management system is comprised of sediment dams (for sediment laden water runoff from spoil dumps), release dams (for releasing good quality water to the environment), a raw water dam (for storing the allocated raw water supply) and a drainage system which allows for clean water run-off collected by the catchment to be diverted away from the active mining area.
Maintaining an appropriate water balance is a key challenge faced by all mines sites – to ensure the site has enough water storage capacity for wet season or flash flood events but at the same time does not run out of water for activities such as coal processing and dust suppression. At Isaac Plains, a site water balance model has been developed by specialist water engineers. This model is calibrated on a regular basis to ensure the water inputs and outputs are accurate.
This model allows us to run scenarios of extended dry or wet periods. The data generated is then used to improve water management processes and systems on site.
At Isaac Plains, we undertake rehabilitation on a progressive basis with consultation between the environmental, technical services and production teams. All rehabilitation is carried out with future land use in mind. Our aim is to return the site to grazing pasture, with areas of native tree, shrub and grass species.
The rehabilitation objective for Isaac Plains is to create a safe, stable and sustainable landform using cost-effective spoil placement methods.
Profiling of the out-of-pit spoil dumps is completed to a slope of no greater than 15% (in compliance with the Environmental Authority). All surfaces are topsoiled, contour-ripped and sown with the nominated native flora species using both tractor and aerial seed sowing methods.
Rehabilitation is viewed as an integral part of the mining process. Stanmore is committed to progressive rehabilitation of site in order to continue to mine and operate in a socially conscious way, as well as drive down our financial assurance and future closure costs.
Since takeover of Isaac Plains Mine, Stanmore has topsoiled and seeded more that 200 hectares, with an additional 198 hectares of rehabilitation planned by 2020.