ABSTRACT
Groundwater is an important resource supporting many ecosystems in the Pilbara region of Western Australia. Large scale dewatering programmes are a widespread feature of iron ore mining in the Pilbara. Pilbara Iron, a member of the Rio Tinto Group, with the aid of MWH, recently completed a closed trial dewatering and re-injection programme which demonstrated how ecosystem protection can be furthered by innovative approaches to mine dewatering. Groundwater mounding and depression in the dewatered aquifer was limited in extent and a rapid recovery was achieved. With no net water usage, water levels within an aquifer associated with potential groundwater dependent ecosystems were relatively unaffected. Comprehensive monitoring of aquifer response during the programme led to improved parameterisation of the existing groundwater model to develop it as a tool for future groundwater management at the site.
