In areas of concentrated petroleum development, the impacts on water levels caused by underground water extraction by individual operations can overlap. The state government may declare these areas to be 'cumulative management areas' (CMAs).
The OGIA prepares underground water impact reports for CMAs. These reports provide assessments of regional impacts on groundwater levels and establish integrated management arrangements, such as regional monitoring strategies. These reports also identify individual responsibilities of tenure holders in implementing various aspects of the strategies.
When prepared, the UWIR is submitted to the Chief Executive of the Department of Environment and Heritage Protection for approval.
The Surat Underground Water Impact Report has been approved for the Surat CMA. A regional groundwater flow model was developed which is used to predict future water level impacts in the coal seams as well as in adjacent aquifers.
The Surat UWIR includes:
With the Surat UWIR now approved, OGIA is overseeing the implementation of the strategies in the report. It has also commenced research activities, in collaboration with other bodies and CSG operators, to further improve understanding of the groundwater flow system. The regional groundwater flow model will be periodically re-developed to incorporate new knowledge emerging from these research activities and from monitoring data.
Through this process, predictions about future impacts on water levels will be progressively refined.