Update of the Surat Underground Water Impact Report
The production of coal seam gas (CSG) involves the pumping of large volumes of groundwater to lower water pressure in coal seams. This has the potential to affect groundwater resources in the coal-bearing formations and in adjacent aquifers connected to the coal formations. The formations that are the target for CSG development in the Surat Basin in Queensland are part of the Great Artesian Basin multi-layered aquifer system and also underlie important alluvial water resources. There are multiple major CSG projects being developed in the area. Queensland has a regulatory framework to manage the impact of CSG water extraction on groundwater resources that includes cumulative management arrangements for areas of intensive development, where the groundwater impacts of multiple projects overlap. In a declared Cumulative Management Area, the Office of Groundwater Impact Assessment (OGIA) carries out a regional assessment of impacts of CSG water extraction, specifies an integrated regional water monitoring network, and assigns responsibilities to individual CSG companies to implement individual parts of the water monitoring network and other management actions. OGIA sets out the results in an underground water impact report (UWIR), which on approval becomes a statutory instrument. OGIA is an independent entity fully funded by a levy on petroleum tenure holders. The first Surat UWIR was approved in 2012. In early 2016, OGIA revised the Surat UWIR using a new regional groundwater flow model that incorporates updated knowledge of the groundwater flow system. The key content of the revised Surat UWIR is presented.