2.1.5.1 Observed data

Surface water – groundwater connectivity has been the focus of several regional investigations in the Namoi river basin. Key findings from the most relevant of these studies for the BA for the Namoi subregion are summarised. In addition, a new baseline assessment of surface water – groundwater connectivity has been made for 2012, and this baseline has been compared to the connectivity assessments made from earlier investigations. The year 2012 was chosen for the baseline connectivity assessment in order to be consistent with companion submethodology M04 (as listed in Table 1) for developing a coal resource development pathway (Lewis, 2014), which has been used to establish the development status of coal mines and coal seam gas (CSG) operations in commercial production as of the last quarter of 2012. The 2012 year represents the baseline status by which to compare potential impacts of future coal and CSG development. The methods employed for the surface water – groundwater connectivity 2012 baseline and previous assessments are further described in the sections below, and include approaches based on: