The Namoi subregion is part of the Northern Inland Catchments Bioregional Assessment. The landforms of the Namoi subregion are characterised by nine Interim Biogeographic Regionalisation of Australia (IBRA; SEWPaC, 2012) subregions (Welsh et al., 2014). There are marked climate gradients across the bioregion with mean annual rainfall decreasing and mean annual temperature increasing from south-east to north-west.
The subregion is dominated by land cleared for agriculture, and much of the remaining remnant vegetation has been substantially altered. Drainage of the subregion is predominantly via the Namoi River and its tributaries and distributaries including the Mooki River, Coxs Creek, Pian Creek and Turragulla Creek. These support many important wetlands, floodplains and lagoons. The forests and woodlands of the Pilliga and Pilliga outwash IBRA subregions represent the largest intact woodlands remaining on the western slopes of NSW (Welsh et al., 2014).
The water-dependent asset register lists in excess of 1800 water-dependent ecological assets (including GDEs, rivers, wetlands lakes and floodplains) that provide habitat for numerous threatened ecological species. Irrigated agriculture is an important industry in the subregion and there are 21 groundwater management units that support a large number of groundwater extraction licences. Thus, the water-dependent asset register also contains 168 economic assets and 41 sociocultural assets (O’Grady et al., 2014).
