query: How long is the Castlereagh River in New South Wales?
passage: Castlereagh River
Estimates of the length of the course of the Castlereagh River from its commencement to its mouth vary from 541 kilometres (336mi),[2] 549km,[3] and 566km.[1] Over its course it drops over 600m.
passage: Castlereagh River
The Castlereagh’s alluvial sandbeds make up what is called the "hyperheic zone". This is the region of saturated sediment below, or adjacent to, a river where surface water and groundwater are actively mixing and exchanged. The movement of the groundwater in the Castlereagh through its alluvial sands is said to be a hyporheic process. In the Castlereagh, the further transit of surface water to the aquifers of the Great Artesian Basin is then enabled through the ancient paleochannels underlying the Castlereagh, and this water movement is a large-scale hyporheic process. (Hutchinson and Webster 1998).