The catchment area of the Macquarie River upstream of Bathurst is 2,897 square kilometres. The total catchment area of this study, which extends to Eglinton, is 2,936 square kilometres. The three principal tributaries are the Fish River which drains the south eastern portion of the catchment, Campbells River which drains the southern portion, and Queen Charlottes Vale Creek which drains the western part of the catchment. The Macquarie River is so named downstream of the confluence of the Fish and Campbells Rivers. Bathurst is situated approximately 10km downstream of this confluence.

The purpose of the study is to review the August 1998 flood, and to update Councils' hydrologic and hydraulic floodplain models.