The Darling River Floodplain (Bogan River confluence to Louth) study area is located within the Darling River Valley floodplain. The study area stretches approximately 130 kilometres along the Darling River Floodplain, from approximately 40 kilometres upstream of Bourke downstream to Louth (some 90km downstream of Bourke). Bourke is located approximately 774 kilometres north-west of Sydney and 369km north-west of its nearest regional centre, Dubbo.

Flooding of the study area can arise from a number of sources remote from the Darling River Valley. It can originate from southern Queensland via the Culgoa, Birrie and Bokhara Rivers; from the Macintyre and Dumaresq Rivers along the Queensland/ New South Wales border; from the northwestern river valleys of New South Wales, the Gwydir and Namoi; from the central New South Wales area of the Castlereagh, Macquarie and Bogan Rivers; and from a combination of all the above. All these sources of flooding affect the whole of the study area.