The lower Lachlan Valley is one of New South Wales' major irrigation developments. The study area for the Lachlan River Floodplain Management Plan extends from Jemalong Gap in the east, downstream to the township of Condobolin in the west, representing a distance of approximately 75 km. The length of the meandering channel in this reach of the river is approximately 120 km. To the north, the study area encompasses the floodplain of the Lachlan River, Goobang Creek and Gunningbland Creek, south west of Began Gate. To the south of the Lachlan River, the study area includes the floodplain of Ulgutherie Creek and areas affected by floodwaters passing across the Lachlan Valley Way through Wilbertroy National Forest.

The objectives of the Flood Study are to:

• investigate existing flood control works
• identify environmentally sensitive areas;
• identify capacities of the existing floodway system;
• identify community and environmentally acceptable areas of floodway:
• identify environmental impacts of the floodway system; and
• develop a hydrologic and hydraulic model procedure for future analysis of works by the DIPNR and others.