Moulamein is located in south-western New South Wales about 100 kilometres west of Deniliquin. The town is situated at the confluence of the Edward River and Billabong Creek which fall within the Murray and Murrumbidgee River systems, respectively. The Edward River is one of the two primary tributaries within the Edward-Wakool River system, which covers an area of more than 7000 square kilometres. The system extends west from the junction of the Edward and Murray Rivers near Mathoura, to Wakool Junction, where the Wakool River joins the Murray.

The first stage in the levee upgrade process involves defining the flood characteristics of the Edward River and Billabong Creek in the vicinity of Moulamein. The primary objective is to determine a floodwater profile for the Edward River and Billabong Creek in the vicinity of the town, so that an assessment of the suitability of the existing crest elevation can be made.