The specific area of the Murrumbidgee River considered by this study is the reach between 11km upstream of Hay and just downstream of Maude. The Study area covers a total floodplain area of approximately 1,800 square kilometres and falls entirely within the Hay Shire Local Government Area. Other main waterways within the study area providing connectivity between the Murrumbidgee River and the floodplain are Coonoon Creek, Eleven Mile Creek, Darcoola Creek, Sand Creek, Fiddlers Creek, Uara Creek (formerly known as Gum Creek), Black Creek and Budgee Creek in addition to a number of unnamed flood runners. The study area comprises a portion of the Hay Irrigation Area and mainly consists of large land holdings with irrigation crops.

The primary objective of Phase A was to establish a 1D / 2D hydraulic model of the study area that adequately represented the hydraulic behaviour of the floodplain. This required the identification of existing floodplain development and incorporation within the hydraulic model. The hydraulic model was then suitable for use in identifying hydraulic ‘hot spots’ within the wider floodplain. To satisfy the study objectives both hydrologic and hydraulic approaches needed to be developed. The study area presented a number of difficulties to applying traditional approaches particularly in the development of study area hydrology.