Improving water management in rural towns such as Wagin, Western Australia, will decrease infrastructure damage caused by water and salinity and produce a ‘new water’ resource. The aim of this paper is to predict feedlot water demand using a bioeconomic model, H20Sheep, to determine if using such a ‘new water’ resource could be a viable option for this production system. Wagin (–33.3075 S, 117.3403 E), a township south-east of Perth, was chosen as the specific location for a sheep feedlot producing prime lambs. In this paper, the H20Sheep model was used to show how feedlot returns are influenced by the price of water, different feeding regimens and climate change. This was done by integrating feed and water intake of lambs, general feedlot water use and waste disposal. To show relative sensitivity of changing other model parameters that are not directly connected with water, changes in the purchase and sale price of lambs were also investigated. As might be expected, H20Sheep shows that returns from a sheep feedlot enterprise can be extremely sensitive to changes in lamb purchase (just over 7% increase will result in negative returns) and sale prices (a 4% decrease will generate a negative outcome). With respect to water, the findings indicate that, while increases in water use in the feedlot and price have to be greater than the increase in relative price of sheep, monitoring the biological parameters associated with water as well as water prices is still important both from a management and an economic perspective. Hence, if towns involved in the Rural Towns – Liquid Assets project, such as Wagin, decide to sell their water, the relevant policy makers should ensure that the sale price enables an effective water management system for the town and is also attractive to end-users such as feedlots.