This paper presents a farm level irrigation microsimulation model of the southern Murray-Darling Basin. The model leverages detailed ABARES survey data to estimate a series of input demand and output supply equations, derived from a normalised quadratic profit function. The parameters from this estimation are then used to simulate the impact on total cost, revenue and profit of a hypothetical 30 per cent increase in the price of water. The model is still under development, with several potential improvements suggested in the conclusion. This is a working paper, provided for the purpose of receiving feedback on the analytical approach to improve future iterations of the microsimulation model.