The Australian Water Balance Model (AWBM) was developed in the early 1990s by Walter Boughton and is now one of the most widely used rainfall-runoff models in Australia. Many GoldSim models incorporate AWBM for estimating runoff around mine sites and for other projects that simulate rainfall runoff in a watershed. This version of AWBM is intended to be used as a module within other GoldSim models but also works as a standalone model. The inputs to the model are precipitation and potential evapotranspiration time series, along with model parameters that describe the catchment. The output is a runoff rate on a per unit area basis, which can be multiplied by the total catchment area for volumetric runoff.