Volumetric Water Pricing, Social Surplus and Supply Augmentation

Abstract

We evaluate the welfare losses of undertaking water supply augmentation in Sydney, Australia with a fixed, regulated water price given weather variability. Stochastic dynamic programming is used to determine dynamically efficient water prices and to estimate the losses in social surplus from premature water supply augmentation. Results show that premature water supply augmentation under the base case reduces the net present value (NPV) of the welfare of households by more than $A 3 billion, or some $A 1,900 NPV per household. While the findings are specific to Sydney, our modeling is of general interest because it could be employed to avoid costly and premature supply augmentation elsewhere.