Integrating Yield and Shortage Management under Multiple Uncertainties

Abstract

An economic-engineering modeling approach is presented for integrating urban water supply reliability analysis with shortage management options such as dry year option and spot market water transfers, water reuse, and long- and short-term water conservation. The integrated model uses a probability plotting position formula to link supply-side yield simulation to probabilistic shortage management optimization. The approach can help joint planning of supply and demand management and estimate the economic value of expanding infrastructure and changing institutional constraints. Results from a case study show that jointly managing supply capacity and operating rule decisions with shortage management decisions within a risk analysis framework can create significant economic savings. The importance of hydrologic and institutional uncertainties is explored. Tuning supply system and reservoir operating policies to match the seasonal and cost characteristics of available shortage management measures is shown to be essential to least-cost planning.