Risk-Based Decision Analysis in the Design of Water Supply Projects

The application of a decision analysis methodology to a small-scale water-supply/aquifer-contamination problem is presented. The main characteristic of the study is the development of a series of alternative strategies to ensure a continuous water supply to a village under variable risk conditions. It is assumed that the risks involved in the analysis reflect the uncertainty as to the hydraulic conductivity. Thus, a stochastic simulation model for groundwater flow and contaminant transport is employed in order to evaluate the implications of uncertainty in the system's behaviour upon the overall design decisions. Alternative decision strategies are formulated by considering both actual and probabilistic costs, and they are finally compared using a risk-cost-benefit objective function.