Drought Management Planning with Economic and Risk Factors

Abstract

Traditional drought management planning has focused on curtailing demand through various conservation measures when regional hydroclimatic indicators reach specific trigger levels. This study suggests a methodology that can augment traditional drought management methods in two ways. First, regional hydroclimatic indicators, which are not necessarily indicative of the impacts of droughts on individual water storage systems, are replaced with system specific indicators in the context of supply reliability, or likelihood of system failure. Second, the study illustrates how economically optimal programs for conjunctive supply and demand management can be developed once the susceptibility of a specific water supply system to drought conditions is quantitatively understood. The method links a stochastic simulation program with a mixed-integer linear program aimed at achieving target levels of supply reliability at minimum economic cost. Results from a case study in Western Massachusetts were used to guide capital planning by indicating a clear need for emergency water sources. Results were also used during a recent drought to justify the avoidance of premature tapping of emergency supplies which could have cost up to $750,000.