An analytical approach to water allocation in the Upper Waitaki : Executive summary of research performed under contract to the Waitaki Catchment Commission and Regional Water Board

Abstract

Water is an increasingly scarce resource in areas such as the Upper Waitaki basin of the South Island of New Zealand. Demands for water derive from a number of competing and complementary uses and water-related activities. These include electric power generation, irrigation of pastoral and arable land, water for stock, recreational uses, fisheries management and the role of water in providing a habitat for plants and animals. The increasing scarcity of water makes its efficient allocation important in order to best satisfy society's expectations. An overall objective of maximising net social benefit was specified. This report is a summarised version of a final contract report submitted to the Waitaki Catchment Commission and Regional Water Board. This summary describes the application of a network flow linear programming model to the allocation of water in a multi-objective optimisation framework. It discusses the validity and usefulness of this type of approach and suggests ways in which the model can be used to provide further information for controlling water flows in the catchment. Multiple reservoirs and interbasin transfers are included in the model formulation. The model may also be used to analyse water flows in other catchments.