Implementation of a water allocation decision support system in the Namoi and Gwydir Valleys

Management of water resources often involves significant negotiation with regard to complex social, economic and environmental trade-offs likely to result from changes in policy or access. In NSW, changes to water allocations and access, through the design and implementation of Water Sharing Plans, involved negotiation between stakeholders representing many different interests and concerns. A key gap identified by many stakeholders involved in these negotiations was easy access to integrated, scientifically sound and generally agreed upon information on the socioeconomic trade-offs likely to result from changes in access, allocation and pricing. In addition, estimates of impacts on the flow regime and on river health are also required. This paper describes the Water Allocation Decision Support System (WAdss) developed to consider these types of trade-offs resulting from changes to access and allocation across the three water systems (unregulated, regulated and groundwater), and its implementation to two NSW catchments, the Gwydir and Namoi catchments. The WAdss has been developed in a modeling platform, ICMS, developed by CSIRO Land and Water. This platform allows for development of a model and data base which can be overlaid by custom built Graphical User Interfaces (GUI). This approach allows for rapid development and testing of both models and interfaces. Model development in ICMS uses a semi-object oriented paradigm, with classes of objects being defined which can be associated with numerous procedural models. An instance of a class (or object) is then associated with a specific model code and a set of data. The WAdss consists of: a generic DSS structure and concept, which is encapsulated in a set of classes and a generic interface, consisting of the code and standard content files; and, specific applications of this generic structure and concept. These applications are defined by an object configuration, a data base and object specific model choice, and a set of application specific files which tailor the ...