A prototype Spatial Decision Support System for the evaluation of water demand and supply management
schemes is presented. The water basin is topologically mapped to a network of spatial objects representing
the physical entities and their connections. Several GIS functions, which include data
input/update, network derivation from the basin map and network building/modification are incorporated.
The tool integrates suitable models for demand site requirements calculation and water allocation.
Alternative scenarios can be constructed, trends and interactions of the complex water system can
be analysed, strategies to solve water allocation conflicts can be evaluated and necessary infrastructure
interventions can be planned in advance in order to meet water needs. The tool is demonstrated
through a case study, involving the current situation and future policies for a typical Greek island.
