E. Manoli

Water supply modeling towards sustainable environmental management in small islands: the case of Paros, Greece

Abstract The present approach has a two-fold emphasis. On one hand, water supply options are modeled and the optimal combination is presented through the identification of the least cost water supply scheme. On the other hand the results may be used towards the delineation of sustainable environmental policy options, particularly in the vulnerable system of small islands. Hence an optimization model has been developed that minimizes the Net Present Value (NPV) of water supply projected costs for the period 2002–2030 for Paros Island, Greece. The non-linear generalized reduced gradient method is used, taking the capacity of water supply options as the decision variable. The model incorporates the operation of groundwater wells and boreholes, surface storage reservoirs, conventional and wind-powered desalination and water hauling by ships. Finally, it estimates the monthly water production as well as the water supply costs. The identified solution involves the combined use of all water supply options and may provide the optimal contribution of each one of the supply sources, on a monthly time step. The results indicate that conventional water supply topped by versatile desalination schemes used for the particularly demanding water consumption peaks may be the focal area of responses for the island of Paros, and by extension for other areas around the world facing similar problems.

Water supply management approaches using RES on the island of Rhodes, Greece

Abstract Desalination powered by renewable energy sources (RES) is presented as an alternative option for the water supply augmentation in the semi-arid region of the island of Rhodes. The case study was chosen as the island relies mostly on the exploitation of groundwater resources and faces serious water shortage problems in an already stressed environment. Alternatives are discussed and compared in contrast to the construction of storage dams to meet urban water needs up to the year 2040. Results may indicate that through the use of financial incentives coupled with holistic water management approaches, desalination powered by RES could be an attractive and environmentally friendly option in an effort to solve problems related to water quantity and quality in semi-arid regions with adequate renewable energy potential.

Towards the formulation of a new strategy of water resource management for urban areas achieved through participatory processes

Stakeholder involvement is recognised as an important factor in the successful implementation of water management plans, particularly when efforts are made to resolve competing and conflicting demands in areas facing water scarcity. Involving stakeholders enables, first, a better understanding of different parties that have an interest in water management problems; second, the process can articulate more clearly the context of agreements and disagreements; and finally it can also significantly contribute to conflict management or conflict resolution. This paper deals with the development of urban water management plans through stakeholder participation in the decision-making process in the Cycladic island of Paros, Greece. In almost all Aegean islands, water scarcity is a critical factor in the management of water resources, resulting in problems related to allocating water and meeting increasing urban water demands. The present approach places a major emphasis on the identification and selection of primary and secondary key stakeholders. Problem analysis was undertaken through the development of a problem tree on the basis of the DPSIR framework. This approach was followed by the formulation of a commonly accepted and agreed upon objective tree, culminating in the definition of alternative water management plans. The adopted public participation process was successful in promoting a common understanding of the water management issues and in forming suggestions on long-range planning and management together with a series of key recommendations in order to meet the increasing urban water demands.