Management of water quality of the Plastiras reservoir

The problems associated with establishing a "safe" minimum level for a reservoir serving multiple and conflicting purposes (hydroelectric power generation, water supply, irrigation and recreation) are discussed. A comprehensive approach of the problem considers three different criteria. The first criterion is water quantity. Available long-term reservoir inflow data are analyzed to establish 'sustainable" water inputs in relation to demands that have to be satisfied. The second criterion is ecology and landscape and considers how fluctuations of the reservoir level affect the lake banks vegetation. It discusses the implications to aesthetic, touristic and beneficial uses. The third criterion is water quality and considers how the fluctuations in lake volume affect the chemical and biological status of the lake. For this purpose a one-dimensional eutrophication model was used. The minimum water level is established from the synthesis of the above, using a multi-criteria analysis.