Application of mathematical modeling in the assessment of water quality of the 'Celije' reservoir

Abstract

The existing reservoir 'Celije' on the Rasina River has been formed as part of the water management program of the Morava watershed (38 000 km2), to protect the Djerdap Reservoir, located downstream, from sedimentation. Through numerous legislative acts and regulations, including the newest Water Resources Master Plan of Serbia, the waters of the Rasina River, or rather, the 'Celije' Reservoir have been designated as a water supply source. The 'Celije' Reservoir was filled in 1979, and, as it was not at that time planned for water supply, no sanitary protection of the reservoir was undertaken which resulted in the degradation of its water quality. Since present documents call for the increase of it's capacity it became necessary to assess how this will affect the quality of water in the reservoir so that one can predict: (1) the adequacy of present technology for the treatment of potable water; (2) when more advanced technology will be needed; (3) which of the seven possible wet wells should be used so that water of the best possible quality will be obtained; and (4) what will be the effects of possible protection measures in the watershed and reservoir itself. To assess the trend of water quality in the 'Celije' Reservoir the HEC-5 mathematical model was used. Based on the analyses of water quality in the reservoir, which have been routinely undertaken since July 1987, the parameters of the model were calibrated. These were used to simulate all situations of interest in reaching the relevant decisions.