Water quality assessment of Aswan High Dam reservoir

Abstract

Egypt is highly dependent on the River Nile as the main source of freshwater. The Aswan High Dam (AHD) was constructed to control the River Nile. AHD reservoir was formed due to the construction of the dam; it is considered as one of the largest man-made lakes in the world. There is currently rising awareness regarding the water quality status of River Nile and in particular the AHD reservoir, the sole reservoir in Egypt. In this work, a comparative study to assess the water quality and trophic state of the southern part of AHD reservoir, Lake Nubia, has been done during low flood periods of 3 successive years (2006–2008). Two water quality indices (NSF WQI and CCME WQI) and two trophic status indices (Carlson TSI and LAWA TI) were used. The results show that the water quality status of Lake Nubia ranges from excellent (according to the Egyptian water quality standards for surface fresh waterways) to good, while the trophic status of the reservoir is eutrophic. A spatial change in results can be noticed due to the morphological and hydrological characteristics of the reservoir. It is recommended that the reservoirs’ different zones should be assigned to different water uses based on comprehensive water quality studies.