(3rd International Conference on Silting Problems in Hydropower Projects, 27-28 February 2008, New Delhi, India, pp. 123-129)
River Satluj, like most of the river flowing through the Himalayas, carries silt load during snow melt and high flow season. Major portion of its catchment area is a cold desert falling within Tibet and is characterized by fragile geological conditions, steep mountain slopes prone to slide and erosion. This mountain scape contributes immensely to the heavy sift load during snow melt and flashfloods. The 1500 MW Nathpa Jhakri Hydro Electric Project (NJHEP) is so far the upstream and most project located on this river and has been in operation for the last over four years. Being a run-of-the river type project, located in the bouldry reach of the river Satluj it is exposed to the onslaught of heavy silt load, a large part of which is hard particles like quartz. Extensive damage by silt has been experienced during the last four years of operation. To mitigate the problem of silt and avoid consequential damage, various silt control measures have been studied and are being implemented on Nathpa Jhakri Project. These measures include the periodic flushing of Nathpa reservoir during the peak flow period. In this paper the observations made during Reservoir Flushing carried out in the peak period of 2007 and the role of reservoir flushing in silt control has been discussed.
