Author(s): R. R. Bhate

Linked Author(s):

Keywords: Orifice Spillway; Sediments; Flood; GLOF; Coastal reservoir; Hydraulic model

Abstract: There are about 5264 completed large dams in India. These dams are invariably equipped with some or other kind of spillway. As this dam building activity has been going on for many years, all easy sites have already been tapped and are left with sites where designers have to face challenges from nature. Recently, while harnessing the hydropower potential of Himalayan rivers, designers are facing issues like high sedimentation concentration flows, narrow valleys with a high magnitude of the flood, leading to the provision of an additional spillway or multi-tier spillways. Melting of glaciers resulting in increased rates of Glacial Lake Outburst Flow (GLOF) is challenging tasks to design a spillway for debris flow. On the other hand, for existing dams in India, there is a large upward revision in the design flood due to improvements in flood assessment techniques and the availability of huge data for flood assessment. This demands an increase in discharging capacity of the spillways by increasing crest length or providing breaching sections. India has got a large seashore and to utilize the freshwater from the rivers joining the sea, multipurpose dams across the sea in the vicinity of the Gulf can be considered. Special design considerations are to be employed for spillway and energy dissipation arrangements as their operational performance is influenced by cyclic tidal variations and storm surges. This paper makes an attempt to discuss the relevant hydraulic aspects for the design of spillways and energy dissipators for efficient and safe operation.

DOI: https://doi.org/10.26077/dffd-1cfb

Year: 2022