Rune-of-river hydropower schemes built across mountainous streams which carry large amount of sediment load experience sediment problems of varying nature due to silting of the diversion structure upto its spill crest and entry of sediment laden water into the power intake. Besides damage to concrete lining of the water conductor system, severe damage occurs to the turbines and other underwater parts due to abrasion necessitating frequent repair/replacement of turbine runner and other underwater parts and in some cases long closure of the power station. Proper design of power intake and of desilting chambers can go a long way to solve the sediment problems at run-of river hydro-electric schemes. The paper discusses the design considerations for the power intake to minimize sediment entry into intake and criteria for efficient and economic design of desilting chambers. A case study has been presented for which the desilting chamber was designed on the basis of the criteria discussed in the paper. The desilting chamber has been performing excellently for more than 30 years.
