Explanation:

 The Nathpa Jhakri project, located in the mountainous area of the state of Himachal Pradesh, about 160 km from the city of Shimla, uses the waters of the upper reaches of the Satluj River for hydroelectric purposes.
The facility includes a 67.50-m-high concrete gravity dam which diverts 400 m³/s of water through four underground sand traps discharging into a headrace tunnel (HRT) that is 27.3 km long, at the end of which a surge tank will be built.