Why do Trishuli hydropower plants have so many tunnels?

Navin Singh KhadkaGlobal environment correspondent Almost all the power plants in the debris-buried Trishuli valley corridor have tunnels. These run-of-river type plants, which essentially use running river water to rotate their turbines and generate electricity, need tunnels mainly to carry water from the intake point to the powerhouse as the two can be at different elevations. Pipelines and canals could achieve this too but in cases like the Trishuli basin, the river’s winding valleys make tha