provides a means for the closure of power tunnel intake during dewatering of penstock or during emergency operations. It is located on the left bank of the river at a short distance from the dam, and it is equipped with conventional trashracks and a Stoney-type sliding gate. From the intake until the surge tank, the water is conveyed through a 2-m, 2-km long waterway consisting of a concrete-lined, 1,180 m long tunnel of circular section, and a 783 m-long riveted steel type section.