After the diversion drift is the waste weir and a 1.70 m width cleaning canal having a 2.5% declivity, which operation is expected to take place through a 1.770 m x 1.45 m gate. The highest level of the protection walls in flooding periods is located at the 2259.90 m.o.s.l. This way, it controls the zone of flow closeness towards the diversion dam and grid。