It is used to control the water level in the system. In water holding structures, the water level is controlled by having another movable pipe in a fixed vertical pipe and moving it up and down. Telescopic valves work according to the siphon system to carry water. Since the water transport process takes place from the water surface, it does not interfere with the sediments at the bottom. For this reason, it is also used in mud removal structures. In addition, they are used to determine the exit level of the water from the system in sedimentation ponds, as they allow precise adjustment in the determination of the water level.
