| 摘要 |
This invention relates to a water control gate mounted to the crest of a spillway for controlling the water level in a reservoir. The control gate includes a variable ballast tank (12) which defines a movable barrier. A pivot arrangement connects the movable barrier to the spillway (14) so that it can pivot between an upper closed position, in which it projects above the crest of the spillway so as to effectively increase the height thereof, and a lower open position. The gate also includes a water inlet communicating with the ballast tank for allowing water into the tank when the water level in the reservoir associated with the spillway rises above a predetermined level, thereby causing the ballast tank to pivot downwardly towards the open position in which water in the reservoir is allowed to flow over the movable barrier and out of the reservoir, and a water outlet communicating with the ballast tank for allowing water in the tank to be drained therefrom so as to cause the tank to pivot upwardly towards the closed position. |
