Three Times of Damming of the main channel of the TGP

The first is the damming of the main channel of the Gezhouba Water Conservancy Project carried out on January 3rd,1981.Through the hard work of the constructors,the dragon-mouth of the damming left is 33.2 meters wide.The flood-discharge of the dragon-mouth is 4190 to 4720 m³/s while the maximum water fall is up to 3.23 meters. The current velocity is 7.1m/s at its extreme.The whole damming took 36.4 hours in total.

The second is the damming of the main channel of the TGP which was started on November 8th,1997.The dragon-mouth left this time is 40 meters wide.The actual flood discharge is 8,480 m³/s while the maximum water fall is 1.24 meters. The fastest current velocity is 3m/s.The second damming of the main channel took 29 hours.

The third damming of the main channel began in December,2002.It was carried out in the Diversion Ditch of the TGP.The big dragon mouth closed on December 6th,2002.The dragon-mouth of the upper banquette is 150 meters while the one of the lower banquette 140 meters.The designed flood-discharge is 10,300 m³/s while the maximum water fall is 4.11m. The current velocity is 10 m/s at its extreme.