The Benefits of Three Gorges Project

Flood Control

Three Gorges Project is the mainstay project of the flood control system in the middle and lower reaches of Yangtze River. The normal impounded level is 175 meters, and the corresponding storage capacity is 39.3 billion cubic meters. During the flood seasons of each year, according to the demand of the flood control, Three Gorges Dam may reduce the impounded level from 175 meters to 145 meters, emptying a storage capacity of 22.15 billion cubic meters to store flood from the upstream. In this way, when the flood goes through Three Gorges Dam, it will be reduced by 30 percent, which can efficiently control the flood from the upstream to the middle and lower reaches of Yangtze River.

Power Generation

By now, Three Gorges Power station is the largest hydropower station in the world. The powerhouses are behind the dam, located at the two sides of the flood discharge dam, with a total length of 1210 meters. The powerhouse on the left bank is 643 meters long, with 14 sets of hydraulic turbine generator units installed, and the powerhouse on the right bank is 576 meters long, with 12 sets of hydraulic turbine generator units installed. So there are 36 sets of hydraulic turbine generator units in all, with 0.7 million KW for each, and the total installed capacity is 18.2million KW, with an annual power generation of 84.7 billion kilowatt per hour. On the right bank of the dam, there are 6 underground hydraulic turbine generator units, with an installed capacity of 0.7 million for each, amounting to an installed capacity of 4.2 million.

Navigation

The navigation facilities of Three Gorges Project are set to solve the problem of how the hoe ships sail through the three gorges dam. The highest water level of the upstream is 175 meters, while the lowest water level of the down stream is 62 meters, with a drop of 113 meters. The permanent ship lock adopts 5 stages to disassemble the 113 meters drop. On each line of the shop lock, there are five chambers, transportation system, discharge system, and strobes. When the ship lock is working, the transportation system will connect with the upstream, and the discharge system collects with the downstream, thus the water from the upstream will flow into the chamber, and the water level of the upstream will be equal to that of the chamber. The water flows down from the chambers and makes the level of the chamber equal to that of the downstream. In this way, ships can sail through the dam with the ship lock. The whole process will cost 160 minutes. If the ship wants to get through it faster, then it may go through by the ship lift, which is just like a water elevator, and can handle a ship with 3000-ton passenger in 30 minutes. With the highest elevation of 113 meters, the ship lift is the most gigantic and complex in technique in the world.