Three Gorges Dam calculated based on the average flow rate at the dam site, assuming the water level is 175 m and the plant gross efficiency is 90.15%. The actual power output in 2008 was obtained based on the monthly electricity sent to the grid. The Three Gorges Dam reached its design-maximum reservoir water level of for the first time on October 26, 2010, in which the intended annual power-generation capacity of 84.7 TWh was realized. In 2012, the dam's 32 generating units generated a record 98.1 TWh of electricity, which accounts for 14% of China's total hydro generation. The State Grid Corporation
Three Gorges with terrain lowering gradually from south to north. The western and eastern parts of the area, between the southern mountains and Bashan Mountain (), in the north, are comparatively lower; and in the past, the river flowed to the east through the region. As the crust of the locality continued to rise, the river's erosion intensified, and the Three Gorges were carved. The natural beauty of the Three Gorges along the Yangtze River has been appreciated for hundreds of years. In the Northern Wei (北魏) dynasty, Li Daoyuan (郦道元) described them in his work "Shui Jing Zhu" (水经注), or the