Xiaonanhai Dam total of 338 freshwater fish species have been identified on the Yangtze. 189 live in the area — currently a preservation — and many of those are found in no other river basin in China. An official study by the Yangtze River Commission in 2003 concluded that the Xiaonanhai dam could not be recommended due to its "unremarkable economic returns". According to "Chongqing Daily", project cost per-kilowatt is triple that compared with other projects along the Yangtze: with total investment estimated at ¥32 billion, the project will cost ¥16,000 per-kilowatt of capacity, whereas the Three Gorges dam, Xiluodu Dam and
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