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 Dam 1947. After the 1949 Communist takeover, Mao Zedong supported the project, but began the Gezhouba Dam project nearby first, and economic problems including the Great Leap Forward and the Cultural Revolution slowed progress. After the 1954 Yangtze River Floods, in 1956, Mao Zedong authored "Swimming", a poem about his fascination with a dam on the Yangtze River. In 1958, after the Hundred Flowers Campaign, some engineers who spoke out against the project were imprisoned. During the 1980s, the idea of a dam reemerged. The National People's Congress approved the dam in 1992: out of 2,633 delegates, 1,767 voted in favour,