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 Reservoir Region narrow and where the geography is complex. The mountainous areas represent 74% of the region only with 4.3% plain area in the river valley and 21.7% hilly area. The climate of the reservoir region of the Three Gorges Project is the subtropical monsoon climate. Its location is in the transfer between the northern temperate zone and the subtropical zone, where it is hot and it rains a lot with the annual rainfall of about 1100 mm. The valley of the Three Gorges Reservoir Region below 500 m has an annual temperature 17–19 °C and, with the frost-free period annually lasts