If approved, the Zhuyangxi and Xiaonanhai hydropower projects would bring to four the number of dams spanning the central section of China’s longest river.

Gezhouba, completed in 1988, was the first dam to block the Yangtze. Forty kilometres further upstream, construction of the concrete dam at the Three Gorges project, which stretches for 2.3 kilometres across the river, is to be completed in May. (All parts of the mammoth project are due to be finished by 2009.)

Cai Qihua, director of the Changjiang [Yangtze] Water Resources Commission, recently led an inspection tour to the proposed Xiaonanhai and Zhuyangxi dam sites, the Chongqing Morning Post reported.

Xiaonanhai is located 40 kilometres upstream of metropolitan Chongqing (and 650 kilometres upstream of the Three Gorges dam), while Zhuyangxi is 140 km upstream of Chongqing.

The design institute of the CWRC, which was also the principal designer of the Three Gorges project, has begun doing design work on both of the proposed new dams.

Xiaonanhai, the smaller of the two projects, with one gigawatt of installed generating capacity, would be built first, China News Service (Zhongxinshe) reported. Zhuyangxi would have a generating capacity of 3 gigawatts, cost US$3.75 billion, and be built between 2009 and 2016, the Chongqing Morning Post reported.

At least 21 large dams are also planned or under construction on the Jinsha River, as the
upper Yangtze is called. The four biggest projects (Xiluodu, Xiangjiaba, Baihetan and Wudongde) are being constructed by the company building the Three Gorges dam, and are slated to have a combined installed capacity of 38.5 gigawatts, twice that of Three Gorges. Apart from producing power, the four dams are designed to tackle a serious problem facing the Three Gorges reservoir: They are supposed to help block silt and prevent a dangerous buildup of sediment behind the Three Gorges dam.

The construction of more than 100 large dams on the upper Yangtze has already worsened the flood risk on the river, a Chinese expert told the Fourth World Water Forum in Mexico City yesterday [Mar 21].

Cheng Xiaotao of the Beijing-based China Institute of Water Resources and Hydropower Research said the dams were causing longer-lasting and higher floods. He advocated shifting from flood control to the non-structural approaches of flood management. (World Water Forum Bulletin [PDF], Mar 22)

Fact box: YANGTZE / JINSHA DAMS
Above: Three Gorges dam on the Yangtze
YANGTZE: Two dams currently span the river. Plans for two more have just been announced
Dam	Location	Size (GW)	Status
Gezhouba	Hubei	2.7	built
Three Gorges	Hubei	18.2	under construction/ being commissioned
Zhuyangxi	Chongqing	3	proposed
Xiaonanhai	Chongqing	1	proposed
JINSHA: Below, five of the more than 20 large dams planned for the Jinsha (as the Yangtze is called upstream of Chongqing municipality)
Dam	Location	Size (GW)	Status
Xiluodu	Sichuan/Yunnan	12.6	under construction
Xiangjiaba	Sichuan/Yunnan	6	under construction
Baihetan	Sichuan/Yunnan	12.5	site preparation
Wudongde	Sichuan/Yunnan	7.4	site preparation
Hutiaoxia (Tiger Leaping Gorge)	Yunnan	2.8	designed