The Hydrolancang cascade: Fact box

By Other News Sources on August 1, 2008 • ( Leave a comment )

August 1, 2008

Information on eight Hydrolancang dams on the Lancang (upper Mekong) River in Yunnan (Updated 08/01/08).

The Hydrolancang cascade

The Jinghong dam shown here under construction was completed in June 2008. (See our Jinghong photo gallery.)
Hydrolancang’s existing and proposed dams along an 800-km stretch of the Lancang (upper Mekong) River in Yunnan province (from upstream to downstream):
Projects	Installed capacity (MW)	Dam height (metres)	Reservoir capacity (m³)	Estimated cost (US$millions)	Status
Gongguoqiao	750	130	348 million	625	Due to start: 2006 Completion: 2008
Xiaowan	4,200	292	15 billion	4,000	Under construction. Completion: 2010
Manwan	1,500	136	920 million	473	Completed: 1996
Dachaoshan	1,350	111	940 million	600	Completed: 2003
Nuozhadu	5,500	261.5	23.7 billion	5,000	Under construction. Completion: 2015
Jinghong	1,500	108	1.2 billion	1,760	Completed: 2008
Ganlanba	150	65	72.4 million	n/a	n/a
Mengsong	600	n/a	n/a	n/a	n/a
**Notes:Run-of-river versus storage reservoirs: Six of the eight dams are “seasonal reservoirs,” with output dependent on seasonal flows rather than storage capacity behind the dams. The two other dams – Xiaowan and Nuozhadu – will function as giant cisterns or storage reservoirs operated to maintain baseload power production throughout the year and downstream flow through the seasonal reservoirs. If completed, Xiaowan will be the world’s tallest arch dam, with 38 times as much design storage capacity as the Manwan dam, and a reservoir that will stretch 169 km upstream. The Nuozhadu reservoir will stretch 226 km upstream. Hydrolancang’s power output crippled by water shortages: Hydrolancang’s Manwan and Dachaoshan dams were barely operational this March due to low flows in the Lancang River. Power production was 350 MW below average for March, when river flows are usually at their lowest. Water levels behind the two dams were almost at the “dead level,” below which the turbines cannot operate, according to Yunnan Daily (20 March 2005). Kunming Daily reported that the Yunnan grid company (a subsidiary of China Southern Power Grid) had to cut back hydro exports to Guangdong province by 200 MW while importing 300 MW of coal-fired power from neighbouring Guizhou province to meet demand within the province (China Power News Network, 31 March 2006). Sources:** Department of Water Environment at the Institute for Water and Hydropower Research. “Main Features of Cascade Hydropower Projects on Middle and Lower Reaches of Lancang River,” Hydrolancang website