New Century Weekly Wednesday, September 1, 2010 This article was originally published by the New Century Weekly (Xinshiji zhoukan) on Aug 17, 2010. It has been translated by Probe International. On July 29, 2010 the Three Gorges Project Construction Committee (TGPCC)—acting under the State Council—hosted a conference to discuss when to fill Three Gorges’ reservoir this year. The preliminary plan, decided at the conference, is to begin filling the reservoir on September 10, which is earlier than last year. Since then, the plan has been sent to relevant government departments, provinces and municipalities for their comments. According to the original feasibility study for Three Gorges, the reservoir should not begin to be filled before October 1st. But in recent years, that date has been moved ahead: in 2008, filling began on September 28, and in 2009 it started much earlier, on September 15. But both attempts have failed to fill the dam to its official, maximum height, or Normal Pool Level (NPL) of 175 metres. In 2008, the reservoir water level rose to 172.8 metres, but stopped short of 175 metres because of concerns a higher water level would exacerbate landslides and other geological disasters that were occurring upstream. In 2009, the water level reached 171.43 metres before having to release water to relieve the drought-stricken Hunan and Hubei provinces downstream. Jin Xingping, head of the Operation Team in the Yangtze River Flood Control and Drought Relief Headquarters and deputy chief engineer of Changjiang Water Resources Commission (CWRC), says that their ability to raise the dam’s reservoir to 175 metres depends on the volume of water coming from upstream on the Yangtze. Under the circumstances, said Cao Guangjing, general manager of the Three Gorges Corporation, when interviewed by reporters from New Century Weekly, they are likely to start filling the Three Gorges reservoir earlier than expected. Both former senior government officials and experts seem to agree, having already proposed filling the dam as early as September 1st or the end of August. But many factors should be considered in filling the reservoir before October 1st: floods, sedimentation and—not least important—ensuring a secure water supply and stable geological environment downstream of the reservoir. Risk of floods For example, filling the reservoir in September, means the reservoir would be filled in a month that is traditionally part of the flooding season. According to records from Yichang hydrological station, several major floods have occurred at the dam site in September: on September 4, 1896 when maximum flow reached 71,000 cubic metres/second, 67,500 cubic meters/second on September 5, 1945, and 60,800 cubic meters/second on September 9, 2004. One proposal wants to start filling the reservoir on September 10 and increase it to 163 metres by the end of September—about five meters higher than the water level in the same period in 2009. But the Ministry of Water Resources says the reservoir should be no higher than 160 meters by the end of September—a much different plan than that being discussed by other government departments, provinces and municipalities. Hu Xinge says the preliminary calculations show that if officials permit filling to begin on September 10—even in the worst case flood scenario—the reservoir would not exceed 171 metres and so would not affect the dam’s ability to control flooding. But Jin Xingping cautioned, should the September 10 filling date be approved and implemented, the water level at Shashi city and Chenglingji City—both below the dam—should never be allowed to go above the warning level[fn] See this article for more on the warning level.[/fn] and officials should be vigilant in monitoring weather patterns to ensure that downstream flooding doesn't occur. This would help officials know if and when water should be released from the reservoir—thereby, acting as a flood control tool for the Yangtze. Cao Guangjing agrees, adding that from June 2003 to December 2007, the Three Gorges reservoir had an average rate of sedimentation deposition of 130 million tonnes each year—far below original estimates of 320 million to 350 million tonnes annually for this period. During the project’s feasibility study, a number of experts expressed concern about sedimentation. "Professor Huang Wanli in the Qinghua University in particular (was concerned)," Cao Guangjing said. At that time, Professor Huang argued that the final water level of the Three Gorges reservoir should not be more than 156 meters, as it would result in a dangerous buildup of silt and the destruction of the Chongqing Port. Cao says there was a hidden agenda to the first attempt to fill the reservoir to 175 meters in 2008: dam officials wanted to have a first-hand look at how serious sedimentation would be. "This is a plan with which we’re able to take the offensive and assume the defensive as the situation requires. It means we can fill the reservoir to its final water level if everything works out, and we also can stop filling if anything goes wrong,” he says. According to Hu, if the Three Gorges reservoir begins filling on September 10 this year, the projected amount of sediment at Chongqing and the fluctuating backwater region over the next 20 years would be equivalent to just two years estimated in the feasibility study carried out in the 1980s. Security of water supply for downstream area Filling the reservoir is much more than just a bureaucratic game involving several national and local governments: in fact, it involves trading off conflicting goals of flood control, power generation, shipping, downstream water supply and environmental protection against each other. It is easy to see why conflicts arise and why plans for the reservoir’s management are complicated. "Basically, while we are filling the reservoir this year, we are making preparations to fill the reservoir next year, with special reports sent to the Office of the TGPCC," Hu Xinge told a reporter from the New Century Weekly. Once a plan is worked out, the CWRC starts preparing a schedule for filling the reservoir beginning in October and lasting until April next year. "For the past two years, plans to fill the reservoir have been approved by leaders of the Three Gorges Project Construction Committee," Hu Xinge said. After receiving approval, a detailed implementation plan, which needs to be approved by flood control authorities, is made. Throughout the approval process, officials from each province and government department make requests based on their needs. Last year, for example, Chongqing wanted to maintain a relatively high reservoir level—higher than 165 meters in March and 160 meters in April—in order to allow for smooth operations at its port. Chongqing, at the tail end of the reservoir, was concerned about its shipping industry, because last year officials at the dam failed to raise the reservoir to 175 metres, as planned, while they allowed water levels to fall quickly. Hunan (Province) below the dam, however, wants officials to release more water during the dry season in order to increase water supply at Lake Dongting. Liu Kapo, advisor to the government of Hunan and director of Lake Dongting Water Authority, told the New Century Weekly that the lake area desperately needs water in the dry season because of strong demand from industrial and agricultural sectors. Further Reading from Probe International:
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