Upstream dams risk starving Three Gorges of water
Intensive dam-building on the upper Jinsha River - part of the upper reaches of the Yangtze - threaten the massive Three Gorges dam's viability, environmentalists have warned.
A turf war over water supply between the Three Gorges dam and dozens of mega-dams on the upper Yangtze, especially during the dry season, poses a daunting challenge to the world's biggest hydropower project, thirsty for enough water to maximise its power generation.
Government-linked experts such as dam apologist Zhang Boting, of the China Society of Hydropower Engineering, confirmed the Three Gorges' dilemma.
'When the mega-dams such as the Xiangjiaba and the Xiluodu begin filling with water, it is almost impossible for the Three Gorges to have enough water to fill its reservoir,' Zhang said.
The cumulative effect of the dam construction rush on the upper Yangtze has been obvious in recent years. Severe droughts have repeatedly hit the middle and lower reaches of the Yangtze as upstream reservoirs fill with water. Supplies to downstream cities and the mainland's biggest lakes, including the Poyang and the Dongting, have been threatened.
Weng Lida, former head of the Yangtze River Water Resources Protection Commission, said the amount of water all the dams being built or planned on the Yangtze will need every year to reach their maximum power generation capacities far exceeded the total flow of the river.
'It is regrettably true that Three Gorges will not have enough water to raise the reservoir's level to its maximum 175 metres under normal circumstances,' he said. Sichuan-based geologist Fan Xiao and other experts have warned that the Yangtze River could dry up unless the authorities sort out an orderly operation scheme for the dams.
They also point out that, despite all the controversies, the Three Gorges remains the only major hydropower project to have been comprehensively vetted by experts and the last dam project ever approved by the National People's Congress following the disastrous Sanmenxia dam.
The Sanmenxia project, the first dam on the Yellow River, was cleared by the top legislature in 1955.
Mainland authorities admit the dam was a failure due to sediment build-up that caused severe flooding upstream in Shaanxi and threatened the livelihoods of millions. After several failed renovation efforts, the government was forced to build a bigger dam -the Xiaolangdi project - downstream in the 1990s to tackle the calamitous consequences of the Sanmenxia.
However, experts say it does not appear that past lessons have or can be learned. 'As long as there is no overhaul of China's political system or other breakthroughs on long-stalled political reform, there is little hope the problems plaguing dam-building can be tackled,' Fan said.
Although Beijing has long been fiercely criticised for failing to keep influential interest groups, such as power companies, in check, there is little, if any, sign it will reconsider the dam-building frenzy or heed expert or public opinion. Issues that have plagued dam projects for decades, such as grievances over compensation and the negative social and environmental impact, are considered too sensitive for public discussion.