Mekong commission downplays impact of Chinese dams

Bangkok Post 20 November 2004

By Piyaporn Wongruang Tul Pinkaew

A regional water management body of the Mekong basin has downplayed the impact of Chinese dams on water levels in the Mekong river, but an environmental group has criticised its analysis.

Olivier Cogels, chief executive officer of the Mekong River Commission (MRC), said China was operating two dams upstream of the river and was building another two.

The combined storage capacity of two dams, Manwan and Dachaoshan, was less than one billion cubic metres (cu m) while about 60 billion cu m flowed out from China yearly, Dr Cogels said.

"We never concede that the impact is zero," he said, but added that the impact was negligible.

The dams kept some water in the wet seasons and released some in the dry seasons to generate electricity. This helped reduce flooding in the wet season, which could be positive in terms of protecting people from floods, he said.

However, water levels in downstream areas next to China's border could be affected, but that was a local problem, he said.

The MRC was studying rainfall and the Mekong's hydrology in a bid to clarify the situation since there was unusual drought in the basin a few years ago, Dr Cogels said.

China planned a series of cascading dams on the Mekong in late 1980s to generate electricity. Irregular water levels in the Mekong were first noted by Thai fishermen in Chiang Rai's Chiang Khong district when China's first dam became operational in 1993.

Dr Cogels said the MRC had observed some water level fluctuations during dry seasons in areas close to China's border.

The MRC serves as a coordinating body among the four lower Mekong countries – Cambodia, Laos, Thailand and Vietnam – in the management of water resources in the basin. China and Burma are not members but have engaged in some of the organisation's dialogues.

Dr Cogels said China had shown positive response as it had proposed to invest in some mitigation measures. Objectivity was needed if cooperation from China was to come forward. "The relationship on the basis of trust is the most important thing," he said.

However, Witoon Permpongsacharoen, director of the Towards Ecological Recovery and Regional Alliance, said the MRC underestimated the impact of the Chinese dams. Its data was not based on seasonal changes which showed the Mekong's water levels were markedly different in the wet and dry seasons, he said.

Water quality assessment should also be made in order to get the true picture, he added.

Mr Witoon quoted a source from China who works on the river ecology as saying that China had built irrigation systems in order to draw water from the dams for agricultural use even though the dams had less water in storage for electricity generation than planned.

During a high-level roundtable yesterday at the IUCN World Conservation Congress in Bangkok, ministerial officials from Mekong countries, including China, were asked to provide cooperation that would help lead to sustainable development in the basin, said a senior water management source.

Transboundary environmental impact assessment was agreed in principle among the representatives and would be implemented in future projects, he said.

But the Greater Mekong countries including China also agreed that the region's inter-governmental bodies were not doing enough for conservation and needed to step up their efforts.