Go with the flow

China says it remains a developing country despite an impressively rapid rise in the league of global power. By some measures, it is now the world's third-biggest economy and second-largest exporter. However gauged, China is clearly a nation with increasing impact and influence, especially if you live in nearby Southeast Asia.

So it comes as no surprise that China is blamed these days for local troubles almost as ritualistically as the United States, the superpower Beijing says it will never emulate. The latest finger pointing at China comes in the wake of devastating floods in parts of northern Thailand and Laos after the Mekong, Southeast Asia's largest river, overflowed its banks, inundating villages and rice fields, and leaving a swathe of destruction.

The water level on August 15 in Vientiane, the capital of Laos on the banks of the Mekong, was the highest since records began in 1913. Low-lying regions in Cambodia and southern Vietnam are bracing for similar damage.

Some Thais hit by the floods, as well as non-governmental organisations campaigning against dam building, say that water released from the reservoirs of three big Chinese dams on the upper reaches of the Mekong swelled the run-off from a tropical storm and heavy monsoon rain across northern Laos and China's Yunnan province earlier this month. But the Mekong River Commission, in a statement last Monday, pointed out that the volume of releasable water held by the three Chinese hydropower dams to generate electricity was too small to have been a significant factor in the flooding. The commission, established by the governments of Cambodia, Laos, Thailand and Vietnam in 1995 at the end of a long period of conflict in the region, helps co-ordinate management of the Mekong basin in Southeast Asia.

As the world's 12th-longest river, the Mekong runs through or between six countries - China, Myanmar and the four commission member states. Although the Mekong starts high in China's Qinghai-Tibetan plateau and flows through China for more than one-third of its total length of over 4,300km, China is not a commission member. Nor is reclusive Myanmar.

The commission says that the combined storage capacity of the three Chinese dams on the upper section of the Mekong is less than one cubic kilometre. It adds that only a small part of this could have been released as the floodwaters in the area accumulated between August 8, when the tropical storm struck, and August 12, when the flood peak in the Mekong was measured in Chiang Saen, in Thailand.

While this may be true, Chinese dam construction on the upper reaches of the Mekong is a legitimate source of concern for downstream Southeast Asian countries. To generate electricity, water has to be released to drive the turbines. Their worry is that too much will be released in the wet season, and too little in the dry season, when the water is needed in Southeast Asia.

This concern will be accentuated when China completes the fourth dam on its section of the Mekong by 2013. This dam in Xiaowan will be 292 metres high, one of the world's tallest. It will generate over 4,000 megawatts of electricity, the equivalent output of at least four nuclear power stations. Its reservoir will impound water in a 190 sq km reservoir that Chinese officials say will hold 15 billion cubic metres of water, nearly five times the volume held by the three existing dams. They say this will reduce the flow of water into Southeast Asia by 17 per cent during the wet season and increase it by 40 per cent in the dry season. Four more Mekong dams are planned in Yunnan, one of which will have a storage capacity similar to Xiaowan. Filling the Xiaowan dam will take between five and 10 years, using half the upper Mekong's flow.

If China is serious when it promises a co-operative and mutually beneficial partnership with Southeast Asia, it should join the Mekong River Commission as a full member, share all hydrological information and integrate its Yunnan dam planning into the development blueprint for the lower Mekong Basin.

Michael Richardson is an energy and security specialist at the Institute of Southeast Asian Studies in Singapore