Concern over the degradation of the ecological system in and around the Mekong River ― which flows through China, Laos, Thailand, Cambodia and Vietnam ― has grabbed the attention of a leading lawmaker in the United States. Senator Jim Webb, chairman of the powerful Senate Committee on Foreign Relations and its Subcommittee on East Asian and Pacific Affairs, issued a statement recently saying he was troubled by the proposed construction in Laos of the Xayaburi Dam on the Mekong mainstream.

The planning behind the dam, said Webb, set “a dangerously harmful precedent as it relates to the environmental health of Southeast Asia. Numerous scientific studies have concluded that construction of the Xayaburi Dam and other proposed mainstream dams will have devastating environmental, economic and social consequences for the entire Mekong sub-region”.

The senator continued: “To avoid irreversible damage to the region, I believe it would be prudent to delay the construction of any mainstream dam along the river, including those along the upper Mekong River, until adequate planning and multilateral coordination can be guaranteed. Absent this collaborative approach, the stability of Southeast Asia is at risk.”

Senator Webb will be asking the U.S. State Department to “invigorate its efforts to support sustainable infrastructure and water security in Southeast Asia”.

Meanwhile, a new report by the World Wildlife Fund seems to offer a way out. According to a study on aquatic ecosystem connectivity, the Mekong region could have equivalent power generation but with dramatically less damage to the river’s functioning by opting for tributary rather than main channel dams.

“No part of the Mekong River still provides connectivity to all the 13 ecosystem types classified by a recent WWF study,” said Nikolai Sindorf of the WWF Conservation Science Program. “The impact of continuing incremental dam development will disconnect more and more ecosystem processes.

”Where it gets alarming is the disproportional amount of negative effects from dam construction on the lower mainstream of the river such as at Xayaburi, a dam proposed in northern Laos. The Mekong is extremely sensitive to the impacts of mainstream dams because of its [geographical] ― a very long mainstream fed by relatively short tributaries.“

According to WWF, Xayaburi, the first of 11 dams proposed for the Mekong mainstream, is projected to produce 1,260 megawatts of power while reducing the river’s basin’s total connectivity by five per cent. In contrast the 1,070 megawatt Nam Theun 2 dam on the Nam Theun River in Laos took only 0.8 percent out of the Mekong’s connectivity, and the 1540 megawatt Se San cascade of six dams decreased connectivity by just 1.2 percent.

The proposed Xayaburi dam would cut off nine aquatic ecosystems upstream, out of a total of 13, using WWF’s classification, while both the Nam Theun 2 and the Se San cascade only block a single ecosystem in relatively smaller parts of the basin.

Ecosystem connectivity is critical to maintain the river and its reproductive processes. Unfortunately, nobody seems to be looking at the dam projects, including Xayaburi, in the context of a basin-wide impact that is measured against ecosystem connectivity.

WWF and others are calling for a ten-year delay before the approval of any mainstream dams, in order to give time to fully consider the costs and benefits of their construction.

Thailand, one of the main stakeholders behind the funding and proposed building of the Xayaburi dam project, is complicit in this controversial project and cannot sit idly by and pretend that this is all Laos’ doing.

In fact, if this project goes ahead, it could go down as one of the worst environmental tragedies of our time. 

(Editorial, The Nation (Thailand))

(Asia News Network)