Hongsa Power Plant 100% completed, Xayaboury Hydropower 70% Completed

Consultation, technology reduce potential environmental harm from Xayaburi project, say engineers


Consultation, technology reduce potential environmental harm from Xayaburi project, say engineers

(KPL) More than six years of studies and consultation by experts from the region and around the world have reduced the potential of harmful environmental impacts from the Xayaburi Hydropower Project, consultants have said.

As a result of the extensive consultation and review process, concerns about sediment transport and fish migration are being remedied during the construction process, and several investigations are continuing.

Poyry Energy’s Knut Sierotski, director of hydropower projects in Asia, and Poyry’s Project Manager Rene Schmidiger offered details and answered questions at the Technical Workshop on the Xayaburi Hydropower Project organised by the Ministry of Energy and Mines in Vientiane on 15 July.

Mr Schmidiger explained how the US$3.8 billion Xayaburi project bridging the Mekong is taking shape. The key construction components are a navigation lock and spillway on the right back and a powerhouse block and fish passage facilities on the left bank. They are separated by an intermediate block that accommodates pumping stations and elements of the fish passage system.

In reviewing the development history of the 1,285 MW power project in northern Laos, Mr Sierotski noted that the Lao PDR first presented the run-of-river scheme to the Mekong River Commission (MRC) for preliminary design guidance in 2009. Six studies in 2010 took the project from a feasibility study through an environmental impact assessment to a power purchase agreement with Thailand’s utility EGAT. The MRC’s six-month prior consultation process with members, development partners and expert consultants ended in April 2011.
The prior consultation process raised many issues regarding dam safety, navigation locks, fish ecology and fisheries, fish passage facilities, sediment transport and socio-economic issues.

“Internationally recognised experts have taken all of the issues into account, and have implemented actions including costly revisions to engineering and compensation plans,” Sierotski said.

In 2011 and 2012, Poyry and the French energy company CNR completed project reviews and made recommendations aimed at addressing concerns and improving the design and environmental aspects of the project.

“Lao PDR agreed to take into account all legitimate comments of the MRC member countries,” said Mr Sierotski. “The 2011 Compliance Report outlined required changes and recommended further investigations. The results of these studies have fundamentally increased the understanding of the sediment regime, especially changes due to Chinese storage barrages upriver.”
Construction began in November 2012 and now stands at around 45 per cent. The second stage of construction began in January this year, altering the flow of the Mekong for the first time. A company boat was the first vessel to pass through the navigation lock on 15 May.

In addition to complying with the basic requirements for consultation set forth in the 1995 Mekong Agreement, the Lao Government has directed developers of Xayaburi, Don Sahong and future Mekong River projects to adhere to global rules and standards for sustainable development of international river basins.

“Interactions between the various stakeholders have created an entire web of various relations and responsibilities,” said Mr Sierotski.

“For example, the MRC consultation process resulted in significant design changes including modification of the navigation lock, the addition of low-level outlets for flushing sediment, the provision of multiple systems for upstream and downstream fish migration, and water pumping facilities to operate the fish passage system.”

“The adapted design of the Xayaburi Hydropower Project now provides a basic reference for other mainstream hydropower schemes in the Lower Mekong Basin. It is recommended that the knowledge gained developing the final design of the project be used for other run-of-river hydropower projects,” he added.

Mr Sierotski said the consultants are preparing more than a dozen studies on fish migration and biomass, sediment collection and passage, water quality and ecology, design and operation of the navigation lock, and dam safety. All of the reports will be presented to the MRC.

“While hydropower development is a non-consumptive, non-polluting use of river water, other human activities pose environmental threats to water quality and ecology,” he said. “Never forget that hydropower is not the only use of Mekong Basin water,” Mr Sierotski said. Among others are mining and agro-industry, irrigation and wastewater from industrialisation and urbanization.