Vientiane Times, 20 December 2014
Chinese storage dams in operation on the Upper Mekong River have already altered water levels in the Lower Mekong all the way down to the Khon Falls in Laos, experts told the recent consultation for the Don Sahong Hydropower Project.
This means there is more water to aid fish migration in the channels adjacent to Don Sahong where a run-of-river scheme is proposed.
Developers of the proposed Don Sahong project said the effect of the Chinese dams means that fish can migrate more easily over the falls during the dry season.
Don Sahong Power Company Environmental Manager Dr Peter Hawkins said the commissioning of the final turbine of China’s Nuozhadu Dam in June 2014 ushered in a new hydropower era, so that historical flow records upstream of Hou Sahong “will no longer be relevant for predicting Mekong River dry season flows in the future.”
He presented these findings during a site visit as part of the Mekong River Commission’s regional public consultations.
Critics of the project which will block the Hou Sahong site research done in the 1990s argue that the Hou Sahong is the only channel that allows year-round fish passage over the Khon Falls and the only channel large enough to support large fish migration.
Those statements have exaggerated researchers’ observations and fishermen’s accounts of 20 year ago, Dr Hawkins said. “The claim that Hou Sahong is the most important migratory route and the only channel that provides year-round fish passage are based on fishers’ stories,” he said.
“Now it’s time to separate fact from fiction,” he said. Chinese dams, the Xiaowan and Nuozhadu in particular, are able to store large amounts of water in the rainy season and release the water in the dry season, evening out the water flows over the year, he said. In the new hydropower era, increased dry season flows will make it easier for fish to migrate in the Xang Pheuak Channel adjacent to Don Sahong. The company has already begun eliminating barriers to fish migration there.
Laos has had the proposed 260-megawatt Don Sahong hydropower project under study and review for eight years since 2006. More than 30 studies and presentations have been completed and shared with member countries and are posted on the MRC and the developer’s websites.
Over the past eight years the Lao government has had the benefit of advice from relevant experts and evidence from necessary investigations and studies, all of which indicate that the Don Sahong is a low-impact project that will utilise the waters of the Mekong River system in a reasonable and equitable manner.
In June 2014, Laos informed the MRC council of its decision to proceed with Prior Consultation for the Don Sahong run-of-the-river project.
Laos agreed to undergo the prior consultation process in order to promote even greater cooperation and put all stakeholders’ comments on an official MRC record.
The six-month prior consultation process will end on January 25, 2015.