The dam that broke is part of a huge project that sits across the Xe-Pian and Xe-Namnoy Rivers. While ostensibly owned by a conglomerate in the Laotian capital of Vientiane, the hydroelectric enterprise is primarily held by South Korean and Thai interests. And the communist government of Laos takes a small share through a state-owned construction firm.
So what went wrong? The 2018 monsoon season has not proven as deadly as last year's (yet), but it's no secret that climate change is exacerbating rainfall across Southeast Asia. From the floodplains of the Brahmaputra in India to the refugee camps of Cox's Bazaar, the deluge is exacting a toll on property and human life. In Laos things are no different: persistent rainfall had blanketed Attapeu province all last week and still continues today.
The threat became clear on Sunday when engineers discovered subsidence (a shift on the structure's surface to a change in water level) in one of the rammed-earth support dams. Known as saddle dams, these auxiliary reservoirs draw overspill away from the main dam wall and divert river water. Engineers conducted emergency repairs through the rain and through the night. But they laboured in vain. In a last-ditch effort on Monday morning the dam operators opened the floodgates to relieve pressure on the failing structure.
A partial evacuation order followed on Sunday night and was made complete the following afternoon. By 4:00pm thousands of villagers downstream had been alerted: but for many it was too late. At 8:00pm the dam fractured. A wall of water (5 billion cubic metres in all) swept away villages, forests, and entire communities. Many survivors simply couldn't believe how quickly the rushing waters of overspill (a regular occurrence) became a torrent. 27 people have been reported dead so far and another 130 are missing; families have watched in horror as homes and livestock have disappeared in the overnight flood. What's left is a murky brown sludge that is knee-deep in some places but laps at the eaves in others. Rescue operations are underway to retrieve thousands stranded atop their roofs.
This is a national issue: It is a stated ambition of the Laotian government to transform its multitude of rivers and valleys into the battery of southeast Asia. Hydroelectric power is cheap, reliable and extremely clean. A willing government could carve through mountains and hills, divert rivers and dam entire landscapes. And Vientiane's argument for doing so is a persuasive one. The Laotian gold-mining and timber industries have watched their profits dwindle. But the country still has access to a seemingly infinite amount of water in and around the Mekong. On the other hand there are real concerns about the displacement of villages, inequitable distribution of resources and damage to fishing ecosystems. Add to these: disastrous dam collapses.
But it is also an international issue: Attapeu's border location means that any significant problems it faces are also problems for Vietnam and Cambodia. And so Cambodians last week could only watch helplessly as Laotian dam water swamped their properties and villages. And the carcasses of pigs and cows carry diseases as they continue to float downstream.
All in all some 70 hydroelectric dams in Laos are either complete, under construction or being planned. The demand for power is being driven by neighbouring Vietnam and Thailand. In fact, up to 90% of Xe-Pian Xe-Namnoy's power was to be exported to Thailand. Leaders in Laos believed that within two years they could provide Thailand's entire power supply. But not if the dams break.
We hope that preventative measures can be implemented to stop this tragedy from being repeated. But we also know that the climate will continue to become more unpredictable and more violent. This year three-times the average rainfall fell into Xe-Pian Xe-Namnoy, what will it be next year?