A South Korean construction firm has dismissed the latest findings by the Lao government that are cited as the reason for a fatal hydropower dam collapse last year in Laos.
SK Engineering & Construction said in a press release on 29 May that the company could not agree with the findings as they lack scientific basis and data.
In July last year, a saddle dam at the Xe Pian Xe Namnoy hydropower project collapsed after heavy rains, reportedly leaving at least 19 people dead and 6,630 living in emergency shelters and causing severe damage to private property and infrastructure.
The dam was part of a larger hydroelectric project in the region run by the Xe Pian Xe-Namnoy Power Company, a joint venture between SK Engineering & Construction and Korea Western Power, along with other smaller shareholders.
The South Korean firm’s announcement came after the National Investigation Committee (NIC) formed by the Lao government said on 28 May that the dam collapse as not a “force majeure” event and it could have been prevented by adequate treatment measures.
The NIC’s conclusion was based on the result of the investigation by a panel of professional and independent experts (the Independent Expert Panel, or IEP).
Vice President of the NIC Singphet Bounsavatthiphanh said at a press conference that even if rainfall was quite heavy on the days before the collapse of the dam, the reservoir level was still below the maximum operation level and well below the crest level when the failure started, as quoted by Vientiane Times.
Vientiane Times added the IEP also found that the root cause of the failure was related to high permeability combined with erodible horizons mainly due to the existence of canaliculus interconnected paths.
“As the water level rose during the filling of the reservoir, seepage flow developed in the foundation along these paths and horizons with high permeability. This resulted in internal erosion and softening of the laterite soil. When erosion and softening in the foundations reached a certain point, the dam stability was no longer ensured, and a deep rotational sliding at the highest section of the saddle dam was triggered,” the paper said.
This finally led to complete breaching of the saddle dam and its foundations, resulting in the catastrophic uncontrolled release of water from the reservoir, Vientiane Times reported, adding that the foundation is without a doubt involved in the failure, which could have been prevented by adequate treatment measures.
Such findings prompted an immediate rejection by SK Engineering & Construction.
The South Korean firm said it conducted an analysis based on location, methodology and third-party analysis designated by the IEP, and the final data did not support the panel’s conclusion, as quoted by South Korea’s Yonhap News Agency.
“If the destruction was a result of what the IEP claimed, a large amount of soil leakage should have been found at the bottom of the saddle dam before the accident, but that was not the case,” SK Engineering & Construction said.
The company also noted that teams sent by both the South Korean government and by a group of leading engineering firms to investigate the cause of the disaster, at the behest of the government of Laos, have different opinions from those included in the IEP report.
“We urge the Lao government to investigate and verify the cause of the accident in an objective and fair manner in order to find out the concrete cause at a time when the opinions of the specialised parties differ,” the company said.
Meanwhile, SK Engineering & Construction vowed that it will continue to put efforts in recovering damages and compensating victims in Laos regardless of the announcement of the results.