The dam at Vietnam's 7.5-MW Dak Mek 3 hydropower project is being investigated after the structure sustained significant damage last week, HydroWorld.com has learned.

Vietnamese sources report a 60-ton dump truck hit the cement dam November 23, killing the driver and causing large portions of the 60-meter-long, 20-meter-tall dam to collapse into Dak Mek Stream.

The Hong Phat Dak Mek Hydropower Joint Stock Company, which owns the project, says the dam was being built "in accordance with quality standards and the approved design".

Officials with Vietnam's Dak Lak Province have begun their own investigation, however, noting that the damage seemed too significant not to have been caused in some part by construction or design flaws.

The investigators have asked the owners to submit all records related to the Dak Mek 3's design, construction, supervision and quality to the provincial Construction Department for review before December 8.

Work on the US$10 million project had been ongoing since March 2009 and was about 80% complete, according to its owners. The dam had not yet begun retaining water.

HydroWorld.com recently reported that the safety of another Vietnamese hydropower project, the 2,400-MW Son La plant, is also being evaluated.

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