Hydropower developers and representatives of the Mekong River Commission member countries met last week for the last time before finalising guidelines to mitigate the negative impacts of dam construction on the Mekong River, though conservationists expressed doubts about whether such guidelines would make a difference.

In a statement, the MRC said the guidelines – which will be fully disclosed in March – have been two years in the making and are meant to update the existing “preliminary design guidelines” (PDGs) created in 2009.

“The Council Study predicts possible impacts from dam developments and other changes in the basin, while these mitigation guidelines focus on how to mitigate such impacts on the environment,” the statement reads, referring to a five-year study from the organisation which outlines dramatic social, economic and environmental impacts on Lower Mekong Basin countries.

Cambodia is likely to sustain a hit to its gross domestic product on the order of several billion dollars, the study found, and is facing food security risks resulting from a predicted 70 percent decline in floodplain fish production.

According to the MRC, the forthcoming update to the PDGs will “be built on this knowledge”, guiding dam design to reduce impacts and to “find appropriate design solutions”.

The MRC said the new guidelines will be informed by “lessons learnt” from the Xayaburi and Don Sahong dams, two controversial dams currently under construction on the Mekong mainstream.

The guidelines, however, are not legally binding.

Maureen Harris of the NGO International Rivers said this is a concern given the “clear need” for stronger standards and compliance for hydropower projects regionally.

“Experience with other non-binding procedures and initiatives is that they can be ineffective in actually improving outcomes, or doing more than helping to ‘greenwash’ or provide reassurance about environmentally and socially destructive projects,” she wrote.

And while the MRC noted they are reviewing a proposed redesign of the controversial Xayaburi dam in Laos, Harris pointed to a lack of transparency surrounding that process.

“The public was assured that state-of-the-art mitigation measures would be developed. Yet the full details of the redesign – and the results of any mitigation testing and impact monitoring – have not been made public,” she wrote.

According to Harris, mitigation technology is “untested and highly uncertain” and it would be best to seek out forms of energy besides hydropower.

“From the knowledge we have, no amount of mitigation is likely to eliminate or even substantially reduce the massive ecological and social impacts expected from currently proposed Mekong dams,” she said.

A recent report by the think tank the Stimson Center found that the impact of hydropower projects could put Cambodia and Vietnam on the brink of “a food security or economic crisis”, potentially affecting regional security.

The report also noted that hydropower may prove more expensive than promised – citing the fact that Lower Sesan 2 sells power at US $0.091/kwh compared to a promised US $0.06-0.07/kwh. It recommended instead that Cambodia develop alternatives, in particular solar.