While the humanitarian objections to Mondulkiri’s proposed Lower Sesan 2 hydropower dam project are well documented, a report from conservation NGO International Rivers yesterday highlighted an objection of another sort: the Lower Sesan wouldn’t be a very good location for a dam in the first place.

According to the report, which compiled information from the Asian Development Bank (ADB), environmental assessments and local media reports, the Lower Sesan is a poor place for such a project from a logistical standpoint, and the dam would rank among the least efficient in terms of megawatts (MW) of power produced versus land lost to flooding.

“If the project generates more than 10 MW per square kilometre of reservoir, the performance is considered good, 5-10 MW is moderate, and below 5 MW the project ‘needs to be carefully assessed’,” the report reads, citing a technical paper from the ADB. “The Lower Sesan 2 receives a score of only 1.1 MW [per square kilometer] of reservoir.”

The report said that the Lower Sesan is heavily dammed above the proposed site, and even dams upstream are struggling to get enough water to operate at full capacity – due in part to more dams even farther upstream.  

In the dry season, the 400 MW dam would only be able to operate at one-quarter of its capacity.

According to SRP lawmaker Son Chhay, who has long opposed the dam, not only is the project economically unfeasible, its proposed output is still a matter of debate.

“It’s exaggerated,” he said.

Chhay also questioned the prospect of selling half of the dam’s output to Vietnam, which currently imports electricity to Cambodia.  

Right now, Vietnam imports 135 MW of power per day to Phnom Penh alone, according to Electricite du Cambodge.

To contact the reporter on this story: Stuart White at [email protected]

With assistance from Chhay Channyda