The government plans to inaugurate the controversial Lower Sesan II hydropower dam in the “middle of next month”, in a ceremony that will be presided over by Prime Minister Hun Sen, a Stung Treng provincial authority spokesman said on Wednesday.

Stung Treng provincial Mines and Energy department director Nou Sovannara told The Post on Wednesday that he was optimistic the project would improve the livelihoods of people in the province.

However, the dam project in the province, which is near the border with Laos, has not been without controversy.

It has displaced around 1,500 households and flooded tens of thousands of hectares of forest in Stung Treng’s Sesan district.

Conservation groups have also long warned of the damage the dam may cause to the ecosystem along that part of the Mekong River system.

The Lower Sesan II Dam is the biggest hydropower plant project in Cambodia, and it is estimated to have the capacity to generate 400 megawatts of electricity.

Its floodgates were closed on September 25 last year, to create its reservoir and test its turbines.

Stung Treng provincial authority spokesman Men Kong said the hydropower plant will have the capacity to supply electricity to everybody in the province.

In the next phase, the government plans to distribute the electricity it generates to other provinces.

“If everything remains on track, the Lower Sesan II hydropower plant will be officially inaugurated in the middle of December. Prime Minister Hun Sen will preside over the ceremony,” he said.

Kong said cheaper electricity costs would benefit Stung Treng’s cashew, rubber and cassava industries.

“Having [cheap] and abundant electricity, national and international investors may see the potential and invest in factories to process cashew nuts, rubber plants and cassava in Stung Treng. This will lead to more jobs for our people in the province,” he said.

However, fish experts have warned of the damage to migration routes. Ian Baird, a geographer at the University of Wisconsin who studies Mekong River fisheries, said fish rely on the ability to move between the Sesan and Srepok rivers and the Tonle Sap to breed.

He said the negative impact of the Sesan dam will be felt in Laos, Thailand and Vietnam, all of which depend on the Mekong River system’s annual flood cycle to deposit nutrient-rich soil on its banks.

The dam will also prevent fish from migrating upstream to Cambodia’s northern neighbours, he said.

A $781.52 million joint project between China-based Hydrolancang International Energy, Vietnam-based EVN International and Cambodia’s Royal Group, the dam will be privately operated before being handed over to the government after 40 years.