As disputes multiply over the use of the Mekong, including over planned upriver dams in Laos contested by Cambodia and Vietnam, and a newly unveiled Thai plan to divert water to its drought-ravaged farms, the body tasked with mediating among the four nations is losing more than half of its resources.

The Mekong River Commission will see its development partner funding of about $115 million for the past five-year period slashed to just $53 million for 2016-2020, according to Truong Hong Tien, officer in charge of the MRC secretariat.

The body will “decentralise”, shedding roughly half its staff of 150 over the next six months and delegating functions like water-level monitoring to member states.

“It’s too big. We want to become faster, more effective,” Tien said in an interview. “Nature support and water monitoring is something that countries can do by themselves.”

But one Mekong River Commission employee, speaking on condition of anonymity as they were not authorised to speak with the press, said the real reason donors are turning their backs on the MRC is its perceived uselessness to solve regional problems, and cutting staff will only further neuter it.

“The MRC is unable to say anything about [controversial] dams. If one of the countries doesn’t want comments, we can’t make them,” the employee said. “Donors looked at that and said ‘what’s the point of funding you?’”

The disputes over the Lao hydropower dams – particularly the Don Sahong, slated to begin construction at the end of the year – were front and centre at the 22nd MRC meeting at the Intercontinental Hotel yesterday.

“Cambodia, Thailand and Vietnam requested Laos to study environmental impacts, but Laos has denied them,” said Te Navuth, secretary general of Cambodia National Mekong Committee (CNMC). “They said that this project has no effect on anyone.

They don’t follow us.”

Chhith Sam Ath, executive director of the NGO Forum on Cambodia, said the dam’s impact would include loss of biological diversity, fish deaths and increased drought at a time when Cambodia’s water levels are dangerously low already.

Compounding the water use issue, the Thai National Water Board on Tuesday agreed to divert water from rivers forming natural boundaries with Thailand, including the Moei River bordering Myanmar and the Mekong.

The current unprecedented El Niño climate pattern saw Thailand lose nearly a third of its rice crop to drought in 2015.

Suphot Tovichakchaikul, director of Thailand’s Department of Water Resources, said yesterday that no diversion efforts have begun and that the plan could be as long as two years away.

However, the Bangkok Post quoted National Council for Peace and Order deputy spokeswoman Colonel Sirichan Ngathong as saying that Thailand has been building 30 water retention areas since November and will be done by March. They will capture water, which would otherwise flow into the Mekong along its tributaries.

Ministry of Foreign Affairs spokesman Chum Sounry yesterday said he was unaware of the Thai plan. Ministry of Environment representatives could not be reached for comment.

But the employee at the MRC confirmed the plan. He said that while the amount Thailand wants to take – about 2 billion cubic metres per year – would be okay in an average year, the cumulative effect of dams and Thai diversions will leave Cambodia and Vietnam in trouble during another dry year.

“If you decentralise [MRC] to the national level, you will have this – the upstream countries will be able to take the water, and downstream countries like Cambodia and Vietnam will suffer,” he said.