KANDAL, Cambodia - Cambodia’s plan to build a US$1.7 billion (S$2.3 billion) navigation canal linking the capital Phnom Penh’s port to the country’s coast has raised concerns in Vietnam about the larger Chinese military presence it could enable.

The 180km Funan Techo Canal project, which ends in the coastal Cambodian province of Kep near the Vietnam border, is expected to be developed by Chinese state-owned China Road and Bridge Corporation under a build-operate-transfer arrangement.

This will allow the company to operate the canal for some 50 years in return for funding its construction. Work is expected to start in 2024 and end by 2028.

Cambodian officials have touted how the canal would allow Cambodian imports and exports to bypass transits through Vietnamese ports.

Prime Minister Hun Manet has said it would create jobs for the 1.6 million people who live along the proposed route without adding to the country’s external debt.

But researchers from a Vietnam state-backed institute have warned that the canal is a “dual-use” project, which while promoting socio-economic development could also facilitate Chinese military presence deep in Cambodian territory near Vietnam’s rump.

“The locks on the Funan Techo Canal can create the necessary water depths for military vessels to enter from the Gulf of Thailand, or from Ream Naval Base, and travel deep into Cambodia and approach the (Cambodia-Vietnam) border,” said the article written by Mr Dinh Thien and Mr Thanh Minh, two researchers with the Oriental Research Development Institute under the Vietnam Union of Science and Technology Associations.

The March 2024 journal article was reproduced on the website of the People’s Public Security Political Academy on March 18.

“The Funan Techo Canal is not simply a socio-economic project but also has major military value, which would have a strong impact on the defence and security situation of the whole region,” the two researchers said.

Cambodia’s Ream Naval Base is currently being upgraded with the help of China.

Phnom Penh has denied claims it is granting the Chinese navy access to its base in return for this aid, though Chinese warships have been sighted at Ream as recently as March.

Vietnam and China have overlapping territorial claims in the South China Sea.

The concerns raised in the March article are among the latest cited by Vietnamese academics that have so far focused on the possible environmental impact of the canal project.

While Hanoi’s official comments about this have been subdued, Cambodian media reported that Mr Hun Manet tried to assuage Vietnamese Prime Minister Pham Minh Chinh’s concerns about the canal during his official visit to Hanoi in December 2023.

According to an August 2023 document sent by the Cambodia National Mekong Committee to the intergovernmental Mekong River Commission – to which Thailand, Vietnam and Laos also belong – the Funan Techo Canal would be at least 4.7m deep and 50m wide at its bottom.

The document added any impact from the canal would largely be temporary and limited to the construction period.

The March 2024 article by Vietnamese researchers, however, suggests that the canal would reduce the amount of water flowing into Vietnam’s Mekong Delta.

Mr Brian Eyler, director of the US-based Stimson Centre’s South-east Asia Programme, who studies the Mekong River system closely, suggested that the Funan Techo Canal would eventually act like a levee that would prevent water from reaching key parts of the Mekong Delta in southern Vietnam.

This is because the Mekong’s water flow can be as wide as 50km across when it heads downstream during the wet season in the latter months of the year, he told The Straits Times.

“What the canal is going to do, is cut across that large flood plain,” he said.

“The canal is going to act like a dam. Water that typically will move downstream will hit the canal and start to move towards the ocean laterally with gravity and the gradient of land... That will create a dry zone south of the canal and a wetter zone north of the canal.”

When asked by ST about the environmental impact of the canal project, Cambodia’s Ministry of Public Works and Transport declined to comment.

Although work on the canal is expected to start in 2024, many locals living along its proposed route remain in the dark about how it will be carried out.

Mr Chey Saman, the chief of Somrong Thom commune in Kandal province, where the canal will pass through, told ST: “Villagers always ask me what the project is about, how big it’s going to be, and what’s the impact on their land.

“They want fair value for their land. They keep asking me, but I don’t have any answers for them yet.”

Still, he remains a keen supporter of the development.

“Currently, farmers here have no way to directly sell their products on the global market, they can do so now only by having their goods pass through Vietnam and Thailand. So they get low prices for their crops,” he said.

“This canal will allow direct exports and increase export prices, helping to improve livelihoods.”

Meanwhile, retired teacher Yin Yinthy is concerned about whether she would have to relocate her home and farm by Preak Ta Ek stream, another section in Kandal province where the canal is due to be built.

The 65-year-old woman farms corn for a living with her husband on a 1.2ha plot next to the stream, while their home sits within 50m of the canal.

“I learnt about the Funan Techo Canal via Facebook,” she said, frustrated that no officials in her neighbourhood could answer her questions about the project.

“I am not sure how official the news is. I keep thinking about whether it will impact my house, my farmland – and whether there will be compensation, and whether it will be enough for me to get a new place.”

• Additional reporting by Cheng Sokhorng

Correction note: In an earlier version of the story, we wrote that Mr Brian Eyler had suggested that the Funan Techo Canal might “cut across that large flood bank” instead of “cut across that large flood plain”. This has been corrected.