A New Perspective: From a Single Engineering Project to a Basin-Wide Hydrological System
Figure 1: Groundbreaking Ceremony for Section II of the Funan Techo Canal Project, held on 11 April 2026 in Borei Chulsar District, Takeo Province. The ceremony was presided over by Prime Minister Hun Manet, accompanied by Chinese Ambassador Wang Wenbin. Seated in the front row on the red carpet, from left to right, are the Chinese Ambassador to Cambodia, Prime Minister Hun Manet, and Deputy Prime Minister Sun Chanthol, Vice Chairman of the Council for the Development of Cambodia (CDC), who oversees national infrastructure and investment. Source: Agence Kampuchea Presse (AKP)
Developments Since the Groundbreaking Ceremony: Progress and Persistent Questions
One of the questions most frequently raised by readers is
straightforward:
What is the current status of Cambodia's Funan Techo Canal
Project?
This question is particularly timely because two years have
now passed since the official groundbreaking ceremony of 5 August 2024, an
event staged on an unprecedented national scale. The canal was presented as a
flagship megaproject, a symbol of Cambodian national pride, and a legacy closely
associated with the Hun family's political leadership. At that time, the
Cambodian government confidently announced that the canal would be completed
and become operational by 2028.
Figure 2: The
groundbreaking ceremony of the Funan Techo Canal at the small village
of Prek Takeo, Kien Svay District, Kandal Province, on 5 August
2024, coinciding with Hun Sen's birthday. The ceremony was chaired by his son,
Prime Minister Hun Manet. Behind the ceremonial stage stood a giant
Khmer-language banner proclaiming: "We Support the Funan Techo
Canal." This location marks the beginning of Section I, a canal
segment extending more than 20 kilometers, drawing water directly from
the Lower Mekong River, upstream of Vietnam's Mekong Delta. Source:
Khmer Times, 5 August 2024.
Figure 3: Map of the Funan Techo Canal Project. The canal (red line) diverts water from both distributaries of the Lower Mekong: the Lower Mekong River (light blue), which later becomes Vietnam's Tiền River, and the Bassac River (dark blue), which becomes the Hậu River downstream in the Mekong Delta. Source: Radio Free Asia (RFA)
As of August 2026, two years after the commencement of Section I, it has become evident that the Funan Techo Canal remains in the stage of phased construction, rather than full-scale excavation along its planned 180-kilometeralignment. The available evidence suggests that the project has yet to enter comprehensive construction across the entire route originally envisioned. Based on its current pace, it is increasingly likely that this ambitious undertaking will require substantially more time than initially projected before reaching completion.
Over the past two years, the project’s development can be
summarized as follows:
Following the groundbreaking ceremony
on 5 August 2024, Reuters reported that by the end of 2024, there had been
virtually no significant construction activity at the ceremony site, while the
arrangements for securing financing from the Chinese side remained unclear.
During 2025, Cambodia and China
reached agreements on financing and the BOT model (Build-Operate-Transfer),
while also carrying out boundary marking, surveying, and logistical
preparations. In the initial phase, the Phnom Penh authorities indicated that a
Chinese company might finance the entire project. Subsequently, the investment
structure was revised, with Cambodian investors expected to
hold 51% and the Chinese side 49%.
A major turning point came in April
2025, during Chinese President Xi Jinping’s visit to Cambodia, when the two
sides signed an agreement to develop a 151.6-kilometer canal section,
valued at approximately US$1.2 billion. Prime Minister Hun Manet stated at
the time that this infrastructure project was significant for Cambodia’s
economic sovereignty, logistics capacity, and long-term national development.
By early 2026, some residential areas
along the canal alignment had not yet been cleared and remained subject to
negotiations over land compensation. In addition, China provided a US$400
million concessional loan to finance the construction of navigation locks,
irrigation systems, and bridges crossing the canal.
On 11 April 2026, four months ago,
Cambodia held the groundbreaking ceremony for Section II of the
project in Borei Chulsar District, Takeo Province. Prime Minister Hun Manet
presided over the ceremony together with Chinese Ambassador to Cambodia Wang
Wenbin. The investor and contractor are a Cambodian-Chinese joint venture, with
the Chinese state-owned China Communications Construction Company (CCCC) playing
a major role. This is the largest section of the entire project.
Section I, by contrast, is only
approximately 26 kilometers long. It begins at a branch of the Upper
Mekong River in Kien Svay District, Kandal Province, where the original
groundbreaking ceremony was held on 5 August 2024. Cambodian Deputy Prime
Minister Sun Chanthol reported that boundary identification and map
verification for the initial section had achieved some progress. Authorities
had marked 155 land boundaries and allocated nearly US$71
million for compensation in this area.
The Funan Techo Canal Project
(FTC) is intended not merely as an inland waterway connecting Cambodia’s
river system with the Gulf of Thailand. It is also expected to provide water
for agricultural production and aquaculture, promote the development of
economic zones, logistics centers, ports, and expand tourism activities in the
localities along the canal corridor.
According to information released by Cambodia’s Ministry of
Information on 27 May 2026, Section II has a total investment of
approximately US$1.17 billion and an expected construction period
of 36 months, or three years, beginning with the groundbreaking in April
2026. This would mean completion in April 2029.
Figure 5. Graphic representation of the Funan Techo Canal released by Cambodia’s Ministry of Public Works and Transport. [Image source: Royal Government of Cambodia]
Why the 2028 Completion Target Is Difficult to Achieve
The stated objective of completing the entire project by 2028 therefore
appears entirely unrealistic. There are at least three major reasons:
1. The enormous scale of construction
The canal is approximately 180 kilometers long, 80–100
meters wide, and about 5.4 meters deep, and will require:
numerous bridges;
navigation locks;
water-regulation structures;
ports;
logistics infrastructure; and
the relocation and clearance of
residential areas and other sites along the right-of-way.
2. Financing
Although Beijing has reiterated its commitment to supporting
completion of the project, the scale of investment and financing mechanism
have already been revised several times over the past two years.
3. Technical and environmental issues
Experts from a number of research institutions, including
the Stimson Center and the Mekong River Commission (MRC),
continue to point to the lack of transparent data concerning:
the volume of water to be diverted
from the Mekong River;
impacts on the Mekong Delta;
the operating regime of the
navigation locks;
impacts on the natural flood regime;
and
sediment loss.
From a purely construction-engineering perspective, completing
a 180-kilometer canal within approximately three years (2026–2029) would
already be a formidable undertaking.
Based on Cambodia’s own experience with major infrastructure
projects, the Phnom Penh–Sihanoukville Expressway, which is narrower,
shallower in construction requirements, and does not involve complex navigation
locks, took three years and six months to complete.
A scenario anticipated by many experts is therefore that the
project may have to be delayed until 2030 or beyond, or that different sections
will be completed sequentially and subsequently connected before the entire
canal is brought into full operation.
Three Major Questions Concerning Impacts on the Mekong Delta
Because of growing concern over the canal’s potential impacts on
the Mekong Delta, three questions have become the focus of the most
intense debate:
Will the Funan Techo Canal actually
reduce the volume of Mekong River water flowing into Vietnam?
To what extent will it reduce the
sediment supply reaching the Mekong Delta?
How significant will the canal’s
impact be compared with the impacts of the 12 hydropower dams on the Mekong
mainstream?
Figure 6: Underwater clearance of unexploded ordnance (UXO / Unexploded Ordnance) to ensure safety during construction of the Funan Techo Canal.
[Khmer Times, 26 February 2025]
The Impacts Must Be Viewed Within the Entire Mekong River System
CONCERNS ABOUT THE IMPACTS ON THE MEKONG DELTA
The Funan Techo Canal is not merely a stand-alone
transportation project. It will constitute a Multi-Purpose Integrated
Project affecting an already fragile ecosystem within the Mekong River
Basin.
The question, therefore, is not simply: “Will this canal
cause the Mekong Delta to dry out?” Rather, the more important question
is: “To what extent will it interact synergistically with the impacts
already produced by the chain of upstream dams?”
There are three issues that need to be considered
separately:
1. Water Discharge: There Will Be an Impact, but It May Not Be
the Greatest One
From a hydrological perspective, Cambodia argues that the amount
of water required for navigation will be only about 5 m³/s, a very small
volume compared with the discharge of the Mekong River, and therefore that the
impact will be negligible.
However, many experts are convinced that the Funan Techo Canal
is not simply a navigation canal.
Recent Cambodian documents and official statements indicate that
the project is also intended to:
irrigate approximately 300,000
hectares of agricultural land;
provide water for domestic use;
support urban development; and
facilitate the development of
industrial zones along both sides of the canal.
Thus, the amount of water withdrawn from the Mekong–Bassac
river system would be substantially greater than the initial figure
of 5 m³/s cited for navigation.
This is also an issue that the Stimson Center,
the Mekong River Commission (MRC), and environmental advocates have argued
needs to be clarified through comprehensive feasibility studies.
2. The Greatest Concern May Not Be “Loss of Water,” but “Loss of
Floods”
This is a point that has received relatively little emphasis in
the Vietnamese media.
Researchers at the Stimson Center have suggested that the canal,
with its elevated embankments, could alter the pathways through which
wet-season floodwaters spread.
For the Mekong Delta, floods are not simply natural disasters.
They also bring essential ecological benefits: sediment, nutrients, fish
larvae and juveniles, freshwater, and the natural capacity to flush saltwater
from the delta.
If floodwaters are retained or diverted upstream in Cambodia,
provinces in the upper reaches of the Vietnamese Mekong Delta, such as An
Giang, Dong Thap, and Kien Giang, could receive less floodwater.
This could lead to:
declining natural fishery production;
reduced sediment deposition; and
weakened natural protection against
saltwater intrusion.
In other words, “loss of water, loss of floods” may
become the greatest risk.
3. Saltwater Intrusion
The Mekong Delta is already under four major pressures:
sea-level rise;
groundwater extraction;
declining dry-season flows; and
saltwater intrusion.
If the Funan Techo Canal withdraws additional water during the
dry season, even if only by a few percent, it could potentially result in:
saltwater penetrating farther inland;
longer periods of salinity intrusion;
greater damage to rice-growing areas
and fruit orchards; and
reduced sediment delivery to the
delta.
To date, no international model has demonstrated with precision
the magnitude of these potential impacts, partly because Cambodia has not yet
released a Strategic Environmental Assessment (SEA) Report, detailed
engineering plans, and operating procedures that would allow independent
scientists to fully assess and verify the consequences.
In my view, the Mekong Delta is currently being affected
simultaneously by four major variables:
|
Major factor |
Relative impact |
|
Upstream Mekong hydropower dam cascade |
★★★★★ |
|
Climate change and El Niño |
★★★★★ |
|
Groundwater extraction and land subsidence in the Mekong Delta |
★★★★☆ |
|
Funan Techo Canal |
★★★☆☆ (not
yet quantifiable) |
In other words, Funan Techo may not be the “only threat,”
but it could become “the straw that breaks the camel’s back.”
This assessment is also increasingly appearing in Mekong
research circles.
A Broader Perspective Is Needed
After many years of following developments in the Mekong, I have
come to believe that a broader perspective is urgently needed.
Around 2000, when I published Cửu
Long Cạn Dòng, Biển Đông Dậy Sóng (The Mekong, Drying Up and the
South China Sea in Turmoil), attention was focused primarily on the
upstream mainstream hydropower dams on the Mekong.
In the years that followed,
particularly from 2023 onward, I, together with many other experts, began to
pay greater attention to “new variables.” The Funan Techo Canal is
one of them, because its implications extend beyond water volume. It could
potentially alter the hydrological patterns of the Cambodian floodplain, the
Mekong Delta, and the Tonle Sap, the freshwater lake regarded as one of
the largest such lakes in the world. I have repeatedly described Tonle Sap as
the “ecological heart” of the entire Lower Mekong Basin.
In my view, our concern today can no longer be limited to the
upstream mainstream dams. We must broaden the framework to encompass five
major propositions.
I. First Warning: “Hydropower Dams Are Transforming the Mekong
from a Natural River into a Regulated River”
When I wrote the two books Cửu Long Cạn Dòng, Biển Đông
Dậy Sóng and Mekong Dòng Sông Nghẽn Mạch (Mekong:
The Occluding River), many people still viewed dams primarily as structures
that stored and released water for electricity generation.
But by 2026, our assessment has changed. We can now see that:
the seasonal flow regime has
been “flattened”
flood peaks have become lower;
anomalous water releases have
increasingly occurred during the dry season; and
the biological rhythms of the entire
basin have been altered.
Today, many hydrologists are increasingly reluctant to describe
the downstream Mekong flow regime simply as a “natural hydrograph.”
II. Second Warning: “Sediment Is the Most Precious Asset”
Twenty years ago, much of the attention was focused on the
quantity of water.
Today, the research community increasingly recognizes that:
The Mekong will not necessarily die first from lack of water. It
may die from the loss of sediment.
According to numerous studies, the sediment reaching the delta
has declined dramatically because upstream reservoirs and dams retain a large
proportion of the river’s sediment load.
This contributes to:
increased riverbank and coastal
erosion; and
the gradual loss of the delta’s
natural fertility.
III. Third Warning: The Delta May Sink Faster Than Sea Level
Rises
When my books were first published, public discussion often
centered on the idea:
“Climate change will submerge the delta.”
Today, geologists increasingly emphasize another reality:
The delta is sinking under its own weight and human pressures,
in some areas faster than sea level is rising.
The principal causes include:
groundwater extraction;
insufficient sediment replenishment;
and
natural and human-induced compaction
of the deltaic sediments.
In other words:
The Mekong Delta is being attacked from below by land subsidence
and from outside by sea-level rise.
This is something that few people fully appreciated 15–20 years
ago.
IV. Fourth Warning: Funan Techo Is Not Merely “A Canal”
This is the point that, in my view, needs to be updated from the
perspective of when the earlier books were written.
If, in 2017 or 2020, someone had asked me:
“What is the greatest threat?”
I would have answered:
“The 11 mainstream hydropower dams.”
But by 2026, the answer must be different and the
perspective broader:
“The greatest threat is the absence of an integrated
water-regulation system for the entire Lower Mekong Basin.”
And Funan Techo must be regarded as a new link in that
system.
One particularly clear and noteworthy development is that the
objectives of the Funan Techo project appear to have expanded beyond navigation toward irrigation,
with potential implications for water regulation and agricultural economic
development along the canal corridor.
At the same time, many experts have argued that the canal’s
embankments and navigation-lock system could alter the natural flood regime in
Cambodia and transmit impacts downstream to the Mekong Delta if operated on a
large scale.
In other words:
Funan Techo is not merely a navigation canal. It is a
water-management infrastructure project.
That distinction is highly significant and differs substantially
from the way the Phnom Penh authorities have publicly characterized the
project.
V. Fifth Warning: The Greatest Crisis Is a “Water Governance
Crisis”
This is becoming increasingly evident with the passage of time.
Today, the issue is no longer simply:
China builds dams in the Upper
Basin;
Laos builds dams in the Lower
Basin; and
Cambodia excavates the Funan
Techo Canal.
The deeper issue is this:
There is currently no sufficiently strong basin-wide governance
mechanism capable of requiring all countries to share data, conduct meaningful
consultation, and assess transboundary impacts.
Even in the case of Funan Techo, the Mekong River
Commission (MRC) has indicated that it has so far received only basic
information and continues to seek comprehensive feasibility studies and
technical documentation from Cambodia in order to assess the project’s impacts
on the basin as a whole.
This is precisely the “governance impasse” that many
experts are now emphasizing.
I have long hoped to write a third book, tentatively titled:
Mekong After the Dams: The Era of Water-Regulation
Infrastructure
It would complete a three-volume Mekong trilogy.
The new book would examine four emerging variables:
The Funan Techo Canal as an
additional water-regulation infrastructure project, rather than merely a
transportation route;
Climate change, with increasingly
frequent droughts and climate extremes;
Delta subsidence, now regarded as one
of the most urgent threats facing the Mekong Delta; and
Basin governance, emphasizing that
the Mekong crisis today is no longer a story of individual dams or individual
canals, but of an entire system suffering from inadequate coordination.
A Shift in the Way We Study the Mekong
A fundamental shift in Mekong research is needed across three
stages of development over the past three decades:
Stage I: 1995–2005
The focus was primarily on Chinese hydropower dams in the
Upper Mekong Basin.
Stage II: 2005–2015
The focus expanded to include mainstream dams and major
tributary projects in Laos and Cambodia.
Stage III: 2015–2026
The entire basin increasingly needs to be understood as
an interconnected system, in which hydropower dams, climate change,
groundwater extraction, land subsidence, sand mining, and now the Funan
Techo Canal interact and reinforce one another.
This is the approach most appropriate for the years ahead.
What to Watch Between 2024 and 2030
Having followed the development of the Funan Techo project
since 2024, I believe that from now through 2030, a number of
critical milestones and turning points will deserve close observation:
Will actual construction progress
keep pace with the announced schedule?
Will Cambodia release comprehensive
hydrological data and operational information?
How will the assessments of the
Mekong River Commission (MRC), the international scientific community, and the
Vietnamese government evolve?
And, most importantly, will the
impacts actually measured in the Tonle Sap region and the Mekong Delta
correspond to the projections currently being made?
These questions will determine whether Funan Techo ultimately
remains primarily a transportation project, or becomes something much
larger: a new water-regulation system embedded within the already stressed
hydrological architecture of the Lower Mekong Basin.
This Is the
Most Appropriate Approach for the Years Ahead
Given the continuous monitoring of the Funan Techo Canal Project
from 2024 to the present, and certainly from now until 2030, there will be many
important milestones and turning points:
Whether the actual construction
progress can keep pace with the announced schedule;
Whether Cambodia will fully disclose
hydrological data and operational procedures;
How the assessments by the Mekong
River Commission (MRC), the international scientific community, and the
Vietnamese government will evolve;
And most importantly, whether the
measurable impacts observed in Tonlé Sap Lake and the Mekong Delta will
correspond with current predictions.
Tonlé Sap Lake
in the Context of Hydrological Decline
A Lake That Has Continuously
Deteriorated
The question is: By the 2026 Wet Season, where has the
Mekong River water gone?
According to the Mekong Dam Monitor (7–20 July 2026), the
annual flood season arrived more than six weeks late. The Tonlé Sap River,
which normally experiences a powerful seasonal reversal of flow into Tonlé Sap
Lake, showed an unusually weakened reversal this year.
The abnormal behavior of the Mekong Basin during this year's wet
season resulted in only approximately 4.03 billion cubic meters (m³) of
reverse-flow water, far below the historical average of more than 11
billion cubic meters (m³).
The extraordinary phenomenon of the Tonlé Sap River’s annual
reverse flow during the Wet Season is a life-sustaining mechanism
that nourishes Tonlé Sap Lake, the world’s largest freshwater fishery lake.
However, upstream hydropower dams, particularly those in China, have been
storing enormous volumes of water in their reservoirs, weakening the natural
flow regime of the Mekong River. During only the past week, major Chinese
reservoirs retained approximately 2 billion m³ of water.
Monitoring of seasonal flooding shows that the flooded area
decreased from approximately 7,400 km² at the end of June to only 6,000
km² in early July, contrary to the normal pattern, when the flooded area
should expand rapidly during this period.
During the first week of July 2026, the total amount of
water retained by major dams throughout the entire Mekong Basin reached 2.44
billion m³. Among them, the Xiaowan and Nuozhadu dams in China, and the
Sirindhorn Dam in Thailand, had the greatest impacts. Water levels
along the Mekong River on the Thailand–Laos border remained approximately 2
meters below normal levels.
Unanswered
Questions and Directions for Future Research
After seven articles forming a kind of “chronicle of the
Funan Techo Canal Project,” this eighth article continues by raising
several unanswered questions:
When will Cambodia fully release the Feasibility
Study?
When will Cambodia publicly disclose
the complete hydraulic modeling data and operational procedures?
When will the Mekong River
Commission (MRC) conduct a comprehensive assessment of transboundary
impacts?
What monitoring systems will be used
to track changes in the ecological “heart” of Tonlé Sap Lake and the Mekong
Delta?
These are the questions that this eighth article continues to
raise, opening an urgently needed direction for future research.
We need to continue monitoring and updating the latest Mekong
research through:
Synthesizing the newest scientific
studies;
Comparing data from year to year;
Analyzing maps, satellite imagery,
and hydrological records;
Constructing a comprehensive timeline
of the entire Mekong Basin from the 1950s to the present.
The Mekong, a river that has sustained more than 70 million
people throughout its basin, has always faced challenges and
transformations of historic significance. Let us protect environmental
justice for them.
NGÔ THẾ VINH
05 August 2024 – 05 August 2026
Related Articles:
1/ From the Khmer Funan Empire to the Historic Funan
Techo Canal of the Kingdom of Cambodia.
Ngo The Vinh
Vietnam Ecology Press
2/ Funan: The Historic Canal and the Project's
Implementation Steps under the Father-and-Son Dynasties.
Ngo The Vinh
Vietnam Ecology Press
3/ RFA Interview with Dr. Ngo The Vinh on the Funan
Canal and the Mekong Delta.
Vietnam Ecology Press
4/ The Funan Techo Canal Project: Vietnam–Cambodia
Responses, A Case of “Different Beds, Same Dream.”
Ngo The Vinh
Vietnam Ecology Press
5/ For Whom the Bell Tolls: August 5, 2024 — The
Groundbreaking Ceremony of the Funan Techo Canal.
Ngo The Vinh
Vietnam Ecology Press
6/ The Funan Techo Canal after the Earthquake of
05.08.2024: An Ending to a Beginning, Yet Still Time to Seek Justice for the 20
Million Residents of the Mekong Delta.
Ngo The Vinh
Vietnam Ecology Press
7/ An Update on the Progress of the Funan Techo Canal
Project from May 2023 to December 2025.
Dr. Ngô Thế Vinh, author of two books on environmental issues, Cửu Long Cạn Dòng, Biển Đông Dậy Sóng [2000] and Mekong Dòng Sông Nghẽn Mạch [2007], as well as numerous analytical essays on environmental and development issues throughout the Mekong River Basin and the Mekong Delta. This is his eighth article concerning the Funan Techo Canal Project, offering a new perspective that shifts the analytical framework from “a single engineering project” to “an integrated hydrological system” affecting the entire basin. This perspective will also form the central theme of his forthcoming book on what may become the Mekong River Basin's greatest crisis: “Water Governance.” [Author's photograph taken while crossing the Tonle Sap, December 2001].