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THE POLITICS OF THE SE SAN 3 STUDIES
by Mak Sithirith
For the Mekong Symposium in Tokyo, 11-12 September, 2000

1) Introduction

    The Se San River that flows through Vietnam's Central highlands, then into Cambodia's Ratanakiri and Stung Treng provinces, is an important Mekong tributary and a habitat for migrating fish that enter the Se San system for feeding and spawning. Together, the Se San, the Sre Pok, the largest tributaries of the Se San, and the Se Kong River contribute 16.7 percent of the flow at the downstream town of Kratie[1]. The Se San Basin has a drainage area of 17,100 km2, including 11,000 km2 in Vietnam and 6,100 km2 in Cambodia[2].

    In Ratanakiri, the Se San is a large lowland river with deep-water areas and pockets of seasonally inundated forests. Most of the 18,000 people living along the river in Cambodia eat fish they catch for home consumption and many people also catch fish to sell [3]. In Vietnam, the river flows through mountains that are home to mostly Jarai and Bahnar people and the site of some of the largest intact areas of forest in Vietnam [4].

    Since the 1950s, this river has been a key target for hydropower development. The Asian Development Bank (ADB) is now the primary institution promoting hydropower development in the region. The Bank recently noted that the Se San River is recognized as one of the top three rivers in Vietnam in terms of hydropower potential5.. In 1993, the construction of Yali Falls dam in Vietnam began on the Se San, about 70 km from the Cambodian border, with a reservoir of 64.5 km2.. This dam is the second largest dam in Vietnam and the first large dam in Se San. It will generate electricity of 720 MW with a total cost of US$ 1 billion [6].

    At least 32 people in Ratanakiri have been drowned by the surges and rainy season flooding since the hydrological problems in the Se San first begun. Unusual and dramatic fluctuations in river levels along the Se San River have caused major downstream environmental and socio-economic impacts. These impacts have been especially serious for many indigenous people living along the Se San River in Ratanakiri. The water quality has been seriously deteriorated and affected people’s health. The downstream agricultural lands has flooded and both fisheries and forestry [7].

2) The Politics of the Studies of the Se San 3 Hydropower Project

The ADB and other dam promoters have undertaken a series of studies to canvass the possibilities for dam building in the Mekong at the same time that several other master plans and studies are underway. In some cases, the same dams or river basins have been studied more than ten times and yet there is still insufficient information available to determine environmental impacts. In addition, local communities in areas where dams are being studied usually have no information about the proposed project. The final outcome of these multiple plans and studies is not certain [8].

Studies on hydropower development on the Se San has been carried out since 1960. Nippon Koei carried out a development plan study of the Upper Se San river during the first half of the 1960’s. The study indicated an inventory in the long run including power development in total at six power sites. Later, the Power Investigation and Design Company (PIDC) of the Ministry of Energy of Vietnam updated the hydropower development plans for the upper Se San in Vietnam, including Se San 3 [9].

From 1997 to 1999, the ADB funded the Se Kong-Se San-Nam Theun River Basins’ Hydropower Study. The ADB's Se Kong-Se San-Nan Teun (SKSSNT) study was to identify at least six projects suitable for implementation within the basin and was completed in two phases [10].. After the initial ranking, the six selected for further study included the Se San 3. However, after further study in Phase 2, the Se San 3 was excluded from the top six priority project [11].

At the same time as the ADB study, the Review of the Master Plan for the Se San River by SWECO proposed to build the Se San 3 only after completing the Se San 4 and the Yali Falls dams. In February 1999, SWECO completed a feasibility study on the proposed Se San 3 hydropower project [12].

The Se San 3 was not one of the six priority's projects according to the ADB’s SKSSNT Study and was not the first priority in SWECO study. But in July 1999, the ADB commissioned a Project Preparatory Technical Assistance to prepare Se San 3 for construction by the end of 2000. This is despite the fact that the project appeared in the development plan of the ADB's SKSSNT Study phase one for 2006 and was proposed after the Se San 4 in SWECO Review of (Vietnam) Masterplan [13].

Despite these actions, the funding for Se San 3 was unclear. The ADB had agreed to provide Vietnam with US$ 80 million to fund only part of the construction cost for the Se San 3. The ADB had intended to develop the Se San 3 projects as a partnership between the State and the private sector while there is no single investor interested [16].

The Se San 3 is in environment category A [17] and the existing study of environment impact assessment is inadequate. Nevertheless, the ADB proceeded with plans to finance the Se San 3 dam regardless of the environmental and social impacts [18]..

Following the disastrous downstream impacts of Yali Falls reported in March 2000 and the widespread concerns expressed about the Se San 3 project, the Bank now has developed a new study plan for Se San 3. This study is to complete the required environmental, social and technical analyses of upstream and downstream impacts of hydropower development in the Se San River basin both in Vietnam and Cambodia [14].

Each of these studies relies on the previous studies. Experiences show that despite spending millions of dollars over the past 40 years studying the possible building of dams on the rivers of the Mekong Region, the dam builders and their consultants know very little about the region, its ecosystems and its people. For instance, the Norconsult'1994 study stated that the lower Se San area is unihabitated. In fact, Stung Treng and Ratanakiri provinces are home to 120, 000 people [15].

The Yali Falls dam and the Se San 3 dam cases indicate that the study is conducted neither for mitigating the impact nor looking for alternatives other than dams but for forwarding the project to the implementation. The statements of the bank up to date indicates they have already concluded that the Se San 3 dam must be built and now they have developed a new study to prove this conclusion [19].

The ADB was the major donor in the studies on the Se Kong-Se San-Nam Theun River Basin, followed by SIDA, NORAD and swiss aid agencies. Other than protests of environmentalists and local communities advocates, there is no reason for the Bank to cancel the Se San 3. The Se San 3 is one of the top three rivers in Vietnam for hydropower development that could generate hard currency and it will facilitate economic cooperation among the countries of the subregion through cross border trade in electricity [20].. The ADB staff maintain that the hydropower projects can enhance sustainability as they use a renewable resource to generate energy while giving rise to no regional or global pollution effects [21].

3) The Changes of Purpose of the Se San 3 After Impacts of Yali Falls

The impacts of Yali Falls dam on downstream Se San in Cambodia have received great attention from outside Cambodia. The damages and suffering which occurred on downstream Se San in Cambodia recently have posed a major question to ADB who intended to fund the proposed Se Se 3, 20 km downstream of Yali.

Follwoing pressure from international donors, ADB start to promote the Se San 3 as a model hydropower project, taking into full consideration environmental and social issues [22].. In addition, ADB staff said the ADB was considering the construction of the Se San dams as a means to mitigate the downstream impacts of the Yali Falls dam [23].. It is still unclear what they mean by a model project or why they started calling it as such just recently. Nor is it clear why Se San 3 was dropped out of the top six priority projects of the SKSSNT Study if it was a model project.

The decree to which the Se San 3 could be a model project and mitigate the impact of the Yali Falls is questionable, since the EIA study shows that it will create additional impacts for downstream as well. It is clear according to Brett Lane, a biodiversity consultant involved with preparing the ADB funded EIA and EMP for the Se San 3 dam that it has the potential to significantly affect the downstream riparian and in-stream environment in the Se San River, as far down as the Mekong. Although effects may diminish further downstream, they may still be significant enough to alter the hydrological regime of the flood plain wetland. The two dams between them will remove most of the sediment from the water. This may have consequences for the stability of the natural floodplain levees in the lower Se San River if it erodes faster than it builds up (particularly if flood peaks are lower and deposition on the levees is slowed or eliminated). This could result in the permanent or seasonally premature draining of floodplain wetlands. Alternatively, if the river level sits slightly higher than the floodplain, then the dissipation of flows across the floodplain in the upstream part of the plain may reduce delivery of water to wetlands further downstream (quite apart from the peaks due to regulation)[24].

It is not possible for the ADB to argue that the Se San 3 dam will mitigate the impact of Yali Falls, considering that the SKSSNT Study completely ignored any existing or potential impacts of the Yali Falls dam. Se San 3 dam would be owned either by Electricity of Vietnam or a private company or a combination of the two. Whoever owns it will be primarily motivated by profit and so are very unlikely to use the dam for any purpose other than electricity generation. The two functions (re-regulation and electricity generation) are not complementary but opposing. In other words, if the dam is used primarily to generate electricity it will cause the same problems with irregular flooding as Yali Falls. If it is used to re-regulate water flow, it will not be able to produce the required amount of electricity.

The Feasibility Study of the proposed Se San 3 dam indicates that the outflow from the Se San 3 turbines would occur over a shorter time period with a higher flow per second than that of Yali Falls. As the design discharge of 485 cubic meter/s at the Se San 3 hydropower project is somewhat higher than the corresponding design discharge of 420 cubic meter/s of Yali Falls, the intended daily operating hours of Se San 3 hydropower project will probably, on the average, be somewhat shorter than that of Yali. This would make the sudden flood downstream of Se San worse that the floods from Yali Falls, not better. One may thus argue that the Se San 3 will not mitigate the environmental impacts, but only extend the prevailing impact further downstream [25].

As already mentioned, the ADB started to consider the Se San 3 after the downstream impacts of Yali Falls began to be reported in March this year. In July, at a conference at the University of Sydney, which received considerable international attention, the ADB was urged to defer a decision about Se San 3 until more details studies on likely impacts have been completed[26]. In response, the ADB’s Se San 3 project loan has been deferred. The priority now is to investigate environmental, social upstream and downstream impacts of hydropower development[27]. The study will likely lead the Bank to redesign the Se San 3 to serve a regulation function for Yali as well as produce energy28.

4) Lack of Participation and Consultation

Although numbers of studies were conducted on the Se San River, very little mention the potential downstream impacts in Cambodia, especially cumulative impacts of these existing dam projects on communities and their environment. The downstream impacts on the Mekong River, and the Tonle San were ignored. None of these studies have been explained to people downstream in Cambodia and none of these studies by dam proponents, consultants, or funders indicate the involvement and participation of the communities living in the river basins29.

The EIA of Yali Falls studied by Electrowatt failed to discuss the downstream impacts of the dam in any detail at all. The study covered an area of 8 km long and 1 km wide below the dam30. Both villagers and local government officials living in Ratanakiri Province know little about the Yali Falls dam, and even less about other dams proposed for the Se San Basin[31]. Regarding the SKSSNT study, Mr. Khy Taing Lim, the Head of Cambodian National Mekong Committee, said in an interview with Watershed in October 1998 that he had not seen this study[32]. If he did not know, how could people in Ratanakiri and Stung Trehng possibly know about this?

The Halcrow's SKSSNT study was a non-participatory study added to a mountain of studies written over the past 40 years. These studies were conducted by consultants who normally sit at their desks in offices in Bangkok, Amsterdam, Oslo and London and far from the local communities living in these river basins[33].

5) The Views of People in the Lower Se San in Cambodia

The problems of Yali Falls have not been resolved and the affected communities remained uncompensated. The transboundary solutions to these problems have been very weak. There is no specific guarantee to ensure people’s safety in the future.

The Government of Vietnam and those international organizations, foreign governments and companies who have supported the building of Yali Falls dam should take responsibility for the losses that local people have already experienced, including the loss of life and the loss of livelihoods. Local people living along the Se San River are not in favor of regulating the Se San River so that dry season river flow are higher than natural flows and rainy season flows are reduced from natural flows.

Village people living along the Se San River in Ratankairi province are adamant that they do not want the proposed Se San 3 dam to be built 20 km downstream from the Yali Falls in Vietnam. They are also adamant that the ADB and oterh foreign agencies should withdraw all supports for the Se San 3 dam and other dams planned in the Se San River Basin in Vietnam.

Village people living along the Se San River would like to see the Yali Falls dam decommisioned and the Se San River returned to its natural state. However, if this is not immediately possible, measures need to be adopted to mitigate the downstream impacts in Cambodia, including releasing water from the dam in a way that replicates natural flows[34].

6) Conclusion

There have been many studies of the proposed hydropower dams on the Se San, Se Kong and Nam Theun basin. These studies typically have not been released in Cambodia and none have involved communities in these studies. The knowledge of the dam proponents about the region is inadequate.

The new study of the Se San 3 will most likely lead to redesign and construction of the Se San 3 with the ADB as funder. The ADB are not likely to give up the Se San 3 project as, so far, they have put a large amount of money, time and effort into preparing it. The Se San River is a potential area for hydropower development and the incident of protest against the dam is still very low.

However, the above-mentioned experiences show that, despite the appearance of technical objectivity which technical studies provide, the final conclusion is likely to be a political decision made in response to public reaction. The protection of local community rights along the Se San river will depend in large part on the vigilance of civil society organization in promoting their cause.


1 TERRA Briefing, 1999. Damming the Se San, 17 November 1999, Bangkok, Thailand. pp. 1. 
2 ADB. 1995. Subregional Infrastructure Project in Indochina and the Great Mekong Areas: A Compendium of Project Profiles. Prepared for the Forum for Comprehensive Development of Indochina, Tokyo, Japan. 26-27 February 1995, Manila. 
3 Baird, I. 1995. A Rapid Study of Fish and Fisheries and Livelihoods and Natural Resources along the Se San River, Oxfam.
4 Lang, C.1998. Vietnam: The Yali Falls Dam Project on the Social and Environmental Context, 1994 Master Plan. 
5 TERRA Briefing, 1999. op. cit. 
6 TERRA, 1996. The Yali Falls dam Project, Watershed, Vol. 1, No. 2, November 1995-Febraury 1999, Bangkok, Thailand. 
7 Provincial Fishery Office of Ratanakiri and NTFP, 2000. The Report of Study of the Downstream Impacts of the Yali Falls Dams in the Se San River Basin in Ratanakiri Province. 
8 TERRA Briefing Paper, The Se Kong-Se Sa-Nam Theun Bassins Hydropower Study. 1999. 
9 Investigation and Design Company No.1 and Nippon Koei, Yali Hydropower Project Feasibility Study, Main Report, March 1990, Tokyo, Japan.
10 TERRA, Briefing Paper, The Se Kong-Se Sa-Nam Theun Bassins Hydropower Study.
11 TERRA Briefing, 1999. op.cit.
12 Ibid.
13 Ibid. 
16 Vietnam News Agency; ADB's Cooperation with Vietnam and MRC, Hanoi, 10 March 2000.
17 Se San 3, 2000. Project Profile, ADB Website.
18 TERRA, 2000. ADB to fund Se San 3 dam in Vietnam. op.cit.
14 ADB, Se San 3 Hydropower in Vietnam, 31 July 2000, Manila, The Philippine
15 TERRA, Se Kong-Se San and Nam Theun: Too Many Studies, Watershed, Vol. 3, No. 2, November 1997-February 1998, Bangkok, Thailand. 
19 TERRA, 2000. Information through E-mail. 
20 TERRA. 1996. Asian Development: Money and Power in the Mekong Region, Bangkok, Thailand.
21 McCully, P. 1997. Asian Development Bank Studies More Mekong Dams, World Rivers Review, International River Network, Berkeley. California. 
22 ADB. Media Briefing Paper No.5, Se San 3 Hydropower Project-Vietnam, May, 2000, Manila, Philippine.
23 TERRA. 2000. Information through E-mail from TERRA.
24 Brett Lane, Biodiversity Consultant, Se San 3 Hydropower Project, February 27, 2000. 
25 TERRA, 2000. Relevant quotes from the Feasibility Study on the Se San Hydropower Project Volume VI: Annex to Environmental Impacts Study, SWECO, Feb 99. 
26 Environment News Service, Mekong Basin Dams Claim Lives, Cause Poverty, June 27, 2000, Sydney, Australia.
27 ADB. Statement about the defer of Se San 3 Project, Manila, July 30, 2000.
28 TERRA. 2000. Information through E-mail from TERRA. 
29 TERRA, Se Kong-Se San and Nam Theun: Too Many Studies, Watershed, Vol. 3, No. 2, November 1997-February 1998, Bangkok, Thailand. 
30 TERRA Briefing, Daming the Mekong, 17 November 2000
31 Koma and Phalla, 2000. Incidents at the e San River.
32 TERRA, Se Kong-Se San and Nam Theun: Too Many Studies, op.cit.
33 TERRA, Se Kong-Se San and Nam Theun: Too Many Studies, op.cit. 
34 TERRA, Watershed, Maginalizing the Local, Vol 6. No. 1, July-October 2000.

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