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dam-l LS: Four Mekong-related submissions to WCD
DONG NAI No. 3 and DONG NAI No. 4 COMBINED HYDROPOWER PROJECT
Submitted by WWF Vietnam
Country: Vietnam, Lam Dong Province
Background: This scheme is under development and is part of the wider
Master Plan on Dong Nai River and Surrounding Basins Water Resources
Development. The Master Plan has several goals; formal irrigation
development, hydro-power development, flash flood mitigation and countering
salt-water intrusion from the sea. Dong Nai No. 3 and No. 4 dams will be
located in the middle reaches of the Dong Nai River. Both dams will have
power generating capacity. The large reservoir of Dong Nai No. 3 will
supply water to the smaller reservoir of Dong Nai No. 4 in order to be able
to fine-tune peak electricity demands.
Dam Site: The Master Plan foresees in rockfill dams while the
pre-feasibility study advises on concrete gravity dams (rolled compacted
concrete, RCC). Some features of the proposed dams are given below:
Attributes of the dams and reservoirs Unit Dong Nai No. 3 Dong Nai No. 4
Catchment Area km2 3,578 3,861
Mean Natural Discharge m3/sec 106 116
Probable Max. Flow m3/sec 9,400 9,550
Dam Height m 116.4 90.5
Dam Volume 106m3 1,754 118
Effective Storage Volume 106m3 1,186 30
Reservoir Area km2 53.5 4.2
Maximum Power Discharge m3/sec 224 240
Installed Capacity MW 250 286
Average Annual Energy GWh/year 735 903
Main Donors: Master Plan and Pre-Feasibility Study have been carried out by
Nippon Koei Co. Ltd, financed by the Japanese International Cooperation
Agency (JICA). The Japanese Government is the prospective donor to
implement this project.
Estimated Cost (US$): Unknown
Year Built: Feasibility Studies are underway as of date (mid 1999).
Responsible Authorities: The bulk of the financial support for this project
is foreseen to be the Government of Japan. The dams will be operated by the
Vietnam Government’s Electricity Corporation.
Main Purpose(s): The purpose of both dams is to generate power for
Vietnam’s rapidly growing electricity demands. The specific purpose of
Dong Nai No. 4 is to fine-tune peak electricity demands.
Environmental Impact Assessment Carried Out: An overall EIA has been
carried out by Nippon Koei Co. Ltd., one of the prospective engineering
companies to construct the dams. Two longer term studies have been
commissioned by JICA. One is to study the hydrology of a wetland complex
with the down-stream Cat Tien National Park which partly depends on peak
discharges in the Dong Nai River to feed water into its wetland. This study
is being carried out by Cat Tien National Park under technical supervision
of Nippon Koei. A second study is investigating in more detail the
ecosystems at the dam and reservoir sites and further downstream effects.
This study is being carried out the Power Engineering Consulting Company
which is a subsidiary of the Vietnam’s Government Electricity Corporation
(the future client of the project). This company sub-contracted the
Institute of Tropical Biology in Ho Chi Minh City to execute the study at
the value of USD 44,000.
Mitigating Measures Taken / Proposed: JICA suggests to shift the location
of Dong Nai No. 3 dam a bit further upstream in order to avoid the
inundation of a suspected land-slide area. More detailed mitigating
measures could be suggested as a result of the findings of the currently
on-going environmental impact assessments.
Biological Impacts: The proposed site of Dong Nai No. 3 dam & reservoir
consists of denuded Dipterocarpaceae forest. Large parts of the area have
been developed into coffee plantations. An estimated 5,000 people live in
this area who will have to be re-settled. The proposed site of Dong Nai No.
4 dam & reservoir consists of a deep gorge vegetated with undisturbed
primary Dipetrocarpeae spp and Lagerstroemia spp rain forest combined with
bamboo stands. Whilst this forest type is rare in Vietnam, the area may
well host species such as Tiger Panthera tigris, Clouded Leopard Neofelis
nebulosa, Javan Rhino Rhinoceros sondaicus annamiticus, Otters and
Orange-necked Patridge Arborophila davidi (these species, of which some are
endemic, are known to survive in the nearby Cat Tien National Park). This
valuable forest will be inundated by the Dong Nai No. 4 reservoir. Possible
ecological effects could be felt further downstream in Cat Tien National
Park. This national park has a wetland which water supply is derived
partially by an inundating flow of Dong Nai River when it is in spate. The
hydrology of this system is not understood yet but there is a realistic
possibility that the Dong Nai No. 3 & 4 scheme will diminish the peak
discharge of Dong Nai River and thus may result in less flooding of the Cat
Tien National Park wetlands. These wetlands are not only important for its
fish and waterfowl populations (amongst which White-winged Wood-duck
Cairina scutulata) but also act as grazing ground for large herbivores such
as Gaur Bos gaurus and Asian Elephants Elephas maximus. Furthermore,
constructing Dong Nai No. 3 & 4 will result in a much improved
accessibility of the area. Its nearest point to Cat Tien National Park is
estimated to be 25 30 km. This area is known to have the last remaining
population of Javan Rhino on mainland Asia. Improved accessibility will
result in increased pressure on the Park’s resources and will complicate an
effective protection of the Park.
WWF In-Country Involvement: WWF executes a large project in Cat Tien
National Park and its bufferzones. Staff of this project is following
developments of the Dong Nai No. 3 & 4 project.
Conservation Activities Underway: Cat Tien National Park is currently
seeking to nominate its wetlands as internationally important under the
Ramsar Convention.
References:
JICA & Socialist Republic of Vietnam (1996): The Master Plan Study on Dong
Nai River and Surrounding Basins Water Resources Development
Polet, G. and Tran Van Mui (1999): Notes on the Wetlands of Cat Tien
National Park, Vietnam in Vida Silvestre Neotropical Vol. 7 No. 1
Contributor: Gert Polet; Chief Technical Advisor WWF - Cat Tien National
Park Conservation Project (wwfhcmc@fmail.vnn.vn).
_______________________________
Proposed Prek Thnot Hydropower Project, Cambodia
Submitted by NGO Forum on Cambodia
1. Background Information
The proposed Prek Thnot dam project is located on the Prek Thnot River in
Kompong Speu, about 70 kilometers west of Phnom Penh. The construction of
the Prek Thnot project began in 1969, but was suspended due to
deteriorating security in 1973. The priority of the dam was for flood
control, irrigation and electricity.
The project would have a generating capacity of 18 MW of electricity, and
was originally designed to irrigate 70,000 hectares of land in three
provinces; Kompong Speu, Kandal and Takeo. However, the study in 1991
estimates that the project would irrigate from 27,500 to 34,000 hectares of
suitable land. The Prek Thnot dam links a series of small mountainous areas
with earth and rockfill dams to a length of over 10 kilometers and maximum
height of 28.3 meters. The dam would flood an area of 256 square kilometers
or 25,600 hectares.
Within the proposed reservoir area, 1994 study estimates there are about 43
villages (33 villages in Phnom Srouch district, 9 villages in Oral district
and 1 village in Samrong Tong district), 43 public offices, 15 schools and
11 temples. The reservoir will submerge around 22,000 hectares including
10,566 hectares of private lands1.
The study of Oxfam Land Study Project estimates that 15,200 people or 2,967
families will be affected by the dam. The estimation of the Nippon Koei
study in 1994 of 17,600 affected people or 3,491 affected families may be
an overestimation. However, the population continues to increase due to a
high birth rate and in-migration.
The total cost of the project was estimated in 1991 to be US$ 188-212
million: US$ 114.3 million for the dam and power facility; either US$ 97.7
million or US$ 73.6 million for the irrigation (depending on various
options); and US$ 9.36 million for resettlement. It is anticipated that in
the future costs will be much higher. The study also concluded that the
project as worthwhile with an internal rate of return of 18% and economic
rate of return of 10%, although they were unable to include a detailed
study of environmental and socio-economic effects2.
Three sites, totaling 9,000 hectares, were designated in 1994 as
resettlement areas. Hong Samnam, the most suitable site for resettlement
has a total area of 6,000 hectares and the rest lies in Tang Samrong and
Chambak areas with a total area of 1,500 hectares each.
2. Environmental Impact Assessment
No proper environmental impact assessment of the Prek Thnot dam has ever
been done. In the 1960s, such a thing was not considered necessary. The
1991 report was not able to do a proper EIA study either. The subsequent
1994 Nippon Koei "Environment Study" spent less than one month collecting
data in the field and was not able to add much new knowledge of the
situation, as security constraints were still serious at the time.
3. Social Impact Assessment
There is already a social impact on villages in the reservoir area as many
development agencies do not dare to invest their projects in this area. A
complete social impact assessment has yet to be done as the previous study
was done at a time of insecurity. The conclusions are mainly based on
estimations. In addition, more people have since migrated into this area;
including demobilized soldiers and people from the border of
Cambodia-Thailand and other places. Population growth in this area is very
high. In this case, the impact of the dam on the people and their
livelihoods may be greater than was previously estimated.
4. Stakeholder Participation
There is no open debate about the project. People in the reservoir areas
seem to lack information about the dam. The 1994 study revealed that people
won't mind to move away. The proponents from the government have always
assumed that local people won't object to this dam because such a dam will
increase the development of the country. The proponents are pro-government
and talk about one side of the dam. The local people do not have a chance
to hear the view from other groups like NGOs and the government won't
accept this role. The local people seem to lack the information to make a
decision.
5. Resettlement Site
· Land: Each family will receive less amount of land place in the proposed
resettlement site than in their current location. Moreover, much land in
the reserved resettlement site has already been grabbed by others and some
lands has been granted to private company. Lack of existing land title will
lead to problems in the land reallocation.
· Compensation: The suggested compensation is mainly directed to housing,
land and infrastructure development but does not include the transition
support necessary to maintain the living condition of the local people. The
process of compensation is not clear already and may be complicated when
the project starts.
· Breakdown of village communities: The villagers feel uncertainty about
the guarantee that they will move together to the same place. Villagers
seem to have no idea about where they will be relocated.
· The reserved resettlement site is an upland and shrub land area. Some
areas have been mined, and some areas have security problems such as robbery.
6. The cost and benefit
Since the dam will cost more than $200 million, it is essential that the
real cost and benefit of the project is properly evaluated before the
government borrows money that the next generation will have to pay.
_______________________________________________
Attention to the WCD,
The enclosed abstract-proposal I am submitting for East and South - East
Asia Regional Consultation in Vietnam in February 2000.
I appreciate very much time you spend for the consideration of my
presentation.
Cordially,
Michael Rozengurt.
Controversial influence of impounded large rivers on their
delta-estuary-coastal ecosystems.
ROZENGURT, M.A., Ph.D., P.H., Coastal Consulting, 8888 Lauderdale Ct.,
Unit 216 F, Huntington Beach, CA 92646, U.S.A. Tel.(714)536-4403, E-mail
:mrozengurt@juno.com
Riverine-estuarine- systems are the parts of the coastal seas of oceans
where contact and interaction between environment, plants, and animals
occurs tens to hundreds of times faster than in other areas of the earth.
The influences of these processes on regime characteristics and
biological productivity of coastal ecosystems have been recognized by an
international community of oceanographers both in the Northern and
Southern hemispheres. Historically, the fresh water repels salt water
intrusion, flushes the natural and human introduced pollutants from the
deltas and estuaries and provides a rich supply of inorganic and organic
matter to the coastal embayments. These areas had provided about 80% of
the world fishery composed of species whose life history is directly or
indirectly dependent on a volume of runoff and timing of its discharges
to the adjacent ecosystems.
The abilities of coastal ecosystems to be adjusted to the
temporary impact of natural external regime disturbances are based on
four major fundamental principles: (1) Stochastic and stochastic-periodic
nature of their environment; (2)The ability to maintain the vital ranges
of dynamic, physical, and chemical equilibrium among different parts of
adjacent systems; (3) Ecological continue of the rivers into coastal
seas, and (4) Biological tolerance of living resources to optimal natural
alterations of regime characteristics of ecosystems. The significance of
these principles is governed by river unimpaired runoff.
However, a massive implementation of large dams and water conveyance
facilities have transformed unimpaired runoffs to impaired fluxes that
changed beyond recognition the environment of coastal ecosystems.
Cumulative effects of systematic inland water withdrawals of millions of
acre feet (thousands of cubic kilometers) undocumented in recent history
have resulted in chronic depletion of the spring and annual runoffs
ranging from -35 to -90% of the perennial natural norms computed as
the average more than 55 years as opposed to its natural ±25 to ± 30%.
The excessive reductions of runoffs have been accompanied by the
cumulative losses of millions of tons of oxygen, organic and inorganic
matter and sediment vitally to the survival of coastal ecosystems of the
world ocean. Subsequently, it had taken 10 to 15 years to have the
functioning of major river-coastal ecosystems' continuum impeded. This,
in turn, has led to an anomalous predominance of years of subnormal
wetness or droughts despite would be unimpaired runoff. As a result,
the accumulation of entropy occurred whose visible indicators are:
sluggish water masses' circulation, increased detention time of polluted
waters, insufficient of self-purification of delta-estuary ecosystems
from salt water intrusion, and other natural and man-induced pollutants,
eutrophication, hypoxia and anoxia.
In sums, man's perceived needs have produced the new, artificially
impoverished ecosystems on a global scale, namely: "the impounded
delta-estuary-coastal seas." The scale of this development has
triggered a precipitous decline of commercial and recreational catches'
valuable fish and shellfish.
The major failures to foresee the deprivation of coastal ecosystems can
be partially attributed to (1) statistics of impaired (deterministic)
runoffs have been analyzed by unfortunate use of methods of stochastic
hydrology developed for unimpaired runoff fluctuations; (2) accordingly,
modeling and prediction of impaired water and salt balance of modified
ecosystems and living resource have not been tuned to would be stochastic
probability of occurrence of observed events, and (3) the postulates of
Laws of Thermodynamic have been ignored and scales of ecological
tolerance and limitations of ecosystems to water withdrawals beyond
which entropy tends to reach measurable maximum. This, in turn, has
accelerated the despoliation of coastal seas the world over.
_________________________
Alternate approaches for managing the effects of hydro dams on Mekong River
fisheries resources
by
David A. Levy, Ph.D., Charles D. D. Howard, P.Eng., Christopher Hatfield, M.Sc.
Proposed submission for the World Commission on Dams, East and South-East
Asia Regional Consultation, February 2000
Throughout the 1980’s and until 1997, rapidly increasing power demands in
Thailand and Vietnam prompted consideration of various possible hydro
projects on the Mekong River mainstem and its tributaries. Hydro projects
offer a readily available source of power which can be transferred between
the Mekong riparian countries and produce foreign revenue for economically
disadvantaged countries in the region e.g., Cambodia and Lao PDR. If these
projects are carefully designed and operated they can provide overall net
benefits to the region without incurring unacceptable irreversible damage
to the natural environment of the river or the downstream estuary.
Within the Mekong River mainstem, it was estimated by the Mekong River
Commission that 12 proposed “run-of-the-river” projects would have a total
capacity of 13,000 MW, resulting in the flooding of 1900 km2, and
displacing about 60,000 people. Within particular Mekong River
tributaries, there can be multiple projects that generate cumulative
impacts. One example is in the Sekong River in Lao PDR, where the Huay Ho
project was recently completed in 1999, the Se Pian/Se Nam Noi project is
presently under construction, the Xe Kaman project is in the latter stage
of feasibility studies, and the Sekong 5 project is currently at the
pre-feasibility stage.
Benefits and Costs of Hydro Projects
The essential criterion for a hydro project is to produce net benefit that
exceeds its cost. From the perspective of an electric power utility the
measures of benefit and cost are obvious, mostly immediate, and related
primarily to the project construction and the power generated. From the
perspective of the broader community in the region, and in the country, the
costs and benefits are less obvious, long-term, and diffuse.
For the society affected by the project the costs include lost
opportunities for using the river valley bottom for other purposes, like
farming, mining, forestry, nature preservation, and reduced benefits from
existing resources like the fishery. The costs may also include disruption
to the local communities and the natural environment directly affected by
the flooding and operation of the project.
The water management benefits to society may include improved navigation,
flood damage reduction, irrigation, and sustained minimum flows for water
supply for villages, cities, and for industry along the river downstream.
If the project is part of a broader plan for development, the economic
benefits to society include the infrastructure that is supported by a hydro
project, like roads, communications, and development of industries and
businesses that depend on electricity.
Inter-generational Equity
There is no doubt that hydro projects can be beneficial. The concern is
that they may be more beneficial to some at an unacceptable cost to others.
This is always true in the short term that mostly benefits the developers
from the present value of revenues. But hydro is a renewable resource that
brings benefits to future generations long after the initial shock of
change has passed. A project should not unduly penalize future generations
for the sake of immediate non-renewable gains - there must be
inter-generational equity in the way in which natural resources are exploited.
The challenge for this renewable hydroelectric resource is to manage the
short-term costs and inequities so that in the long-term there is
opportunity for realizing the full suite of benefits to the overall
society. In the developing world the operation of many existing dams is
being reconsidered from this perspective.
It is now accepted that hydro projects must be operated to provide the
maximum benefit to society, not just to the project owners. For continued
operation of existing projects, interveners are given the opportunity to
take over if they can provide greater overall benefits. For new projects,
the developers must show that there are overall net benefits to society,
and reasonable equity in how these benefits are distributed.
Environmental Impact Assessments
Under commonly applied EIA procedures, generating meaningful hydro impact
predictions in the Mekong watershed can be extremely challenging. It is
estimated that there are over 2000 fish species present, some of which have
not yet been taxonomically identified. Life history, distribution,
abundance and population status for most fish species are poorly
understood. There are a large number of endemic species, and over 50 fish
species (some of which are presently declining) exploited in commercial and
artesanal fisheries. Migratory species, e.g. pangasiid catfish, with
seasonal migrations tied to the annual flooding cycle, are extremely
vulnerable to hydro impoundments, which block their migratory routes.
Categories of environmental impact related to Mekong River hydro projects
include the effects of water level fluctuations, the effects of reduced
downstream flows, water quality alterations, and the effects on migratory fish.
In terms of relative complexity, prediction and management of the impacts
from a Mekong River hydro project, is probably an order of magnitude more
difficult than a comparable temperate zone hydro project. Undoubtedly,
environmental and economic decisions regarding Mekong hydro projects will
be based on inadequate fisheries baseline data and inadequate ecological
understanding.
Managing Uncertainties
Unfortunately, methods for determining non-economic benefit depend on
social and natural sciences that are not well established. Predictive
capabilities are not strong in many important areas. There is much to learn
about how to measure adequate flows for fish, effects of reservoirs on the
shoreline and water quality, the response of animal populations, and the
ways in which people will adjust to a new environment. To manage these
uncertainties, hydro projects must be inherently planned for flexibility in
operations as the consequences become apparent and more knowledge is gained.
In the design stage, provision should be made for alternative methods of
water release, at different times of year, to deal effectively with
unanticipated future hydrological, economic, social and natural
circumstances. Monitoring of the physical, biological and socio-economic
systems must be part of the project design. Parameters must be measured and
the results continually analyzed, so that on-going operation of the project
can be guided towards regimes that maximize actual overall benefits.
Alternate Approaches
To realize the maximum benefit from these Mekong River hydro projects it
will be necessary to manage the impacts on Mekong River fisheries
resources. The following considerations are necessary:
1. EIA predictions for Mekong River hydro projects will likely be
incomplete and inaccurate. This technical uncertainty needs to be
explicitly recognized with allowances provided for fish protection by means
of appropriate adaptive management arrangements.
2. Long-term fisheries monitoring programs need to be developed and agreed
to by proponents well in advance of project approval. Fisheries monitoring
should be initiated at least three years prior to construction to permit
the collection of “pre-impact” fisheries data sets. The preferred
monitoring design for Mekong River hydro projects is referred to as MBACI
(Multiple Before-After Control-Impact) and is based on a period of sampling
before and after development, together with multiple control and impact
locations.
3. Long-term fisheries mitigation plans and mitigation works need to be
developed and agreed to by proponents well in advance of project approval.
They need to be incorporated into the project design.
4. Hydro reservoirs provide unique aquaculture and fisheries development
opportunities; for example, Nam Ngum Reservoir in Lao PDR produces annual
fish catches which are valued at approximately $US 1 million per annum.
Prior to Mekong hydro project approval, aquaculture development and
fisheries management plans should be prepared and implemented to offset
negative fisheries impacts and provide additional economic development
opportunities for the local region.
5. Planning processes for Mekong tributaries and main stem reaches need to
be developed and implemented to provide a broad management context for the
evaluation of individual hydro project impacts. The entire watershed needs
to be classified into a discrete number of smaller management and planning
units.
6. There are many examples of dams that benefit fisheries and other natural
resources. The challenge is to anticipate the uncertainties in predicting
these benefits and to plan projects that are robust, and able to respond
effectively when new knowledge is gained.
7. Project planning must include more than construction and operation of
the project. It must include ongoing monitoring and measurement of all of
the benefits and costs so that opportunities for positive operational
change can be realized.
8. Mekong River riparian countries need to demonstrate commitment to
sustainable development by means of appropriate legislation, effective
enforcement, and viable fisheries and environmental management arrangements.
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Aviva Imhof
South-East Asia Campaigner
International Rivers Network
1847 Berkeley Way, Berkeley CA 94703 USA
Tel: + 1 510 848 1155 (ext. 312), Fax: + 1 510 848 1008
Email: aviva@irn.org, Web: http://www.irn.org
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