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1 

 

 

 

Review 

A comprehensive review of the environmental 

impacts of hydropower projects in Sarawak, 

Malaysia 
Xavier O’neal Durin1, Brendon Moi Xuen Ming1, Prashanth Prashobh Karunakaran1, Lucas 

Leong Wun Sin1, Hadi Nabipour Afrouzi1*, Kamyar Mehranzamir2 

1Faculty of Engineering, Computing, and Science, Swinburne University of Technology Sarawak, 93350 Kuching, Malaysia 
2Department of Electrical and Electronic Engineering, Faculty of Science and Engineering, University of Nottingham   

Malaysia, Jalan Broga, 43500 Semenyih, Selangor, Malaysia  

A R T I C L E   I N F O 
 

Article history: 
Received 06 April 2022  
Received in revised form 
10 May 2022 
Accepted  18 May 2022 
 
Keywords: 
Environmental, Social, Impact,  
Greenhouse gases, Hydropower,  
Sarawak 
 
*Corresponding author 
Email address:  
Hafrouzi@swinburne.edu.my 
 
 
DOI: 10.55670/fpll.fuen.1.3.1 

A B S T R A C T 
 

Sarawak is a state in Malaysia that has many potential sites for hydropower 
dams as Sarawak houses many hilly areas which are yet to be developed. As a 
result, many hydropower dams were proposed in Sarawak. This paper reviews 
the environmental and social impacts of hydropower projects in Sarawak. The 
murky river waters of Sarawak contributed to a high level of sedimentation in 
the hydroelectric plant reservoirs which increases the emission of greenhouse 
gases through mineralization and indirectly affects the lifespan of a 
hydroelectric plant. The ecosystem is adversely affected by the loss of trees, 
destruction of habitat for flora and fauna, and the narrowing of rivers due to 
sedimentation. The construction of hydropower plants forces nearby 
indigenous communities to relocate, which are given compensation by the 
Sarawak government. The issues behind the relocation process are explored in 
this paper with further details. The communities that are affected by the 
construction of the hydropower dams will have to be displaced from their 
original lands; thus, the approach by the government to compensate the 
affected locals in Sarawak is explored in this paper. 

 

 
1. Introduction  

Hydropower is widely utilized all over the world as it 
provides multiple benefits to various countries. For 
example, Nigeria utilizes hydropower as a decentralized 
power source to solve the country’s limited power supply 
[1]. On the other hand, China has built more than 47000 
dams all over the country [2, 3], including the biggest dam in 
the world namely the Three Gorges Dam which can produce 
up to 84.7 billion kilowatt-hours per year of electricity, 
equivalent to the amount of energy that could be produced 
by burning 50 million tons of coal [4]. Another country that 
also utilizes hydropower would be Malaysia. Malaysia has 
multiple dams throughout the nation, with Sarawak 
generating most of the hydropower energy [5, 6]. Sarawak is 
a state in Malaysia situated on the island of Borneo that is 
blessed with a vast number of rainforests. The Bornean 
rainforests hold biodiversity of flora and fauna, boasting an 
estimated 4% of the world’s plant species and 5% of the 
world’s birds and mammals, consisting of 222 species of 
mammals, 420 species of birds, 3000 tree species, and 

15000 flowering plant species [7].  Over the past few 
decades, there has been a surge in the development of lands 
in Sarawak, which is the largest state in Malaysia out of the 
thirteen [8]. This has led to an increase in power demand in 
Sarawak. Initially, fossil fuels such as diesel, coal, and natural 
gas were used for the power plants in Sarawak, meeting the 
power demand of 1250 MW based on the year 2015 [9]. 
However, due to diesel, coal, and natural gas being non-
renewable resources, sustainable approaches to generating 
renewable energy were introduced. One of them is 
hydropower generation. It is estimated that 12 hydroelectric 
power plants and two coal power plants will be built in 
Sarawak by 2030 with a total capacity of 9380 MW to cater 
to the increasing power demand in the future [9]. Although 
hydropower generation is praised for being a sustainable 
renewable source of electricity generation in Sarawak, the 
construction of HEPs will inevitably affect the environment 
in terms of environmental degradation and water quality 
deterioration [10-19]. 

 

 

 

Future Energy 

Open Access Journal 

https://doi.org/10.55670/fpll.fuen.1.3.1 

 

 

 

 

 

 

November 2022| Volume 01 | Issue 03 | Pages 01-10 

Journal homepage: https://fupubco.com/fuen 

 
ISSN 2832-0328 

mailto:Hafrouzi@swinburne.edu.my
https://doi.org/10.55670/fpll.fuen.1.3.1
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X.O Durin et al. /Future Energy                                                                                             November 2022| Volume 01 | Issue 03 | Pages 01-10 

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1.1 Power generation in Sarawak 
Sarawak is a powerhouse when it comes it hydropower 

generation in Malaysia. With the geographical advantage of 
Sarawak in favor of hydropower, there are many potential 
sites for hydropower plants, as shown in Figure 1. As of 
2021, there are three major hydropower plants operating in 
Sarawak, which are the Bakun, Murum, and Batang Ai HEP. 
Figure 2 shows the state of the Bakun Dam in 2010. Baleh 
hydropower plant is also another major hydropower plant 
currently under construction which is expected to be 
operational in 2026. Aside from these major hydropower 
plants, Sarawak has coal-fired, gas, and diesel major power 
plants. The summary of which can be found in the table 
below. According to Table 1, the majority of Sarawak’s 
power generation is from the renewable source of energy 
with hydropower as the source of generation, totaling about 
57.1%, excluding ongoing projects, after the commissioning 
of the Tanjung Kidurong Extension project [21]. After the 
completion of Baleh HEP, hydropower will be contributing 
64.6% of the total power generation of major plants. 

Figure 2. Bakun Dam in Sarawak, Malaysia [22] 

 
 
 
 

1.2 Sarawak Corridor of Renewable Energy (SCORE) 
The Malaysian Federal Government created five 

economic development corridors to stimulate global and 
domestic industrial investments, and SCORE is one of them. 
The objectives of SCORE are to secure a total of RM334 
billion of private and public investments by 2030 for the 
development of Sarawak [23]. The corridor spans a length of 
320 km [24]. These industrial zones will then be supplied 
with an inexpensive and renewable source of energy 
harnessed from hydropower plants. Under SCORE projects, 
there are a total of twelve mega-dams proposed in Sarawak 
to sustain the developments under SCORE, two of which are 
already completed with the third one under construction. 
The first dam to emerge from this project, the Bakun dam, 
has an impoundment area of 720 km2, which is roughly 
about the size of Singapore [22]. Followed by Bakun dam is 
Murum dam with a reservoir size of 245km2 and lastly, Baleh 
Dam will have a reservoir size of 588 km2 [25].   

2. Environmental Impacts of Hydropower 

Given that hydroelectric power is a type of renewable 
energy, it releases a very small amount of carbon into the air 
[5]. According to [20], the carbon intensity of the electricity 
supply in Sarawak has decreased by 72% as depicted in 
Figure 3. The water supply can also be used as drinking 
water and irrigation for agricultural usage. Hydropower also 
helps in storing water which protects aquifers from 
depletion. This will reduce the frequency of floods and 
droughts. However, the water supply and irrigation can 
reduce the water available for power generation and 
therefore reduce the power generation output [26]. Being a 
type of renewable energy, hydropower plants do not 
produce any waste, unlike coal or fossil fuel power plants. 
Not to mention that it can prevent excess GHG (greenhouse 
gases) emissions. Thus, air pollution is reduced along with 
the frequency of acid rain and smog occurring in the state.   

Figure 1: Hydropower plants in Sarawak in 2017 [20] 



X.O Durin et al. /Future Energy                                                                                             November 2022| Volume 01 | Issue 03 | Pages 01-10 

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2.1 Sedimentation and GHG emissions 
Most rivers have a balanced inflow and outflow of 

sedimentations which controls the accumulation of 
sediments in the river [27]. When the river is impounded, 
the imbalance will accumulate sediments [28]. 
Sedimentation in the impoundment area of the hydro dams 
contributes to GHG emissions through the mineralization 
process where it decomposes to produce CO2 (carbon 
dioxide) and CH4 (methane). Reservoirs with higher 
sediments raise aquatic weeds such as algae, and other 
plants, which increases the emission of carbon dioxide up to 
0.03 pounds [29]. Additionally, the formation of large dam 
reservoirs increases the emission of greenhouse gases 
through the decaying of biomass from the vegetation in the 
large, flooded areas [26]. Although hydropower is 
considered a clean source of energy since it produces 
significantly fewer emissions compared to coal, hydropower 
has a ‘stored’ potential of GHG emissions that lies dormant 
within the sedimentation in its reservoirs [30].  

Table 1. List of major power plants in Sarawak according 
to Sarawak Energy Berhad [21] 

 
Uncontrolled release of the sediments during the 

decommissioning of hydro dam affects both upstream and 
downstream rivers which may potentially impact the aqua 
life and riffle-pool habitats, deposition downstream, 
destabilization of stream banks, and a large amount of GHG 
emissions [31, 32].  

 
Figure 3. Carbon Intensity for Electricity Supply in 

Sarawak since Major Hydro Development [20] 
 
The study conducted by Pacca analyzed the CO2 

emissions during the decommissioning of Glen Canyon Dam, 
and he found that if all sedimentations are mineralized 
during decommissioning, the CO2 emissions amounted to 
33,000,000 metric tons. To put this into a better perspective, 
the construction of the dam emitted 800,000 metric tons, 
while the emissions associated with biomass decay in the 
reservoir during its operation was 3,500,000 metric tons 
[32]. The estimated yearly CH4 emission of major 
hydropower dams in Malaysia is 387,340,000 kg, with 
Sarawak contributing the majority of it at a total of 60.9% 
from Bakun, Murum, and Batang Ai dams, of which, Bakun 
dam contributed the most at 41.26%, followed by Murum 
dam at 14.54% of the total emission in Malaysia [25]. 

Sedimentation issue is especially serious in Sarawak 
due to the vast rainforest region that is prone to rainfall. The 
study in reference [33] revealed that logging activities 
impacted the water quality of the streams after rainfall in 
terms of the increase of suspended solids from 8.3mg/L to 
104.1mg/L. Upstream logging, unsustainable agricultural 
methods, and erosion contributed to high levels of 
sedimentation, with Bakun dam reservoir recording more 
than 500mg/l of sediments or an annual inflow of 9,000,000 
tons [22,24]. Sedimentation, if not controlled, can indirectly 
affect the lifespan of a hydropower plant by reducing the 
water storage capacity, increasing wear on machinery, and 
negatively impacting downstream rivers as the 
decommissioning of dams are motivated by maintenance 
cost, environmental or regulatory requirements [31, 34]. 
Concrete dams that are built according to standards can 
easily reach a lifespan of 100 years, while the 
hydromechanical components such as the gates and motors 
are up to 30 to 50 years [35].  

2.2 Geological and Ecological Impacts 
The construction of hydropower dams will include 

some degree of deforestation and land loss due to 
submersion. Figure 4 and Figure 5 show the forest 
geography before and after the construction of Bakun and 
Murum Dam. It is evident that a huge amount of 
deforestation took place for the establishment of both dams, 
and a huge amount of land was submerged underwater. This 
will result in the destruction of wildlife and cause some 
wildlife population loss. The construction of the Murum Dam 
had threatened the population of 300 rare and endangered 
species [6]. In 2018 itself, the remaining intact forest was at 
an estimated 7.72 million hectares, which was around 62% 
of Sarawak state, while the 13 hydroelectric dam projects 

Plant Type Power 
Gener
ation 
(MW) 

Status 

Batang Ai 
Hydroelectric 
Plant 

Hydro 
(Concrete Face 
Rockfill Dam) 

108 Commissioned 

Murum 
Hydroelectric 
Plant 

Hydro 
(Concrete Face 
Gravity Dam) 

944 Commissioned 

Bakun 
Hydroelectric 
Plant 

Hydro 
(Concrete Face 
Rockfill Dam) 

2400 Commissioned 

Baleh 
Hydroelectric 
Plant 

Hydro 
(Concrete Face 
Rockfill Dam) 

1285 Ongoing (2026) 

Bintulu 
Kidurong 
Power Station 

Gas 
Combined 

Cycle – 
317MW 

Open Cycle – 
165MW 

482 Commissioned 

Bintulu 
Tanjung 
Kidurong 
Extension – 
Combined 
Cycle Gas 
Turbine 

Gas 421 x2 
Commissioning 

(2021) 

Miri Power 
Station 

Gas 102 Commissioned 

Mukah Power 
Station 

Coal 135 x2 Commissioned 

Sejingkat 
Power Station 

Coal 210 Commissioned 

Balingian 
Power Station 

Coal 312 x2 
Commissioned 

(2019) 

Kuching 
Power Station 

Diesel 64 Commissioned 



X.O Durin et al. /Future Energy                                                                                             November 2022| Volume 01 | Issue 03 | Pages 01-10 

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will collectively impact 1.7 million hectares of forests in 
Sarawak [36].   

 
Figure 4. Location of Bakun and Murum Dam in 1995 

before the construction 
 

 
Figure 5. Location of Bakun and Murum Dam in 2016 after 

construction 
 
Methods of rapid conversion where the areas 

deforested is replanted within a five-year period after 
clearance [37], cannot be applied here as the dams will 
drown out the once forested areas.  As the hydropower 
plants in Sarawak are situated in rural areas, the 
transmission of the generated power would require the 
cutting of tall trees in the forests to cater to the Right of Way 
as shown in Figure 6 of the transmission lines [26]. The 
transmission lines proposed for Baleh HEP are rated at 
500kV and will require an easement of 50 m. This 
transmission line has a span of 176 km in length and would 
total up to an area of about 880 hectares or 8,800,000 m2 
[38].   

Other than that, the construction will bring destruction 
to the habitats of aquatic life and inhibit the migration of fish 
[5]. For example, the Bakun dam has a catchment area of 1.5 
million hectares, and a reservoir area of 70,000 hectares will 
destroy six rare and endangered species of fish. Plus, the 
construction of the dam will change the hydrological regime 
of the area affected, and this will cause changes in water 
level, timing, and temperature [40]. This will severely affect 
the surrounding aquatic ecosystem. This also applies to all 
the protected flora and fauna, including the Silvered Leaf 
Monkeys and Bornean Gibbons. Plus, some hydroelectric 
dams will be located near certain protected areas, such as 
the Mulu National Park, which is home to one of the world’s 
largest caves and a UNESCO World Heritage Site. Figure 7 
shows the location of hydropower dams that will intrude on 

some protected areas in Sarawak if the dams are to be 
constructed in the future with no changes to their location. 

2.3 Displacement of Communities 
The construction of hydroelectric power plants in 

Sarawak affects the livelihood of communities downstream 
when large communities are forced to relocate [41]. These 
indigenous groups rely on the forest and river integrity for 
their daily lives. Not only will the construction of the dam 
force these people to relocate, but the act itself is also 
considered an ethnocide as it destroys the lifestyle that 
these communities have. Prior to relocation, the residents of 
Sungai Asap relied mostly on the forest for their sustenance. 
After their relocation, they can no longer rely on the forest 
but are tied to the cash economy, with wages that are not 
compatible with the living costs. The relocation of large 
communities living at the hydropower project site to new 
sites may involve deforestation as lands will be cleared to 
make way for new settlements [26]. Figure 8 shows the 
relocation of indigenous communities at the Bakun dam site 
to the resettlement area at Sungai Asap, which is situated 
about 30 km from the Bakun dam site [42]. Based on the 
statistics released by Sungai Asap District Office, the 
population affected by the Bakun dam in 1998 was 9428 
people [42]. That population accounts for 26.75% of the 
people in the Belaga district in Sarawak. 

2.4 Soil Erosion 
A study was conducted by the United Nations 

Development Program, and it was found that fully developed 
dams in Sarawak could ruin the water quality and water 
levels [43]. This may lead to floods in the future. Aside from 
that, the construction of ongoing and planned hydropower 
dams will increase the number of landslides occurring in the 
region. Given that Sarawak has a tropical climate, rainfall 
frequently occurs throughout the state. Deforestation will 
remove the trees that are supposed to control the water 
levels through absorption. The rise in water-level, increased 
geological pressure, disturbances and deforestation will 
create favorable conditions for frequent landslides [36]. 
Figure 9 shows the areas in Sarawak that may be vulnerable 
to landslides if the planned hydroelectric dams were to be 
constructed as it is. 

 

Figure 6.  An example of Right of Way for EHV 
Transmission Lines [39] 



X.O Durin et al. /Future Energy                                                                                             November 2022| Volume 01 | Issue 03 | Pages 01-10 

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Figure 7. The Pan-Borneo Highway and hydroelectric dams 
in Sarawak penetrating protected areas and key habitats of 

threatened species in Borneo [36] 
 

 
Figure 8. Map location for the Sungai Asap Resettlement 

Area [42] 
 

 

 
Figure 9. Pan-Borneo Highway and hydroelectric dams in 

Sarawak and imminent frontiers of landslides. The highway 
and hydroelectric dams with highly vulnerable landslide 

locations (circled) [36] 

3. Mitigation Actions 

There are different ways to mitigate the environmental 
impact caused by hydropower dams and such methods 
include a full-cost benefit appraisal of the development of 
the hydropower plants by the relevant authority [36]. The 

appraisal covers the overall cost of the project, maintenance, 
and support services for the relocated communities. A 
commonly used appraisal is the environmental impact 
assessment or EIA, which considers other implications on 
communities, culture, and economy aside from ecological 
impacts. [29]. However, past evidence indicated the 
implementation of EIA in Sarawak does not protect native 
customary land rights since it is not easily accessible and 
that the natives are disregarded from the whole assessment 
process [44]. Thus, stricter enforcement is needed to ensure 
that all responsible parties are involved in the hydropower 
project. One of the mitigation actions suggested was the 
construction of small-scale hydropower plants or even the 
installation of mini-hydro systems instead of large-scale 
ones to save space and minimize the environmental effects 
[5, 45].  There have been several projects covering the 
installation of mini-hydro systems in Sarawak, namely in 
Bakelalan, located at the foothills of Sarawak’s highest 
mountain, Gunung Murud [46]. Previously, locals at 
Bakelalan depended on diesel-powered generators for 
power [47].  However, being located so inland, the access 
roads were difficult to come by, which lead to high costs of 
diesel that only kept escalating and only to be worse during 
the wet seasons when the access roads are rendered useless, 
leading to a drop in diesel supply.  This motivated the 
construction of a mini-hydro project; the public works 
department (PWDS) worked in good faith and cooperation 
with the local communities.  The Bakelalan community 
constructed the dam, penstock, and turbine house and laid 
the pipeline and after completion, PWDS distributed and 
managed the power network.  The project ended up 
providing 30kW of energy that was distributed to 400 
people of the Buduk Nur community 24 hours a day at the 
cost of RM600,000, which was a huge step up from the diesel 
power the community depended on that was at best run 4-6 
hours daily [46]. These dams could be constructed at rivers 
near remote rural areas as a decentralized unit.  

Aside from this, the flow of water from the reservoir can 
be regulated to minimize the impact on aquatic life. 
Minimum flow release would allow some flow below the 
power plant, which helps maintain the current water 
ecological conditions [40]. On the other hand, sedimentation 
can be tackled through dredging [48] or through the 
construction of small-scale weirs [49] that can trap sand and 
particles for removal. Apart from that, turbine technology 
could be investigated with the view of being fish-friendly to 
reduce the impact on the population of aquatic life. In the 
development of fish-friendly turbine technologies, the focus 
is on the mortality rates of the fish passing through the 
turbines. The Voith Minimum Gap Runner (MGR) was based 
on the Kaplan turbine, which is the conventional turbine 
used in the hydropower dams. The MGR has smaller gaps 
between the runners and the turbine walls, which helps to 
prevent the fish passing through from being crushed by the 
runners. The injury rate of fish passing through the MGR is 
1.5% as compared to 2.5% for the Kaplan turbine [50]. 
Figure 10 shows an improved version of the MGR, the Alden 
turbine which enables no gap between the blades’ tips and 
the turbine walls. 

Other suggestions include a resettlement policy for the 
communities to be relocated. The government should 
compensate these communities with provisions such as 
land, money, and an alternate source of livelihood. Mussa et 
al covered-on dam removals as a mitigation method, given 
that it is the more frequently used management option 
around the world [40]. This focuses on old dams to be 



X.O Durin et al. /Future Energy                                                                                             November 2022| Volume 01 | Issue 03 | Pages 01-10 

6 

 

renovated or small dams that are no longer used. Lastly, fish 
nurseries can be set up to conserve aquatic wildlife. The 
fertilization, hatching, growth, and release can be artificially 
managed to sustain the population of the aquatic life.  

 

 

 

 

 

 

 

 

Figure 10. Physical model of an Alden turbine runner [51] 

4. Discussion 

4.1 Flora and Fauna 
According to our review, hydropower will pose a threat 

to the environment as it is especially to flora and fauna 
surrounding the construction area. The state already has 
three large dams currently operating, which are Murum, 
Batang Ai, and Bakun. There are more dams on the way, with 
one of them being the Baleh dam which was estimated to be 
in commission by 2025. In section 2.2, Figures 4 and 5 
showed how much of the forest was left after the 
deforestation for the construction of the Bakun and Murum 
dam. As the deforestation process is necessary for the 
construction of the dam, an environmental impact 
assessment or EIA would be the alternative option to 
mitigate the environmental impact caused by the 
hydropower project.  

Amidst the development of the state’s power 
generation, there are ways that can indirectly mitigate the 
environmental impact of hydropower.  The equipment of the 
dams in commission can be improved such as the efficiency 
of power generation by the turbine. If the efficiency of the 
turbine can be improved, this would reduce the area needed 
for the construction of hydropower dams. Other ways 
include minimizing the transmission loss along the power 
lines or increasing the efficiency of energy utilization on the 
receiving end of the line. This would be a cost-effective 
method to meet the state’s energy demand without 
expending any additional cost on constructing new 
hydropower plants.  

Additionally, hybrid floating photovoltaics-
hydropower technology can be implemented in the 
hydropower dams in Sarawak to reduce the number of 
hydropower dams to be constructed in the future. As shown 
in Figure 11, the hybrid FPV-hydropower system maximizes 
the land used for a hydropower dam [52]. The hybrid FPV-
hydropower system can generate more power than a 
conventional hydropower system. This would, in turn, 
reduce the need to construct more hydropower plants in 
Sarawak in the future. Furthermore, the floating solar 
photovoltaics used in the hybrid FPV-hydropower system is 
also a clean, renewable energy source and has low carbon 
emissions, like hydropower. Hence, the balance of the 
ecosystem in Sarawak in the future can be maintained. 

4.2 Relocation 
Following the decades upon decades of the continuous 

construction of hydropower dams in low and middle-income 

countries, there has yet to be any comprehensive remedy to 
cope with the severe impacts on the local people, even with 
the multiple frameworks developed such as the Dams and 
Development: a New Framework for Decision making made 
by The World Commission on Dams (WCD), or even 
sustainability guidelines launched by the International 
Hydropower Association (IHA) and even with the rising rate 
of social impact assessment techniques [53]. If any future 
hydropower project affects an indigenous community, the 
relocation process can be improved. While the dam itself 
may displace their home, the community may not need to 
abandon the river on which their livelihood depends. It may 
be possible for them to move downstream along the river, 
given that the state of the river does not deteriorate upon the 
introduction of the dam. Also, the government must oversee 
the process of relocation to ensure that an agreement can be 
reached between the indigenous community and the 
organization responsible for the construction. According to 
Sarawak Ordinance, whenever necessary, the power to enter 
on land for purposes of construction as written was to 
enable the works in relation to the installation of any system 
of distribution of energy under that Ordinance, a licensee 
may do works on any land other than state land.  It is also 
stated that compensation to all persons interested for any 
disturbance, damage, or disability that may be caused by it 
would be given. Before entering any land, the licensee was 
required to give notice to the owner or occupier of the land 
stating the works that were to be done on the land; this 
notice was to be deemed to be properly given and sent by 
registered post or left at the usual or last known place of 
abode of the person-related.  However, if the person cannot 
be found, the notice will be fixed conspicuously on some part 
of the land, the owner who received the notice was given 14 
days upon placement of the notice to lodge an objection.  The 
objection lodged shall allow an inquiry to be held by the 
Director of Lands and Surveys to hear out all parties before 
deciding either to unconditionally or subject to terms, 
conditions and stipulations, as he thinks, is fit and authorize 
or prohibit any acts mentioned in the notice.  If an objection 
is not lodged within the time limit of 14 days, the licensee 
may immediately enter the land and do all the acts specified 
in that notice [54].  

 

 
Figure 11. A hybrid FPV-hydropower system could be 

implemented in existing hydropower dams in Sarawak [52] 
 
In Sarawak, we can draw the case of the Bakun dam, 

where around 50% of the impounded land was lands 
claimed under customary rights and the cost of resettlement 



X.O Durin et al. /Future Energy                                                                                             November 2022| Volume 01 | Issue 03 | Pages 01-10 

7 

 

was funded by the Federal Government while the actual 
implementation of the resettlement would be undertaken by 
the State Government.  In terms of farm compensation, it 
would be given according to the number of fruit trees.  It was 
discovered that the rate changes that were initially 
promised were around RM50-52 per tree, however, the final 
compensation was around RM5-9 or RM 30, according to 
different villagers interviewed. There was also individual 
compensation for people born in 1998 where they were 
given RM13,000 per person, and compensation for burial 
grounds where those who wanted to move the grave were 
given a compensation of RM4000 and RM 1500/2000 to not 
move the grave [55]. Despite that, these payments have been 
criticized for not being a more sustainable method of 
compensation for the people that were removed from their 
lands [56]. The compensation that was received by the locals 
was perceived as too little, which was mainly due to the land 
compensation because now, each family was only provided 
with three acres of land in the resettlement sites as 
compensation for the lost land that was used as the reservoir 
area which had been voiced out [56, 57].  Thus, it would be 
wise for the government to have plans in place to give out 
proper compensation to be given to smoothen the relocation 
process while reducing the social impact to as little as 
possible.  A system that reconstructs the tendering methods 
needs to be adapted to entice participation from local 
communities since, with a different approach, one can 
minimize the potential of corruption related to the 
management of high volumes of the public participation in 
energy supply [58].  

At the same time, from a social policy perspective, we 
can see the positive effects of the relocation of the locals that 
were located in the reservoir area since they were now given 
access to better welfare services. At the resettlement site, 
people are given easier access to roads, clinics, and schools 
where the people previously had to travel by boat for an 
entire day just to reach the hospital. 

4.3 Sedimentation and Greenhouse Gases 
The sedimentation levels in Sarawak are especially high 

due to deforestation, which causes erosion of soil, causing 
the river waters to be murky. The amount of GHG released 
from the sediments found within hydropower dams was 
reviewed under section 2.1, and it was found that the GHG 
emission in Sarawak is the largest compared to Peninsular 
Malaysia at 60.9%. Majority of which is contributed by 
Bakun dam due to its large surface area of 695km2. Thus, the 
contribution of GHG emission due to HEP from the upcoming 
Baleh dam is expected to be high as well since the projected 
surface area is 588km2. Additionally, more major HEPs are 
planned for Sarawak under SCORE projects as well. 
However, the GHG emissions due to HEPs are still 
significantly lower than thermal power plants at 11g of CO2 
per kWh generation compared to 943g of CO2 per kWh 
generation of coal-fired power plants [59]. 

As discussed under section 2.1, sedimentation also 
indirectly affects the lifespan of the hydropower dams. Since 
the sedimentation levels are high in Sarawak rivers, as 
evident from the annual inflow of 9,000,000 tons of 
sediments settling into the reservoir of Bakun dam, the 
lifespan of Bakun Dam is estimated to be only 50 years [60]. 
While Sarawak has yet to decommission any of its dams, the 
environmental impacts of dam decommissioning should be 
taken into consideration as the Batang Ai dam, which was 
commissioned in 1985, is nearing its end-of-life expectancy, 
accounting for the 50-year lifespan of Bakun Dam. 

Hydroelectric dams can be repurposed after they are 
decommissioned as a water supply for irrigation and 
commercial uses, as well as recreation sites for tourism. 
These would require the lowering of the decommissioned 
hydroelectric dams. Some decommissioned hydroelectric 
dams which are demolished would require the restoration 
of rivers.  

Since sedimentation contributes the most to 
greenhouse gas emissions of HEPs, the issue can be solved in 
multiple ways. One of the ways to remove sediments is 
through periodic mechanical dredging. This method utilizes 
dredgers, which are machines that are specialized in 
removing sediments that lie in water bodies. This should 
help in reducing the accumulation of sediments in the long 
run. To assist in catching the sediments, small-scale weirs 
can be constructed to trap them for removal in the future. 
Another method that can be implemented is the installation 
of a dedicated channel or canal in the dam to flush sediments 
periodically. This should help regulate the sediment build-
up and ensure that GHG gas emissions are controlled. To 
tackle the emission of greenhouse gases from the sediments 
after demolishing the hydroelectric dams, the dig and 
dewater approach can be implemented where the 
decommissioned hydroelectric dam is drained, and the 
dried sediments are removed from the location. 

5. Conclusion 

To summarize, hydropower plants pose a threat to 
Sarawak’s forests, rivers, and the communities living nearby 
the dams. The felling of trees and impoundment of the dam 
leads to soil erosion and major loss, which will inevitably 
negatively impact the ecosystem of Sarawak, leading to the 
extinction of some flora and fauna species that are endemic 
to Sarawak. As Sarawak is bound for the construction of 
more major hydropower dams, this would mean a lot of 
forests would be submerged in the future. Sarawak would 
then require proper management such as the EIA to ensure 
that their ecosystem is preserved in the future. Aside from 
the forest ecosystem, indigenous communities living by the 
rivers are also affected and must be relocated to allow the 
project to progress. Oftentimes, these communities are not 
properly compensated upon relocation, and the people that 
were relocated before were unable to obtain proper 
compensation. These people had to reach out for legal 
methods through the court to obtain somewhat fair 
compensation for their relocation from their original lands. 
It is imperative for the government to give proper 
compensation that is planned well to satisfy these 
communities and ensure that they are conforming to the 
norms of a functioning society in future relocations that may 
occur when constructing a dam. It is also vital for the 
government to ensure the organization in charge of the 
hydropower project obtains a consensus from the 
indigenous communities who are to be relocated. This 
would ensure that both sides can negotiate the terms and 
conditions of the relocation process and compensation and 
that the communities are not left out throughout the entire 
process of the project. Although hydropower is portrayed as 
a clean source of renewable energy, there are still GHG 
emissions associated with it through sedimentation, albeit at 
a much smaller scale compared to coal-fired power plants. 
The impoundment of the dam slows the flowing river 
current, which disrupts the natural sedimentation inflow 
and outflow, creating an imbalance that causes it to 
accumulate in the reservoir. Sedimentation indirectly affects 
the lifespan of HEPs by decreasing the dam capacity and 



X.O Durin et al. /Future Energy                                                                                             November 2022| Volume 01 | Issue 03 | Pages 01-10 

8 

 

increased wear on the machinery. A large amount of 
sedimentation discharged during decommissioning will 
potentially threaten the ecosystem downstream from the 
HEPs and cause some rivers to become shallow and 
eventually dry out. Hence, sediment management is a must 
in HEPs to ensure the lifetime of the dam as well as to keep 
the environment safe. The HEPs in Sarawak must be 
monitored and maintained regularly in the future as the 
dams are so big that any cracks in the dams may cause the 
entire state to be flooded if the dams were to experience 
total failure. In the distant future, Sarawak may need to 
prepare other renewable energy alternatives to 
hydropower, such as solar power plants or wind farms, as 
the estimated lifespan of hydropower plants in Sarawak is 
about 50 to 70 years. The oldest HEP in Sarawak, which is 
the Batang Ai dam, is nearly three-quarters of its estimated 
lifespan. Additionally, Sarawak can look into the potential of 
hybrid FPV-hydropower systems to be integrated into the 
existing HEPs to reduce the reliance on hydropower. 
Currently, there are many hydro projects being planned in 
Sarawak, and these planning must be taken seriously in 
Sarawak to keep Sarawak’s rivers and forests safe in the 
future. These mitigation methods have to be further studied 
to enable the government to have more control over the 
construction of these hydroelectric dams, which ultimately, 
as a renewable source of energy, has more to be desired.  
Especially in a developing nation like Malaysia, a 
breakthrough would likely enable a sustainable future in 
terms of power generation in the long run. 

Ethical issue 
The authors are aware of and comply with best practices 

in publication ethics, specifically with regard to authorship 
(avoidance of guest authorship), dual submission, 
manipulation of figures, competing interests, and 
compliance with policies on research ethics. The authors 
adhere to publication requirements that the submitted work 
is original and has not been published elsewhere in any 
language. 

Data availability statement 
Data sharing is not applicable to this article as no 

datasets were generated or analyzed during the current 
study. 

Conflict of interest 

The authors declare no potential conflict of interest. 

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