10.1 INTRODUCTION 10.2 KEY ENVIRONMENTAL ISSUES

UKM Pakarunding Sdn. Bhd. (561663-U) 10-1

10.1 INTRODUCTION

This chapter describes the mitigating measures of various activities associated with the

development of the proposed NHEP, on the various environmental components based on the

impacts evaluated from previous chapter.

10.2 KEY ENVIRONMENTAL ISSUES

As mention before, several key issues had been identified in this EIA study. The key issues are

listed below according to major activities in relation to the primary impacts generated by the

Nenggiri HEP development activities. The environmental components that expected to have a

major impact are as follow:-

I. Water quality

II. Hydrology and flood risk

III. Soil erosion

IV. Geology

V. Terrestrial flora & fauna

VI. Socio-economy

THE PROPOSED NENGGIRI HYDROELECTRIC PROJECT

Mitigating Measures


10.3 MITIGATING MEASURES DURING PRE-CONSTRUCTION

This section shall discuss the mitigating measures for the impact arising from activities that will

be carried out during pre-construction phase of the Proposed NHEP. The main potential impacts

arise from the pre-construction phase are listed in Table 10.3.1 below:

Table 10.3.1 Summary of Potential Impacts during Pre-Construction Phase

No Environmental

component Potential impact

1 Noise & vibration I. Noise nuisance due to seismic study for site investigation

study

2 Geology & geotechnics I. Slope erosion due to drilling operation for feasibility study

and site investigation

3 Anthropology I. Anxiety among the villagers of Pos Pulat and Pos Tohoi

4 Socio-economic I. Employment to the local people during Survey and

investigation works

10.3.1 NOISE & VIBRATION

A. Mitigating measures for noise nuisance due to seismic study for site investigation

study

I. Permission must be obtained from the authorities if the blasting activities are to be carried

out for seismic study. The activities should be within normal working hours only and shall

avoid weekend and public holidays.

II. Contractor should ensure blasting vibration and noise does not spread to a noise & vibration

sensitive place/nearest settlement.

10.3.2 GEOLOGY & GEOTECHNICS

A. Mitigating measures for slope erosion due to drilling operation for feasibility

study and site investigation

I. Good drilling procedure to minimize the impact to the environment

II. Good practise during geophysical exploration to reduce impact to the environment

10.3.3 ANTHROPOLOGY

A. Mitigating measures for anxiety among the villagers of Pos Pulat and Pos Tohoi

I. In order to reduce the uncertainty and anxiety feelings faced by the affected Orang Asli

communities, direct and continuous engagement with the village leaders is necessary.

II. The Orang Asli should be furnished with accurate information and any issue or

dissatisfactions raised by the members of the community.

III. The Project Proponent should up-date JAKOA Gua Musang with all the necessary information

so that they could play a positive role in advising the Orang Asli. JAKOA Gua Musang should

be made as an important player in handling the Orang Asli regarding the Nenggiri Dam

Project.


Mitigating Measures


10.3.4 SOCIO-ECONOMIC

A. Employment to the local people during survey and investigation works

I. In order to support the growth of the local economy, employment and business

opportunities such as sub-contracting works and supply of essentials materials should be

given, with greater priority, to the local residents or nearby residents especially in the

surveyed villages. Participation of the locals will enhance the economy.


Mitigating Measures


10.4 MITIGATING MEASURE DURING CONSTRUCTION

This section shall discuss the mitigating measures for the impact arising from activities that will

be carried out during construction phase of the Proposed NHEP. The main potential impacts arise

from the construction phase are listed in Table 10.4.1 below:

Table 10.4.1 Summary of Potential Impacts during Construction Phase

No Environmental


1 Air quality I. Generation of air pollutants

2 Noise & vibration

I. Noise from machineries used during construction stage II. Noise from Earthworks and transportation of construction

materials III. Noise from site preparation IV. Noise from river diversion V. Noise from construction of the re-regulating dam

VI. Noise from excavation for the re-regulating pond VII. Noise from construction of access roads

3 Water quality I. Siltation of downstream rivers

II. Introduce solids pollutants in the Sg. Nenggiri network

4 Hydrology

I. Sediment transport into the river II. Flash flood & localized flooding

III. Surface erosion and sedimentation IV. Change of the existing hydrologic regime

5 Soil erosion I. Occurrence of soil erosion

6 Geology &

geotechnics

I. Stability of the soil/rock slope formations II. Slope failures

III. Change of surface morphology IV. Construction of diversion tunnel V. Main Dam and RCC Section of Saddle Dam

VI. Re-Regulating Dam Construction VII. Saddle Dam Construction

7 Waste management I. Biomass management from land clearing of dam site

8 Landuse I. Permanent landuse changes

9 Archaeology I. Possibility of new discovery of Neolithic settlement

II. Loss of existing archaeological sites III. Damage the structure of cave

10 Terrestrial flora I. Loss of vegetation

11 Terrestrial fauna

I. Illegal hunting and poaching II. Human-wildlife conflict & wildlife displacement

III. Loss of habitats IV. Disturbance to wildlife

12 Freshwater ecology I. Damaging the river habitat and deteriorate water quality

II. Contamination in the river system III. Sediment load to the rivers

13 Anthropology I. Animals migrate into Orang Asli villages

II. Tension and worries among the Orang Asli dwellers III. Villagers exposed to the road accidents


Mitigating Measures


No Environmental


IV. Job opportunities to the local people

14 Ecotourism I. Reduce/loss of ecotourism attraction places

15 Socio-economic

I. Presence of foreign workers in local community II. Conflict between local community and foreign workers

III. Affected the livelihood of villagers IV. Production of waste V. Waste from demobilization

VI. Water quality deterioration VII. Accident risk to local people

16 Public health I. Communicable diseases outbreak

II. Motor traffic accident

10.4.1 AIR QUALITY

A. Mitigating measures for generation of air pollutants

I. To prevent the increasing of the suspended dust into the atmosphere, water spraying should

be carried out periodically for suppressing dust during dry period.

II. Truck that will carry the construction material should be cover up properly to minimize the

suspended dust into the atmosphere

III. A wash through should be installed at the entrance of the construction yard to prevent the

dust and mud from entering the public roads.

IV. Good maintenance of the construction vehicle and fuel combustion equipment to minimize

gasses emission.


A. Mitigating measures for noise from machineries used during construction stage

I. Noisy machinery and vehicles must be checked for proper installation of noise control

components such as mufflers and soundproof enclosures to reduce noise

B. Mitigating measures for noise from earthworks and transportation of construction

materials

I. The impact of overall noise level emitted can be mitigated and minimised by restricting noisy

construction activities to day time and working days only when working or vehicle passing

close to residential areas.

II. Permission must be obtained from the authorities for transportation of construction material

if passing near those areas outside the normal working hours.

C. Mitigating measures for noise from site preparation, river diversion, excavation of

the re-regulating pond, access road, power intake, spillway and saddle dam.

I. Restricting noisy construction activities to day time and working days only when working or

vehicle passing close to residential areas.

II. Noisy machinery and vehicles must be checked for proper installation of noise control

components such as mufflers and soundproof enclosures to reduce noise.


Mitigating Measures


D. Mitigating measures for noise from construction of the re-regulating dam



II. Permission must be obtained from the authorities for transportation of construction material

if passing near those areas outside the normal working hours.

III. Noisy machinery and vehicles must be checked for proper installation of noise control


10.4.3 WATER QUALITY

A. Mitigating measures for Siltation of downstream rivers

I. Proper and adequate LD-P2M2 measures should be implemented where earthworks and

construction of hauling roads are carried out to mitigate impacts of erosion on water quality.

B. Mitigating measures for introduced pollutants in the Sg. Nenggiri network

I. Debris from the dam construction and other solid wastes should be collected and disposed of

at designated and approved dumping ground. Similarly, sewage and waste water from base

camp should be properly handled as recommended in waste management section.

II. Solid waste and water discharges especially sewage, should not be allowed to reach water

bodies without treatment.

C. Mitigating measures for chemical pollutant into the receiving river

I. Oil and fuel spillages or leakages from transport, storage and operation of equipment should

be collected and handled as scheduled waste and being managed as recommended in

schedule management section.

10.4.4 HYDROLOGY

A. Mitigating measures for sediment transport into the river

I. The site clearing impact from this activity can be minimised by scheduling the cutting and

removal of biomass.

II. If possible, the construction of access road should be far away from the water courses as

recommended in LDP2M2 section.

B. Mitigating measures for flash flood & localized flooding

I. Existing road can be used to access dam site areas and monitoring stations. For drilling

activities, the construction of perimeter trench or bund can avoid loose soils to be washed

away by runoff.

II. Proper line channel must be constructed and installed along the diversion tunnel/ river. The

size must be adequate to cater river discharge during normal and flood flows.

C. Mitigating measures for surface erosion and sedimentation

I. Proper terrains must be constructed beside the steep roads to avoid landslide or slope

failure. Wherever river crossing to be made, a proper bridge must be constructed bank to

bank to avoid minimal disturbance to water body.


Mitigating Measures


II. Adequate LD-P2M2 measures should be implemented where earthworks and construction of

hauling roads are carried out to mitigate impacts of erosion.

D. Mitigating measures for change of the existing hydrologic regime

I. Proper maintenance of silt and sediment traps must be established at major sediment

sources such as Sg. Perias and upstream of Sg. Nenggiri.

10.4.5 SOIL EROSION

A. Mitigating measures for soil erosion

I. Mulching or other type of surface protection to prevent direct impact of rainfall should be

applied. In order to minimize the amount of sediment entering the rivers, LDP2M2 should be

implemented in river feeding the dam. Among the options are mulching, terracing,

scrub/bush and plant buffer zone. Cover management factor values of these option can be

referred in Table 3.8 and Table 3.9 from the Guideline for Erosion and Sediment Control in

Malaysia (DID 2010).

II. The erosion control plan could include silt trap, sediment trap or sedimentation ponds.

Monitoring program for TSS level at the discharge point must be implemented. De-silting

operation must be conducted on regular basis to ensure the effectiveness of the sediment

ponds.

III. Table 10.4.2 showed the potential soil erosion during construction after incorporating

conservation measure. Map showing the potential soil loss is presented in Figure 10.4.1 The

amount of potential soil loss is reduce to low (<50 ton/ha/yr) and moderately high (50-100

ton/ha/yr).


Mitigating Measures


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Mitigating Measures


Table 10.4.2: Prediction of Potential Rate of Soil Loss during Constructions with Conservation Measures in Ton/Ha/Yr

Station Location Erosivity Index (R)

(MJmm/ ha.hr)

K (ton/ha) (ha.hr)/ (MJ.mm)

LS LS max C

Mulch (50% cover)

C Scrub/ Bush (25% cover)

P terrace *0.18

P Buffer *0.8

P Sediment

Pond *0.5

A Ton/ha/yr

Amax Erosion Risk

Category

ST 1 Sg. Puian 14601.13 0.030 10.79 25.24 0.25 0.4 212.69 945.28 590.80 34.03 79.60 Low Mod high

ST 2 Sg. Jenera 14601.13 0.063 4.77 11.29 0.25 0.4 197.45 877.56 548.47 31.59 74.77 Low Mod high

ST 3 Sg. Rela 14601.13 0.031 9.95 19.98 0.25 0.4 202.67 900.74 562.96 32.43 65.11 Low Mod high

ST 4 Sg. Wias 14601.13 0.029 7.63 27.36 0.25 0.4 145.39 646.16 403.85 23.26 83.41 Low Mod high

ST 5 Sg. Wok 14601.13 0.033 8.34 15.81 0.25 0.4 180.83 803.70 502.32 28.93 54.85 Low Mod high

ST 6 Kg. Penggei 14601.13 0.031 10.32 18.26 0.25 0.4 210.20 934.24 583.90 33.63 59.51 Low Mod high

ST 7 Sg. Kalwing 14601.13 0.038 5.18 23.07 0.25 0.4 129.33 574.82 359.26 20.69 92.16 Low Mod high

ST 8 Kg.K. Jenera 14601.13 0.018 6.63 19.90 0.25 0.4 78.41 348.50 217.81 12.55 37.66 Low Low

ST 9 Kg. Tohoi 14601.13 0.008 6.34 16.48 0.25 0.4 33.33 148.11 92.57 5.33 13.86 VeryLow Low

ST 10 Kg. Star 14601.13 0.021 8.81 18.26 0.25 0.4 121.56 540.27 337.67 19.45 40.31 Low Low

ST 12 Sg. Kalau 14601.13 0.056 9.91 16.31 0.25 0.4 364.64 1620.61 1012.88 58.34 96.02 Mod high Mod high

ST 11 Sg. Nenggiri 14601.13 0.015 7.04 14.01 0.25 0.4 63.38 308.38 192.73 11.10 22.09 Low Low

ST 13 Sg. Lah 14601.13 0.045 5.09 13.94 0.25 0.4 150.50 668.88 418.05 24.08 65.95 Low Mod high

ST 14 Sg. Nenggiri 14601.13 0.057 5.69 10.32 0.25 0.4 213.10 947.12 591.95 34.10 61.84 Low Mod high

ST 15 Kg. Betis 14601.13 0.052 4.13 12.07 0.25 0.4 141.11 627.15 391.97 22.58 65.98 Low Mod high

ST 16 Sg. Nenggiri 14601.13 0.030 4.77 16.48 0.25 0.4 94.02 417.88 261.18 15.04 51.98 Low Mod high

ST 17 Sg. Ber 14601.13 0.052 8.04 14.01 0.25 0.4 274.70 1220.89 763.06 43.95 76.59 Low Mod high

ST 18 Sg. Belatop 14601.13 0.029 11.29 19.09 0.25 0.4 215.13 956.11 597.57 34.42 58.20 Low Mod high

ST 19 Sg. Berok 14601.13 0.019 9.03 18.26 0.25 0.4 112.73 501.02 313.14 18.04 36.47 Low Low


Mitigating Measures


Figure 10.4.1 Map Showing the Potential Soil Loss during Construction with Conservation Measures


Mitigating Measures


Data showing the potential sediment yield during construction calculated from soil loss and

sediment delivery ratio is shown in Table 10.4.3.

Table 10.4.3 Prediction of Potential Sediment Yield during Construction with Application of

Conservation Measures Calculated from Soil Loss and SDR

Station Location

Sub Catchment

Area, A (km2)

Soil Erosion (SE)

(Ton/ha/yr)

SE (Ton/ha/yr)

LS Max SDR

Sediment Yield (SY)

(Ton/ha/yr

SY (Ton/ha/yr)

LS Max

ST 1 Sg. Puian 3.218 34.03 79.60 0.45 15.26 35.70

ST 2 Sg. Jenera 0.316 31.59 74.77 0.58 18.29 43.28

ST 3 Sg. Rela 1.481 32.43 65.11 0.49 15.84 31.81

ST 4 Sg. Wias 1.015 23.26 83.41 0.51 11.84 42.47

ST 5 Kg. Wok 1.372 28.93 54.85 0.49 14.25 27.02

ST 6 Kg. Penggei 1.327 33.63 59.51 0.49 16.63 29.42

ST 7 Sg. Kalwing 4.078 20.69 92.16 0.44 9.04 40.27

ST 8 Kg. K. Jenera 6.564 12.55 37.66 0.41 5.20 15.61

ST 9 Kg. Tohoi 3.476 5.33 13.86 0.44 2.37 6.16

ST 10 Kg. Star 3.981 19.45 40.31 0.44 8.52 17.66

ST 11 Sg. Kalau 0.649 58.34 96.02 0.53 31.20 51.35

ST 12 Sg. Nenggiri 1.267 11.10 22.09 0.50 5.52 10.98

ST 13 Sg. Lah 0.515 24.08 65.95 0.55 13.21 36.18

ST 14 Sg. Nenggiri 3.098 34.10 61.84 0.45 15.36 27.85

ST 15 Kg. Betis 0.857 22.58 65.98 0.52 11.71 34.23

ST 16 Sg. Nenggiri 1.991 15.04 51.98 0.47 7.11 24.57

ST 17 Sg. Ber 3.847 43.95 76.59 0.44 19.33 33.68

ST 18 Sg. Balatop 0.224 34.42 58.20 0.60 20.70 34.99

ST 19 Sg. Berok 1.577 18.04 36.47 0.49 8.75 17.69

Data showing the potential sediment yield during construction with mitigation calculated using

MUSLE is shown in Table 10.4.5.4 and Figure 10.4.2. Installation of conservation measures could

reduce the amount of sediment yield significantly during construction. Sediment yield can be

defined as the amount of sediment reaching or passing a point of interest in a given period of

time. They are the amount of particles that actually reached the river system.


Mitigating Measures


Table 10.4.4: Prediction of Potential Sediment Yield under Construction with Conservation Measure - MUSLE

Station River Sub

Catchment Area, A(m2)

Runoff Volume, V(m3)

Peak Flow Discharge, [Qp=CIA]

(m3/s)

K Factor

LS Factor

LS Factor max

CP *0.25*0.18*0.5

ESCP 90%,

Effeciency (0.1)

SY (ton)

SY (ton) max

ST 1 Sg. Puian 3218268 79652.14 0.088 0.03 10.79 25.24 0.0225 0.10 5.11 11.94

ST 2 Sg. Jenera 316200 7825.95 0.087 0.063 4.77 11.29 0.0225 0.10 0.46 1.09

ST 3 Sg. Rela 1480500 36642.38 0.041 0.031 9.95 19.98 0.0225 0.10 1.04 2.09

ST 4 Sg. Wias 1015400 25131.15 0.028 0.029 7.63 27.36 0.0225 0.10 0.35 1.26

ST 5 Kg. Wok 1371900 33954.52 0.038 0.033 8.34 15.81 0.0225 0.10 0.80 1.51

ST 6 Kg. Penggei 1327400 122452.65 0.036 0.031 10.32 18.26 0.0225 0.10 3.17 5.61

ST 7 Sg. Kalwing 4078200 100935.45 0.112 0.038 5.18 23.07 0.0225 0.10 5.01 22.30

ST 8 Kg. K. Jenera

6563600 162449.1 0.181 0.018 6.63 19.9 0.0225 0.10 7.90 23.70

ST 9 Kg. Tohoi 3476100 86033.48 0.096 0.008 6.34 16.48 0.0225 0.10 0.94 2.45

ST 10 Kg. Star 3981200 98534.7 0.109 0.021 8.81 18.26 0.0225 0.10 4.47 9.27

ST 11 Sg. Kalau 649400 16072.65 0.179 0.056 9.91 16.31 0.0225 0.10 3.59 5.91

ST 12 Sg. Nenggiri 1266898 31355.71 0.035 0.015 7.04 14.01 0.0225 0.10 0.26 0.52

ST 13 Sg. Lah 515142 12749.75 0.142 0.045 5.09 13.94 0.0225 0.10 0.93 2.56

ST 14 Sg. Nenggiri 3097780 76670.07 0.085 0.057 5.69 10.32 0.0225 0.10 4.76 8.63

ST 15 Kg. Betis 857300 21218.18 0.236 0.052 4.13 12.07 0.0225 0.10 2.42 7.07

ST 16 Sg. Nenggiri 1990900 49274.78 0.055 0.03 4.77 16.48 0.0225 0.10 0.87 3.01

ST 17 Sg. Ber 3847175 95217.58 0.106 0.052 8.04 14.01 0.0225 0.10 9.49 16.54

ST 18 Sg. Balatop 223834 5539.89 0.006 0.029 11.29 19.09 0.0225 0.10 0.02 0.04

ST 19 Sg. Berok 1577354 39039.51 0.043 0.019 9.03 18.26 0.0225 0.10 0.65 1.31


Mitigating Measures


Figure 10.4.2 Map Showing the Potential Sediment Yield during Construction with Conservation Measures Using MUSLE


Mitigating Measures




Mitigating Measures


10.4.5.1 Land Disturbing Pollution Prevention and Mitigating Measure (LD-P2M2)

Plan

The purpose of this section is to provide a set of best practice site management procedures to

control the severity and extent of soil erosion and pollutant transport during the construction

phase of the project.

Clearing of the site and the construction of erosion and sediment controls is to comply with the

requirements of the Environment Quality Act 1974. Due consideration should be given to stripped

topsoil being retained and reused in drains, disturbed areas and rehabilitation of the site. The

construction contractor will be responsible for the implementation, inspection, repair and

modification of the specified erosion and sediment controls.

The climate in the vicinity of the site is characterised by distinct Monsoon seasons. During the wet

season from November to January, access to the site may be limited by flooding and heavy

rainfall, making progress of work on-site slow. This is when the BMPs for erosion and sediment

control need to be regularly maintained to ensure that erosion by the heavy rainfall is kept under

control. The rest of the year, there will be fairly even rainfall from convectional storms which can

be intense at times.

10.1.1.1 Principles of Erosion And Sediment Control (ESC)

The principles of effective erosion and sediment control for the proposed clearing activity on site

are based on the following:

Access roads should be built with minimum cuts into the surrounding hillsides

Construction planning will have to integrate ESC measures into their phases

ESC plans will need to be updated and modified to suit site requirements as the construction

proceeds

Soil disturbance should be minimized as much as possible

Runoff through the site should be controlled

Soil erosion should be minimized through stabilization of disturbed areas

Maximise sediment retention on site;

Maintain all ESC measures in proper working order at all times; and

Monitor the site and adjust ESC practices to maintain the required performance standard.

10.1.1.2 Site Installation Sequence

The following sediment and erosion controls will be implemented on the site;

Large trees in such zones should not be uprooted (should that be the requirement for the rest of

the trees in the inundated area) until all logging has been completed for the whole area, and the

area has been stabilized

Tree Clearing – Clearing of vegetation will be undertaken where necessary and is to be

restricted to identified areas only;

Access Controls – Used to stop the conveyance of sediment from inside the construction site to

outside through the tyres of construction vehicles.


Mitigating Measures


Diversion Channels– Used to divert clean water from upstream catchments around the site,

and convey flow within disturbed areas to sediment basins;

Catch Drains – Used on the downstream side of the construction to capture contaminated

runoff;

Silt Fences – Used to intercept runoff from disturbed areas and aims to temporarily pond up-

slope water allowing settlement. These will be used in the detailed construction drawing where

needed

Check Dams – Used to reduce velocities within open drains. This will protect the open drain

itself from erosion. These will be used in the detailed construction drawing where needed

Water Bar – Used to reduce the volume of runoff flowing down the slope of an unpaved road.

These will be used in the detailed construction drawing where needed

Level Spreaders – Used to reduce velocities and return channelized flow to sheet flow. These

will be used in the detailed construction drawing where needed

Sediment Basins / sediment trap – Used to trap and retain sediment via settlement of

suspended particles;

These controls are Best Management Practices (BMP) in use by Guideline for Erosion and

Sediment Control in Malaysia, Urban Storm Water Management Manual for Malaysia and Certified

Professionals in Erosion and Sediment Control (CPESC).

10.1.1.3 Erosion and Sediment Controls

The following erosion and sediment controls have been developed and adopted for the proposed

development.

I. Diversion Drains

Diversion drains will divert outside runoff from entering into the site, and hence creating erosion

problems. They will incorporate “Check Dams” to slow down the speed of the flow in the drains.

II. Catch Drains

Catch Drains will be utilised on the downstream side of the disturbed area to capture runoff from

the construction area. These drains will direct runoff into sediment basins where it will be treated

prior to release. Check dams will also be installed within the catch drains.

III. Check Dams

Check Dams will be utilised within the proposed diversion drains on the upstream side of the

proposed works and within the proposed catch drains on the downstream site of the disturbed

areas. These devices will be used to reduce the speed of flow and also enable large sediment to

settle out behind the “dams”, effectively acting as mini sediment ponds along the length of the

drains.

Check Dams are to be composed of 100 mm rock spalls with a height of 400 mm longitudinal

spacing of the check dams within the drains.


Mitigating Measures


IV. Sediment Fences

Where earth bunds are not suitable for e.g. due to the vegetated nature of the terrain, sediment

fences can be used. These are to ensure that runoff that spills over from the earth drains are

controlled from flowing down a slope and creating erosion problems.

V. Level Spreaders

Level spreaders are constructed along the contour line and consist of a level entry that allows

concentrated flow to spread over a nominated flow width before discharging as sheet flow down a

stable slope.

VI. Water bars

Water bars or turnouts are used to cut down the volume of surface runoff flowing down the slope

of an Access Road. This will significantly reduce the capacity of the runoff to erode the road

surface and carry away sediment.

VII. Silt Traps / Sediment Basins

Sediment Basins are the final controls to filter out sediment from runoff coming out of the land

disturbance site. The Basins are detention ponds suitably sized to enable sediment to settle out

while flowing through them. However, in cases where the clay content of the sediment is high,

flocculants may have to be added into the ponds periodically, to accelerate the process of

sediment deposition. This will have to be determined during the detailed design stage, when

samples of the runoff can be taken to assess the clay content, besides the soil samples already

taken. Amounts of flocculent to be added will also need to be designed for.

Silt traps are smaller versions of sediment basins and are used for smaller areas, to lessen the

impact for the whole area. Typically, an area of about 20 hectare will contain one sediment basin

while also having about 5 Silt Traps scattered around it.


Mitigating Measures




Mitigating Measures


Figure 10.4.3 Typical LD-P2M2 for Main Dam Area


Mitigating Measures


Figure 10.4.4 Typical Cross Section of Hill Slope at Main Dam Area


Mitigating Measures


Figure 10.4.5 Location of Proposed Access Road


Mitigating Measures


Figure 10.4.6 Typical LD-P2M2 at Proposed Access Road Area


Mitigating Measures


Figure 10.4.7 Detailed Sediment Trap for the Proposed Access Road Area


Mitigating Measures


Figure 10.4.8 Detailed Earth Drain for the Proposed Access Road Area


Mitigating Measures


Figure 10.4.9 Location of Contractor’s Camp


Mitigating Measures


Figure 10.4.10 Typical LD-P2M2 at Contractor’s Camp


Existing Physical Environment


Figure 10.4.11 Layout Plan for the Excavation Area


Mitigating Measures


Figure 10.4.12 Cross Section of a Hill Slope at the Excavation Area


Mitigating Measures


Figure 10.4.13 LD-P2M2 at the Saddle Dam Area


Mitigating Measures


Figure 10.4.14 Typical Cross Section Of Hill Slope At Saddle Dam Area


Mitigating Measures



A. Mitigating measures for stability of the soil/rock slope formations

I. Construction should follow the design specifications to minimize the impact on soil and rock

slope stability.

B. Mitigating measures for slope failures

I. Detailed slope mapping on the limestone vertical cliff should be done to identify the hazard

and risk of the falling rocks and perform remedial measures to control the rock falls. The

use of LIDAR Scanning on the vertical slopes can effectively map all the rock discontinuities.

The Guideline from Jabatan Mineral and Geosains should be followed, i.e. “Garis Panduan

Penentuan Zon Bahaya Di Sekitar Bukit Batu Kapur”.

C. Mitigating measures for change of surface morphology

I. Construction should follow the design specifications to minimize the impact of major siltation

in water.

II. Minimize the operation that can result in permanent change of surface morphology

especially areas outside the main dam construction and its main reservoir.

III. Draining and stabilizing of potentially unstable area before impoundment to prevent slope

failure and soil saturation around impoundment perimeter to be look into. Present survey

conducted on existing slopes along the Sg. Nenggiri has shown that most of the slopes are

stable due to the cohesiveness of the clayey soil.

IV. Continuous monitoring of the micro-seismicity induced by inundation of reservoir using local

seismograph stations to be undertaken.

D. Mitigating measures for construction of diversion tunnels

I. The tunnel slope face (normally at vertical slope angle) shall be strengthened and support by

using engineering rock stability measures such as rock bolts with a combination with

shotcrete. Support measures shall be determined based on rock mass classification of the

rock mass at the tunnel face.

II. The control of blasting technique is important to prevent higher degree of disturbance to the

rock surrounding openings (rock damage and over-break). A design of safe blast hole

patterns of underground opening to avoid rock damage demands test blast method, coupled

with recording of seismic effect. Measuring of seismic effects of blasting on the surface shall

be carried out with intention to define the safe mode of blasting. Smooth blasting shall also

be utilised and can significantly reduce the amount of shotcreting and ground supports. The

blasting is controlled by the drilling pattern of the hole. The blast hole shall be drilled in

accordance with the designed drilling pattern. The drilling will be performed by drilling

jumbo (Figure 10.4.15).


Mitigating Measures


Figure 10.4.15 Face Drilling for Blasting by Drilling Jumbo

III. The connection between the blasting detonators, the detonating cord, and the shunt of

blasting wire shall be checked. Authorized shot firer must make sure that the people, tools,

lightings and equipment have been evacuated before blasting. A warning announcement and

signal shall be given before blasting, allowing all people in the area to move to safer areas.

IV. Good ventilation of the tunnel shall be provided to easily remove the dust and fumes after

the blasting operation. The workers shall also have a respiratory apparatus working in the

dusty environment. After blasting, no one is allowed to approach to the face. Firstly, at

least 15 minutes after starting ventilation, shot firer shall proceed to the face to see whether

there is any misfire explosive, and supervisor will check face condition and air quality, then

inform and allow other people to enter blasted area. When the face is clear, water will be

sprayed to face wall and crown of tunnel to reduce the dust from blasting.

V. The blasted rocks shall be removed from the working tunnel face (mucking). The loosened

pieces of rocks shall be scaled off from the face of the tunnel to prevent rock falls that are

dangerous to workers inside the tunnel (scaling and trimming). The mucking operation is

carried out using wheel loader or Schaeff loader (Figure 10.4.16). The tunnel muck is loaded

into 20-ton dump trucks, transporting the tunnel muck to the temporary stock yard place in

designed spoil bank at construction yard. Scaling and trimming of blasted profiles shall be

done to remove loose rocks resulted from the blasting, and to trim and remove any

underbreak to ensure the excavated profiles conform to the design as indicated in the design

drawings and the surface is smooth. Scaling and trimming shall be conducted using a

breaker or other machineries. Once the excavated area has been scaled and trimmed, the

excavation profile shall be checked by surveyor. Underbreaks and overbreaks shall be

measured, and the underbreak shall be trimmed and removed and re-excavated in

accordance with the design.


Mitigating Measures


Figure 10.4.16 Mucking by Schaeff Load and 20-ton Dump truck

VI. Tunnel shall be support immediately depending upon the standing time of the rock mass

after excavation which is greatly controlled by the quality of the rock masses at the tunnel

section. Ground support methods shall be utilised to support the tunnel such as by using

steel ribs, shortcrete and rock bolts. The thickness, length and spacing of support methods

shall be decided by the value of the rock mass quality.

Steel Rib

A set of steel rib will be installed using machineries such as Drilling Jumbo. H-125 and H-200

size of the steel rib shall be used in accordance with the rock condition. After setting steel rib

to the designated position, the steel ribs are connected to the previous set by tie-rods.

Shotcrete

Especially in the section where the rock condition is poor and cutting face or perimeter is

likely to collapse easily, the initial shotcrete shall be applied prior to the installation of steel

rib support. An initial layer of 30 to 50 mm shall be applied in line with the support type to

cover the excavated surface and prevent deterioration of the newly excavated rock surface.

Rock Bolt

After the shotcrete is applied, rock bolts shall be installed. Specified type of rock dowel

length of 3.0 m - 4.0 m shall be used depending on the geological condition.

VII. Groundwater in rocks especially in fractures and faults shall be identified and located and

remedial measures shall be conducted to prevent flooding and seepage of groundwater into

the tunnel.

E. Mitigating measure for main dam and RCC section of Saddle Dam

I. Specific foundation preparation for RCC dam foundation work shall be conducted as follows;

(a) Excavation to the designated rock condition – slightly to moderately weathered rock; (b)

cleaning of the rock surfaces; and (c) treating irregularities such as holes, joints, shear

zones, weak seams, surface mudrocks which may deteriorate, overhangs, irregular surfaces,

and other areas of the rock foundation unsuitable for the foundation of the RCC dams.

II. The pressure gradient (problem with high pore pressure) in the foundation shall be

controlled using standard practice such as installing the following features:-


Mitigating Measures


a. Grout curtain within the foundation, shall be built near the upstream face of the dam. The

main purpose of this grout curtain is to reduce the permeability of the foundation by

grouting defects and joints within the rock foundation. The grout curtain shall be used to

reduce the permeability to reduce leakage, reduce the seepage erosion (piping potential) in

foundation and reduce the uplift pressure. Construction of the grout curtain comprises the

drilling of holes and injection of grout-based slurry at pressure into these holes to infiltrate

higher permeability joints and defects within the foundation.

b. Drainage curtain within the foundation and dam, located near the upstream face of the dam

but downstream of the grout curtain in the foundation zone. The main purpose of this

drainage curtain is to provide a higher permeability area immediately downstream of the

relatively impermeable grouted zone. The drainage curtain was designed to intercept

seepage through the grout curtain and upstream face of the dam and reduce the phreatic

surface in the body of the dam and foundation downstream of the drainage curtain.

Figure 10.4.17 The Location of Grout Curtain and Drainage Curtain in the Foundation of

the Dam

III. The aggregates for RCC dam construction must be very strong and free from reactive exotic

minerals such as pyrite. RCC mix must ensure that the following aspects are taken into

consideration: watertightness, strength, density, durability and crack control. All aggregate

for RCC mixture shall be processed from approved limestone source from the approved

quarry. Limestone is processed as aggregates because its great ultimate stretching strain is

in favour of anti-cracking for concrete. For design purposes, the composition of the mixes

has been assumed as shown in Table 10.4.5. It is intended to utilize a single RCC mix

throughout the dam. However, if this cannot practically and economically meet the design

criteria, zoned areas of different mixes shall be used.


Mitigating Measures


Table 10.4.5 RCC Proposed Design Mix

Material Unit Range

Nominal Maximum Aggregate Size

Mm 50

Free Water kg/m3 110-130

Portal Cement kg/m3 60-75

Natural Pozzolan /Fly Ash kg/m3 100-120

Fine Aggregate kg/m3 700-770

Coarse Aggregate kg/m3 1300-1400

F. Mitigating measure for re-regulating dam construction

I. The cofferdam shall be constructed to prevent any surface water leakage or groundwater

seepage from underneath the cofferdam. All major cofferdams shall be planned, designed,

and constructed to the same level of engineering competency as for main dams.

Excavations for permanent structures shall be made so as not to undermine the cofferdam

foundation or otherwise lead to instability.

II. The mitigating measures for the Re-Regulating dam construction is similar with the RCC of

the main dam and is already described in details in previous section.

III. Main Dam Reservoir (Site Clearing) - Good management practice during clearing and

excavation of the top soil shall be adopted to prevent erosion and slope failures (landslides)

especially at higher terrain with steep slopes.

IV. Excavation of Re-Regulating Pond - The excavated material shall be used to build the

embankment for the permanent Main Access Road portion that goes thru the Re-regulating

pond.

V. Power Intake and Spillway Construction - No remedial measures needed since this

construction stage will not affect the geology and geotechnical of rocks.

VI. Continuous monitoring of slope shall be conducted together with the mitigating measures to

stabilize the slopes. A study of possible induced seismic activity should be made at least in

cases where the reservoir exceeds 5 × 108 m3 in volume, or 100 m in depth.

VII. Special precautions when cutting a new slope for access road construction. The slopes shall

be cut at suitable angle to prevent slope failure.

G. Mitigating measure for saddle dam construction

I. River Diversion - There is no river passing through the Saddle Dam. Therefore, no river

diversion works will be necessary at the Saddle Dam Site.

II. Saddle Dam composition - To avoid the risk of differential settlement that may affect the

dam body along the buried cliff interface, the saddle dam shall be designed as a composite

structure. The left bank (eastern) portion of the dam is an RCC structure. The right bank

portion is an earth-fill embankment that wraps around the right end of the RCC structure to

mitigate against any settlement cracks that may develop in the RCC over time. The interface

between the RCC and earth-fill sections of the saddle dam is located near the buried cliff

interface between karstified limestone/marble and adjacent clay/silty clay overburden.

III. The mitigating measures for RCC have been explained in the previous section.

IV. Earth Fill saddle dam:

(a) The footprint of earth-fill embankment shall be stripped to remove organic soil, alluvium,

weak clays and major tree roots. The dam body shall be founded on moderately weathered


Mitigating Measures


or fresh karstified limestone/marble. For the left (RCC) portion of the dam, foundation

material is karstified limestone/marble and excavation depths will vary from 5 to 40m. . In

order to minimise differential settlement, arching and associated effects, it shall be

necessary to trim protrusions and infill depressions with dental concrete to achieve a regular

profile. This shall allow placement and compaction of the first layer of core-fill without

undue difficulty.

(b) Consolidation grouting shall be required for the rest of the dam foundation to improve the

strength of the foundation and minimize the settlement and deformation of the dam. It is

also important to reduce the development of pore pressures within the dam and foundation.

Consolidation grouting is also aimed at improving the behaviour of the foundation in terms

of increasing bearing capacity and reducing elasticity. Consolidation grouting is typically

undertaken within the foundation on a 2 x 2m grid, beneath core and shoulder earthfill zone

and extends to 10m below the karstified limestone/marble surface. For the area with deep

overburden underlain by weathered metamorphic bedrock at depth, the consolidation

grouting shall cover the foundation beneath core earth-fill zone and shall extend to 10m

below dam foundation.

In order to control the pressure gradient through the dam and foundation, a single line of

grout curtain shall be constructed within the foundation, beneath the core earth-fill zone

through overburden material and/or karstified limestone/marble until 10 m below

metamorphic rock. The main purpose of this grout curtain is to reduce the permeability of

the foundation by grouting defects and joints within the foundation rock.

V. The 1986 Feasibility Study Report (FSR) identified areas of coarser fill from residual

metamorphic rock that would be suitable for the shoulders of a zoned dam. The material

from excavations for the diversion tunnels and main dam foundation shall be reused as

construction materials for this dam (subject to the suitability of the materials from further

laboratory tests). Suitable materials shall be stockpiled near the designated spoil dumping

area. The best quality clay derived from residual bedrock and sourced from designated

areas near the saddle dam shall be reserved for the central core of the dam. Clay material

shall also be hauled from designated borrow areas for placement at the Clay Core zone of

the earth-fill embankment Sand drains shall be built into the shoulders of the dam to

accelerate the rate of pore-water pressure dissipation. The material for sand drain shall be

obtained from the river bed of Nenggri.

Estimated materials volumes for the construction earth-fill dam are as follows:

Table 10.4.6 Estimated materials volume

Earth material (zoned) Volume (m3)

Clay Core Materials 30,000

Shoulder Materials 300,000

Fine Filter 25,0000

Coarse Filter 5,000

Layered Rip-rap zone 25,000


Mitigating Measures


H. Mitigating measures for construction of resettlement area

I. The soil erosion will be at minimum once the soils are stable and fully covered with slope

protection, buildings, and concrete pavements. Therefore, to avoid excessive erosion during

construction, all bare slopes (cut and fill slopes) shall be covered with temporary plastic

sheet at all times. Avoid cutting the slopes during wet season (heavy rainfall) to reduce

excessive erosion of soil.

II. Minimise cutting of new slopes. Cut slope with a ratio 1:1.5 and fill slope of 1:2.0 shall be

utilised during construction of cut and fill slopes. Minimise the design to avoid excessive

permanent change of surface morphology and topography.

III. Cutting shall be minimised and the height of cut and fill shall be limited to slopes of 6m

before benching. The use of drain on each bench shall be placed to drain the water out

from the slope. Slope angle of weak soil shall be reduced. Avoid excessive overloading on

soft materials without any engineering ground improvement to enhance the stability. Avoid

cutting slopes at steep angle to reduce the risk of slope failure.

10.4.7 WASTE MANAGEMENT

A. Mitigating measures for biomass management from land clearing of dam site

In view of the above potential impacts due to the biomass, the large amount of biomass

generated from the project, the following mitigating measures are proposed:

I. The amount of biomass left on-site should be minimised as far as possible, by maximising

collection of timber logs (stems and branches >30cm diameter) and maximising collection of

woody materials useful for chipboard industries (stems and branches with ~5cm <diameter

<30cm). A brief on chipboard is given in Figure 10.4.17 below. There are a number of

chipboard manufacturers in Malaysia, one large manufacturer is MIECO Chipboard Berhad,

with plants located in Gebeng and Kechau Tui, Pahang, Malaysia.

II. Biomass not taken out and left on site will be piled as rip-rap across slopes, to act as erosion

control barrier. Left in the pile the biomass eventually rots and fertilises the area (if not

submerged) encouraging regrowth of shrubs and eventually trees.

III. Rip-rap piles should also be carefully made along the river banks; these should act as filters,

and prevent pieces of broken twigs from being carried by runoffs into the river.

IV. Expected removal of unwanted biomass in the 2,145 hectares of forest reserve areas and

another 2,080.75 hectares of agricultural areas, (other than the merchantable logs) i.e. roots,

branches and shrubs should follow proper guidelines and disposal should be at the designated

approved dumpsites by local authority.

V. Cutting and stacking of branches require large number of workers; locals should be employed

and they should be disciplined on waste management (see next).


Mitigating Measures


Chipboard

Wood pieces which have no timber value are machine debarked and chipped into particles.

The particles are glued together under heat and pressure to form a chipboard. When glued

between two pieces of wood laminates, the laminated chipboard can be used for various

parts of furniture and construction parts. There will be a lot of value addition to the final

product. The construction style has changed and demand of chipboard and laminated board

has significantly increased.

Figure 10.4.18 Use of woody remnants biomass for making chipboard

B. Mitigating measures for Sewage and Sullage Management

Potential pollution of surroundings by sanitary wastewater and garbage may be minimized by

providing sufficient number of mobile toilets and treating the effluent from the toilet and the

sullage in self-contained packaged small sewage treatment (SST) units which are readily

available in the market. An example is shown below (Figure 10.4.18) Only clear effluent from the

unit which satisfies the Standard A of the Environmental Quality (Sewage) Regulation 2009,

EQ(S)R, 2009 (see Table 10.4.8 below) with ammoniacal-N at less than 5 mg/L should be

discharged to the receiving water bodies. The SST units may be dug up and reused elsewhere,

once the construction period is over. There are several campsites ad working areas, as shown in

Table 10.4.9; each of these should have the SST unit(s) according to the number of people residing

in at the camp or depot (see Figure 10.4.19) Otherwise the sewage and sullage may be regularly

carried by tanker to a nearest sewage treatment plant whose discharge meets the EQ(S)R, 2009


Mitigating Measures


limits, however this entails long transport, and risk of accident, leakage, etc., and over the long

term would be more expensive.

Table 10.4.7 Environmental Quality (Sewage) Regulations 2009 Emission Limits

Parameter Unit Std A Std B

(a) Temperature oC 40 40

(b) pH Value — 6.0-9.0 5.5-9.0

(c) BOD5 at 20°C mg/L 20 50

(d) COD mg/L 120 200

(e) Suspended Solids mg/L 50 100

(f) Oil and Grease mg/L 5.0 10.0

(g) Ammoniacal Nitrogen (enclosed water body) mg/L 5.0 5.0

(h) Ammoniacal Nitrogen (river) mg/L 10.0 20.0

(i) Nitrate – Nitrogen (river) mg/L 20.0 50.0

(j) Nitrate – Nitrogen (enclosed water body) mg/L 10.0 10.0

(k) Phosphorous (enclosed water body) mg/L 5.0 10.0

Figure 10.4.19: Example of Packaged Sewage Treatment Plant


Mitigating Measures


Table 10.4.8 Base Camps and Storage Areas in Hectares


Mitigating Measures


Figure 10.4.20 Locations of Base Camps and Storage Areas


Mitigating Measures




Mitigating Measures


C. Mitigating measure for garbage management

With respect to garbage management sufficient number of covered garbage bins at required

locations should be provided and garbage should be collected everyday and disposed by a licenced

commercial garbage collector. The biodegradables have to be regularly and promptly collected to

avoid leachate, odour and pests, while the non-putrescibles may be collected about once a

fortnight (dry collection).

Otherwise, considering the remoteness of the area, putrescibles and canteen wastes may be

composted in in-situ composters such that only paper, plastics and bottles may be segregated and

disposed about once a fortnight (Figure 10.4.21) Such composters are now available in the market

(e.g. envirosource composter, refer: www.envirosourcesb.com). If the biodegradables are

composted at home in home unit composters (see picture below), then collection trips may be

reduced to about once per fortnight, reducing the number of truck-trips in the area to about 10%.

The non-putrescible materials maybe sent to recovery centres for recovery of metals, plastics,

paper and cardboard, and glass. All mitigating measures related to construction will be the

responsibility of the contractor undertaking the project, thus should be included in the tender

document, and as part of the EMP activities.

Home Unit Composters

Home unit composters for disposal of putresibles from kitchen

wastes, leaving only metals, plastics, papers, etc for dry disposal

or recycling (www.envirosourcesb.com). Such disposal removes

the most unpleasant part of MSW.

Composter home units

Garbage

organics turned into compost

Compost collection

from composter

bottom

View of garbage organics in composter

http://www.envirosourcesb.com/


Mitigating Measures


Larger,

centralised

composters

Figure 10.4.21 Composting of putrescible wastes to prevent leachate, odour and pest

proliferation

D. Mitigating measure for construction waste

I. The contractor has to be made responsible for proper management of wastes at site and the

daily SOP has to include site management to ensure all wastes are properly taken care of. The

SOP becomes part of the EMP for the Site Environmental Officer (EO).

II. All waste disposal is the responsibility of the contractor; a part of progress payment should be

retained and released only upon satisfactory site waste management.

III. As far as possible wastes should be sold to recyclers, eg, metal scraps, cardboards, plastics,

etc.

IV. Unrecyclable wastes to be properly disposed at nearest landfill.

E. Mitigating measure for schedule waste

I. For scheduled wastes, the DOE has to be notified of their generation via the online scheduled

waste reporting system. These wastes shall be stored in secure storage areas, constructed in

accordance to requirements of the Environmental Quality (Scheduled Wastes) Regulations

2005, EQ (SW)R 2005. All aspects of management of scheduled wastes have to be in

compliance with the EQ (SW)R 2005, such as, scheduled wastes can only be collected and

transported by licensed collectors and transporters, and their labelling, handling and storage

have to be as stipulated by the EQ(SW)R 2005. Clearly labelled and secure storage facilities

have to be erected to ensure that people and premise are safe from possible fire, waste

spillage, reactions, etc. Fuel and waste oil storage bases have to be bunded, with bunded

volume at 110% of maximum tank volume. Any spillage shall be promptly collected and

managed as scheduled waste(s). All wastes have to be accounted for and audited against the

raw materials (lubricants, etc) brought in.


Mitigating Measures


10.4.8 LANDUSE

A. Mitigating measures for permanent landuse changes

I. Loss of current forest is considered residual. Only left vegetation should be retained to go and

aid in forest floor protection.

10.4.9 ARCHAEOLOGY

A. Mitigating measures for possibility of new discovery of Neolithic settlement

I. There is a possibility of new discovery of open sites associated with Neolithic settlement on

the river banks of Sungai Nenggiri. The new data will be valuable for Malaysia archaeology

especially in Kelantan because there are only a few data concerning open sites Neolithic

settlement in Hulu Kelantan.

II. New discovery of the archaeological sites should be reported to the Jabatan Warisan.

B. Mitigating measures for loss of existing archaeological sites

I. Archaeological excavation on all archaeological sites affected by the dam construction should

already begin before the impoundment period. Excavation licence should be submitted to the

Jabatan Warisan Negara before any archaeological excavation begins.

II. Surface survey to be carried out, so any archaeological findings can be recorded and rescue

excavation can be arranged. The survey can be conduct by archaeologist, contractors or local

villagers especially who are familiars with prehistoric artefacts especially polished stone tools

and pottery shards which associated with Neolithic settlement.

III. All found artefacts are recommended to be stored or displayed at public access location at

Gua Musang town. A Further communication by Jabatan Wariasan Negara and Perbadanan

Musium Kelantan with Gua Musang Districts Authority could make possible for this rescue

plan.

IV. Any excavation of the archaeological sites should involve the Jabatan Warisan Negara officers.

V. Prepare the temporary storage sites and safely guard for all the archaeological findings during

excavation before stored at permanent places or gallery. This to make sure that the items is

not missing and properly managed.

C. Mitigating measures for main dam construction

Rescue all archaeological context data through rescue excavation before dam construction and

record in database.

D. Mitigating measures for re-regulating and saddle dam construction

Periodic monitoring by archaeologist or trained ground worker with archaeological knowledge

should be undertaken.

10.4.10 TERRESTRIAL FLORA

A. Mitigating measures for loss of vegetation

I. The proposed development is situated in logged-over forest areas, hence the existing and

abandoned logging roads and base camps should be utilised to minimize disturbances to the

natural ecology.


Mitigating Measures


II. Planting of shrubs and trees which are the natural habitat of the area along the unpaved

areas such as on both sides of road shoulders in the Proposed Project site would enhance the

landscape of the area and also helps to prevent erosion.

III. Some parts of the access roads that pass through low lying flood-prone such as Pos Tohoi,

should be reinforced and upgraded.

IV. Similar to Rescue and Salvage Operation of Wildlife, plants that include wildings, herbs,

gingers, and ferns should be salvaged, replanted and grown in temporary nursery established

by the project proponent. Assistance from Kelantan Forestry Department should be requested.

All expenses for plants salvage operation should be covered by the logging concessionaires.

The plants may be used later in restoration activities.

V. The most important species that need to be conserved is Suregada multiflora var. lamellata.

VI. Ecosystem function rely on common species (Keith et al. 2015), hence rescue operation and

recovery plan should also be undertaken for common species other than the selected

threatened flora species. The wildings of Dipterocarpaceae species of a lowland dipterocarp

forest in this study site should be rescued as well.

B. Mitigating measures for loss of forest tree species biomass

I. Expected removal of unwanted biomass in the 2,145 hectares of forest reserve areas and

another 2,080.75 hectares of agricultural areas, (other than the merchantable logs) i.e. roots,

branches and shrubs should follow proper guidelines and disposal should be at the designated

approved dumpsites. No open burning is allowed. Some of the biomass can be utilized in the

LD-P2M2.

II. Some of the plant parts can also be utilized as rip-rap in marshy grounds during construction

works and used as protective materials against surface erosion of exposed ground.

Table 10.4.9 List of Dipterocarpaceae Species of a Lowland Dipterocarp Forest

Dipterocarpaceae species to be rescued for replanting

Anisoptera scaphula Dipterocarpus cornutus Dipterocarpus oblongifolius Dryobalanops oblongifolia ssp. occidentalis Hopea mengerawan

Hopea pierrei Shorea leprosula

Shorea ovalis ssp. ovalis Vatica bella Vatica nitens

C. Mitigating measures for construction of resettlement area

I. Access Road, Base Camp, Resettlement Houses and Facilities

To minimize significant impacts on the biotic components, the Project Proponent should adopt

sound development approach and design concept that aim to reduce the loss of natural land

cover, minimize earthworks and balance any cut and fill activities.


Mitigating Measures


II. Site Clearing and Earthworks

Temporary drainage and adequate silt traps and retention ponds should be constructed to

cater for the increased surface run-off and sediment loads during the site clearing and

earthwork phase. The run-off should be collected and should not be discharged directly into

Sg. Perias, Sg. Nenggiri and their tributaries thus allowing sufficient time for solids to settle

down.

The silt traps and retention ponds should be regularly de-sludged to prevent overflow. The

collected sludge and turbid water should not be discharged directly into the nearby rivers.

Only settled water should be allowed to be discharged into Sg. Perias, Sg. Nenggiri and their

tributaries. The silt traps and retention ponds should be effectively and properly maintained

by the project proponent and its contractors until the completion of the construction phase.

Mature forest trees that are felled and removed for construction works should be replanted to

provide food and shelter for the resident wildlife and other fauna. Fruit trees such as petai,

jering, durian, rambutan, mango, etc. should be planted under tree crop enrichment scheme

to provide extra food resource for the Orang Asli and others.

III. Abandonment

Proper land treatment measures would include surface levelling, ground re-compaction and

re-vegetation to improve its physical and functional characteristics. Abandonment in the

exposed bare area should be mitigated by encouraging natural regeneration of ground cover

and riparian vegetation.

All abandoned structures should be dismantled. Any exposed ground should be compacted

and planted with vegetation so as to minimize erosion.

10.4.11 TERRESTRIAL FAUNA

A. Mitigating measures for illegal hunting and poaching

I. Workers need to be educated on the important of maintaining diversity of flora and fauna by

developer, contactor and PERHILITAN. They also need to be brief on the local laws. Site

supervisors need to be responsible in managing their employee.

II. Regularly law enforcement (e.g. PERHILITAN) need to monitor workers at the work areas. If

possible, do not allow workers to live inside or closer to forest area except during working

hours and only at the work areas. Further, solid waste and sewage disposal, construction of

temporary buildings, storage facilities and working areas need to be properly managed to stop

pollution.

III. The remaining forests and rivers along the chosen access roads should be legally protected

on-the-ground from further degradation. Considerations in the placement of culvert

installations that would reduce sedimentation or surface runoff on stream flow. Since most of

study areas are logged forest and plantation, the number of amphibian and reptiles species

from this study is considered low due to excessive change of microclimate, thus reduced

abundance and diversity.


Mitigating Measures


B. Mitigating measures for human-wildlife conflict & wildlife displacement

I. Site clearing and subsequent activities (e.g. earthworks) are to be carried out in phases to

minimize the size of exposed areas at any particular time. This will hopefully allow some

wildlife (terrestrial and arboreal) to take refuge in nearby habitats.

II. Any sighting of endangered wildlife within the reserve or adjacent to the work areas need to

be reported to the Department of Wildlife and National Park (PERHILITAN).

C. Mitigating measures for loss of habitats

I. No proper mitigation can be provided except try to minimize the work areas and ensuring no

encroachment of wildlife inside the work areas (See site preparation section above).

II. The presence of endangered wildlife species need to be reported to PERHILITAN where

proper action can be made.

III. Rehabilitation by planting the open areas with native species immediately after removal will

help to enhanced plant regeneration process, thus the plant cover will develop faster and

erosion process will be reduced.

IV. The procedure of planting native species at the open areas generally needs to be based on

the local plant community. However totally barren area may not yet suitable to be planted

with the local species, thus introduction of exotic species may be required. Other local plant

species that may be planted earlier is the fruit and flowering species that may attract birds.

D. Mitigating measures for disturbance to wildlife

I. Minimize the work areas and ensuring no encroachment of wildlife inside the work areas (See

site preparation section above).

II. The presence of endangered wildlife species need to be reported to PERHILITAN where

proper action can be made.

III. Project activities should be carried out in stages to allow some wildlife (terrestrial and

arboreal) to take refuge in nearby habitats.

10.4.12 FRESHWATER ECOLOGY

A. Mitigating measures for damaging the river habitat and deteriorate water quality

I. The contractors must follow the JPS established guideline for river reserve and river corridor.

No any activity is allowed within river corridor area and plant wastes are not allowed to be

dumped in the river corridor zone even in the river body.

II. The contractor must use existing logging bridge where possible and new temporary bridge

crossed the river should be installed to avoid the disturbance of the existing river flow and

river habitat. No river crossing should be practiced at upstream rivers or streams that will not

be impounded by the Dam. This includes upstream of Sg. Beruk, Sg. Perias, Sg. Jenera, Sg.

Puian and Sg. Wias.

B. Mitigating measures for contamination in the river system

I. All retention ponds and sedimentation controller recommended by LDP2M2 should be

prepared and followed accordingly. A regular inspection must be conducted to confirm the

efficiency of those methods to cater sedimentations especially during rainy periods.

II. An oil and grease trap should be installed at oil/diesel tank and machinery workshop to

overcome oil or grease leakage to the riverine system.


Mitigating Measures


III. Biological contamination from worker basecamps can be control by using proper waste

management system.

IV. Proper sewage system must be install according to the schedule waste regulations.

V. A signage for “no fishing” must be located at strategic place to ensure all workers aware that

fishing is prohibited.

VI. The contractor should have a proper waste management practice as recommended in waste

management section.

C. Mitigating measures for sediment load to the river

I. The contractors are strongly recommended to conduct clearing activity during dry period to

avoid vigorous surface runoff since timber forest is located at hilly area. River corridor must

be left untouched to role as buffer to minimize sedimentation.

II. The LDP2M2 recommendation for sedimentation control such as preparation of sediment pond

and silt curtain must be followed.

III. The ‘matau’ should be located above the flood elevation to avoid drifted during heavy rain and

cause serious river damage.

IV. River crossing by machinery at outside of inundation area is prohibited and temporary bridge

or existing bridge must be used.

V. Site clearing and logging should be conducted in phases to reduce disturbance. This will

minimize total bare areas and allow shrubs and weeds to grow and cover the exposed soil. A

detail protocol of land proposed by LDP2M2 must be followed.

VI. The biomass should be removed and disposed-off. Disposed by burning should not be allowed

as it can create other environmental issues. A suitable dumping site must be provided.

10.4.13 ANTHROPOLOGY

A. Mitigating measures for animals migrating into Orang Asli villages

I. Catch and relocate the animals (e.g. elephant) to a new sanctuary must be conducted. Advice

and help from the Department of Wildlife must be secured.

B. Mitigating measures for tension and worries among the Orang Asli dwellers

I. In order to mitigate the worries caused by the presence of foreign workers in the proximity of

the villages, the workers must be advised not to visit the village frequently.

II. To reduce any feeling of uneasiness related to the presence of heavy vehicles in the Orang

Asli area, it is recommended that all the vehicles should be parked away from the villages.

III. Access road to the working sites should avoid using the existing road running through the

Orang Asli village. Road deviation must be constructed where necessary.

C. Mitigating measures for villagers exposed to the road accidents

I. To avoid accidents to road users at the project sites, steps to improve the existing road must

be taken.

II. The road must be broadened and surfaced with proper material to avoid it from being

destroyed by heavy vehicles usage.

III. Road signage must be put in place to guide road users.


Mitigating Measures


D. Job opportunities to the local people

I. To encourage Orang Asli to seek employment during the construction period, information

regarding the job openings must be circulated to the villagers.

II. The Penghulu and the Pengerusi JKKK and also JAKOA Gua Musang must be used to help in

recruiting interested individuals.

E. Mitigating issues of losing roaming areas and tanah adat.

I. Roaming the jungle is only carried out by few individuals when necessary. It has not been

practised like what they have done before. The destruction of the forest for commercial

crops plantation surrounding their village have reduced this activity. In reality such activity is

seldom conducted today. According to one Penghulu, the people in his village prefer to roam in

Gua Musang rather than into the forest, because the forest now is very far away from their

homes. The Orang Asli also found it more profitable to work as labourers in the Oil Palm

plantation rather than roaming the jungle.


A. Mitigating measures for presence of foreign workers in local community

I. Racial clashes and other social problems especially at the base camp could be avoided if

workers’ interest could be looked after, cordial relationship should be maintained and cultural

tolerance had been initially brainwashed to them. Different nationalities should be placed or

camped differently in order to avoid from the racial clashed.

II. Plants, base camps, workshops, etc. if not completely dismantle and remove will mar the

general aesthetics of the surrounding area. The remaining structures left unattended will over

time become unsafe, endangering unsuspecting persons who happen to pass through the

area. Proper action should be taken care in order to demolish the waste properly.

B. Mitigating measures for conflict between local community and foreign workers

Workers at the base camp should not be mixed among the locals and foreigners to avoid racial

clash, different in cultures and beliefs.

C. Mitigating measures for affected the livelihood of villagers

I. The construction activities such as earthworks and removal of vegetation should be plan

properly to minimised the surface runoff and erosion into the Sg. Nenggiri.

II. All LD-P2M2 measures shall be installed and properly maintained to protect the Sg.Nenggiri

and its networks hence, protect the livelihood of villagers who their life is depend on Sg.

Nenggiri resources.

D. Mitigating measures for production of waste

I. Proper waste management system should be employ during the construction of Nenggiri Dam,

in particularly the solid waste. This is to prevent the existance of the breeding ground for

mosquitoes.

II. Proper sanitatiion facilities should be installed to prevent any health problems to the workers.

III. Regular housekeeping of the project site should be implement to maintained cleanliness and

prevent overproduce of solid waste.


Mitigating Measures


E. Mitigating measures for waste from demobilization

I. All waste from the demobilization should be collected and disposed at the approved dumpsite.

II. The scheduled waste should be managed accordingly to the standard procedures.

III. Any exposed areas after the demobilisation should be properly rehabilitated.

F. Mitigating measures for grave yard

I. The abandoned grave yard should be relocated and follow the procedures such as inform or

look for their heirs and also inform the Pejabat Agama Islam Gua Musang.

10.4.15 ECOTOURISM

A. Mitigating measures for Reduce/loss of ecotourism attraction places

I. All ecotourism sites that associated with archaeology sites must be recorded and rescue before

the construction of Nenggiri HEP initiates.

II. Unnecessary opening of a new area (for borrow areas, quarries, spoil dumps) shall be avoided

to minimise the size and extent of the disturbed area.

10.4.16 PUBLIC HEALTH

A. Mitigating measures for outbreak of communicable diseases

I. The project proponent has to adhere to the Malaysian guidelines on worker intake that

required each of the employees to have a full medical check-up.

II. The project proponent has to establish a comprehensive medical surveillance system to

monitor those workers' health.

III. Regular health campaigns usually help to prevent any outbreak at the workers base camp, if

any.

IV. Exposure to all workers about the local Malaysian culture and laws that have to be embedded

in each worker attitude and behaviour.

V. Worker's camp equipped with a dedicated solid waste management system of the entire area

of development.

VI. The contractors involved should follow the standard operating procedure, including type of

vehicle used, route and schedule for the waste collection. Delaying in the waste collection

must be minimised.

VII. The cleanliness of the whole development areas needs to be put as the first priority by all

parties, including workers, developer and local government agencies. Any renovation has to

get the local authority clearance and to be carried out only by registered contractors with good

housekeeping practises.

B. Mitigating measures for motor traffic accident

I. The transit of large load or machineries needs to be escorted by safety personnel.

II. The route of transportation needs to be identified and as far as possible, avoid congested

roads and junctions.

III. Extra road signage needs to be implemented.

IV. At every dangerous spot, project proponent needs to put a control point to ease the traffic

and to prevent any collision.


Mitigating Measures


V. All planted vegetation and trees need to be trimmed regularly to ensure no blind view for

coming vehicles or pedestrian.

VI. Zebra crossing, yellow lines, traffic lights and bumpers may need to be in-situ on certain

critical points.


Mitigating Measures


10.5 MITIGATING MEASURE DURING LOGGING

This section shall discuss the mitigating measures for the impact arising from activities that will be

carried out during logging/vegetation clearance phase. The main potential impacts arise from the

logging/vegetation clearance phase are listed in Table 10.5.1 below:

Table 10.5.1 Summary of Potential Impacts during Logging Phase

No Environmental


1 Air quality I. Dust pollution

2 Noise & vibration I. Noise nuisance from construction of access road for logging

II. Noise nuisance due to movement of Heavy Vehicles & machineries

3 Water quality

I. Sediment pollution in river systems II. River water contamination

III. Sedimentation due to soil erosion IV. Increase in solid pollution, organic pollutions

4 Hydrology I. Runoff and flash flood

II. Degradation of river capacity

5 Soil erosion I. Occurrence of soil erosion

6 Geology &

geotechnics I. Slope failures

7 Waste management I. Biomass waste

II. Sewage from workers camp

8 Archaeology I. Damaging the archaeological sites

9 Terrestrial flora

I. Loss of commercially and ecologically important species. II. Landslides and mud slides, especially during the wet season

Loss of carbon sequestration (Dr. Wan Ju) (nilai loss of carbon)

10 Terrestrial fauna

I. Loss of habitats II. Loss of direction

III. Displaced and stranded IV. Wildlife-human conflicts V. Poaching

11 Freshwater ecology I. Loss of aquatic communities due to sedimentation load in the

river system II. Oil and grease contamination in the river system

12 Anthropology I. Affect the tranquillity of the Orang Asli community

II. Loss of roaming area

13 Ecotourism I. Loss of ecotourism site

14 Socio-economic I. Employment opportunities

II. Impact on tranquillity III. Human-wildlife conflict

15 Public health I. Increase in vector borne disease incidents


Mitigating Measures


10.5.1 AIR QUALITY

A. Mitigating measures for generated of air pollutants

I. For dust control, cleared areas especially in the pathway of vehicles should be hosed down or

dampened to settle the dust by using water sprays.

II. The speed at which lorries ply unpaved roads or dry mud tracks should be restricted as dust

generation would be excessive at high speeds on these roads, especially during dry periods.

III. All the heavy vehicles such as land bulldozers shall be cleaned before leaving the worksite and

entering the main roads.


A. Mitigating measures for noise nuisance from construction of access road for

logging





B. Mitigating measures for noise nuisance due to movement of Heavy Vehicles &

machineries






A. Mitigating measures for sediment pollution in river system

I. The construction of access road and logging track must be plan properly and should locate

away from river.

II. Buffer zone must be preserved along the river to minimize the sediment transport to the river.

III. Any open area of exposed soil should be promptly turfed or covered. Perimeter drain of

particular construction area should be built to manage the runoff water during rain.

IV. Implementation of all mitigating measures as stated in LD-P2M2.

10.5.4 HYDROLOGY

A. Mitigating measures for runoff and flash flood

I. All access road during logging period must be proper designed and maintained. If possible,

the construction of access road should be far away from the water courses (at least 20 m

from the riverbanks).

II. Proper terrains must be constructed beside the steep roads to avoid landslide or slope failure.

Wherever river crossing to be made, a proper bridge must be constructed bank to bank to

avoid minimal disturbance to water body.


Mitigating Measures


III. Table drains, culverts and other drainage structures such as those needed to channel run-off

water to road-side filter strips prior to entry into streams should be installed concurrently with

access road construction.

IV. Install cross-drains in on abandoned roads, skid trails, landings, etc. with slopes >10% (5

degrees) to ensure water runoff is channelled off the road and into surrounding forest.

V. Cross drain spacing should be proportional to the slope of the road i.e. steeper gradients have

more frequent cross drains. Generally "cross-drains" on roads of moderate slope (10%)

should be spaced at 30-50 meter intervals. Cross drains prevent soil erosion and loss of

culverts and bridges, preserving skid trails, roads and landings for use in future selective

harvesting operations.

B. Mitigating measures for degradation of river capacity

I. Earthwork for logging activities and transporting the logging using heavy vehicle should be

carried out during suitable time period (month of the year), proper methods (such as partial

mechanization method) and procedures and selection of machineries to reduce unnecessary

surface erosion.

10.5.5 SOIL EROSION

Mitigating measures to be adopted during logging phase can be referred to section 10.4.7.

Conceptual drawing of the proposed mitigating measures is shown in Figure 10.5.2.


Mitigating Measures




Mitigating Measures


Figure 10.5.1 Location of the Deforestation Area


Mitigating Measures


Figure 10.5.2 Zoom in LD-P2M2 at the Deforestation Area


Mitigating Measures



A. Mitigating measures for slope failure

I. Proper design and maintenance of slope along the construction of new timber tracks to be

conducted. Avoid design steep slope (>35o) in soil material. Use benches/berns for higher and

steeper slope.

10.5.7 ARCHAEOLOGY

A. Mitigating measures for damaging the archaeological sites

I. Continuous monitoring at the logging area should be taken especially along the river banks of

Sg. Nenggiri, Gunung Kemiri and also at the main dam. If any new sites being found during

the activities, rescue excavation and documentation should be carried out.

II. Proper training to the contractor who involve in lodging activity on how to identify prehistoric

artefacts, ecofacts and features.


A. Mitigating measures for loss of commercially and ecologically important species

I. Any areas of more than 300 m above mean sea level i.e. hill dipterocarp forest must not be

logged.

II. The logging method must follow Operational Forest Harvesting Plan (OFHP) and comply with

the existing Reduced Impact Logging (RIL) for maximum protection of forest reserve areas.

III. Logging would be supervised by the Kelantan State Forestry to ensure no unnecessary logging

in areas outside the reservoir, construction site and roads.

IV. Rescue plan for hyper endemic species Suregada multiflora var. lamelata must be prepared

and approved by the Jabatan Perhutanan.

B. Mitigating measures for forest diebacks

I. Unnecessary tree cutting and land opening and clearing should be avoided to minimize the size

and extent of the area that will be disturbed within the six affected forest reserves i.e. Hutan

Rizab Sungai Terah, Hutan Rizab Berangkat, Hutan Rizab Nenggiri, Hutan Rizab Balah, Hutan

Rizab Sungai Perias and to a lesser extent the Hutan Rizab Gunung Setong Selatan.

II. Clear felling of trees and earthwork should be conducted in phases. The first phase should

focus from the areas adjacent to open areas and move towards intact forests to ensure no

wildlife are trapped.

C. Mitigating measures for landslides and mud slides, especially during the wet

season.

I. Choosing the right alignment for new roads to dispose biomass is also required to reduce

erosion and also to reduce cutting and earthworks to minimize disturbance to the remaining

habitats.

II. After tree clearing, for biomass disposal, woody materials from tree residuals should be reused

as natural biomass filter for sediment, rip-rap and for natural topsoil cover.

III. Stacking of biomass must be done on-site, especially near streams or rivers to minimise

sediment load in surface runoff discharging into any waterways and to minimise sedimentation

problems.


Mitigating Measures


IV. Harvesting must be done in drier months i.e. February to September and avoid the monsoon

season, October to January.

D. Mitigating measures for carbon sequestration

I. Malaysia has reiterated its commitment to retain 50% of its forest areas after signing an

agreement with 195 countries at the Paris climate change talks (COP21) to reduce

greenhouse gas emissions through carbon sequestration. Hence, the carbon stocking though

replanting to offset the carbon loss should be monitored by both project proponent and

Kelantan Forestry Department.

II. Kelantan Forestry Department is suggested to classify a minimum of 5% of forest reserves in

this project area as water catchment forest to ensure enough water supply and clean water.

III. Increase plant species richness and measures to improve the river-margin vegetation such as

replanting of Dipterocarpus oblongifolius (Keruing Neram), Dracontomelon dao (Sengkuang),

Neolamarckia cadamba (Kelempayan), Pterocymbium tinctorium (Melembu) and Pterygota

alata (Kasah).


A. Mitigating measures for loss of habitat

I. The ultimate impact of this project on the wildlife are i) land clearing in which associated with

logging for site preparation and dam construction, and ii) creation of reservoir. For these two

(2) main activities the most important impact is loss of habitat, which is cannot mitigate and

the loss will be permanent.

II. Since the inundation areas is estimated only 20% to 30% cover by forest mostly logged and

degraded forest areas (other areas are plantation both rubber and oil palm), the effect on

wildlife will be lower. The number of species generally found in plantations is those common

one. Elephants were not found within the proposed catchment areas except near Pos Pulat

with one or 2 resident individuals (based on survey in Jun 2016). The main elephant herd was

found inhabiting Nenggiri Forest Reserve, possibly the same herd roaming Balah Forest

Reserve and causing conflict near Pos Pulat and near Kg Kuala Cha (adjacent to Gua Cha).

B. Mitigating measures for loss of direction & mitigating measures for displaced and

stranded

I. Loss of direction can be minimised by monitoring of the wildlife via field survey, report from

locals, camera trapping at the high density wildlife area. Similarly the displaced and stranded

wildlife can be minimised via similar process and mitigated by guiding them back into the

forest.

C. Mitigating measures for wildlife-human conflicts

I. Conflict wildlife individuals can be mitigated differently either guiding back to the wild or

translocation (although this mitigating measure is the last option and apply only to highly

conflict wildlife that cannot be mitigated at the conflict area).

II. Early assessment is very important because mitigating of wildlife by translocation is very

expensive. As indicated above early assessment involve monitoring of the wildlife via field

survey, report from locals, camera trapping at the high density wildlife area. Educating the

surrounding community such as plantation owners is another strategy to minimise the conflict.

In high conflict area, to avoid the conflict like elephant, the following measure can be


Mitigating Measures


proposed to the plantation owners; i) constructing dry moat 6 to 7 feet deep, and ii)

construction of electric fence. Detail application of these measures need to be discuss in detail

with PERHILITAN.

D. Mitigating measures for poaching

I. Illegal poaching activities can be minimised by several ways; i) regular law enforcement and

road block, ii) cutting off all unused logging roads by trenching or boom gate, and iii)

educating workers and locals via pamphlets and talks. Law enforcement and road block only

can be done by the authority which is PERHILITAN.

To further mitigate all of the above impacts, design and establishing a good and comprehensive

Wildlife Management Plan (WMP) is needed.


A. Mitigating measures for loss of aquatic communities due to sedimentation load in

the river system

I. All logging activities strictly must follow ESCP recommendations which include land clearance

locations, phases, sizes and sedimentation control strategies. The ESCP simulates the amount

of soil erosion and surface runoff pattern and suggest the best sedimentation control. This

would minimise impacts of logging to the river communities.

B. Mitigating measures for oil and grease contamination in the river system

I. Any machinery repairing and servicing activities should only be conducted at oil and grease

leak protected area. The oil and grease trap must be installed to prevent from any oil and

grease leak.

II. A clear “No Fishing Allowed” signage must be put especially near the near the base camp and

river. The workers also need to be informed regarding Malaysian Fisheries Law regarding

illegal fishing.


A. Mitigating measures for affecting the tranquillity of the Orang Asli community

I. To reduce the impact of noise from logging activities on the Orang Asli community, it is

recommended that the work should be done only during the day.

II. Log gathering station (matau) should be located away from the settlements, and an access

road should be constructed away from the villages to avoid accidents.

III. Warning signage must be installed to inform people from getting close to the working area. In

fact it is important to inform the village heads to request his community from entering or

getting near the working spot where trees are being cut. This can avoid people from being hit

by falling trees.


Mitigating Measures



A. Employment opportunities

I. The need of workers is necessary during felling and earthwork activities. It is expected more

than 10 workers will be hired during logging stage. Moreover, the needs of the workers will

enhance the nearby settlement near Kuala Betis and Pulau Setelu by trading and providing the

necessary needs of the workers. It helps to enhance the local economies.

B. Mitigating measures for impact on tranquillity

I. Project Proponent/contractor must visually observe, monitor and control all the machinery

that been used in logging and site preparation phase. The Project Proponent/contractor also

must have time limit for the movement of heavy machinery near the village in order to

minimize the noise annoyance especially during late evening.

II. Project site also must be border marking for the determination on working area and also to

avoid unnecessary trespassing from local people and wildlife that can cause incident.

C. Mitigating measures for human-wildlife conflict

I. Conflict wildlife individuals can be mitigated differently either guiding back to the wild or

translocation (although this mitigating measure is the last option and apply only to highly

conflict wildlife that cannot be mitigated at the conflict area).

II. Project site also must be border marking for the determination on working area and also to

avoid unnecessary trespassing from local people and wildlife that can cause incident.


A. Mitigating measures for vector borne disease

I. To promote abatement of vector breeding areas by a well-behaved housekeeping and

appropriate waste management at all sites. This embraces through-out the project activities by

application of environmental controls like breeding area destruction, water container

elimination or covering.

II. In addition, to minimize human-vector contact using appropriate work attire, mosquito

repellents, and applying insecticide net at windows at working container and base camp.

Provide workers with knowledge, particularly on vector-borne diseases and surveillance

activity.


Mitigating Measures


10.6 MITIGATING MEASURE DURING QUARRYING


carried out during quarrying phase. The main potential impacts arise from the quarrying phase are

listed in Table 10.6.1 below:

Table 10.6.1 Summary of potential impacts during quarrying phase

No Environmental


1 Air quality I. Dust emission

2 Noise & vibration I. Noise from drilling and blasting activities

II. Noise due to transportation of materials

3 Water quality I. Increase the water turbidity and the suspended solids levels

4 Geology &

geotechnics

I. Slope Failure II. Falling rocks

III. Permanent loss of limestone IV. Alter of landforms

5 Freshwater ecology I. Increase of Suspended Solid

6 Socio-economic I. Affected the livelihood of villagers

II. Affected the tranquillity of villagers

7 Ecotourism I. Loss of Potential Ecotourism sites

10.6.1 AIR QUALITY

A. Mitigating measures for dust emission

I. Sheeting vehicles carrying dusty materials on leaving the site to prevent materials being blown

from the vehicles.

II. Temporary cover on exposed soil shall be implemented to reduce air-borne dust pollution.

III. Water sprinkling on unpaved area using a water tanker.

IV. Explosive materials will be stored, handled and used according to applicable regulation and

guidelines.

V. Explosive will be detonated at sufficient setback distances to control for dust / debris

expulsion.

VI. Use of best practice management techniques during extraction and loading of raw materials.

B. Mitigating measures for gasses emission

I. Regular maintenance of vehicles would help in reducing the emissions of smoke and soot into

the atmosphere. Dust generated from the construction site need to be monitored from time to

time.


Mitigating Measures



A. Mitigating measures for noise from drilling and blasting activities & mitigating

measures for noise due to transportation of materials

I. The impact of overall noise level emitted from this activity can be mitigated and minimised by

restricting vehicle passing close to residential and noise sensitive areas to day time and

working days only when working or.



III. Special permission must be obtained from the authorities if the activities are to be carried out

outside the normal working hours as well as during weekend and public holidays which may

affect the nearby residential and noise sensitive areas as mentioned above.

B. Mitigating measures for vibration from drilling and blasting activities

I. Special permission must be obtained from the authorities if the activities are to be carried out

outside the normal working hours as well as during weekend and public holidays which may

affect the nearby residential and vibration sensitive areas as mentioned above.


A. Mitigating measures for increase the water turbidity and the suspended solids

levels

I. Dust and particulate matter and solid waste from blasting, excavation works, slope cutting and

crushing activities, should be prevented from reaching water directly whether by themselves or

through runoff by means of silt curtains or sediment ponds.

B. Mitigating measures for residual solid into the receiving river thus inflating the

levels of TSS

I. Waste water from stone washing should flow into sediment pond or other treatment system

before being discharge into water body. Similarly, solid waste from recovery process should

undergo mitigating measure.

II. In the event of abandonment, all unfinished products and structures should be removed from

the site or be protected from erosion.


A. Mitigating measures for slope failure

I. Quarry of limestone should follow the quarry design specifications to minimize the impact on

slope failure and safety for workers.

B. Mitigating measures for falling rocks

I. Good blasting practise should be strictly followed to reduce the impacts of dust, ground

vibration and flying rocks that can affect the safety of workers on site


Mitigating Measures


C. Mitigating measures for alter of landforms

I. The location of quarry sites should be restricted to rocks inside the perimeter of main dam,

saddle dam and main reservoir only. The use of existing rock quarries at the vicinity of the

proposed dam site to be given high priority.

II. Existing top soil (granite and meta-sediment residual soils) within the perimeter of the

proposed project site to be reused. These materials are suitable to be used as clay core

construction material for proposed saddle dam.

10.6.5 ARCHAEOLOGY

A. Permanent Loss of Prehistoric Archaeological Site

I. All findings of archaeological sites in the quarry area should be recorded.

II. Rescue excavation should be done before any quarrying activities.


A. Permanent loss of terrestrial flora at the re-regulating dam area.

I. The permanent loss of flora especially orchard plants own by the locals cannot be mitigated.


A. Mitigating measures for sedimentation load into river

I. Silt curtain and silt trap must be installed to avoid direct sedimentation in the nearby river.

Water waste from washing activities should not to be drained directly into the river.

II. Temporary sedimentation ponds must be prepared to allow coarse particle to participate and

only nearly clear water is allowed to be drained into the river.

III. Since quarry location located nearer to the town, all repairing and servicing activities should be

conducted at nearby town and outside from the proposed area to avoid oil and grease

contamination.

10.6.8 SOCIO-ECONOMICS

A. Mitigating measures for affected the livelihood of villagers

I. All mitigating measures that has been proposed in LD-P2M2 should be installed and follow to

prevent the deteriorated of water quality of the Sg. Nenggiri.

II. Quarrying activities such as slope cutting, crushing, and stone washing should be plan properly

to avoid any residue or surface runoff into the Sg. Nenggiri.

B. Mitigating measures for affected the tranquillity of villagers

I. The residents should be informed of the commencement of the quarrying work/construction

works and of their likely duration of completion.

II. Schedule of work time should be accommodative to the needs of the people. Thus late

working hours should be limited to 8 pm only.

III. Proper signage should be installed where appropriate (e.g. at access road) to prompt and

caution the villagers about the quarrying work.


Mitigating Measures


10.6.9 ECOTOURISM

A. Mitigating measures Damaging of the ecotourism sites

I. Continuous monitoring of the ecotourism should be done to minimise damage to the

ecotourism sites (mainly caves).

II. Unnecessary opening of a new area shall be avoided to minimise the size and extent of the

disturbed area.

III. To protect the Sg. Nenggiri, the washing of stone activities must be away from the river and

the discharge water should be prevented from reaching water directly by applying the LD-

P2M2 measures.


Mitigating Measures


10.7 MITIGATING MEASURE DURING IMPOUNDMENT


carried out during impoundment phase of the Proposed NHEP. The main potential impacts arise

from the impoundment phase are listed in Table 10.7.1 below:

Table 10.7.1 Summary of potential impacts during impoundment phase

No Environmental


1 Noise & vibration I. Change of the ground vibration profile

2 Water quality I. Depletion of the level of dissolved oxygen

II. Water Quality stratification III. Biodegradation

3 Hydrology I. Reduction in water flow downstream of the dam

II. Changes in hydrological regime

4 Geology &

geotechnics I. Micro-seismic activity

II. Slope Failure

5 Hydrogeology

I. Change in groundwater level around the reservoir II. Change in the occurrence of spring flow

III. Water losses IV. Slope instability

6 Terrestrial flora

I. Submerged of the remnant vegetation II. Remnant biomass on impoundment water quality

7 Terrestrial fauna I. Permanent loss of wildlife habitat

II. Species survival III. Species population blooming

8 Freshwater ecology I. Alteration of river regime from lotic to lentic

9 Anthropology

I. Stress to the relocation of affected communities II. Inundation of existing access roads

10 Archaeology I. Undated of historic or cultural site

11 Ecotourism I. Reduce white water rafting opportunities

II. Reduce/loss of ecotourism attraction places

12 Socio-Economics

I. Food security II. Loss of assets

III. Health IV. Mobility

10.7.1 AIR QUALITY

A. Mitigating measures for production of noxious gases

I. The production of noxious gases can be reduced by removing the vegetation as much as

possible in the reservoir area.

II. The level of H2S and CH4 emission should be periodically monitored via a permanent

monitoring station/s to prevent the health impact to the nearest community around the

reservoir.


Mitigating Measures



A. Mitigating measures for depletion of the level of dissolved oxygen

I. Since the decomposition of inundated vegetation can depleted the dissolved oxygen level, it

can be avoided by total clearing of submerged area before the impoundment begin.

10.7.3 HYDROLOGY

A. Mitigating measures for reduction in water flow/hydrology alteration

I. The availability of flow in the river during reservoir impoundment is crucial, especially during

dry seasons or low flow. The low flow analysis was made to predict the potential

environmental impacts during dry season at the Sg. Nenggiri based on design flow. Therefore,

the environmental flow requirement was proposed, based on specific approach, technique and

methods that required in maintaining water quality and sustaining river ecology during and

after reservoir filling.

II. It is suggested that permanent weather stations must be established to monitor continuously

climate parameters such as rainfall, evaporation, wind characteristics etc. The established data

may help to study the long term trend on climate scenario within the catchment. Since 1980,

the permanent climatological station was fixed at downstream of Sg. Nenggiri near Bertam.

The combination data to other permanent future stations at upstream sites may help to design

accurate climate characteristics of the Sg. Nenggiri Basin especially the water balance of the

catchment, design rainfall runoff, evapotranspiration and other extreme rainfall analysis.

B. Mitigating measures for changes in hydrological regime

I. Monitoring during and following filling of the reservoir.

This procedure refers to the stage in which the respective impacts occur due to changes in the

hydrological regime. As such, more detailed monitoring is required, initially at smaller time

intervals, with a view to creating a database for future analyses. Therefore, during

impoundment period and in subsequent months, close monitoring should be taken on a

monthly basis, followed by bimonthly samples the following year, and, finally, quarterly

samples beginning the third year following filling of the reservoir. Monitoring measures at the

future reservoir, as well as maintenance of the collection points at the Nenggiri Dam, should

be ongoing and permanent.

10.7.4 GEOLOGY & GEOTECHNIC

A. Mitigating measures for micro-seismic activity

I. Continuous monitoring of seismic activity during impoundment of the dam

B. Mitigating measures for slope failure

I. Continuous monitoring of the steep limestone cliff and other slopes during impoundment of the

dam. The increasing water level in the reservoir will affect the stability of limestone cliff / soil

slopes


Mitigating Measures


C. Mitigating measures for loss of surface water

I. Continuous monitoring of water level in the reservoir to monitor for water losses through karst

features in limestone.

10.7.5 HYDROGEOLOGY

A. Mitigating measures for change in groundwater level around the reservoir

I. Groundwater condition, particular the level and flow, in the project site and the surrounding

area shall be monitored. The collected information need to be properly kept and recorded.

B. Mitigating measures for change in the occurrence of spring flow

I. The occurrence of springs flow in the area around the reservoir and at the dam sites needs to

be identified and monitored. Nature of the springs discharges need to be assessed and the

appropriate measures such as drains or inversely, preventive measures where necessary need

to be imposed.

C. Mitigating measures for water losses

I. Further and detailed studies need to be carried out to verify and assess the extent and

intensity of karst solution and location of the karst features (such as cavities, cave openings,

solution features, seepage points and other water ways) within the marbly massive. The

hazard leakage from the reservoir into the karstic marble need to be quantitatively verified

through an appropriate study utilizing sufficient data and information.

D. Mitigating measures for slope instability

I. Groundwater condition shall be taking into account in all slope design and mitigating or

remedial measures for slope failure.

10.7.6 ARCHAEOLOGY

A. Mitigating measures for undated of archaeological sites

I. Project proponent must make sure all archaeological sites that will be submerged are already

excavated before impoundment. Signboard that shows all archaeological sites that already

submerged should be built on the top of the hill. The archaeological sites that were not

affected should be preserving.


A. Mitigating measures for submerged of the remnant vegetation

I. Second brushing may be needed before impoundment to reduce the effects of vegetative

decay in the submerged water.

II. The loss of flora due to land clearing and inundation to be mitigated through restoration and

landscape enhancement.

III. Remnant biomass should be transported to the legal dumping site and only minor biomass

waste should be left for inundation. With a minimum biomass left, biodegradation process

would not be significant to form hazardous gasses such as methane and hydrogen sulphide.


Mitigating Measures


B. Mitigating measures for changes of species composition

I. Reforestation plan of disturbed sites should take into consideration the original flora species

composition and abundance prior to the project construction (Appendix 1). Selection of plant

species should be suitable with the type of degraded habitat or site condition. Ideally selected

species would be effective to reduce erosion and siltation (pioneer and forest margin plant

species), provide food sources for wildlife (forest fruit trees) and create forest corridors for

wildlife to move to adjacent intact forests.


A. Mitigating measures for permanent loss of habitat

I. Designing and estimating the rate of filing is very important to make sure no wildlife will be

trapped inside the isolated patches (or islands).

II. Inundated areas need to be monitored for any displaced wildlife and if require this wildlife

need to be ‘guide’ to safe ground before water levels reaching the critical stages. Sometimes

Mother Nature is not cooperating where evacuation plan is needed. If the filling rate is too

high, evacuation plan may be required with the help of PERHILITAN.

III. The evacuation plan is needed to be incorporated inside a detail Wildlife Management Plan

(WMP) which should be included in this plan are i) how to evacuate or capture these stranded

animals, ii) who will be responsible to capture them, iii) where to release them, iv) how to

monitor after release to ensure their survival (See mitigating measure during logging above).

B. Mitigating measures for local extinctions of aquatic life

I. For aquatic organisms, where poor water quality would result from the decay of flooded

biomass, forest clearing within the impoundment area should be completed before reservoir

filling.


A. Mitigating measures for alteration of river regime from lothic to lenthic, species

loss, survival and population bloom

I. Water filling into the reservoir should be slow enough to allow active aquatic communities to

escape upstream or adapt with new stagnant water environment. Common fast flowing water

fish such as cyprinid would has chance to make migration further upstream. The impoundment

period proposed by proponent is between 6 to 12 month which considered slow enough for

fish to do migration.

II. The impoundment rate must also take into account the environmental flow requirement for

downstream aquatic communities. Slow impoundment and constant release rate would provide

appropriate adaptation of aquatic organisms to the change.

III. Environmental flow for downstream must be sufficient enough to ensure the sustainability of

river live. The consideration should focus on fish diversity and other resident needs as.

According to fish indicator species at downstream site, a minimum water depth needed to be

maintained is 1m. Result from simulation demonstrates that minimum flow that should be

released by re-regulating dam is 39m3/s.

IV. Kelah restocking is recommended to be done at upstream of impoundment zone. This area will

remain almost like existing and suitable for Kelah growth. A regular monitoring is


Mitigating Measures


recommended to ensure a good population growth rate. This activity is being conducted at

previous HEP dam (Tembat and Puah dam, Terengganu) using telemetry communication to

monitor kelah survival and migratory.

V. There are several large tributaries such as Sg. Jenera, Sg. Puian, Sg. Perias etc. at upstream of

Sg. Nenggiri therefore the species could do their migratory to this area and continue with their

natural behaviour such as migratory and spawning. It is not recommended to do fish

conservation at downstream of the dam as the area is too closed to the community of

settlement.

VI. Restocking only conducted to important native, threatened or endangered species such as

Kelah and Krai.

VII. A clear and effective signage of no invasive species release recommended to be put at

strategic locations.


A. Mitigating measures to reduce stress related to the relocation exercise.

I. The moving schedule must be made known to every household heads.

II. The type of supports provided to them must also be made known.

III. The elderly, women and children must be given priority in the exercise.

IV. Moving allowance must be paid to all household heads.

V. The facilities in the new settlements sites must be ready for use.

VI. The schools built to replace the old school must be ready and could be used immediately.

VII. The basic infra structures must be in place and functional.

B. Mitigating issues related to loss of traditional graveyard sites caused by

impoundment of the dam.

I. The Orang Asli is not keen to relocate the traditional graves to a new site. It should not be

practised because it is against their traditional belief. It is also difficult to identify the graves

because there are no grave markers. They suggest that the people or the village be

compensated. Negotiations with the village leaders pertaining to the amount of compensation

should be carried out. The grave should also be identified and the individuals related dead

should produce documents to support his claims.


A. Mitigating measures for Food Insecurity.

I. Proper management with regards to food supply especially during the impoundment activities.

B. Mitigating measures for Loss of assets.

I. Livestock at the nearby reservoir like cows, hens, duck, should be transferred to the safe place

before the inundation activities start.

II. The damage of this farms, vegetables and cash crop should be taken care or compensated.

C. Mitigating measures for morbidity.

I. Residents should be literate especially with regards to drinking water and anything about

health.


Mitigating Measures


D. Mitigating measures for social disarticulation.

I. Provide basic needs before the reservoir inundation activities starts to be operated.

E. Mitigating measures for the affected sand mining activity

I. State government should allow or suggest for new site of the company.

II. Project Proponent should compensate to the loss of income during the impoundment stage.

10.7.12 ECOTOURISM

A. Mitigating measures Reduce white water rafting opportunities

I. New ecotourism activities that are compatible with the impoundment phase can be promoted

as a substitute to the white water rafting.

II. Impoundment rate should be slow enough for the adaptation of the ecotourism activities and

affected community that involved in the ecotourism.

B. Mitigating measures Reduce/loss of ecotourism attraction places

I. All ecotourism sites that associated with archaeology sites must be recorded and rescue before

the construction of the Proposed NHEP initiates.

II. All archaeological sites that not affected or partly submerged must be preserved and upgrade

for the future ecotourism attraction.

III. Project proponent must seek advice from the relevant agencies on how to conserve the

affected ecotourism sites.


Mitigating Measures


10.8 MITIGATING MEASURE DURING OPERATION


carried out during operation phase of the Nenggiri HEP. The main potential impacts arise from the

operation phase are listed in Table 10.8.1 below:

Table 10.8.1 Summary of Potential Impacts during Operation Phase

No Environmental


1 Air quality I. Gasses emission

2 Noise & vibration I. Changes to the ground vibration profile

3 Water quality

I. Deterioration of water quality

II. The production of hazardous gases

III. Increase the levels of suspended solids in reservoir

IV. Impact of agrochemical

4 Hydrology I. Dam as flood mitigation

II. Reduction in water flow

Soil erosion I. Sedimentation into the Nenggiri reservoir

5 Geology &

geotechnics

I. Micro-seismic activity

II. Slope stability

III. Loss of surface water

6 Terrestrial fauna

I. Reduce the habitat availability

II. Creation of new riparian habitat

III. Illegal hunting by new access roads

7 Freshwater ecology

I. Hypolimnion effect

II. Loss of spawning grounds

III. Habitat loss due to ecosystem change

IV. Fishing activity

V. Introduction of cage aquaculture

8 Anthropology

I. Livelihood changes

9 Socio-economic

I. Economic opportunity

II. Providing additional power source/electricity

III. Employment opportunity

10 Public health I. Outbreak of communicable diseases

11 Ecotourism I. Creation of new ecotourism activities


Mitigating Measures


10.8.1 AIR QUALITY

A. Mitigating measures for gasses emission

I. Operating of a hydroelectric plant will not emit any significant amount of pollutant gasses.

II. The level of H2S and CH4 emission should be periodically monitored via a permanent

monitoring station/s to prevent the health impact to the nearest community around the

reservoir.


A. Mitigating measures for changes to the ground vibration profile

I. The micro-seismic pattern needs to be monitored, either during commissioning or continuously

during operations, to detect any possible tremors or small-scale earthquakes that may

compromise the integrity of the dam structure and safety of the dam as well as the

surrounding populace.


A. Mitigating measures for deterioration of water quality

I. Major problems in reservoir usage include thermal stratification (due to the depth of water in

the reservoir), sediment and nutrients trapping by the dam. The approaches to mitigate

include physical measures, operational measures and structural modifications.

II. Regulating the water flow at downstream of the re-regulating dam to 39m3/s, capable to

reduce sedimentation within the 90% of the existing scenario. This will ensure sufficient water

volume and water quality especially at Bertam water intake. Detail assessment / modelling for

sediment transport is given in Appendix 10.

B. Mitigating measures for modification of physical, chemical and biological

characteristics of water

I. Physical mitigating measures include the control of water quality in the reservoir, selective

withdrawal of reservoir water with acceptable water quality and aeration of reservoir releases.

C. Mitigating measures for toxicity in reservoir

I. Operation measures include optimizing the reservoir operating rule such as maintaining a

minimum discharge and limiting the maximum discharge.

II. Structural modifications involve changes to the structure of the dam and its outlet works so

that water can be withdrawn from the reservoir at different depths.

III. The use of pesticide to control weed should be banned and replaced with physically cutting

them with grass cutter.

10.8.4 HYDROLOGY

A. Flood

I. There is no significant threat of neither floods nor droughts due to this development is

foreseen. The decrease in flood levels as assessed is expected to be minimal up to Kemubu.

There must be a detail on flood modelling study during operation of the proposed dam.


Mitigating Measures


II. To minimize the impacts of water reduction to the immediate river after the dam as well as to

the aquatic life, the detail Environmental Flow Assessment (EFA) has been carried out (See in

EFA model section).

III. Permanent stream flow gauging should be carried out at recommended sites upstream of the

dam to enable long-term data to be taken to detect any hydrological change. These changes

could affect the environmental flow and base flow that maintain the health and ecology of the

rivers and other aquatic life forms especially during the dry season. Detection for

morphological change in the river system is also important, as any changes in the widths,

depths and velocity of flows in the rivers will affect the riparian ecosystems, vegetation,

nutrient and food chains for the aquatic fishes.

B. Mitigating measures for Reduction of water flow

The environmental flow need to be simulated to fulfil minimum requirement for aquatic life and

human need. According to simulated data, minimum requirement water depth for fish survival

is 39 m3/s. The flow must constantly release during dry period and can be reduced accordingly

during wet season.

10.8.5 SOIL EROSION

A. Mitigating measures for Sedimentation into the Nenggiri reservoir

The potential rate of soil loss during operational when all conservation measure are already

installed is shown in Table 10.8.2 and Figure 10.8.1 Potential rate of soil loss amount to very low

(<10 ton/ha/yr) to low (<50 ton/ha/yr).


Mitigating Measures




Mitigating Measures


Table 10.8.2 Predicted potential rate of soil loss during operational with conservation measure in ton/ha/yr

Station River Erosivity Index (R)

(MJmm/ ha.hr)

K (ton/ha)(ha.hr)/

(MJ.mm) LS

LS max

C Mulch 75%

(*0.13)

C Scrub/bush

(25% cover)

P terrace *0.18

P Buffer *0.8

P Sediment

Pond *0.5

A Ton/ha/yr

A max

Erosion Risk

Category

ST 1 Sg. Puian 14601.13 0.030 10.79 25.24 0.13 0.40 110.60 491.54 307.22 17.70 41.39 Low

ST 2 Sg. Jenera 14601.13 0.063 4.77 11.29 0.13 0.40 102.67 456.33 285.21 16.43 38.88 Low

ST 3 Sg. Rela 14601.13 0.031 9.95 19.98 0.13 0.40 105.39 468.39 292.74 16.86 33.86 Low

ST 4 Sg. Wias 14601.13 0.029 7.63 27.36 0.13 0.40 75.60 336.00 210.00 12.10 43.37 Low

ST 5 Sg. Wok 14601.13 0.033 8.34 15.81 0.13 0.40 94.03 417.93 261.20 15.05 28.52 Low

ST 6 Kg. Penggei 14601.13 0.031 10.32 18.26 0.13 0.40 109.31 485.80 303.63 17.49 30.94 Low

ST 7 Sg. Kalwing 14601.13 0.038 5.18 23.07 0.13 0.40 67.25 298.90 186.82 10.76 47.92 Low

ST 8 Kg. K. Jenera 14601.13 0.018 6.63 19.90 0.13 0.40 40.77 181.22 113.26 6.52 19.58 Low

ST 9 Kg. Tohoi 14601.13 0.008 6.34 16.48 0.13 0.40 17.33 77.02 48.14 2.77 7.21 Very Low

ST 10 Kg. Star 14601.13 0.021 8.81 18.26 0.13 0.40 63.21 280.94 175.59 10.11 20.96 Low

ST 11 Sg. Kalau 14601.13 0.056 9.91 16.31 0.13 0.40 189.61 842.72 526.70 30.34 49.93 Low

ST 12 Sg. Nenggiri 14601.13 0.015 7.04 14.01 0.13 0.40 36.08 160.36 100.22 5.77 11.49 Very Low

ST 13 Sg. Lah 14601.13 0.045 5.09 13.94 0.13 0.40 78.26 347.82 217.39 12.52 34.29 Low

ST 14 Sg. Nenggiri 14601.13 0.057 5.69 10.32 0.13 0.40 110.81 492.50 307.81 17.73 32.16 Low

ST 15 Kg. Betis 14601.13 0.052 4.13 12.07 0.13 0.40 73.38 326.12 203.82 11.74 34.31 Low

ST 16 Sg. Nenggiri 14601.13 0.030 4.77 16.48 0.13 0.40 48.89 217.30 135.81 7.82 27.03 Low

ST 17 Sg. Ber 14601.13 0.052 8.04 14.01 0.13 0.40 142.84 634.86 396.79 22.86 39.83 Low

ST 18 Sg. Belatop 14601.13 0.029 11.29 19.09 0.13 0.40 111.87 497.18 310.74 17.90 30.26 Low

ST 19 Sg. Berok 14601.13 0.019 9.03 18.26 0.13 0.40 58.62 260.53 162.83 9.38 18.97 Very Low


Mitigating Measures


Figure 10.8.1 Map showing the potential soil loss during operational with mitigating measures


Mitigating Measures


The amount of sediment yield predicted to reach the river system greatly reduced after installation

of conservation measures as calculated using soil loss and SDR values as shown in Table 10.8.3

and as calculated by using MUSLE in Table 10.8.4 and visually presented in Figure 10.8.2.

Table 10.8.3 Prediction of potential sediment yield during operational with application of conservation measures calculated using soil loss and SDR

Station Location

Sub Catchment

Area, A (km2)

Soil Erosion (SE)

(Ton/ha/yr)

SE (Ton/ha/yr)

LS Max SDR

Sediment Yield (SY)

(Ton)

SY (Ton) LS Max

ST 1 Sg. Puian 3.218 17.70 41.39 0.45 7.94 18.56

ST 2 Sg. Jenera 0.316 16.43 38.88 0.58 9.51 22.51

ST 3 Sg. Rela 1.481 16.86 33.86 0.49 8.24 16.54

ST 4 Sg. Wias 1.015 12.10 43.37 0.51 6.16 22.08

ST 5 Kg. Wok 1.372 15.05 28.52 0.49 7.41 14.05

ST 6 Kg. Penggei 1.327 17.49 30.94 0.49 8.65 15.30

ST 7 Sg. Kalwing 4.078 10.76 47.92 0.44 4.70 20.94

ST 8 Kg. K. Jenera 6.564 6.52 19.58 0.41 2.70 8.12

ST 9 Kg. Tohoi 3.476 2.77 7.21 0.44 1.23 3.21

ST 10 Kg. Star 3.981 10.11 20.96 0.44 4.43 9.18

ST 11 Sg. Kalau 0.649 30.34 49.93 0.53 16.23 26.70

ST 12 Sg. Nenggiri 1.267 5.77 11.49 0.50 2.87 5.71

ST 13 Sg. Lah 0.515 12.52 34.29 0.55 6.87 18.81

ST 14 Sg. Nenggiri 3.098 17.73 32.16 0.45 7.98 14.48

ST 15 Kg. Betis 0.857 11.74 34.31 0.52 6.09 17.80

ST 16 Sg. Nenggiri 1.991 7.82 27.03 0.47 3.70 12.78

ST 17 Sg. Ber 3.847 22.86 39.83 0.44 10.05 17.52

ST 18 Sg. Balatop 0.224 17.90 30.26 0.60 10.76 18.19

ST 19 Sg. Berok 1.577 9.38 18.97 0.49 4.55 9.20


Mitigating Measures


Table 10.8.4 Prediction of potential sediment yield during operational with conservation measures using MUSLE

Station Location/River Sub

Catchment Area, A(m2)

Runoff Volume, V(m3)

Peak Flow Discharge,

[Qp=CIA](m3/s)

K Factor

LS Factor

LS Factor max

CP *0.25*0.4

*0.18*0.8*0.5

ESCP 90%, Effeciency

(0.1)

SY (ton)

SY (ton) max

ST 1 Sg. Puian 3218268 79652.14 0.088 0.030 10.79 25.24 0.0072 0.10 1.63 3.82

ST 2 Sg. Jenera 316200 7825.95 0.087 0.063 4.77 11.29 0.0072 0.10 0.15 0.35

ST 3 Sg. Rela 1480500 36642.38 0.041 0.031 9.95 19.98 0.0072 0.10 0.33 0.67

ST 4 Sg. Wias 1015400 25131.15 0.028 0.029 7.63 27.36 0.0072 0.10 0.11 0.40

ST 5 Kg. Wok 1371900 33954.52 0.038 0.033 8.34 15.81 0.0072 0.10 0.26 0.48

ST 6 Kg. Penggei 1327400 122452.65 0.036 0.031 10.32 18.26 0.0072 0.10 1.02 1.80

ST 7 Sg. Kalwing 4078200 100935.45 0.112 0.038 5.18 23.07 0.0072 0.10 1.60 7.14

ST 8 Kg. K. Jenera 6563600 162449.10 0.181 0.018 6.63 19.90 0.0072 0.10 2.53 7.58

ST 9 Kg. Tohoi 3476100 86033.48 0.096 0.008 6.34 16.48 0.0072 0.10 0.30 0.78

ST 10 Kg. Star 3981200 98534.70 0.109 0.021 8.81 18.26 0.0072 0.10 1.43 2.97

ST 11 Sg. Kalau 649400 16072.65 0.179 0.056 9.91 16.31 0.0072 0.10 1.15 1.89

ST 12 Sg. Nenggiri 1266898 31355.71 0.035 0.015 7.04 14.01 0.0072 0.10 0.08 0.17

ST 13 Sg. Lah 515142 12749.75 0.142 0.045 5.09 13.94 0.0072 0.10 0.30 0.82

ST 14 Sg. Nenggiri 3097780 76670.07 0.085 0.057 5.69 10.32 0.0072 0.10 1.52 2.76

ST 15 Kg. Betis 857300 21218.18 0.236 0.052 4.13 12.07 0.0072 0.10 0.77 2.26

ST 16 Sg. Nenggiri 1990900 49274.78 0.055 0.030 4.77 16.48 0.0072 0.10 0.28 0.96

ST 17 Sg. Ber 3847175 95217.58 0.106 0.052 8.04 14.01 0.0072 0.10 3.04 5.29

ST 18 Sg. Balatop 223834 5539.89 0.006 0.029 11.29 19.09 0.0072 0.10 0.01 0.01

ST 19 Sg. Berok 1577354 39039.51 0.043 0.019 9.03 18.26 0.0072 0.10 0.21 0.42


Mitigating Measures


Figure 10.8.2 Map Showing the Potential Sediment Yield During Operational With Conservation Measures Using MUSLE


Mitigating Measures




Mitigating Measures



A. Mitigating measures for micro-seismic activity

I. Continuous monitoring of seismic activity during operation of the dam

B. Mitigating measures for slope stability

I. Continuous monitoring and maintenance of the steep limestone cliff during operation of the

dam. The use of real time movement sensor is highly recommended. Monitor the

effectiveness of remedial measures used to stabilise the rock slopes to be undertaken

C. Mitigating measures for loss of surface water

I. Continuous monitoring of water level in the reservoir to monitor for water losses through karst

features in limestone.

D. Mitigating measures for new settlement area

I. All slopes shall be protected at all times and vegetated to increase the factor of safety. Cut

slopes and embankment slopes shall be continuously monitored for any signs of slope failure.

Slopes inventory shall be utilised at this stage.

10.8.6.1 WASTE MANAGEMENT

A. Mitigating measures for schedule waste

I. For scheduled wastes, the DOE has to be notified of their generation via the online scheduled

waste reporting system. These wastes shall be stored in secure storage areas, constructed in

accordance to requirements of the Environmental Quality (Scheduled Wastes) Regulations

2005, EQ(SW)R 2005. All aspects of management of scheduled wastes have to be in

compliance with the EQ(SW)R 2005, such as, scheduled wastes can only be collected and

transported by licensed collectors and transporters, and their labelling, handling and storage

have to be as stipulated by the EQ(SW)R 2005. Clearly labelled and secure storage facilities

have to be erected to ensure that people and premise are safe from possible fire, waste

spillage, reactions, etc. Fuel and waste oil storage bases have to be bunded, with bunded

volume at 110% of maximum tank volume. Any spillage shall be promptly collected and

managed as scheduled waste(s). All wastes have to be accounted for and audited against the

raw materials (lubricants, etc.) brought in.


A. Mitigating measures for forest resources

I. Allowing the flow after the dam at the minimal ecological requirement is to be ensured.

II. The movement of vehicles along the service road/logging roads inside the catchment area

should be regulated to prevent all illegal hunting and poaching activities of forest resources.

III. Buffer zone of minimum 50 m along all river and streams and no logging should be allowed

within the buffer zone to reduce waterways sedimentation through river banks erosion


Mitigating Measures


B. Mitigating measures for forest landscape

I. Restoration and landscape enhancement to be maintained including reservoir islands for

conservation and refuge for wildlife.

II. Enrichment planting preferably involving all stakeholders i.e. local community, related

agencies and project proponent.

III. Best Management Practices, BMPs (Trussart et al. 2002), is to either adopt an area equivalent

to lost land in order to offset the carbon loss or to substitute the loss forest grounds and

enhance degraded forests through reforestation activities by the project proponent.

C. Mitigating measures for new settlement area

I. To minimize significant impacts on the biotic components, the Project Proponent should adopt

sound development/management approach and design concept that aim to reduce further

loss of natural land cover, riparian zone and remaining forest area. The riparian reserve of Sg.

Perias, Sg. Nenggiri and their tributaries are essential for conservation of the surrounding

forest, local flora and fauna, as well as to control against upstream flooding beyond the

Nenggiri Dam. A minimum (400 m) buffer zone of natural vegetation should be preserved

between the river banks and the Orang Asli resettlement area. This would prevent permanent

damage to the riparian habitats of Sg. Perias, Sg. Nenggiri and their tributaries due to

cumulative impacts of the proposed resettlement area and other dam related development

activities.


A. Mitigating measures for reduction of Stream Flow and Stage

I. Many aquatic wildlife including frogs, do not rely on the main streams which will be affected

by the proposed Project, but rather on other small tributaries. The smaller tributaries may be

indirectly affected by the proposed Project.

II. To minimise the impact, regular environmental monitoring of the tributaries nearest to the

Project sites should be made and releasing minimum environmental flow downstream will help

the existing main stream to provide habitat for many important aquatic species. The

suggested minimum flow is 5 cubic m/s.

III. Further to ensure the stream and lake ecosystem is functioning, wildlife and lake management

plan is needed for sustainable management of the catchment during operation phase.

B. Mitigating measures for reduce the habitat availability and creation of new riparian

habitat

I. The impact (the existence of reservoir) is expected to be permanent. However the displaced

terrestrial wildlife can be mitigated through i) catching and transferring to another areas, and

ii) guiding back to the existing habitat. This mitigating measures can be incorporated as part

of comprehensive wildlife management plan. Creating this plan need to be further discussed

with the authority which is PERHILITAN.

C. Mitigating measures for illegal hunting by new access roads

I. Hunting activities can be stopped by regulating the movement of vehicles that use the service

road (or logging road) to the intakes, power house, saddle dam, re-regulating dam, and


Mitigating Measures


outfall. Mitigating poaching activity can be made according procedures described in Mitigating

Measures during Logging section above.

D. Specific Mitigating Measure for Elephant during Operation

I. According to inventory data the most important wildlife species that need conservation

attention is elephant due to several reasons; i) this is the largest species which require large

home range, ii) the change of habitat and land use within the catchment is predicted to have

greater impact in this species, iii) if this species is not well mitigated, the conflict incidences

within and surrounding catchment is predicted to increase, and iv) this is an umbrella species

and Totally Protected under the local law (Wildlife Act 2010).

The impact of Dam (reservoir) as indicated in potential impact would be minimal as shown by

GIS simulation based on habitat suitability and connectivity for elephant (See Figure 10.8.7.1

and 10.8.7.2 below). However, specific mitigating measures for elephant that proposed to be

implemented will be based on several scenarios and considerations.

Assumption 1. Note that at present elephant is still roam Nengiri Forest Reserve, Balah

Forest reserve and Berangkat Forest Reserve. Considering that there will be no disturbance,

and opening and clearing of forest habitat, it is predicted that the existing forest habitat now

could sustain (or carrying capacity) 10 to 15 elephant individuals. No mitigation is needed

except leave along this herd to roam the area. Simulation also indicated that after completion

of this herd can easily move from one to another forest reserves (See Figure 10.8.3 and

10.8.4).


Mitigating Measures




Mitigating Measures


Figure 10.8.3 The GIS Simulation Predicting Habitat Suitability (Green) And Connectivity (Red) For Elephant With The Catchment Of Nengiri Dam Project Before The Project Begin.


Mitigating Measures


Figure 10.8.4 The GIS Simulation Predicting Habitat Suitability (Green) And Connectivity (Red) For Elephant With The Catchment Of Nengiri Dam Project After The Reservoir Is Created.


Mitigating Measures


Assumption 2. Should the habitat size and quality shrunk due to future development and

disturbance not relate to the existing project, it is predicted that the resources availability will

be reduced. The catchment areas may not be suitable to sustain this elephant herd. Thus,

translocation is needed. However, how many elephants need to be translocated and where to

be released will need more detail population and habitat study.

Assumption 3. Apart from translocation, the issue of habitat availability for the elephants

within the catchment can be mitigated if movement (or migration) of this herd can be directed

to the north where more suitable habitat available for the elephant such as Setong Forest

reserve and Temenggor Forest Reserve. However, corridors to link these reserve is needed. To

establish the right corridors, require further detail habitat suitability and connectivity studies

with detail habitat types (or land use type). Satellite collars and camera trapping study may be

needed to evaluate the function of these established corridors.

It is important to mention that all of the above recommendations can only be executed by or with

permission of the Department of Wildlife and National Parks. Detail management plan to mitigate

these issues should be further discuss with the department.


A. Mitigating measures for the production of hazardous gases

I. Vegetation that would be inundated should be removed and transported to legal dumping

site. Only small trees and bushes allowed to be inundated since only at small proportion of

inundation size and would not produce any significant biodegradation effects.

B. Mitigating measures for Hypolimnion effect

I. Top layer water must be released by main dam and by re-regulating to the downstream to

ensure good water released to support downstream river life. Adequate environmental flow

must be release to the protection of the spawning and nursery gravel beds.

II. Seven different fish species were recorded at downstream of the proposed dam and from that

a native fish (Hypsibarbus pirrei) was chosen as indicator for environmental flow calculation.

III. A minimum of one-meter water depth must be retained for this species and to achieve this, a

minimum of 39 m3/s of water must be release by the re-regulating dam.

C. Mitigating measures for loss of spawning grounds and disappear of intolerant

species

I. Stocking the reservoir with selected native species will replenish the losses resulting from the

disappearance. The fish should be allowed to growth up to market size. This provides

alternative way of subsistence and income and avoids high pressure of the illegal fishing from

native stocks. Some native species that heavily caught are catfish, freshwater prawn and carp.

The proponent should consult with state fisheries agency for better planning and restoration

purpose.


Mitigating Measures



A. Mitigating measures for resettlement of Orang Asli

I. The impact of the project during operation is very minimal if any, because the community

involved has been relocated to a new place. But to help the Orang Asli benefits from the

project, support from other related government agencies is needed. For example, to enable

the Orang Asli improve their economic well-being, the Orang Asli should be encourage to

develop aquaculture.

II. JAKOA and the Department of fisheries can extend their support to the Orang Asli. JAKOA

and the Tourism Department can help the Orang Asli to develop water sport, boating

activities, home-stay and Orang Asli Cultural Center to attract tourism. All these activities

could improve the Orang Asli income.

10.8.11 SOCIO-ECONOMICS

A. Mitigating measures for loss of sand mining activity

I. The compensation should be considered by the Project Proponent. New location at least with

the same amount of sand production should be given to the sand mining company by the

state government if their concession period is still effective.


A. Mitigating measures for outbreak of communicable diseases

I. The project proponent has to adhere to the local municipal guidelines on building cleanliness

and housekeeping to prevent any breeding sites for mosquito or pests.

II. The project proponent has to establish a monitoring system to monitor the presence of

vectors and pests within the site.

III. Regular health campaigns usually help to prevent any outbreaks.

IV. There should be a dedicated solid waste management system of the entire area of the

project.

V. The cleanliness of the whole development areas needs to be put as the first priority by all

parties, including developer, and purchasers. Any restoration or extension has to fetch the

local authority clearance and to be taken out exclusively by registered contractors with good

housekeeping practises.

10.1 INTRODUCTION 10.2 KEY ENVIRONMENTAL ISSUES

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Transcript of 10.1 INTRODUCTION 10.2 KEY ENVIRONMENTAL ISSUES