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L&T HIMACHAL HYDROPOWER LIMITED

COMPREHENSIVE ENVIRONMENTAL IMPACT ASSESSMENT STUDY FOR

SACHKHAS HYDRO ELECTRIC PROJECT, DISTRICT CHAMBA, HIMACHAL PRADESH

WAPCOS LIMITED(A Government of India Undertaking)

76 C, Sector 18, Gurgaon - 122015, Haryana, INDIATel. +91-124-2397396, Fax. +91-124-2397392

Email: [email protected]

VOLUME–I EIA REPORT

MAY 2013

CONTENTS

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CONTENTS

CHAPTER-1 INTRODUCTION

1.1 GENERAL 1-1

1.2 PROJECT PROFILE 1-1

1.3 LEGAL AND POLICY FRAMEWORK 1-3

1.4 SCOPE OF THE EIA STUDY 1-4

1.5 STAGES IN AN EIA STUDY 1-5

1.6 REGISTRATION WITH QUALITY COUNCIL OF INDIA (QCI)/NABET 1-6

1.7 OUTLINE OF THE REPORT 1-6

CHAPTER-2 PROJECT DESCRIPTION

2.1 INTRODUCTION 2-1

2.2 ALTERNATIVES CONSIDERED 2-2

2.3 PROJECT DESCRIPTION 2-6

2.4 SECONDARY POWER HOUSE 2-10

2.5 SALIENT FEATURES 2-12

2.6 LAND REQUIREMENT 2-14

2.7 ACCESS TO THE SITE 2-15

2.8 INFRASTRUCTURE PLAN 2-15

CHAPTER-3 CONSTRUCTION METHODOLOGY

3.1 GENERAL 3-1

3.2 RIVER DIVERSION 3-1

3.3 COFFER DAM 3-3

3.4 DAM 3-3

3.5 PRESSURE SHAFT 3-5

3.6 POWER HOUSE COMPLEX 3-8

3.7 TAIL RACE TUNNEL 3-9

CHAPTER-4 METHODOLOGY ADOPTED FOR THE EIA STUDY


4.2 STUDY AREA 4-1

4.3 SCOPING MATRIX 4-2

4.4 DATA COLLECTION 4-4

4.5 SUMMARY OF DATA COLLECTION 4-7

4.6 IMPACT PREDICTION 4-8

4.7 ENVIRONMENTAL MANAGEMENT PLAN AND COST ESTIMATES 4-8

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4.8 CATCHMENT AREA TREATMENT PLAN 4-9

4.9 LOCAL AREA DEVELOPMENT PLAN 4-9

4.10 ENVIRONMENTAL MONITORING PROGRAMME 4-9

CHAPTER-5 HYDROLOGY

5.1 CHENAB RIVER SYSTEMS 5-1

5.2 THE CATCHMENT AND PHYSIOGRAPHIC PARAMETERS 5-2

5.3 HYPSOMETRIC CURVE 5-3

5.4 GAUGE & DISCHARGE 5-7

5.5 STREAM FLOW CHARACTERISTICS 5-8

5.6 WATER AVAILABILITY 5-8

5.7 DESIGN FLOOD 5-9

5.8 RECOMMENDATIONS 5-15

5.9 SEDIMENT DATA AVAILABILITY 5-17

CHAPTER-6 TOPOGRAPHICAL AND GEOLOGICAL ASPECTS


6.2 PHYSIOGRAPHY AND DRAINAGE 6-1

6.3 REGIONAL GEOLOGY OF THE AREA 6-2

6.4 STRUCTURE, TECTONICS AND METAMORPHISM 6-4

6.5 TECHTONIC SETUP OF THE PROJECT AREA 6-7

6.6 SEISMO-TECTONICS AND SEISMICITY 6-7

6.7 GEO-TECHNICAL APPRAISAL OF THE COMPONENT STRUCTURES 6-10

CHAPTER-7 BASELINE SETTING FOR PHYSICO-CHEMICAL ASPECTS

7.1 GENERAL 7-1

7.2 METEOROLOGY 7-1

7.3 SOILS 7-6

7.4 WATER QUALITY 7-9

7.5 NOISE ENVIRONMENT 7-14

7.6 AMBIENT AIR QUALITY 7-16

7.7 LAND USE PATTERN 7-19

CHAPTER-8 BASELINE SETTING FOR ECOLOGICAL ASPECTS

8.1 GENERAL 8-1

8.2 FOREST & FOREST TYPES 8-1

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8.3 REMOTE SENSING ASSESSMENT OF FLORA 8-2

8.4 METHODOLOGY 8-6

8.5 FINDINGS OF THE FIELD STUDIES 8-7

8.6 LICHENS & FUNGI 8-15

8.7 ECONOMICALLY IMPORTANT PLANT SPEICES 8-17

8.8 RET SPECIES 8-20

8.9 FAUNA 8-20

8.10 AQUATIC ECOLOGY 8-28

8.11 FISH COMPOSITION AND STATUS 8-38

CHAPTER-9 PREDICTION OF IMPACTS

9.1 GENERAL 9-1

9.2 IMPACTS ON WATER ENVIRONMENT 9-4

9.3 IMPACTS ON AIR ENVIRONMENT 9-11

9.4 IMPACTS ON NOISE ENVIRONMENT 9-13

9.5 IMPACTS ON LAND ENVIRONMENT 9-18

9.6 IMPACTS ON BIOLOGICAL ENVIRONMENT 9-23

9.7 IMPACTS ON SOCIO-ECONOMIC ENVIRONMENT 9-29

9.8 INCREASED INCIDENCE OF WATER-RELATED DISEASES 9-30

CHAPTER-1

INTRODUCTION

L&T Himachal Hydropower Limited EIA Report for Sach Khas HEP, Chamba, HP

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CHAPTER-1

INTRODUCTION

1.1 GENERAL

The state of Himachal Pradesh is located in the vicinity of Dhauladhar and Pir Panjal ranges

of Western Himalaya and lies between 32° 22’ 40’’ t o 33° 12’ 40’’ N latitudes and 75° 45’ 55’’

to 79° 04’ 20’’ E longitudes. The state has a geogr aphical area of 55,673 sq km demarcated

into 12 districts, 109 tehsils/sub-tehsils and 57 urban areas with a total population of 60,

77,248 persons as per 2001 Census.

The geographic location and physiography of the state result in varying climatic conditions

and diverse natural ecosystems. The variations in climatic conditions range from lower

tropical regions to cold and alpine conditions in the upper regions. Many areas in the north

and east in Himachal Pradesh are snow-bound and glaciated. These glacial are the source

of many perennial river systems in the state. The prominent rivers rising from these upland

glacial areas are Sutlej, Beas, Parbati and Ravi – all south and southwest flowing rivers. The

perennial availability of water and the conductive geographic terrain have allowed

harnessing of energy from these rivers. The project location map is given in Figure-1.1.

Figure 1-1: Project Location Map

1.2 PROJECT PROFILE

The proposed Sach Khas Hydro Electric Project (HEP), in Chamba District of Himachal

Pradesh about 54 km downstream of Udaipur town, is on river Chenab as identified by


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Himachal Pradesh State Electricity Board (HPSEB) in their ranking studies. The Sach Khas

HE project is proposed on river Chenab in Himachal Pradesh between longitudes 76° 25’

30.143” E to 76° 25’ 3.8’’ E and latitudes 32° 57’ 55.123” to N 32° 58’ 7.5’’N. The project

envisages harnessing the hydro-power potential of the river from EL 2219 m to EL 2149 m.

A concrete gravity dam is proposed across the river and underground power house with an

installed capacity of (260+7) MW is proposed immediately downstream of the dam. Out of

this 260 MW is proposed to be generated by the main powerhouse, whereas 2 units of 7MW

each (one acting as standby) are proposed to be installed to utilize the mandatory

environmental releases. The catchment area intercepted at the dam site is 6588 sq. km.

About 3973 sq. km. of the catchment is snow fed.

The nearest rail head is Kalka railway station, which is about 520 km from Project site. The

proposed Sach Khas HEP is at a distance of about 270 km from Bhuntar (Kullu) airport,

which is the nearest airport. The project site is well accessible by three routes ie. First from

Jammu & Kashmir through Kishtwar town; second from Pathankote - Chamba town and third

through Kullu-Manali-Udaipur via Rohtang pass, however the third route is the most

favourable. The project site is located at a distance of about 60 kms downstream from

Udaipur. The projects in cascade development u/s and d/s of Sach Khas Hydro-electric

project is shown Figure-1.2.

Figure- 1.2: Line schematic of hydro projects u/s & d/s of Sach Khas HEP


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1.3 LEGAL AND POLICY FRAMEWORK

Under the Environment Protection Act (EPA), 1986, various rules have been promulgated to

control pollution and manage environmental issues. EIA Notification, 2006 imposes certain

restrictions and prohibitions on new projects or activities, or on the expansion or

modernization of existing projects or activities based on their potential environmental

impacts. These project categories are listed in the notification and clearance process defined

based on their capacities to obtain prior environmental clearance.

State Pollution Control Boards issue NOCs and “Consent” under Air and Water Act to

various projects. Hydroelectric projects are considered as Red Category projects by HPPCB.

Forest and Fisheries Department of Himachal Pradesh have also issued specific notification

with respect to Catchment Area Treatment (CAT) and Fisheries management applicable on

hydroelectric projects in state.

1.3.1 EIA Notification, 2006

260+7 MW Sach Khas HEP is a Category A project (> 50 MW), as per item 1 (c) of Schedule

attached to EIA notification of September 2006 and requires Environmental Appraisal from

the Ministry of Environment & Forests (MoEF), Government of India.

The appraisal process involves three stages:

• Scoping • Public Consultation • Appraisal

Scoping: An application for scoping was submitted to MoEF in the month of July 2010 for

issuance of Terms of Reference (TOR) to undertake EIA study. Subsequently, a

presentation was made before Expert Appraisal Committee (EAC) for River Valley and

Hydroelectric Projects of Ministry of Environment and Forests (MoEF) for Prior

Environmental Clearance (Scoping) on 21.08.10 and the same was accorded by Ministry of

Environment & Forests (MOEF) vide letter no. J-12011/25/2010-IA-I dated on

20/09/2010.Later on, during studies and investigations project proponent optimized the

capacity of the project to 267 MW (260+7 MW) within the same allotted domain and the

same was approved by the Directorate of Energy, Government of Himachal Pradesh vide

letter no. HPDOE/CE(Energy)/Sach-Khas/2012-5037-38 dated 3 October, 2012,Further the

enhanced capacity (260+7MW) ToR was accorded by Ministry of Environment & Forests

(MOEF) vide letter no. J-12011/25/2010-IA-I dated 22nd February, 2013. A copy of the TOR

approved by MoEF is is enclosed as Annexure-I.

Public Consultation: On completion of draft EIA report and its executive summary, Public

consultation will be conducted through stipulated public consultation process to be organized

by Himachal Pradesh State Pollution Control Board (HPPCB). Outcome of the Public


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Consultation process in the form of report detailing the proceedings and video of the entire

event will be submitted to MoEF by HPPCB.

Appraisal: On completion of Public Consultation process, incorporation of suggestions, if

any during the public consultation, final report will be prepared, submitted and presented to

the Expert Appraisal Committee for River Valley and hydroelectric projects at MoEF for final

approval.

1.3.2 State Level Clearances

The Department of Environment & Scientific Technologies, state government of Himachal

Pradesh was set up in April, 2007 with an objective to improve the effectiveness of

environmental management, protect vulnerable ecosystems and enhance sustainability of

development. The Environmental Impact Assessment and monitoring of Environment

Management Plan Report prepared by the Project Proponent is reviewed by the Department

of Environment and Scientific Technologies. A committee constituted by the department with

members from State Pollution Control Board, Forest Department, Fisheries Department, etc.

reviews the EIA reports before Public Consultation as per EIA Notification of September

2006.

Various state departments have also lately issued specific notifications to be taken into

consideration by project developers in Himachal Pradesh. Relevant notifications for

Hydropower projects are briefly described.

Notification on Catchment Area Treatment (CAT) Plan

Department of Forest has issues a notification no. FFE-B-F-(2)-72/2004-Pt-II dated August

03, 2009 setting out the requirements of preparation of CAT plan and defining the minimum

cost of this component as 2.5% of the project cost. It was later modified vide notification no.

FFE-B-F-(2)-72/2004-Pt-II dated September 30, 2009.

Notification on Fisheries

Department of Fisheries has come out with a notification no. Fish-F (5)-1/2008 dated May 2,

2008 specifically for the hydro power projects to specify the compensation to be paid by

developers for various categories of Projects.

1.4 SCOPE OF THE EIA STUDY

The brief scope of EIA study includes:

- Assessment of the existing status of physico-chemical, ecological and socio-economic aspects of environment

- Identification of potential impacts on various environmental components due to activities envisaged during construction and operation phases of the proposed Sach-Khas project.

- Prediction of significant impacts on various aspects of environment. - Delineation of Environmental Management Plan (EMP) outlining measures to minimize

adverse impacts during construction and operational phases of the proposed project.


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- Formulation of Resettlement and Rehabilitation (R&R) Plan, if any - Formulation of Catchment Area Treatment (CAT) Plan. - Formulation of environmental quality monitoring programme for implementation during

construction and operation phases. - Estimation of Cost for implementation of Environmental Management Plan,

Resettlement and Rehabilitation Plan, Catchment Area Treatment Plan and Environmental Monitoring Programme.

1.5 STAGES IN AN EIA STUDY

The purpose of this section is to enumerate the steps involved in an Environmental Impact

Assessment (EIA) study, which are described in the following paragraphs.

Scoping: An exhaustive list of all likely impacts drawing information from as many sources

as possible was prepared. The next step was to select a manageable number of attributes

which were likely to be affected as a result of the proposed Sach-Khas hydroelectric project.

The various criteria applied for selection of the important impacts were follows:

• Magnitude • Extent • Significance

Description of Environment: Before the start of the project, it is essential to ascertain the

baseline levels of appropriate environmental parameters which could be significantly

affected by the implementation of the project. The baseline status assessed as a part of

CEIA study involved both field work and review of data collected from secondary sources.

Prediction of Impacts: is essentially a process to forecast the future environmental

conditions of the project area that might be expected to occur as a result of the construction

and operation of the proposed Sach Khas hydroelectric project. An attempt was generally

made to forecast future environmental conditions quantitatively to the extent possible. But for

certain parameters which cannot be quantified, general approach was to discuss such

intangible impacts in quantitative terms so that planners and decision-makers are aware of

their existence as well as their possible implications.

Environmental Management Plan: the approach for formulation of an Environmental

Management Plan (EMP) is to maximize the positive environmental impacts and minimize

the negative ones. The steps suggested include modifications of plans, engineering designs,

construction schedules and techniques, as well as operational and management practices.

After selection of suitable environmental mitigation measures, cost required for

implementation of various management measures was also estimated.

Environmental Monitoring Programme: An Environmental Monitoring Programme for

implementation during project construction and operation phases has been estimated to

oversee the environmental safeguards, to ascertain the agreement between prediction and


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reality and to suggest remedial measures not foreseen during the planning stage but arising

during operation and to generate data for further use.

1.6 REGISTRATION WITH QUALITY COUNCIL OF INDIA (QCI)/NABET

WAPCOS Limited is accreditated by QCI/NABET and the Certificate is enclosed as

Annexure-II.

1.7 OUTLINE OF THE REPORT

The document for the Comprehensive EIA study for the proposed Sach Khas hydroelectric

project has been presented in two volumes. Volume-I presents the Environmental Impact

Assessment (EIA) study and Volume-II delineates the Environmental Management Plan.

The present document (Volume - I) outlines the findings of the EIA study for the proposed

Sach Khas hydroelectric project.

The contents of the document are organized as follows:

Chapter-1 The Chapter gives an overview of the need for the project. The policy, legal and

administrative framework for environmental clearance has been summarized. The objectives

and need for EIA study too have been covered.

Chapter-2 gives a brief description of the proposed Sach Khas hydroelectric project.

Chapter-3 gives a brief description of the methodology and schedule to adopt for

construction of the proposed Sach Khas hydroelectric project.

Chapter-4 outlines the methodology adopted for conducting the Comprehensive EIA study

for the proposed Sach Khas hydroelectric project.

Chapter-5 covers the hydrological aspects of the proposed Sach Khas hydroelectric project.

The data was mainly collected from the DPR prepared for the proposed Sach Khas

hydroelectric project.

Chapter-6 covers the geological and seismicity related aspects.

Chapter-7 covers the environmental baseline conditions covering physical aspects of

environment. The baseline study involved both field work and review of existing documents,

which is necessary for identification of data which may already have been collected for other

purposes.

Chapter-8 presents the information on ecological aspects of the Study Area. The study is

based on collection of data from various secondary data sources. As a part of the

Comprehensive EIA study, detailed ecological survey for was conducted for three seasons. The

findings of the survey were analysed and ecological characteristics of the study area have been

described in this Chapter.

Chapter-9 describes the anticipated positive and negative impacts as a result of the

construction and operation of the proposed Sach Khas hydro-power project. It is essentially a

process to forecast the future environmental conditions of the project area that might be

expected to occur as a result of the construction and operation of the proposed project. An


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attempt was generally made to forecast future environmental conditions quantitatively to the

extent possible. But for certain parameters, which cannot be quantified, general approach has

been to discuss such intangible impacts in qualitative terms so that planners and decision-

makers are aware of their existence as well as their possible implications.

CHAPTER-2

PROJECT DESCRIPTION


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CHAPTER-2

PROJECT DESCRIPTION

2.1 INTRODUCTION

The proposed Sach Khas Hydroelectric project is located in the Pangi valley of Chamba

District of Himachal Pradesh. The proposed scheme lies between longitudes 76o 25’ 30.143”

E to 76o 25’ 3.8” E and latitudes 32o 57’ 55.123” N to 32o 58’ 7.5” N.

The river Chenab in project vicinity flows in the northern direction with a slight inclination

towards the east. The Sach Khas hydroelectric project is located near the Shin village (close

to the Cheninala confluence with the Chenab river) with the location of the diversion

structure proposed slightly upstream of the village and the underground powerhouse

structure at the toe of the dam. The project is planned as a dam toe scheme. Head needed

for power generation is envisaged to be harnessed entirely by the diversion structure as the

powerhouse is merely 300m downstream from the dam axis.

As per the information provided by Himachal Pradesh State Electricity Board (HPSEB), a 40

m high (above river bed level) diversion structure is proposed across the river Chenab

located just 2.5 km up-stream of the Mokha Nala confluence, at about 200 m downstream of

the point where the river takes a westward bend, wherein the river bed elevation is 2185m.

The envisaged tail water level upstream of the Saichu Nala confluence is 2150 m.

After confirmation of levels at the site, and after the reconnaissance site visit, it emerged that

a diversion site exists, which is prima-facie suited for a concrete dam of about 77m height

(above the river bed level) located 1.1 km upstream of the Cheninala confluence, a left bank

tributary with Chenab. The river at the site flows through a narrow gorge exposing bedrock

on both the abutments. Adequate straight reach is available downstream of the river bend

where all the head works components can be housed. The live storage of the proposed

diversion scheme is 8.69 Mm3. Since the proposed scheme is a Dam-toe powerhouse, the

need for a headrace tunnel (HRT) has been eliminated. Also it has been proposed to locate

the crest of the sluice spillway sufficiently below the power intakes in the dam body to take

care of bed load depositions and entry of sediments into the intakes. Thus no desilting

chambers are required. Three intakes each leading to 5.8m diameter penstocks have been

planned to be located on three of the right bank non-overflow blocks. Three penstocks off-

taking from the intakes are proposed to direct the flows to an underground powerhouse on

the right bank of the Chenab river housing 3 units of 86.67 MW turbines with a total installed

capacity of 260 MW.

As regards the powerhouse location, it was seen during the reconnaissance visit that the site

originally envisaged by HPSEB for an underground powerhouse is located on the right bank

of the river about 0.5km upstream of its confluence with the Saichunala. However, after

numerous investigations and detailed survey carried out at site, the new powerhouse is


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proposed to be located as an underground structure on the right bank of the Chenab River at

a distance of about 200m from the present dam toe and about 850m upstream of the

Cheninala confluence with the Chenab.

2.2 ALTERNATIVES CONSIDERED

Layout 1: (Diversion site as per tender)

As per this alternative, the water of the river Chandra-Bhaga are proposed to be diverted into

a water conductor system for generation of power in an underground powerhouse located

near Sach Khas village. The diversion site is located 2.5km downstream of the confluence of

Mokhanala with the river Chenab. The river bed level at the proposed diversion site is El.

2170.0m, based on the survey data. The FRL envisaged for the scheme was El. 2219m.

A design discharge of 513.75 cumec (including 20% for desanding chamber flushing) is

proposed to be led through the power intake located on the right bank into three feeder

tunnels. Each feeder tunnel leads into a 254m long desanding chamber. The water through

each desanding chamber is let into a link tunnel through a transition placed at right angles to

the desander alignment. The three link tunnels join to form a single a head race tunnel about

4.5km long and 10.0m in diameter, which feed an underground powerhouse located about

500m upstream of the Saichunala confluence with the Chandra-Bhaga River. The allotted

tail water level at the TRT outlet should be El. 2150m which has been revised to 2149m.

Considering an average river slope of 1 in 165, and another 1.5km to Saichu from

Cheninala, the tail water levels 500m upstream of Saichunala are much lower than the

allotted levels at about El.2135m.

This layout was rejected due to following reasons:-

• Gross hydraulic head, in this case, is beyond the allotted levels

• Larger requirement of forest land as surge shaft being on surface would be located

in the forest area

• Construction adits for the head race tunnel and their approaches would be located in

forest area

• Geology in the proposed intake area is not favorable and would require extensive

excavation which would endanger the Killar – Tindi Road

• The Head race tunnel alignment passes through folded rock mass strata which would

make tunneling extremely difficult.

• Very low peaking power, as sufficient live storage would not be available.

Layout 2: (Diversion site about 300m upstream of BakhanwalNala)

In this alternative, the diversion site is proposed to be shifted 850m downstream of the

diversion site as envisaged in Layout 1. The diversion site is located just 300m upstream of


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the northward bend that the river takes after the Bakanwalnala confluence with the Chenab

River. The bed level at this location would be at El. 2165.0m.

Shifting the diversion site to this location envisages layout similar to alternative-1. Since

there are no intermediate villages between the two alternative dam sites (Layout 1and

Layout 2), valley being steep, no submergence problems are anticipated. Considering FRL

as 2219m, this will lead to an increase in the dam height by about 10m. However, the

peaking operations of the plant will not possible in this alternative too.

Due to the side intakes, and fragile geology at intake site on the right bank with potential

slide zone at the upstream of intake location, huge excavation for slope stabilization would

be required and the excavations shall extend beyond the present alignment of the SKT road,

which shall need to be realigned above this area and into the forest on Rai Dhank bend.

This was not considered practically feasible in view of the single approach road to the Pangi

Valley. Also for locating desilting chambers, long HRT, etc., large amount of land would be

needed in addition to land for development of the project facility areas.

Alternately, a diversion structure with a powerhouse in the nearby downstream reach can be

considered. This alternative would not result in realization of full head as the head utilized

would reduce considerably from 70m to mere 47m. The tail water levels at this site would be

El. 2172 (as per the survey data) against the allotted levels of El. 2149m. Therefore, this

alternate does not result in optimal utilization of the river potential.

Layout 3: (Diversion site near PH-1 Pillar)

There are two types of arrangements feasible in this location. Prima facie, diversion site is

located 1.3km upstream of the Cheninala confluence with Chenab. The river takes a small

north-east bend and then flows straight north. There is an RCC pillar PH-1 constructed along

the road side, designated as a control point of survey.

This proposal comprises a diversion scheme either with a surface power house or an

underground power house, immediate downstream of the dam. The bed level of the river at

this location is about El. 2146.5m. Foundation rock is available at depths of about 20m. A

92m high dam from the deepest foundation can be envisaged. About 250m downstream of

the dam axis, on the right bank, the hill slopes relatively flat and would provide the terrain for

siting a surface powerhouse, with the power intake from the body of the dam. However, the

tail race channel would be quite long, envisaging a downstream collection basin/surge

chamber, which would result in acquisition of large tact of forest land. The powerhouse being

an open structure, heavy hill cutting and stabilization measures would be needed and extent

of the excavation would necessitate diversion of the existing SKT road which invariably

would also involve larger forest area.


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Alternately, an intake along the right bank 30m upstream of the dam axis can also be

constructed, through which 500m long pressure shafts will take the water to the powerhouse

for power generation. But this underground arrangement would warrant a side intake on the

right bank hill, an upstream surge shaft, and a huge underground powerhouse and

transformer cavity. This would involve huge excavation in the intake area where the

excavation would encroach the Sansari-Killad – Tindi road necessitating acquisition of larger

areas in forest again and realignment of the SansariKilarTandi Road. In view of the

disruption/realignment of the SKT road and requirement of large forest areas this scheme is

not considered.

Layout - 4: (Diversion site downstream of Layout 3)

Considering the alternative arrangements explained in the above layout 3, another

arrangement was considered, which involved shifting of the diversion structure downstream

of the location in layout-3 by 250m (i.e 1100m upstream of Cheninala confluence with the

Chenab). By doing so, the length of the pressure tunnels gets reduced to 300m, eliminating

the requirements for surge chamber. An underground powerhouse proposed just 300m

downstream of this dam axis is also possible. The geology is competent and can house the

pressure tunnels and underground powerhouse. Consistent with the allotted tail water levels

at El. 2149m, the bed level of the river is at about El. 2145m. The underground powerhouse

is proposed on the right bank of the river Chenab. This alternative envisages the utilization of

about 70m gross head.

Given the bed level of the river El. 2145 m and probable foundation rock depths at El.

2132m, a dam of about 90m high is envisaged. The hill slopes on the right bank are

relatively flat than the left bank slopes, which permits the housing of the power intakes in the

body of the dam on the right bank, eliminating the side intake which invariably would

endanger and undercut the SKT road in addition to involving larger forest area. The waters

from the river would be taken to the underground powerhouse on the right bank through

three nos. of 5.8m dia steel penstocks, with average length of 300m.

With the intakes in the body of the dam thereby dispensing away the side intake, with the

desilting basin, long HRT, underground transformer hall and shorter, tailrace, the

requirement of forest land shall be significantly less. The SKT road too shall not need to be

realigned.


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Layout - 5: Diversion site upstream of CheniNala

The last alternative studied is locating a diversion site further 750m downstream of the

above option and 300m upstream of CheniNala confluence with the Chenab. This layout is

schematized on the left bank; as there were visible rock exposure and the river valley is also

relatively narrow than the above. The bed level at this location is at El. 2142.0m, which is 7m

below the allotted levels.

Although, there are no schemes planned across Chenab, immediately below SachKhas,

except the Duggar HEP which is far below. This location is thus avoided as the bed levels

are much below than the allotted levels for the project.

Layout considered for final adoption

Based on the different layouts detailed above (Refer project layout), the scheme described

at Layout – 4 (diversion site 1100m upstream of CheniNala) is the most suited one, from the

consideration of given levels for the project. Considering favorable geology and rock

exposures, the layout could further be optimized into a simpler model. As the construction

period in each year is extremely limited due to the unpredictable and extreme winter weather

condition reduction in construction period of the project is of utmost importance. This project

layout would eventually bring down the construction period, as major project components,

like desanders, headrace tunnels, surge shafts, etc. have been avoided.

The storage requirement as per the Indus Water Treaty (IWT) is also under this alternative.

No diversion/realignment of existing SKT road is envisaged. Further, it is proposed that

major construction facilities shall be located in the reservoir submergence area bringing in

substantial reduction in requirement of forest land which otherwise would have been

necessary to locate these facilities in addition to forest land required for locating permanent

project components. Thus, huge forest area requirement for locating project components, as

envisaged in other layouts, could be reduced in this alternative.

To take care of the mandatory environmental flows, scheme envisages releasing these

required flows through a surface powerhouse on the left bank housing a 7MW unit. To have

100% redundancy, another unit of 7 MW is also proposed to be installed in the proposed

powerhouse. The additional unit would operate in the contingency of first unit of 7 MW either

under forced or planned outage. This would ensure that the mandatory environmental

release is available continuously even if one unit of 7 MW is out of service. Hence, the

project layout described at alternate – 4 is considered for detailed study in the DPR. A map

showing various alternatives studied is enclosed as Figure-2.1.


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Figure-2.1: Various Alternatives considered for Sach Khas Hydroelectric Project

2.3 PROJECT DESCRIPTION

Diversion Works

The diversion site is planned in a narrow gorge of the river located about 1.08km upstream

of the confluence of the Cheni Nala with the river Chenab near Shin village. The bed level at

the proposed diversion site is about 2145m. Since the FRL of proposed scheme is 2219.0m,

a 77m high structure above the river bed level is envisaged. The proposed location has been

marked at site by HPSEB. This location is immediately downstream of the sharp bend in

river. However, it has been seen that enough straight reach is available between the

diversion site and this bend so as not to cause any problems later on. Also immediately

downstream of the proposed location the river width broadens and again constricts to a

narrow width at a location where the tailrace tunnel outlet is planned.

At Sach Khas, the proposed dam can be categorized as a small reservoir (as per the gross

storage criteria) and a large dam (as per the hydraulic head criteria of more than 30m).

Since the hydraulic head lies in the large category, the recommended design floods as per

Cl. 3.1.3. of IS 11223 would be a PMF.


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• PMF has been calculated as 9047 cumec (as per hydrology studies).

• Minimum available live storage between FRL (2219m) and MDDL (2209.30m) is

8.69 MCM.

• River bed elevation at the proposed dam axis is 2145m.

• Right abutment is characterized by rock scraps at 60o up to EL 2170m followed

by 25 o to35 o slopes upto EL 2190m.

• Left bank rises above the river bed at angle of 45 o to55 o with break in slopes at

EL 2160, 2190 and 2220m.

Keeping in view the above requirements and data, and after an assessment of the

topographic and geological conditions at the proposed site, a concrete gravity dam with a

breast-walled sluice spillway has been adopted as diversion structure. The dam top is

proposed at El. 2222m after accounting for a freeboard of 3m. The structure would thus have

a height of 77m from the deepest bed level. Based on the storage requirements for peaking,

the MDDL has been fixed at El. 2209.30. Five sluices of size 7.5m (width) x 12.3m (height)

have been proposed to pass the PMF with one gate in inoperative condition. The diversion

dam has been conceptualized considering foundation rock strata at a shallow depth of

around 13m below the river bed. Energy dissipation is envisaged by the use of a trajectory

bucket and a suitably located plunge pool. A sluice type gravity dam with foundation resting

over the bed rock is proposed in the present case. Regarding the hydraulics of the structure,

low level sluices with crest placed at 22m above the river bed level are proposed to pass the

design flood of 9047cumec. Energy dissipation shall occur through a trajectory type bucket

dissipater, discharging the excess flow into a pre-formed plunge pool with its center situated

at a distance of about 90m downstream of the sluice lip. It has been planned for the deepest

level of the plunge pool be excavated up to the probable scour depth calculated under the

prevailing discharge and flow conditions.

Since the river bed slope is of the order of 1 in 165, diversion structure will form a reservoir

with an approximate length of 8.3 km at FRL (2219m) and 7.3km at MDDL(2209.30). The

gross storage capacity of the reservoir is estimated as 25.24 Mm3 and the live storage

capacity is envisaged as 8.69Mm3. The reservoir is expected to trap most of the bed load

suspended sediment load thus eliminating the need of desilting chambers. Five low level

sluices with crest at 2167m of size 7.5m width and 12.3m height are proposed for flood

passage. Drawdown flushing of the reservoir shall be carried out through these sluices for

flushing out of the sediment entrapped in the reservoir. Detailed studies on sedimentation

and reservoir flushing can be taken up at detailed planning stage.


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Power Intake

Three number of power intakes are proposed to be located in three of the non-overflow

blocks immediately adjacent to the overflow blocks on the right bank to draw a total diversion

discharge of 428.12 cumec. Additional discharge for silt flushing is not planned for due to the

provision of trapping the sediments in the reservoir itself. The invert of intake is proposed at

El. 2196.9 m which is 29.9m above the sluice crest. The proposed invert level satisfies the

criteria for minimum submergence below the MDDL of 2209.30 m to prevent the formation of

vertices. The control arrangement at the inlet is proposed in the form of vertical lift gates with

provision for emergency gate grooves.

Three breast walled type structures are proposed with a bell-mouth inlet transition and with

accelerating velocities from the trash rack location to the mouth of penstocks. Each of the

intakes in turn feeds a 5.8m diameter penstock with a design discharge of 142.707 cumec.

The lengths of the penstock are calculated to 254, 268 and 282meters from the shortest to

the longest respectively.

The trash rack is planned to be located with an inclination of 12 degrees to the dam axis with

the top starting at a distance of 3m from the same. The bottom of the trash rack will rest on a

cantilever portion emerging from the body of the dam. The elevation of floor (trash rack

sitting) is 2193.30 m thus making the total vertical height of the trash rack to be 28.7m. Two

end piers each of width 2.4m and two intermediate piers each of width 1.2m will be provided

to support the trash rack.

The hydraulic design features of the power intake are:

• Maximum velocity through trash racks is restricted to 0.9m/sec in unclogged

condition and 1.2m/sec in 25% clogged condition, when operating at MDDL. This

satisfies the requirement of paragraph 6.1 and 6.2 of BIS 11388-1995

“Recommendations for design of trash rack for intakes”.

• The design velocity through the penstock is 5.4m/sec for normal operating

condition.

• Accelerating type of flow is proposed at the inlet of the power intake structure.

• The power intake has been designed to cater to the applicable flow condition and

relevant submergence requirements.

Pressure Shaft

Three circular pressure shafts each of diameter 5.8m have been proposed to carry the

design discharge from the intake to the powerhouse. The pressure shafts begin immediately

after the transition near the intake and bend vertically, moving parallel to the downstream

slope of the dam. They lie exposed on the downstream surface of the dam for a short reach


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before being underground. They also consist of a compound bend near the toe of the dam

after which the pressure shafts become horizontal and continue on their way to the

powerhouse. There exists yet another horizontal bend in the pressure shafts near the

powerhouse after which the pressure shafts are connected to the Main Inlet Valve. The

lengths of the pressure shaft are calculated to 254, 268 and 282meters from the shortest to

the longest respectively.

The centerline of the pressure shaft at start, after the intake is proposed to be at 2199.80m

and the centerline of the machines in the powerhouse is proposed at 2138.00m, registering

a fall of 61.8m.The pressure shafts are designed such that any need for a surge shaft is

eliminated.

Powerhouse

The underground powerhouse is proposed on the right bank of the river Chenab about 200m

downstream of the toe of the dam. The water from the tailrace tunnel is proposed to

discharge into river Chenab. This site has been considered suitable for underground

powerhouse from geological considerations. The governing tailwater level has been fixed at

EL. 2149m as per the allotted level. The powerhouse is proposed to facilitate the housing of

three units, each of 86.67 MW Francis turbines.

The centerline of the turbine units is proposed at El. 2138.00m after catering to a setting

head of 9.00m below the minimum tailwater level of El. 2147.00m. The erection bay floor

level is proposed at 2151.15m while the generator hall floor level is proposed at El.

2146.15m. The length of the control block is 15m and it is located adjacent to the machine

hall at the left side of the powerhouse cavern. A 35m long service bay is located right side of

the powerhouse cavern. An adit with invert level of El. 2165.40m at the portal is planned on

the right of the powerhouse opening directly into the service bay.

Machine Hall

The internal dimensions of the powerhouse cavern has been proposed as 126m (L) x 23m

(W) x 48.5m (H). The operating floor level is kept at El. 2151.15m. The length of the machine

hall would be 76m. The unit bay is proposed with 21.5 m spacing. The EOT crane beam is

proposed at El. 2163.65m, i.e. 12.5m above the operating floor level.

Each unit is proposed with a draft tube separated by one RCC piers in between. At the draft

tube gate location, the width of each draft tube bay is 11.5m and height is 6.65m. The draft

tube gates are proposed to be operated from a deck in the transformer cavern.


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Conductor System

The water conductor system consists of three penstocks of 5.8m diameter located on the

right bank of the river downstream of the dam toe. These convey the water to an

underground powerhouse housing three units each of 86.67 MW, totaling to the installed

capacity of 260 MW. The penstocks are exposed to the surface for a short stretch after they

leave the dam body before going underground again. The length of the penstocks and their

diameter are so designed that the need of a surge shaft is eliminated.

Tailrace Tunnel

The outflow from the end of each of the draft tubes is proposed to be conveyed into

respective tailrace tunnels downstream of the powerhouse. These TRTs then carry the

discharge back into the river Chenab. Each TRT is D shaped and has size of 6.6m x 6.0m.

The invert elevation of the TRTs at the outlet portal is 2145.00.

2.4 SECONDARY POWER HOUSE

As per environmental regulations, it has been stated that a minimum of 20% of the average

flow occurring during the lean period i.e. December to March has to be released to take into

account the environmental aspects of the downstream region. This flow in the other months

is compensated by the additional water that is routed through the spillways.

The average discharge for SachKhas HEP from December to March in the year 1993-1994

(which is the 90% dependable year) comes out to be 60.04 cumec. Thus a constant release

of 12.01 cumec (Accounting to 20% of the average discharge) has to be constantly released.

With a view of utilization of this extra discharge for power generation a secondary intake,

pressure shaft and powerhouse has been provided in the left bank, immediately at the toe of

the dam.

Secondary Power Intake

It is proposed to provide a secondary intake in the Non-overflow block adjacent to the sluice

block on the left bank to draw a total diversion discharge of 12.01 cumec. As in the case of

the main intakes additional discharge for silt flushing is not planned for due to the provision

of trapping the sediments in the reservoir itself. The centerline of the intake is proposed at

2202.80m with the invert at El. 2201.55 m which is 34.55m above the sluice crest. The

proposed invert level satisfies the criteria for minimum submergence below the MDDL of

2209.30 m to prevent the formation of vertices. The control arrangement of this inlet is

proposed in the form of a vertical lift gate. All the hydraulic design features of the secondary

intake are consistent with the hydraulic design features of the primary intake.


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Secondary Pressure shaft

A 2.5m diameter secondary pressure shaft takes off immediately after the end of the

transition following the intake. It is proposed that it runs horizontally for a distance of

11.029m before the beginning of the first vertical bend. Then it runs parallel to the

downstream face of the dam. Like the primary pressure shafts it is also exposed to the

surface for a short length before it dives underground. The initial vertical bend is followed by

a second one of radius 8.0m after which the pressure shaft travels horizontally. It is also

proposed that the pressure shaft is bifurcated into two, each of diameter 1.75m before

entering the powerhouse.

The centerline of the pressure shaft at start, after the intake is proposed to be at 2202.80m

and the centerline of the machines in the powerhouse is proposed at 2139.45m, registering

a fall of 63.35m. The pressure shaft is designed such that any need for a surge shaft is

eliminated.

Secondary Powerhouse

A surface powerhouse is proposed on the right bank of the river Chenab about 10m

downstream of the toe of the dam. The water from the tailrace tunnel is proposed to

discharge into river Chenab at around the location of the plunge pool of the main dam. The

governing min tailwater level has been fixed at EL. 2145.20m as per the rating curves

developed. The powerhouse is proposed to facilitate the housing of two units, each of 7.0

MW Francis turbines. Out of these two one is proposed to act as a standby unit.

Secondary TRT

The outflow from the end of each of the draft tubes is proposed to be conveyed into

respective tailrace tunnels downstream of the powerhouse. Each TRT is D shaped and has

size of 3m x 3m. After running for a certain distance the unit TRTs merge to form into one.

The larger TRT formed after the unit TRTs merged is proposed to be of D-Shaped with a

size of 3.6m x 3m. The TRT travels with a up slope up to the outlet portal at which it is

proposed that the discharge will occur at a gentle slope of 1 in 300.

The project layout map is enclosed as Figure-2.2.


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Figure-2.2: Layout of Sach Khas Hydroelectric Project

2.5 SALIENT FEATURES

The Salient features of Sach Khas hydroelectric project are given in Table-2.1.

Table-2.1: Salient Features of Sach Khas Hydro-Electric Project Project Location River and Hydrology River Chenab Catchment Area 6588 sq.km. Average Bed Slope 1 in 165 PMF 9047 cumecs Concrete Dam & Spillway Top of Dam El. 2222m River Bed Level El. 2145m Deepest Foundation level El. 2132m (assumed) Full Reservoir Level El. 2219m Minimum Drawdown Level El. 2209.30m Dam length at Top 241.5m Type of Spillway Sluice Spillway Crest Elevation El. 2167m Sluice Size 7.5m (W) x 12.3m (H) Reservoir Gross storage 25.24 MCM Live Storage 8.69 MCM Reservoir Stretch at FRL 8.2 km (approx.)


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Reservoir Stretch at MDDL 7.2 km (approx.) Intake (on right non -overflow blocks) Number 3 Intake Invert El. 2196.9 Trash Rack Size (single panel) 3.95m (W) x 4.089m (H),

48 nos. (4panel per bay, 4 bays per intake) Design Discharge per intake 142.707cumec Gate Operation Level El. 2222m Size of Gates 6.6m (W) X 5.8m (H) Secondary intake on Left Non -Overflow Block Number 1 Intake Invert El. 2201.55 Trash rack Size (single) 3.6m (w) x 3.64m (h), 3 panels Design Discharge 12 cumec Gate Operation Level El. 2222 Size of Gates 2.2m (w) x 3.96m (h) Pressure Shaft Number 3 Diameter 5.8 Length 254, 268 and 282m Secondary Pressure Shaft on left abutment block of dam Number 1 Diameter 2.5 Lengthupto bifurcation 92.0m Diameter after bifurcation 1.75m Length after bifurcation 33.5m & 28m Powerhouse (on Right Bank) Type Underground Size 126m (L) x 23m (W) x 48.5m (H) Number of Units 3 Installed Capacity 3 x 86.7 MW + 2 X 7 MW Type of turbines Francis Centre line of machine El. 2139.6 Unit Design Discharge 142.707cumec Normal TWL El. 2149.0m Min. TWL El. 2147.0m Gross Head 68.1m Net Head 66.86m Secondary Powerhouse (on Left Bank) Type Surface Size 52m (L) x 15m (w) x 32m (H) Number of Units 1 + 1 standby Installed Capacity 7 MW each Type of Turbine Francis Centre line of machine El. 2139.5 Unit design discharge 12 cumec Normal TWL El. 2149.0m Min. TWL El. 2145.0m Tailrace Tunnel Number 3 Nos. Shape D-Shape Height 6m


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Length 99.75m,113.13m,132.35m Design Discharge 142.707 X 3 HFL at TRT outlet El. 2158.0m Power Generation 90% Dependable year 999.92GWh 50% Dependable Year 1009.44 GWh

Source: DPR

2.6 LAND REQUIREMENT

Land would be acquired on permanent basis for:

• Reservoir • Dam & Power House, • Downstream coffer dam and outlet portals of diversion tunnels, • All muck disposal and borrow areas/ quarries, • All access roads to the permanent works, • Explosive magazines and access roads, • Project site office/Job facilities

The total land required for the project is 125.62, About 118.22 ha is forest land and the

balance land 7.40 ha is private land. The details are given in Table-2.2.

Table-2.2: Land requirement for the project

Sr. No Project Component/ Activity Area (ha) 1 Submergence Area: a) Forest Land 81.88 b) Non-Forest Land (Private Land) 0.28

Total Area of Submergence 82.16 2 Muck Dumping Area 10.53 3 Quarry 3.03 4 Dam & Power House 9.54 5 Project Site Offices/Job Facilities: 5.25 6 Explosive Magazine 0.23 7 Sub-surface (Underground Works) Area 2.44 8. Approach Roads to explosive magazine,

Project facilities & Quarry 5.32

9. Township & Office (Private land on lease basis)

7.12

TOTAL 125.62 Source: DPR


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2.7 ACCESS TO THE SITE

There are three accesses available for the project site, first from Jammu & Kashmir through

Kishtwar town; second from Pathankote - Chamba town and third through Kullu-Manali via

Rohtang pass. The most favourable approach is the third one through Kullu-Manali via

Rohtang pass. This approach from Manali to Udaipur and further to site location is

characterized by overflowing nallahs, bridges and culverts. The project area is about 220 km

from Manali and about 14.3 km upstream of Killar. Manali is situated at a distance of approx.

550 kms from Delhi and Udaipur at a distance of around 200 kms from Manali. The project

site is located at a distance of about 60 kms downstream from Udaipur. The road up to

Manali is in good condition. Further, to reach Udaipur, Rohtang pass situated at a distance

of 140 km and at EL. 3195m has to be crossed. This stretch officially remains closed from

15th November - 15th May due to heavy snow fall. Double laning of this stretch is under

progress by BRO and a Rohtang Tunnel to bypass this area is also proposed. The road

(partially metaled and partially WBM road) from Udaipur to site is in very bad condition with

numerous big overflowing nallahs; sharp carves and overhanging blocks (rock mass). These

nallahs are to be cleared very frequently during the rainy season by JCB’s/Dozers to make it

approachable. The approach road and cross drainage works needs to be improved before

the start of the construction activities.

A line diagram of the route to project site is shown in Figure-2.3.

Figure-2.3: Project Location distances

The nearest airport is Bhuntar and the nearest rail head is Kiratpur.

2.8 INFRASTRUCTURE PLAN The infrastructure works at proposed Sach Khas hydroelectric project would broadly

comprise of:

• Batching Plant • Crusher Plant • Stores • Fabrication Yard • Workshop • Formwork & Rebar Yard • Workman Camp • Staff Colony • E&M Workshop


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• H&M Workshop • QA/QC Lab • Site Office • Disposal Area • Borrow Areas/Quarries • Project Roads leading to all work sites.

Infrastructure works and facilities required for constructing and maintaining the project are

discussed in following sections. The Infrastructure layout plan has been depicted in Figure-

2.4. The land requirements for various infrastructure works covering residential buildings are

given in Table-2.3. The land requirements for permanent and temporary Nonresidential

buildings are given in Table-2.4 and 2.5 respectively.

Figure-2.4: Infrastructure layout plan


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Table-2.3 Land Requirement for Residential Buildings – (Permanent & Temporary) S. No.

Type of Quarter

Colony Remarks Permanent Temporary

Number of Units

Plinth Area (m2)

Total Plinth Area (m2)

Number of Units

Plinth Area (m2)

Total Plinth Area (m2)

Total No. of units

1 Type A 6 240 1440 1 240 240 7 2 Type B 13 200 2600 15 120 1800 28 3 Type C 10 150 1500 46 100 4600 56 4 Type D 17 100 1700 24 80 1920 43 46 7240 86 8560 132 Total 15800

Source: DPR

Table-2.4: Land Requirement for Permanent Non Residential Buildings

S.No. Description No. Plinth Area (m2)

Total Plinth Area (m 2)

1 General Manager 1 150 150 2 Project Control Office 1 840 840 3 Deputy General Manager 2 150 300 4 Sr. Manager Admn. And Chief Accounts

Officer 1 150 150

5 Public Relation Officer 1 75 75 6 Telephone Exchange 1 100 100 7 Rest House 1 300 300 8 Sub-ordinate Rest House 1 150 150 9 Fire Station 1 50 50 10 Officers Club 1 100 100 11 Staff Club 2 75 150 12 Model Room 1 30 30 13 Market 1 1500 1500 14 Bus Stand 1 50 50 15 Security Post 3 50 150 16 Central Field Stores and Workshops 1 1000 1000 17 Field Testing Labs 1 100 100 Total 5195 Source: DPR

Table2.5: Land Requirement for Temporary Non Residential Buildings

S.No. Description Total Plinth Area (m2) 1 Site Office 1500 2 Store 1500 3 Quality Control Lab 200 4 Pantry 600 5 P&M Office Workshop 4000


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S.No. Description Total Plinth Area (m2) 6 Diesel Dispensing 150 7 D.G.Room 300 8 Repair Shop 800 9 Batching Plant 8500 10 Chilling Plant 3000 11 Cement Godown 2250 12 Stock Pile 2500 13 Mobile Crushing Plant 3000 14 Quality Control Laboratory 400 15 Fabrication shop and yard 3000 16 Carpentry Shop & Lagging Yard 1500 17 Explosive Magazine with Portable 300 18 Department Workmen 550 19 Labour Roof Shed for 200 Nos. 3000 Total 37050 Source: DPR

Road Facilities and Bridges

The transportation of the material would be done by road transport to the project site. The

main highway from Chandigarh to Project Site has been surveyed to study its suitability to

transport heavy loads to the project site. Road through Rohtang Pass will be opened for

seven months in a year and the same road will be utilized for the transport of construction

material.

Workshops at Dam site and Powerhouse Areas

Given the sizes of civil components, all the facilities will be cater to one location to have easy

accessibility through all the components.

Since all the work would be highly mechanized, adequate and self-sufficient repair and

service facilities would be set up at the project site. There are absolutely no services or

Facilities of mechanical nature available near the project area. All mechanical repairs and

servicing will be done in house by providing enough space for workshops, maintaining an

adequate inventory and deputing skilled manpower. Close Monitoring of the inventories of

spares, consumables, and other materials would be done to ensure reduced downtime.

Adequate and competent repair staff would be deployed in the field as well as in the shops

to keep the construction fleet in top operational condition.

Separate workshops would be set up for:

• Earth moving machinery mounted on tracks like shovels, dozers, etc.

• Earth moving machines mounted on tyres like dumpers, loaders, graders etc.


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• Pneumatic, concreting equipment like boomers, wet shotcrete machines, concrete

Pumps etc.

• Transport equipment like buses, trucks, transit mixers, ambulances, light vehicles,

etc.

• Penstock fabrication yard.

Every workshop would have partly covered area in addition to open area. Equipment

requiring major overhaul/repairs would normally be parked under cover. The open areas

would provide parking space for the equipment under minor repair. A store to stock the

spares for the equipment, a site office and toilet facilities would be provided under the

covered space. The penstock fabrication yard would be equipped with two plate bending

rolls, a battery of welding and gas cutting sets, hydro-testing and radiography facility, sand-

blasting and painting equipment and sufficient space to stock the raw plates as well as the

finished ferrules awaiting dispatch. An E.O.T crane of 40 MT capacity erected in the yard

would be deployed for handling the ferrules during different stages of fabrication. A separate

mobile crane of 40 MT would be deployed to handle the plates/ferrules in the stock yard. The

fabrication yard would be partly covered to allow welding and other activities to go on

unhindered under the covered area.

Stores and Warehouses

Keeping the size of the project in view only, a Central warehouse would be set up to stock

the material required for the project. All supplies to the project would be stocked hereon their

arrival from the suppliers. Site stores would be made for daily need at every work site to

stock the specific material required for the work it is meant to cater for. These site stores

would receive material from the central warehouse as per their demand. Inventory control

would be computerized to increase efficiency and also to assist in planning procurement of

material.

Workshops have been proposed for earth moving equipment and for concreting and drilling

equipment at contractors cost. Since all the work would be highly mechanized, adequate and

self-sufficient repair and service facilities would be set up at the project site since none of

these facilities are available in the area nearby. Since all mechanical repairs and servicing

will be done at site, maintaining an adequate inventory and having adequate skilled

manpower available will be essential.

Construction Power

Construction power would be available through two sources 3.5MW Chhoo Hydroelectric

Project and through diesel generating sets. It has been planned that 75% of Power will be

available through diesel generating sets and 25% through Choo Hydroelectric Project. The


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requirement would have to be met only by installing diesel generating sets. The requirement

of construction power would vary at each individual site depending upon the equipment

deployed.

Aggregate and Batching Plants

A total requirement of 7.5 Lac cum of concrete is estimated, where Dam is having the major

concrete quantity of 5.8 Lac cum, since the project is Dam Toe project, the concentration of

construction activity would be confined to one main area.

The set up for aggregate and concrete production for the project would be as below:

Batching Plant of 30 Cum, 60 Cum & 90 Cum and Crusher Plant of 200 TPH will be

deployed to arrange the concrete and aggregate.

Project Areas Roads

To execute the various civil works, roads would be made for linking the work site to other

sites and to job facility areas. They would essentially be unpaved and would be constructed

at a workable gradient so that loaded construction equipment does not have to toil hard to

group slope. An average gradient of 1:15 has been contemplated. These roads would be

connected to the existing roads in the area or to other project roads. The details are given in

Table-2.6.

Table -2.6: Project Road Network Road Distance Length (km) Diversion Tunnel to Disposal Area 4.5 Disposal Area to Cofferdam 4.4 Dam to Disposal Area 4.2 Adit to Bottom of Penstock to Disposal Area 4.0 Construction Adit to Top of Power House to Disposal Area 3.7 Main Access Tunnel to Power House to Disposal Area 3.5 Tail Race Tunnel to Disposal Area 3.7 Diversion Tunnel to Batching Plant 1.0 Intake to Batching Plant 2.0 Dam to Batching Plant 1.5 Adit to Bottom of Penstock to Batching Plant 2.0 Construction Adit to Top of Power House to Batching Plant 2.0 Main Access Tunnel to Power House to Batching Plant 1.5 Tail Race Tunnel to Batching Plant 1.5 Source: DPR

Bridges Required

Both permanent and temporary bridges would be constructed to cross the waterways falling

in the alignments of the roads. The details are given in Table-2.7.


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Table 2.7: Details of Bridges required S.No. Description Approx. Length (m) 1 Bridge at Chenab River Downstream of Tail Race

Tunnel 50

2. Bridge at Ajog Village for access to Township 50 Source: DPR

Muck Dumping Areas

Total muck from excavation of the project components such as Dam, Power house, TRT,

Adits, Pressure shaft etc. worked out, Component wise muck generation, disposal& area

required are presented in the Table 2.8 to 2.10 respectively.

Table- 2.8: Component wise Total Muck Generation S. No. Particulars Approx. Quantity (cum) 1. Diversion Tunnel 1,40,000 2. Dam & Intake 6,00,000 3. Plunge Pool 1,10,000 4. Pressure Shaft 70,000 5. Powerhouse 2,50,000 6. Tail Race Tunnel 20,000 7. Adits 25,000 7. Approach Roads 1,00,000

Total 13,15,000

Source: DPR

Table- 2.9: Total Muck to be disposed after Considering Swelling Factor

S. No. Description Quantity (Cum) 1. Total Excavation 13,15,000 2. Common Excavation 5,26,000 3. Total Rock Excavation = (1) – (2) 7,89,000 4. Reusable Quantity as construction

material 3,94,500

5. Disposable rock muck 3,94,500 6. Disposable rock muck after swelling:

(considering 50% swelling factor) 5,91,750

7. Back fill/fill quantity 1,90,000 8. Disposable common muck = (2) – (7) 3,36,000 9. Disposable common muck after

swelling (considering 25% swelling factor)

4,20,000

10. Total muck to be disposed = (6 ) + (9) 10,11,750 Source: DPR

It is clear from above table that total 10, 11,750 cubic meters muck requires proper disposal.

Most of the area, identified for dumping is planned on the banks of nearest drainages &

away from River HFL. The identified areas are mostly gradually sloping near river bank. The


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drainage side bank of the area will be properly protected and stabilized with Gabions/

Retaining Walls of suitable designed sections.

Table 2.10: Muck Disposal Areas & Capacities S. No. Disposal Site. Area Average road

distance from Dam area

Capacity

(ha) (km) (Lakh cum) 1. Area near Bumbal (R/Bank) 5.46 1 2.30

2. Area near Mindhal Bridge (L/Bank)

0.77 6 0.20


0.66 6 1.10


3.64 6 6.60

Total 10.53 10.20

Source: DPR

About 10.11 Lakh cum. of muck is to be disposed hence capacity of the dumping area is

sufficient to accommodate the muck generated from the project.

It is further elaborated that unused muck would be piled up at an angle of repose at the

proposed dumping sites. For the stabilization of dumped materials various engineering

measures and phyto-remedial measures shall be provided.

Telecommunications

The different work sites, stores, workshop, office, colonies, police station, hospital etc.

should have a reliable telecommunication network, interconnected to the existing

telecommunication network of Himachal Pradesh. An electronic exchange with a minimum

capacity of 50 lines is proposed at the project site during the construction stage. This internal

system should be maintained by Bharat Sanchar Nigam Limited to ensure reliable

connectivity with the rest of the country.

In addition to the above, a wireless VSAT system is also proposed as a standby system for

linking the project site with headquarters, procurement offices and regional offices. After

completion of the project construction, the telecommunication network is proposed to be

maintained to the extent necessary so as to provide a reliable service during plant operation.

Domestic Water supply

There is no treated water supply source available near project site. For the potable water

supply to the main residential colony, a water treatment plant of sufficient capacity is

proposed to be provided in the area earmarked for the main colony complex. There is a

water source at Nearest Nallas which is proposed to be tapped. For the office/field


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hostel/staff hostel complex packaged water treatment plant is proposed to be provided. For

labour/construction colonies, the water sources at nallas and various other small sources will

serve the purpose after providing suitable water treatment.

Sewage treatment Plant

During the construction stage, for main colony complex, it is proposed to provide common

septic tanks with adequate capacities. The above system will facilitate easy maintenance of

the sewerage system. At a later stage, all these septic tanks would be connected to a

common sewer line leading to a sewage treatment plant (STP) which shall be constructed

catering adequate capacity.

Explosive Magazines

For completing the project as per the construction programme, it has been estimated that

one explosive magazine, of 20 MT capacity, would be sufficient to meet the requirement.

The area around the building for explosive and detonators would be fenced and have a

strong gate which would be operated by the armed guard only. Adequate protection of the

building against lightening would also be provided as per IS: 2309.The Explosive Rules of

1983 lay down that a safe distance of 345 m should exist from the magazine structure of 30

MT capacity to any railway line or public road. It also specifies that a safe distance of 690 m

should exist from the magazine to any houses, dwellings, factories etc. As per investigations

at site, the requirement of 690 m safe distance can be met.

CHAPTER-3

CONSTRUCTION

METHODOLOGY


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CHAPTER-3

CONSTRUCTION METHODOLOGY

3.1 GENERAL

The project implementation schedules for construction of a hydroelectric project are drawn

with a view to complete all the works and commission the project in the shortest possible

duration, so that the construction cost in terms of IDC is minimum and the project benefits

are accrued early, Mechanized construction has been planned for all components of the

project to achieve consistent quality with faster progress. Construction activities in different

parts of the project will be so sequenced as to optimize the use of construction equipment

and machinery. Access to the various work sites and all the basic infrastructure facilities will

be provided in advance, before taking up of the main civil structures.

Major assumption considered while making the construction methodology are as below:

• Construction Period: 10.5 years (including infrastructural works)

• Monsoon months – June – September

• Winter (non-working months): November – April

• In a day, 20 hrs working is considered, whereas in a month 26 days working is

considered.

• Efficiency factor of all equipment is considered as 80%.

The methodology proposed to be adopted for construction of various project appurtenances

is summarized in the following sections:

3.2 RIVER DIVERSION

Diversion Tunnel

The diversion of the river will be carried out diversion tunnel which is constructed on left

bank side by constructing a coffer dam across the length of the Dam portion.The Diversion

Tunnel will be of 10 m finished diameter, 780m length and bed slope of 1 in 130. The key

features of diversion tunnel are given in Table-3.1.

Table-3.1: Key Features of Diversion Tunnel Excavated size of Diversion Tunnel (in Class II,III & IV),m 11.6 Excavated size of Diversion Tunnel (in Class V), m 12.2 Finished Diameter of Diversion Tunnel, m 10.0 Cross-sectional area of Diversion Tunnel (in Class I & II,III & IV), m2

109.64

Cross-sectional area of Diversion Tunnel (in Class V), m2 114.84 Total Length of Diversion Tunnel, m 780.0

The type of rocks likely to be encountered on the alignment of Diversion Tunnel is given in

Table-3.2.


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Table-3.2: Type of rocks likely to be encountered Types of Rocks likely to be encountered % Length (m) Good Rock – Class II 25 195.00 Fair Rock – Class III 60 468.00 Poor Rock – Class IV 10 78.00 Very Poor Rock – Class V 5 39.00

Excavation: 1 No., 780m long, 10 m finished diameter, Horse-Shoe shaped diversion tunnel

on the left bank of river Chenab shall be excavated through drilling and blasting by heading

& benching method.

Class II

Excavation in Class II classified in drawing as Good rock will be carried out through drilling &

blasting by heading and benching method. The tunnel excavation will be done by

conventional drill and blast method using hydraulic drill jumbo. Drilling will be done by Two

Boom Drill Jumbo. This will be followed by charging and subsequent blasting of the drilled

face. Excavator of bucket capacity 2.0 Cum and 20 T dumpers will carry out clearing of the

generated muck from blasted face. As the excavation proceeds, rock support system by the

way of rock bolts and shotcrete will be provided in accordance with the approved

construction drawings. Drilling of rock bolts will be carried out with Two Boom Drill Jumbo,

while shotcreting will be done by shotcrete machine.

Excavation Sequence for Class II

• Surveying • Drilling • Charging of drilled holes • Blasting • Defuming • Mucking • Scaling/Trimming • Shotcreting • Rock bolting • Drainage holes

Class III & IV

Excavation in Class III & IV classified in drawing as Fair and Poor rock, will be carried out by

drilling & blasting by heading and benching method. Similar sequence of operation will be

carried out as explained in Class II rock class.

Class V

Excavation in Class V as classified in drawing falls under Very poor rock mass conditions.

For this class, if the rock is highly squeezing, less pull will be considered. In addition to that,


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permanent steel rib support will be provided in accordance with the approved construction

drawings and technical specifications.

The excavation sequence for Class V

• Surveying • Drilling • Charging of drilled holes • Blasting • Defuming • Mucking • Scaling/Trimming • Shotcreting • Rock bolting • Drainage holes • Rib erection & backfill concrete

The total duration required to excavate 780 m long diversion tunnel shall be (9 + 2.0 months,

considering benching will follow heading after 100 m and will be done 1 month after the

Heading), 11.0 months. In order to reduce time, diversion tunnel will be excavated from both

the faces, with one set of equipment for each face. Thus, total duration of excavation will be

reduced to 6 months. Portal excavation will take initial 1 months. Thus, the total duration will

be 7 months. For Lining of diversion tunnel, including 2 months of Lining for Inlet and Outlet

Portal is 7 months. Thus, the total duration for Diversion Tunnel excavation and Lining is

14.0 months.

3.3 COFFER DAM

The coffer dam shall be constructed/repaired three times during entire construction period of

the project. Construction of coffer dam with the placement quantity of around 13526 cum

colcrete for Upstream Cofferdam and 5409 Cum for Downstream Cofferdam (for one time

construction) shall be carried out in a period of 2 months including excavation, grouting, etc.

It is proposed to use the useful excavated muck from the Diversion tunnel as well as

abutment excavation in the construction of coffer dam.

The height of the cofferdam will vary based on the river bed. The central hearting zone will

be formed with colcrete. The top of the hearting zone will be 1m below the top level of the

cofferdam. The Colcrete will be overlaid with M 20 concrete.

3.4 DAM

Excavation

In principle this is indicative method of excavation, which will be developed during

construction stages for exact routing of construction ramps, zones, levels to be tackled.

Excavation requiring no blasting operation shall be executed in accordance with theoretical


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cut line defined by cross section on the construction drawing taking into account the nature

of ground. Surfaces shall be perfectly levelled and excavations carried out to ensure final

shape.. Excavations in rock requiring blasting shall be carried out in accordance with

blasting specifications. Blasting shall be performed only by licensed and skilled operators

and under the authority of qualified foreman. All the workers involved in blasting works shall

be well trained. Around the blasting area, before blasting, workers shall check that the

affected area is cleared. All blasting works shall be carried out using controlled blasting

technique to minimise any damage to final profile. The depth and spacing of holes, the

amount of explosives to be used for the hole, the distribution of explosives within one hole

and the numbers and sequence of delay detonators shall be selected in order to obtain the

excavations to the lines and grades as specified in the drawings without any over break,

fracturing and loosening of the rock below or beyond the required excavation lines or level or

causing any damages to the adjacent property or permanent work.

The ground of the excavation area shall be blasted in layers with thickness as required to

meet the specified excavation levels, and the end of holes for blasting the final layers shall

not be drilled closer than 0.3 m to the required final level or line. Any excavation surface for

permanent works after blasting shall exhibit a regular fracture plane between barrels without

back break and with half barrels visible over the major portion of the surface.

The method of pre-splitting will be adopted in areas where it is necessary to keep the sound

rock without any cracks for the structures. Such cracks for the final contour are created by

blasting prior to the rest of the holes for blasting pattern.

Blast pattern shall be accurately set out and holes shall be collared within 50mm of the

required position. Holes, which are over drilled, shall be fully stemmed to the required depth

before charging up takes place. All perimeter holes for surface blasting shall be drilled to a

depth of 1 m below the bottom of any production holes adjacent to perimeter plane.

Controlled perimeter blasting techniques shall be used only and if required to obtain the

excavation faces on permanent works to the lines, grades and levels as specified and on

faces steeper than 1V: 1H.

The material excavated and kept in temporary storage for using later for back filling shall be

well protected, to maintain the material properly regardless of the weather conditions. The

storage area shall be safe with slopes in accordance with angle of internal friction with

materials and with necessary drainage to prevent water flooding during heavy rainfall.

Hydraulic excavators will be used to load the excavated soil / blasted rock into the dumpers,

which will be disposed of to the disposal yard. All the necessary slope protection measures

such as rock anchors, shotcreting wherever necessary will be installed simultaneously going

down with the excavation.


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Concreting

In the first phase, concreting of Dam block up to EL 2167.00 m will be completed. In the First

phase, second phase, concreting of piers and breast wall will be done from EL 2167.00m to

EL 2222.00m. In the second stage concreting of power intake block and NOF blocks on the

right bank will be completed. In the third phase concreting of NOF on the left bank will be

completed. At last concreting of bridge will be done. A 8.0 m wide bridge is provided over the

spillway with EL at + 2222.00m. Concreting in dam bays will be done on completion of

excavation work in these portions. For the bottom portion in sluice way bays, where

thickness varies through the longitudinal direction concreting will be done on completion of

excavation work in these portions. For the bottom portions in sluice way bays, where

thickness varies through the longitudinal direction concreting will be done through the Tower

crane. L&T formwork shutters will be mobilized for shutters of 1.50m lift. For installation of

gates, first stage embedded parts are placed while concreting is done.

Green concrete from the batching plant will be transported by 6 Cum Transit Mixers to the

location.

Bridge over the pier will be constructed in-situ by fixing form work from the spillway section.

Necessary embedment will be provided to spillway portion to take care of staging for the

bridge. RCC deck slab of the bridge will be concreted using formwork supported on

temporary brackets fixed to the main beams of the bridge by providing inserts during

concreting of the piers. Kerbs and handrails will be placed on both sides all along the length

of the bridge.

3.5 PRESSURE SHAFT

Three Circular pressure shafts each of diameter 5.8 m have been proposed to carry the

design discharge from the Intake to Power House. For all the three pressure shaft

excavation will be done through the construction Adit.

Adit to Pressure Shaft Bottom

Adit to Pressue Shaft bottom is of 7m finished dia and 137m long. A time of Two month

duration is required for Adit to bottom of Pressure Shaft excavation including portal

excavation

Excavation (Bottom Horizontal Portion)

The excavation of bottom horizontal portion of Pressure Shaft will be taken up as soon as

the Adit to Pressure Shaft has been completed. The tunnel excavation will be done by

conventional drill and blast method using two boom drill jumbo. For all classes of rock type,

full face excavation will be carried out. This will be followed by charging and subsequent

blasting of the drilled face. Excavator will carry out loading of the generated muck whereas


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20T capacity dumpers will do the mucking and disposal. As the excavation proceeds, rock

support system by the way of rock bolts and shotcrete will be provided in accordance with

the technical specifications and approved construction drawings. Drilling of rock bolts will be

carried out with two boom drill jumbo, while shotrcreting will be done by shotcrete machine.

Excavation Sequence

• Surveying • Drilling • Charging of drilled holes • Blasting • Defuming • Mucking • Scaling/Trimming • Rock bolting • Shotcreting

The salient features of bottom horizontal portion of pressure shaft are given in Table-3.3. A

time of 2 months shall be required for excavation of 220 m long bottom pressure shaft.

Table-3.3: Salient features of bottom horizontal portion of pressure shaft Excavated Size of Pressure Shaft (in Class II, III & IV),m 7.1 Excavated Size of Pressure Shaft (in Class V) m 7.65 Finished Diameter of Pressure Shaft, m 5.8 Excavated Diameter, m 7.65 Cross-sectional area of pressure Shaft(in Class II, III & IV) m2 48.00 Cross-sectional area of pressure Shaft(in Class V) m2 53.00 Maximum Length of Pressure Shaft, m 185

The salient features of inclined pressure shaft are given in Table-3.4.

Table-3.4:Salient features of Inclined Pressure Shaft Excavated size of Inclined Pressure Shaft(in Class II, III & IV),m 7.1 Excavated size of Inclined Pressure Shaft(in Class V),m 7.3 Finished Diameter of Inclined Pressure Shaft, m 5.8 Cross-sectional area of Inclined Pressure Shaft(in Class II, III & IV),, m2

45.00

Cross-sectional Area of Inclined Pressure Shaft(in Class V), m2 48.00 Maximum Length of Inclined Pressure Shaft, m 75.00

Excavation of inclined portion of pressure shaft will be taken up as soon as the bottom

horizontal portion of pressure shaft excavation has been completed.

The pressure shaft initially will be constructed by Alimak raise climbing method from bottom

to top. The shaft shall be excavated full face from the bottom. The drilling can be achieved

by jack hammers for a drill length of 2.4m. The charging also will be done by the Alimak

raise climber platform. The muck generated in each blast shall be collected in the horizontal

pressure shaft tunnel and will be disposed out through adit.


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Liner erection and concreting

Concreting is planned to be carried out in two fronts. After the completion of excavation in

vertical pressure shaft, the lining of vertical shaft will be done by fixing a structural steel liner

and then concreting the remaining portion left around the steel liner. By using the same front

the lining of horizontal portion will be continued and completed.

Horizontal portion of pressure shaft concreting

Rails will be fixed at the invert level matching the alignment of the excavated pressure shaft.

The trolley platform on rails will be used to transport the liner to the required position in the

pressure shaft by winch arrangement. Structural steel liner of required grade will be

positioned on the trolley by crane. The steel liner will be safely secured to the trolley platform

before movement. After transporting the trolley platform along with the steel liner to the

required position, the steel liner piece will be unsecured from the trolley and rose by means

of jack arrangement to release the trolley and removed. The lowered steel liner is positioned

and aligned by means of precast concrete blocks all around. Concrete will be transported

from the batching plant to the entrance of the underground pressure shaft portal by means of

transit mixers. Concrete shall be transported to the concreting location by pumping through

pipes. After fixing the liner pieces and on completion of the alignment, end shutter (bulk

head) will be fixed leaving space for the future liner to be erected and welding to the existing

liner. On completion of fixing the end shutter, concreting will be carried out around the

respective steel liner portion with the help of suitable concrete pump. Repeat the above

process to progress and complete the structural steel liner installation and concrete

encasing.

Inclined Portion of Pressure Shaft Concreting

The liner ferrule will be shifted to the gantry location by trolley, which will be travelling on the

rails. The gantry is used for lowering the liner ferrule to the desired location. The lowered

steel liner is positioned and aligned by means of precast concrete blocks all around.

Concrete will be transported from the batching plant to the entrance of the underground

pressure shaft portal by means of transit mixers. Concrete shall be transported to the

concreting location by pumping through pipes. After fixing the liner pieces and on completion

of the alignment, end shutter (bulk head) will be fixed leaving space for the future liner to be

erected and welded to the existing liner. On completion of fixing, end shutter concreting will

be carried out around the respective steel liner portion with the help of suitable concrete

pump.


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The total duration for Bottom Horizontal Pressure Shaft Concreting of 185 m length shall be

4.5, for 171 m shall be 4months for 157 m shall be 3.5 months considering cycle time of

50m/month. The total duration for Inclined Pressure Shaft Concreting, considering

20m/month, for 80 m shall be 4 months and consecutively for 3 shafts 12 months.

Consider 2 months for Anchor Block Concreting and consecutively for remaining 2 shafts,

total duration will be 6 months.

3.6 POWER HOUSE COMPLEX

The underground powerhouse is proposed on the right bank of the river Chenab about 200m

downstream of the toe of the dam. The water from the tailrace tunnel is proposed to be

discharged into river Chenab.

Power House Excavation

The excavation of Power House underground cavern will be carried out by constructing

ramps for benching down from higher levels to lower ones. The total volume to be excavated

is 1, 21,213cum and timeenvisaged is 12 months. Blasting operations must be carefully

performed in order to minimize rock shattering and overbreaks. Therefore pre splitting will be

required and instantaneous explosive charge shall be controlled so that vibration will be

reduced up to the levels required by technical specifications. Benches vibration will be

reduced up to the levels required by technical specifications. Benches of 1.5-3m height are

envisaged according to rock quality; shotcreting and rock bolting as required, will be carried

out immediately after and in parallel with the excavation stage.

The volume to be excavated are small but the rate of progress will be limited due to the

above mentioned factors. Careful Blasting techniques, limited bench heights as well as the

removal of the ramps required to reach the various level used for mucking the material will

slow the progress of excavation.

Power House Excavation Stages

Stages 1 and 2:

Power house cavern roof, elevation 2172.40m up to 2165.40 m

After reaching the crown portion through the adit, a central drift driven thorough the entire

length of the power house cavern, shall be excavated (stage-1) followed by slashing down

the side material of power house roof (stage-2) to complete the excavation up to elevation

2165.40.Total excavation quantity for stage 1 & 2 is 15650 Cum.

Stage 3

Elevation 2165.40 m to 2146.15 m (Erection bay level)

From this level the excavation will proceed in bunches of 1.5-3meters up to the elevation

2151.15 of the erection bay. A ramp will be left for mucking the material through the crown


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adit until the erection bay Main Access Tunnel excavation is reached and can be used for

material removal from this elevation. The total excavation for stage 3 is 54080 cum.

Stage 4

Elevation 2152.75 m to 2133 m

From erection bay level the excavation will proceed, benching down, to the level of the TRT

with 1.5-3m, benches and leaving a ramp for mucking from erection bay until the TRT level

is reached and can be used. The total excavation quantity for stage 4 is 32120 cum.

Stage 5

Elevation 2133.00 m to 2125.60 m

In continuation, the excavation of draft tubes and drainage pits will take place. Total

excavation quantity for stage 5 is 10970 cum.

Power House Concreting

Power house first stage construction usually is not controlled by the volume of concrete to be

placed but by formwork and reinforcing steel fixing operations. Concrete placing will be done

mainly with concrete pump or concrete bucket handled by EOT crane. The total volume is

34280 cum. The construction sequences of 1st and 2nd stage concrete in power house are

detailed in the construction schedule.

Work will start from service bay and draft tube level of Unit 1, service bay columns will be

completed at the earliest to allow for EOT crane erection; 2 months are foreseen for its

erection. Power House first stage concrete will start after the EOT crane installation. This

crane will be utilized for erection of draft tube lining as well as for concrete and formwork

activities during the entire construction period of the Power House.

Power House second stage construction is controlled by the E&M erection phases. In this

stage concrete placing will commence as soon as the erection of the various components of

the machine is completed and the area is made free from concrete embedment.

Simultaneously slab formwork and pouring for different floors will be carried out to build the

offices and galleries as well as the control room. Architectural works and finishing will be

carried out in parallel to E&M works.

3.7 TAIL RACE TUNNEL

Water exiting from the turbines will be discharged into a tail race tunnel extending from the

substructure of the powerhouse to the banks of Chenab River.


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6.0m finished diameter D shaped Diversion Tunnel will be excavated by conventional Drilling

and Blasting Method in Full Face, with pull depending upon the type and class of rock mass

encountered. The salient features of Tail Race Tunnel are given in Table-3.5.

Table-3.5: Salient features of Tail Race Runnel Excavated size of Tail Race Tunnel (in Class II, III & IV), m

7.3

Excavated size of Tail Race Tunnel (in ClassV), m

7.9

Finished width of Tail Race Tunnel, m 6.6 Cross sectional area of Tail Race Tunnel(in Class I, II, III & IV), m2

44.60

Cross sectional area of Tail Race Tunnel(in Class V), m2

50.21

Maximum Length of Tail Race Tunnel,m 126

The duration for excavation of Tail Race Tunnel shall be 4.5 Months and Portal Excavation

shall take 3 months. Thus, total duration for excavation shall be 7.5 months.For Tail Race

Tunnel Lining duration of 3 months is expected.

CHAPTER-4

METHODOLOGY ADOPTED FOR

THE EIA STUDY


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CHAPTER-4

METHODOLOGY ADOPTED FOR THE EIA STUDY

4.1 INTRODUCTION

Standard methodologies of Environment Impact Assessment have been followed for

conducting the CEIA study for the proposed Sach-Khas hydroelectric project. A brief

description of the methodology adopted for conducting the CEIA study for the proposed

Sach-Khas hydroelectric project is outlined in the present chapter. The information

presented in this Chapter has been presented through various primary as well as secondary

sources.

4.2 STUDY AREA

The study area considered for the CEIA study is given as below:

• Submergence area • Area within 10 km of the periphery of the submergence area • Area to be acquired for siting of various project appurtenances. • Area within 10 km of various project appurtenances • Catchment area intercepted at the barrage site

The study area is enclosed as Figure-4.1.

1L & T Himachal Hydropower Limited

FCC of the Study Area

Figure-4.1: FCC of the Study Area


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4.3 SCOPING MATRIX

Scoping is a tool which gives direction for selection of impacts due to the project activities on

the environment. As a part of the study, scoping exercise was conducted selecting various

types of impacts which can accrue due to hydroelectric project. Based on the project

features, site conditions, various parameters to be covered as a part of the EIA study were

selected. The results of Scoping analysis are presented in Table-4.1.

Table-4.1: Scoping Matrix for EIA study for the proposed Sach-Khas Hydroelectric Project

Aspects of Environment Likely Impacts A. Land Environment Construction phase - Increase in soil erosion from

various construction and quarry sites - Pollution by construction spoils - Acquisition of land for labour camps/ colonies - Solid waste generated from labour camps/colonies

Operation phase

- Acquisition of land for various project appurtenances - Loss of forest land due to acquisition of land for various project appurtenances

B. Water resources & water quality Construction phase

- Impact on water quality of receiving water body due to disposal of runoff from construction Sites carrying high sediment level. - Degradation of water quality due to disposal of effluent from labour, camps/colonies

Operation phase - Modification of hydrologic regime due to diversion of water for hydropower generation

C. Aquatic Ecology Construction phase - Increased pressure on riverine

fisheries as a result of indiscriminate fishing by the Immigrant labour population. - Reduced productivity due to increase in turbidity levels as a result of disposed off waste water from construction sites and labour Camps/colonies.


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Aspects of Environment Likely Impacts Operation phase - Impacts on spawning & breeding

grounds in the stretch downstream of dam site to Tail race disposal site. - Degradation of riverine ecology - Impacts on migratory fish species - Impact on aquatic ecology due to reduction in flow downstream of the dam site upto tail race disposal site.

D. Terrestrial Ecology Construction phase

- Increased pressure from labour to meet their fuel wood requirements during project construction phase - Adverse impacts on flora and fauna due to increased accessibility in the area and increased level of human interferences - Loss of forest due to siting of various project

appurtenances Operation phase

- Impacts on wildlife movement due to the project

- Impacts on wildlife habitats due to Acquisition of forest land for various project appurtenances.

E. Socio-Economic Aspects Construction phase

- Increased employment potential during project construction phase - Development of allied sectors leading to greater employment - Pressure on existing infrastructure Facilities. - Cultural conflicts and law and order issues

due to migration of labour population Operation phase - Loss of community properties, if any

- Impacts on archaeological and cultural monuments, if any - Impacts on mineral reserves, if any

F. Air Pollution

Construction Phase - Impacts due to emission as a result of fuel combustion in various construction equipment

- Impacts due to emission as a result of increased vehicular movement for transportation of men and material during project construction phase

- Fugitive envisions from various sources - Impacts due to emissions from DG set

G. Noise Pollution Construction Phase - Noise due to operation of various

construction equipment - Noise due to increased vehicular

movement - Impacts due to blasting


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Aspects of Environment Likely Impacts - Increased noise levels due to operation of

DG set H. Public Health Construction Phase - Increased incidence of water related

diseases - Transmission of diseases by immigrant

labour population Operation phase - Increased incidence of vector- borne

diseases

Based on the Scoping matrix, the environmental baseline data has been collected. The

project details have been superimposed on environmental baseline conditions to understand

the beneficial and deleterious impacts due to the construction and operation of the proposed

Sach-Khas hydroelectric project.

4.4 DATA COLLECTION

4.4.1 Physico-Chemical Aspects

Primary surveys have been conducted for three seasons namely, monsoon, post-monsoon

and pre-monsoon seasons. The data has been collected for flora, fauna, forest types and

ecological parameters, geological and soil features. During these surveys data and

information was collected on physico-chemical, biological and socio-economic aspects of the

study area. In addition, detailed surveys and studies were also conducted for understanding

bio-diversity in the study area.

As a part of the EIA study, primary data has been collected for three seasons. The details

are given in Table-4.2.

Table-4.2: Details of field studies conducted as a part of CEIA studies

Season Months Monsoon August 2010 Winter November – December 2010 Summer May-June 2011

Geology

The regional geology around the project area highlighting geology, stratigraphy, etc. has

been covered in the EIA Report, as per the available information in the Detailed Project

Report (DPR) of the project.

Hydrology

Hydrological data for river Chenab as available in the Detailed Project Report was collected

and has been suitably incorporated in the Comprehensive EIA study.


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Seismo-tectonics

The regional seismo-tectonics around the project area highlighting seismicity has been

covered in the EIA Report, as per the available information in the Detailed Project Report

(DPR) of the project.

Landuse pattern

Landuse pattern of the study area as well as the catchment area was carried out by standard

methods of analysis of remotely sensed data and followed by ground truth collection and

interpretation of satellite data. For this purpose digital satellite data was procured from

National Remote Sensing Agency, Hyderabad, IRS-P6 LISS-IV. The data was processed

through ERDAS software package available with WAPCOS.

Soil

The soil quality was monitored at various locations in the catchment area. The monitoring

was conducted for three seasons as detailed in Table-4.2. The parameters monitored were:

• pH • Electrical Conductivity • Organic Matter • Sodium • Available Phosphorus • Available Potassium • Available Nitrogen • Cation Exchange Capacity • Particle Size Distribution • Texture

Water Quality

The existing data on water quality has been collected to evaluate river water quality on

upstream and downstream of the project site. The water quality was monitored for various

seasons as listed in Table-4.2. The water samples were collected from the study area and

analyzed for physico-chemical parameters which are listed in Table-4.3.

Table-4.3: Water quality parameters analyzed as a part of the field studies

pH Zinc Electrical Conductivity Mercury Total Dissolved Solids Cadmium Sulphates Magnesium Chlorides Lead Nitrates Manganese Phosphates Cyanides Sodium Hardness Potassium DO Calcium BOD Copper COD Iron Oil & grease Total Coliform Fecal Coliform


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Ambient air quality

The ambient air quality was monitored at three locations in the study area. Monitoring was

conducted for three seasons as listed in Table-4.2. The frequency of monitoring for each

season was twice a week for four consecutive weeks. The parameters monitored were

Respirable Particulate Matter (RPM), Sulphur-dioxide (SO2) and Nitrogen di-oxides (NO2).

Ambient Noise level

As a part of the EIA study noise level was monitored at various locations in the study area.

Monitoring was conducted for various seasons as listed in Table-4.2. At each station, hourly

noise level was monitored during day time. Further day time equivalent noise level was

estimated.

4.4.2 Ecological Aspects

Terrestrial Ecology

Flora

Data on forest type legal status and their extent in the catchment and study area has been

collected from the forest department. The other relevant data on bio-diversity economically

important species medicinal plant, rare and endangered species in the study area and its

surroundings have been collected from secondary sources like Forest research institute and

wildlife department. In addition field studies were conducted to collect data on various

aspects in the study area. The sampling sites were selected based on topography and

floristic composition. The various aspects studied were floral density frequency and

abundance of species of trees, shrubs, herbs and grasses. Plants of economical species

and medicinal use and endangered species were also identified as a part of the study. The

monitoring was conducted for various seasons listed in Table-4.2.

Fauna

The faunal assessment has been done on the basis secondary data collected from different

government offices like forest department, wildlife department, fisheries department, etc. The

presence of wildlife was also confirmed from the local inhabitants depending on the animal

sightings and the frequency of their visits in the catchment area. In addition review of

secondary data was another source of information for studying the fauna of the area. In

addition, sightings of faunal population during ecological survey and then field studies were

also recorded as a part of the data collection exercise.

Aquatic Ecology and Fisheries

Water samples from river Chenab were also collected as a part of field studies. The density

and diversity of periphyton and phytoplanktons, species diversity index and primary

productivity etc. were also studied. The field studies were conducted for various seasons as

listed in Table-4.2.


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The secondary data pertaining to fisheries in river Chenab was collected from Fisheries

Department and through literature review as well. Fishing was done at various sites in the

project area and river stretches both upstream and downstream of the dam site of proposed

Sach Khas hydroelectric project to ascertain the dispersal pattern of fish species.

Identification and measurements of all the fish catch was done and an inventory of the fish

species was also prepared. Various migratory species and the species to be affected due to

conversion of lentic to lotic conditions as a result of commissioning of the proposed project

were also identified.

4.5 SUMMARY OF DATA COLLECTION

The summary of the data collected from various sources is outlined in Table-4.4.

Table-4.4 : Summary of data collected for the Comprehensive EIA study

Aspect Mode of Data collection

Parameters monitored

Frequency Source

Meteorology Secondary Temperature, humidity, rainfall

- India Meteorological Department (IMD)

Water Resources

Secondary Flow, Design hydrograph and design flood hydrograph

- Detailed Project Report (DPR)

Water Quality Primary Physico-chemical and biological parameters

Three seasons

Field studies for monsoon, winter and summer seasons

Ambient air quality

Primary RPM, SPM, SO2, NOx

Three seasons


Noise Primary Hourly noise and equivalent noise level

Three seasons


Landuse Primary and secondary

Land use pattern - NRSA and Ground truth Studies

Geology Secondary

Geological characteristics of the study area

- Detailed Project Report (DPR )

Soils Physico-chemical parameters

Three seasons


Terrestrial Ecology

Primary and secondary

Floral and faunal diversity

Three seasons

Field studies for monsoon, winter and summer seasons Secondary data as available with the Forest and Wildlife


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Aspect Mode of Data collection

Parameters monitored

Frequency Source

Departments Aquatic Ecology

Primary and Secondary

Presence and abundance of various species

Three seasons

Field studies for monsoon, winter and summer seasons Secondary data as available with the Fisheries Department

4.6 IMPACT PREDICTION

Prediction is essentially a process to forecast the future environmental conditions of the

project area that might be expected to occur because of implementation of the project. An

attempt was generally made to forecast future environmental conditions quantitatively to the

extent possible. But for certain parameters, which cannot be quantified, general approach

has been adopted to discuss such intangible impacts in qualitative terms so that planners

and decision-makers are aware of their existence as well as their possible implications.

Impact of project activities has been predicted using mathematical models and overlay

technique (super-imposition of activity on environmental parameter). For intangible impacts

qualitative assessment has been done. The environmental impacts predicted are listed as

below:

- Loss of land. - Impacts on hydrologic regime. - Impacts on water quality. - Increase in incidence of water-related diseases including water-borne and vector-

borne diseases. - Effect on riverine fisheries including migratory fish species. - Increase in air pollution and noise level during project construction phase - Impacts due to sewage generation from labour camps - Impacts due to acquisition of forest land - Impacts due to increase in terrestrial and aquatic ecology due to increased human

interferences during project construction and operation phases

4.7 ENVIRONMENTAL MANAGEMENT PLAN AND COST ESTIMATES

Based on the environmental baseline conditions and project inputs, the adverse impacts

were identified and a set of measures have been suggested as a part of Environmental

Management Plan (EMP) for their amelioration. The management measures have been

suggested for the following aspects:

• Compensatory afforestation • Establishment of Botanical Garden • Habitat improvement for avi-fauna • Afforestation in degraded areas • Conservation and cultivation of Medicinal Plants • Anti-poaching measures


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• Provision of facilities in labour camps (Heating, Water Supply, Sanitation & Sewage Treatment Facilities, Solid Waste Management )

• Provision of free fuel to labour population • Public health delivery system • Restoration of quarry sites and landscaping of construction sites • Disposal of Muck and Reclamation of Muck Disposal Sites • Management of Impact due to construction of road • Water pollution control Control of Air Pollution • Measures for noise control • Greenbelt development plan • Energy Conservation measures • Catchment Area Treatment • Release of Environmental Flows • Fisheries Management Plan

The expenditure required for implementation of these management measures has also

been estimated as a part of the EMP study.

4.8 CATCHMENT AREA TREATMENT PLAN

As a part of the CEIA study, a catchment area treatment plan for the catchment area

intercepted at the project site has been formulated. An amount of 2.5% of the project cost

has been earmarked for implementation of CAT Plan. Various sub-watersheds have been

categorized into different erosion categories, as per Silt Yield Index (SYI) method. For high

and very high erosion categories, a catchment area treatment plan comprising of

engineering and biological measures has been formulated.

4.9 LOCAL AREA DEVELOPMENT PLAN

As a part of the CEIA Study, a Local Area Development Plan (LADP) has been formulated

for implementation in study area villages. An amount of 1.5% of the project cost has been

earmarked for implementation of Local Area Development Plan (LADP).

4.10 ENVIRONMENTAL MONITORING PROGRAMME

It is necessary to continue monitoring of certain parameters to verify the adequacy of various

measures outlined in the Environmental Management Plan (EMP) and to assess the

implementation of mitigative measures. An Environmental Monitoring Programme for critical

parameters has been suggested for implementation during project construction and

operation phases. The cost required for implementation of Environmental Monitoring

Programme has also been indicated.

CHAPTER-5

HYDROLOGY


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CHAPTER-5

HYDROLOGY

5.1 CHENAB RIVER SYSTEMS

The river Chenab on which Sach Khas Hydroelectric Project is proposed to be located is one

of the five major rivers of the great Indus river system. The Chenab river originates from the

snow covered slopes of Great Himalayas in district Lahaul & Spiti and flows through steep

gradient with series of loops and bends. In its upper reaches it is also known as the

Chandrabhaga. In India, Chenab basin spreads over two states namely Himachal Pradesh

and Jammu & Kashmir which comprise of the extreme western sector of the Himalayas. The

Chenab River is formed by two major tributaries in the head reach namely Chandra and

Bhaga rivers. The Chandra River originates from Baralacha La at an elevation of about 4950

m above sea level and is augmented by Chandra Tal. The Bhaga rises in the north-western

slopes of Baralacha pass and is further joined by Jhankar and Millang nalas in the head

reach. The Chandra comes forming a loop changing the course from southerly to westerly

and then to north westerly direction and the Bhaga comes descending in direct westerly

course. The important places in this reach are Koksar on Chandra River and Keylong on

Bhaga river. The Chandra and Bhaga join each other at Tandi (EL 2820 m) south of

Keylong, the district headquarters of Lahaul and Spiti in Himachal Pradesh. These two

streams, after meeting at Tandi in Lahaul Valley, form the Chandrabhaga which flows

forward through the Pangi valley towards Kashmir.

Downstream of Tandi, the Chandrabhaga continues to flow in the north westerly direction

when it meets its first major tributary, Miyar Nala on its right (EL 2590 m) at Udaipur. It is

later joined by Sach Nala on its right which drains a catchment area of 690 sq. km and keeps

flowing in this northerly direction till it is joined by Lujai Nala.

After a short journey from the confluence of Lujai Nala, it enters the Paddar area of Kishtwar

district of Jammu and Kashmir state at EL 1980 m.

About 60% of catchment area at Project site remains perpetually covered by snow and

glaciers and the comparatively high flows between March to June are largely contributed by

snow melting. High discharge in the river between July to September is further compounded

due to monsoon precipitation. The minimum flow occurs during December, January and

February.


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5.2 THE CATCHMENT AND PHYSIOGRAPHIC PARAMETERS

The Sach Khas HE project is proposed on river Chenab is located about 54 km downstream

of Udaipur G&D site (Latitude: 32043’45” N, Longitude: 76039’ E). The substantial part of

project catchment is snowfed with elevation greater than 4500 m. The physiographic

parameters of the project catchment and Udaipur G&D site have been estimated using the

GIS and remote sensing techniques. The catchment area of the project, longest flow path,

centroid, centroidal flow path and equivalent stream slope has been estimated by GIS

processing of SRTM digital elevation model namely srtm_52_06 on Arc GIS 9.3. The

cumulative hypsometric curve for the project catchment has been developed using ILWIS

3.7. The estimated Physiographic parameters are given in Table 5.1 . The physiographic

maps of catchment up to Sach Khas HEP site and Udaipur G&D site are shown in Figures

5.1 and 5.2 respectively.

Table 5.1 Physiographic Parameters of Sach Khas HEP site and Udaipur G&D site

Sach Khas HEP Site Total catchment area 6588 sq.km Snowfed catchment area 3973 sq.km (60.31% of total catchment area) Longest flow path (L) 218.13 km Centroidal flow path (Lc) 89.54 km Equivalent stream slope (S) 8.58 m/km Udaipur G&D Site Total catchment area 5910 sq.km Snowfed catchment area 3860 sq.km (65.31% of total catchment area) Source: DPR

Figure – 5.1 Physiographic Map of catchment up to Sach Khas HEP site


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Figure – 5.2 Physiographic Map of catchment up to Udaipur site

5.3 HYPSOMETRIC CURVE

The hypsometric details of the catchment up to Udaipur G&D site as well as Sach Khas dam

site are given in Figures 5.3 and 5.4 respectively and Tables 5.2 and 5.3 respectively.


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Figure- 5.3 Hypsometric Curve at Udaipur G&D site


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Table-5.2 – Hypsometric details at Udaipur G&D site Elevation (m) Cumulative Area below

elevation (sq.km) Cumulative Percentage of total

area 2611 0.01 0 2700 7.04 0.12 2800 21.08 0.36 2900 46.76 0.79 3000 102.04 1.73 3100 163.30 2.76 3200 229.62 3.89 3300 297.63 5.04 3400 370.70 6.27 3500 451.99 7.65 3600 535.99 9.07 3700 631.91 10.69 3800 743.44 12.58 3900 873.87 14.79 4000 1023.61 17.32 4100 1190.68 20.15 4200 1374.76 23.26 4300 1574.62 26.64 4400 1797.14 30.41 4500 2049.66 34.68 4600 2316.57 39.2 4700 2595.52 43.92 4800 2897.54 49.03 4900 3227.56 54.61 5000 3580.14 60.58 5100 3947.45 66.79 5200 4333.97 73.33 5300 4717.08 79.82 5400 5074.54 85.86 5500 5378.52 91.01 5600 5603.30 94.81 5700 5747.27 97.25 5800 5830.43 98.65 5900 5876.44 99.43 6000 5898.20 99.8 6100 5906.56 99.94 6200 5909.33 99.99 6294 5909.99 100

Source: DPR


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Figure- 5.4 Hypsometric Curve at Sach Khas HEP site

EIA Report for Sach Khas HEP, HP

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Table-5.3 Hypsometric details at Sach Khas HE Project site

Elevation (m) Cumulative Area below elevation (sq.km) Cumulative percentage 2209 0.59 0.01 2400 22.18 0.34 2600 85.41 1.3 2800 146.97 2.23 3000 271.29 4.12 3200 445.78 6.77 3400 639.31 9.71 3500 744.84 11.31 3600 852.85 12.95 3800 1112.17 16.88 4000 1445.64 21.95 4200 1857.22 28.19 4400 2338.68 34.5 4500 2614.68 39.69 4600 2904.12 44.09 4800 3525.72 53.52 5000 4234.66 64.29 5200 5001.52 75.93 5400 5748.18 87.26 5600 6279.89 95.34 5800 6507.46 98.79 6000 6575.28 99.82 6294 6587.67 100

Source: DPR

5.4 GAUGE & DISCHARGE

A brief summary of G&D data availability status of Chenab Basin with respect to Sach Khas

HEP is placed in Table-5.4. These G&D sites have been established and maintained by

Central Water Commission (CWC).

Table-5.4: Details of G&D Sites in Chenab basin

Station Latitude/ Longitude

CA (Sq.km) River Type of Data Data Available

Tandi

32033/00// 76058/00//

1640

Bhaga

Daily G& D Jan 1986 to Jun 2010

Daily Discharge

Jan 1974 to Dec 1985

Ghousal 32023/00// 76058/00// 2477 Chandra Daily

Discharge May 1973 to Dec

2007

Udaipur

32043/00// 76039/00//

5910

Chenab

Daily G& D Jan 1986 to Jun 2010

Daily Discharge

Jan 1974 to Dec 1985

Miyar 32042/00// 76040/00// 956 Miyar Daily

Discharge Jun 1992 to May

2008

Gulabgarh 33016/00// 76010/00// 8548 Chenab Daily

Discharge May 1990 to May

2009

Benzwar 33022/00// 75045/00// 10687 Chenab Daily

Discharge

Source: DPR


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5.5 STREAM FLOW CHARACTERISTICS

A preliminary analysis of discharge data of Tandi, Ghousal, Udaipur, Gulabgarh and

Benzwar is carried out to find out the general stream flow characteristics in the project

catchment. The maximum and minimum daily flows, the 10-daily average flows, average

annual discharge, annual runoffs etc. are computed for these G&D sites. Finally, the average

annual runoffs and specific yields of the catchment are computed and presented in Table-

5.5 to have a comparative picture.

Table-5.5: General flow parameters in the G&D observation sites Parameters Tandi Ghousal Udaipur Gulabgarh Benzwar River Chandra Bhaga Chenab Chenab Chenab CA in sq. km 1640 2477 5910 8548 10687 Maximum discharge in m3/s 816 629 1750 1599 3147

Minimum discharge in m3/s 2 7.25 12 7.32 15

Average annual discharge in m3/s 57.61 106.81 237.53 284.35 417.43

Average annual runoff in Mm3 1816.78 1359.78 7490.70 9012.57 13164.19

Specific yield in mm/sq. km 1107.79 1359.78 1267.46 1054.40 1232

Source: DPR

It is observed from the Table-5.5 , that the flow variation is quite high in the Chenab River. It

is further observed that the maximum and minimum discharges observed at Gulabgarh are

not in line with the maximum and minimums of rest of the sites.

5.6 WATER AVAILABILITY

The 10 daily discharge data at Sach Khas HEP site for the period 1974-75 to 2009-10 is

enclosed as Annexure-II, The 10 daily discharge data at Sach Khas HEP site for 90%

dependable year is given in Table-5.6.

Table-5.6: 10-daily discharge data at Sach Khas HEP site for 90% dependable year Month Discharge (m 3/s) June I 339.77 II 525.26 III 510.65 July I 722.12 II 724.46 III 502.94 August I 552.68 II 443.77 III 522.50 September I 396.95 II 274.44 III 223.06 October I 145.25


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Month Discharge (m 3/s) II 120.17 III 89.18 November I 85.72 II 88.84 III 82.49 December I 75.69 II 74.80 III 62.12 January I 55.62 II 53.73 III 50.29 February I 50.83 II 50.50 III 67.44 March I 49.49 II 58.75 III 71.24 April I 76.02 II 76.02 III 97.76 May I 128.53 II 149.60 III 216.36

Source: DPR

5.7 DESIGN FLOOD

5.7.1 DESIGN FLOOD CRITERIA

A 77 m high concrete gravity dam from river bed level is proposed at Sach Khas dam site on

Chenab River with gross storage capacity of 25.24 M cum at FRL EL 2219 m. The criterion

of selection of inflow design flood for safety of dam as per IS-11223-1985 is given in Table-

5.7.

Table-5.7: Criteria for Selection of Design Flood Classification Gross Storage Static Head at FRL Inflow design flood

for safety of dam Small Between 0.5 and 10 M

cum Between 7.5 m and 12 m 100 year flood

Intermediate Between 10 and 60 M cum

Between 12 m and 30 m Standard Project Flood

Large Greater than 60 M cum Greater than 30 m Probable Maximum Flood

Source: DPR

Gross storage capacity is less than 60 Mm3 but the static head is more than 30 m.

Therefore, the spillway of the proposed dam shall be designed to pass probable maximum

flood.

5.7.2 Methodology Adopted

Floods in Chenab River are generally observed due to heavy rains in its lower catchment

during southwest monsoon season of June to Sept. In order to estimate the probable


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maximum flood under the complex hydro-meteorological conditions in Sach Khas catchment,

it is desirable to separately analyze the contributions of rain storm and snowmelt and then

synthesize them into flood hydrograph with reference to the most severe combinations of

critical hydrological and meteorological parameters/factors that are reasonably possible in

the region. In the absence of the data pertaining to snowfall and seasonal snow cover area;

it is not possible to estimate the snowmelt contributions during the flood conditions. The

base flow is thus assumed to take into account the snowmelt contribution.

The design flood value has been estimated by adopting the following approaches:

• Probabilistic approach using frequency analysis • Deterministic approach using Unit Hydrograph analysis • Transfer from downstream projects using Dicken’s formula

Probabilistic Approach using Frequency Analysis

Annual flood peaks are available for the period 1974-75 to 2009-10 at Udaipur. This annual

peak series have been considered for frequency analysis. Figure-5.5 shows year wise

variation in flood peaks. The visual inspection of data does not indicate significant variation

in the average value for different data sets.

Figure-5.5 Yearly variation of peak floods at Udaipur

Daily discharge observations at Udaipur had been taken once in a day. The peak discharges

are limited to the above condition, which do not take into consideration the possible peak

discharge occurrences during the daily non-recorded hourly gauge observation. However the

frequency analysis has been carried out with this limitation. As it is quite likely that possible

peaks might have been missed for reasons explained above, the design flood peak arrived


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at by frequency analysis has to be maximized appropriately. In view of these factors and to

allow for the possibility of floods due to bursting of temporary blockage of river due to ice and

landslides, the peak discharges have been maximized by 35%, as used in the case of

Chhatru HEP located on the same river in the upstream. The daily observed peak and

maximized peak series are given in Table-5.8 . Detailed statistics of flood peak series are

given in Table-5.9 .

Table – 5.8: Peak Series at Udaipur SL. No. Year Date Daily Flood

Peak (m3/s)

Daily value increased by 35% for Instantaneous

peak 1 1974 18 July 1974 975.00 1316.25 2 1975 16 July 1975 1200.00 1620.00 3 1976 25 July 1976 860.00 1161.00 4 1977 15 July 1977 987.00 1332.45 5 1978 30 June 1978 1076.00 1452.60 6 1979 16 July 1979 993.00 1340.55 7 1980 14 July 1980 1116.00 1506.60 8 1981 29 June 1981 989.00 1335.15 9 1982 30 July 1982 1129.00 1524.15 10 1983 05 August 1983 986.00 1331.10 11 1984 27 June 1984 785.00 1059.75 12 1985 13 July 1985 762.00 1028.70 13 1986 07 July 1986 1081.00 1459.35 14 1987 25 July 1987 1144.00 1544.40 15 1988 22 July 1988 1739.00 2347.65 16 1989 30 July 1989 1750.00 2362.50 17 1990 25 June 1990 1235.00 1667.25 18 1991 20 July 1991 1238.00 1671.30 19 1992 23 July 1992 1284.00 1733.40 20 1993 08 July 1993 911.00 1229.85 21 1994 01 July 1994 1262.00 1703.70 22 1995 19 July 1995 1083.00 1462.05 23 1996 28 June 1996 806.00 1088.10 24 1997 12 August 1997 826.00 1115.10 25 1998 05 July 1998 1097.00 1480.95 26 1999 20 July 1999 1382.00 1865.70 27 2000 01 August 2000 1199.00 1618.65 28 2001 14 August 2001 1278.00 1725.30 29 2002 04 July 2002 1388.00 1873.80 30 2003 27 June 2003 1286.00 1736.10 31 2004 09 July 2004 1177.00 1588.95 32 2005 01 July 2005 1131.00 1526.85 33 2006 06 August 2006 1200.00 1620.00 34 2007 29 June 2007 1023.00 1381.05


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SL. No. Year Date Daily Flood Peak (m3/s)

Daily value increased by 35% for Instantaneous

peak 35 2008 14 June 2008 857.00 1156.95 36 2009 12 August 2009 1220.41 1647.55

Source: DPR

Table-5.9: Detailed Statistics of Instantaneous Peak Series Parameters Statistics Mean 1517.08 Median 1515.38 Mode 1620.00 Standard deviation 305.34 Sample Variance 93234.41 Kurtosis 1.54 Skewness 0.86 Minimum 1028.70 Maximum 2362.50 Count 36

Source: DPR

Application of various Frequency Distributions

To carry out the frequency analysis, the following commonly used distributions have been

applied:

• Gumbel extreme value distribution • Log Pearson type-III distribution • Log Normal 2-Parameter distribution

The summary of the flood frequency analysis by the above three distributions is given in

Table-5.10.

Table-5.10: Summary of Flood Frequency Analysis Sl. No Return

Period (Yrs.)

Log Pearson-III

Log Normal

Gumbel Probability Distribution

1 25 2122.71 2097.57 2500.97 2 50 2268.11 2225.82 2744.07 3 100 2409.74 2347.84 2985.79 4 500 2731.90 2615.66 3545.17 5 1000 2869.84 2726.52 3785.86

6 10000 3332.52 3083.60 4585.44

Source: DPR

Selection of Best fit Distribution

Chi Square Criteria

Chi square test (X 2) has been conducted for goodness of fit for the above-mentioned

theoretical distributions and is shown in Table-5.11.


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Table-5.11: Chi Square criteria for different Distributions

Type of Test

Gumbel Extreme value distribution

Log -Pearson Type III

distribution

2-Parameter Log Normal distribution

X2 3.72 3.72 3.72 Critical X2 5.99 3.84 5.99

Source: DPR

It can be observed from Table-5.11 , that both Gumbel Extreme value and 2-parameter Log

Normal distributions appear to be the best fitting theoretical distribution to the sample data.

We may consider the Gumbel distribution as it gives a higher value. Transferring this value

to Sach Khas by Dicken’s formula we get the design flood as 4975 cumec.

Deterministic Approach Using Unit Hydrograph Analysis

Estimation of Rainfed Catchment

The permanent snowline elevation for the catchment is around 4500 m. From the

hypsometric curve (Table 5.3) the snowfed area has been worked out as 3973 sq. km and

rainfed area is worked out as 2615 sq. km.

Design Storm Studies

Design Storm study of the Sach Khas H.E. Project was entrusted to the Indian

Meteorological Department (IMD), New Delhi. The 1 day SPS and PMP estimates as

supplied by IMD at Sach Khas H.E. Project are 9.5 cm and 13.9 cm respectivelly.

A 24-hour clock hour correction of 15% has been applied to 1-day SPS and PMP as

suggested by India Meteorology Department (IMD). The temporal distribution of rainfall for 1-

day is given in Table-5.12 and plotted in Figure-5.6.

Figure-5.6 Temporal Distribution of Design Storm


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Table-5.12 Temporal Distribution of design Storm

Source: DPR

While carrying out the studies, double bells have been used. Two bells of 12 hours each has

been considered as per current practice with details as under in Table-5.13.

Table-5.13: 24 Hour, 48 Hour Distribution of PMP & SPS 24 Hour Distribution PMP 24 Hr = 15.985 cm

i) 1st Bell (71% of 24 Hour Rainfall) 11.349 cm ii) 2nd Bell (29% of 24 hour Rainfall) 4.636 cm

Source: DPR

Derivation of Unit Hydrograph

Sach Khas Hydroelectric Project, intercepts an area of 6588 sq.km having snowfed area of

3973 sq. km and rainfed area 2615 sq.km. On the basis of above, the unit hydrograph

parameters have been calculated for snow free catchment area only. (Ref.: Flood estimation

report for Western Himalayas - Zone 7). UH ordinates for the Sach Khas catchment are

tabulated in Table-5.14. The ordinates of unit hydrograph are plotted in Figure-5.7.

Table-5.14: Unit Hydrograph Ordinates

Time Discharge Time Discharge (Hrs.) (m3/s) (Hrs.) (m3/s)

0 0 11 490 1 5 12 260 2 13 13 140 3 32 14 85 4 60 15 41 5 110 16 18 6 280 17 12 7 980 18 6 8 1440 19 4 9 1878.61 20 1 10 1415 20.52 0

Source: DPR

Duration (Hrs.) Temporal Distribution (%) 1-Day

0 0 3 30 6 46 9 60 12 71 15 81 18 89 21 96 24 100


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Figure-5.7: Ordinates of Unit hydrograph

Loss Rate

A uniform loss rate of 2 mm/hour has been adopted as suggested by CWC.

Transfer of Design Flood from Baglihar, Ratle and Dulhasti

The design floods fixed for some of the downstream projects in Chenab are transferred to

Sach Khas dam site using Dicken’s formula as shown in Table 5.15 .

Table-5.15 Design floods of downstream projects S.No Name of

project Catchment area in sq km

Design flood in m 3/s Transferred to Sach Khas by Dicken’s formula

1 Baglihar 17325 16500 7990 2 Ratle 14965 14700 7945 3 Dulhasti 10500 8000 5639 Source: DPR

5.8 RECOMMENDATIONS

The floods estimated by all the three approaches are summarized below in Table-5.16. The

flood computed by deterministic approach using UH method is quite high as compared to the

flood obtained by other methods. The design flood of 9047 cumecs has been recommended

based on hydro meteorological approach.

Table – 5.16: Design Flood Estimated by Different methods S. No. Method Flood (Cumecs)

1 Frequency Analysis (10,000 Year Return Period) 4975 2 Hydro-meteorological approach 9047 3 Transferred from Baglihar H.E.Project 7990 4 Transferred from Ratle H.E.Project 7945 Transferred from Dulhasti H.E.Project 5639

Source: DPR

Flood Hydrograph

The ordinates of flood hydrograph are given in Table-5.17 and depicted in Figure-5.8. The

PMF of the project has been taken as 9047 cumec.


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Table-5.17: Ordinates of Flood Hydrograph Duration ( hour) Discharge (m 3/s)

0 790.86 1 791.02 2 791.43 3 792.89 4 795.98 5 802.40 6 817.88 7 862.41 8 943.07 9 1109.98 10 1318.24 11 1578.51 12 1964.38 13 2449.42 14 3024.63 15 3332.94 16 3163.95 17 2625.98 18 2127.42 19 2110.13 20 2431.40 21 3183.79 22 3992.19 23 4719.44 24 5711.67 25 6916.33 26 8324.17 27 9046.75 28 8560.67 29 7097.87 30 5504.54 31 4212.81 32 3074.86 33 2039.16 34 1357.96 35 1092.88 36 954.59 37 878.53 38 834.15 39 811.60

Source: DPR


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Figure-5.8: Design flood hydrograph adopted for Sach Khas hydroelectric project

5.9 SEDIMENT DATA AVAILABILITY

The Silt rate estimated at various sites namely Udaipur, Benzwar and Premnagar Site in

Chenab river basin by CWC are tabulated as in Table-5.18.

Table- 5.18: Details of Silt data G&D Site C. A.

(Sq.km) Type of

Data Period River Sediment

Rate (Ha-m/Sq.

km/Yr.)

Source

Udaipur 5910 Daily Jan’03- May’08

Chenab 0.0287 Calculated

Benzwar 10687 Monthly Jun’73-May’02

Chenab 0.081 Calculated

Premnagar 15490 Avg. Annual

1968 to 1976

Chenab 0.155 Sept 84 Feasibility

Report, Baglihar HEP,

Volume-VI Source: DPR

It may be concluded from Table-5.18 that annual silt yield increases as we go downstream

of the river. The Sach Khas catchment area is nearly half the catchment area of Benzwar

and one-third that of the Premnagar. Sach Khas site is near the vicinity of Udaipur, but the

data availability at Udaipur is of short period, so annual silt yield is linearly interpolated

between Udaipur and Benzwar after taking account of 20% suspended load (as per standard

BIS practice) as bed load for both the sites. The annual silt yield estimated is 0.0433 ha-

m/sq.km/year.

CHAPTER-6

TOPOGRAPHICAL AND

GEOLOGICAL ASPECTS


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CHAPTER-6

TOPOGRAPHICAL AND GEOLOGICAL ASPECTS

6.1 INTRODUCTION

The Sach Khas Hydroelectric Project envisages ±90.0 m high concrete gravity dam across

the river Chenab (N 76025’25” E 32058’), about 8 km downstream of Purthi Village in order

to create a reservoir of the capacity of 8.69 MCM between FRL 2219 m and MDDL of

2209.3m. The water will be conducted through the dam to the underground power house

through 300 m long pressure shafts.

In order to utilize the full potential between (EL 2219.0m) and (EL 2149.0m) & keeping in

view the environmental and ecological balance, various schemes i.e. Alternative II,

Alternative III, Alternative III-A and Alternative IV were investigated. Eventually, the present

scheme with a ±90.0 m high concrete gravity dam with underground power house has been

evolved, which is geotechnically feasible and techno economically viable. Various

alternatives considered for the Sach Khas Hydroelectric Project are summarized in Table

6.1.

The following geotechnical mapping and sub-surface investigations have been carried out to

evaluate various alternative layouts.

Table 6.1: Summary of Geotechnical Mapping and Sub-Surface Investigations (1) Geological mapping of dam site, head race tunnel,

power house, tail race tunnel and diversion tunnel on

1:2000, 1:1000 and 1:500 scale

Cumulative 6000m X 600m

(2) Drill hole core logging Cumulative 1343.27 m

(i) Alternative II 50.50 m

(ii) Alternative III 319.10 m

(iii) Alternative III-A 50.50m

(iv) Alternative IV 923.17 m

(3) Drift logging Cumulative 320 m

(i) Alternative III 100 m

(ii) Alternative IV 220 m

Source: DPR

6.2 PHYSIOGRAPHY AND DRAINAGE

The project area constitutes a part of the Pangi Valley and is characterized by rugged

topography comprising high ranges, deep valleys, escarpments and cliff faces. The area

constitutes a part of great Himalayan ranges; older folded cover sequence and crystalline

complex overprinted by Himalayan fold thrust movement, covering a stretch of the Chandra


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Bhaga Valley. The altitude of the area varies between 2500m and 6000m with several peaks

projecting over ∆6000m above mean sea level. The Shopu or Trishul peak (∆5222m) marks

the boundary of Himachal Pradesh with that of Jammu and Kashmir. The mountains are

bare along the upper reaches whereas they are forest covered along the lower slopes.

The Chenab river is a major river of the Indus Basin, originating from the Great Himalayan

and Pir Panjal ranges. The river formed by two major tributaries in the upper reaches i.e.

Chandra river and Bhaga river. The Chandra originates from Bara-La Che La whereas

Bhaga takes off from Suraj Tal in the vicinity of the Bara-La Cha La; Bhaga River is further

joined by the Jhankar and the Milang Nala before it joints the Chandra at Tandi to form

Chandrabhaga or Chenab River. Further downstream of its confluence, it is joined by other

significant tributaries namely Shansha Nala near Rashil and Thirot Nala at Thirot, Miyar Nala

at Udaipur, Saichu Nala at Dawag, Ajog, Bakanwal, Kulna Nala, Sach and Chhoo Nala in the

vicinity of Purthi, Dheda Nala, Saichu Nala near Cherry and Lu jai and Sansari Nala

downstream of Killar town. The river in its course traverse through the Lahaul, Pattan and

Pangi Vally of the Himachal Pradesh before entering into Jammu and Kashmir, downstream

of Biana Nallah.

The terrain in the upper reaches of tributaries shows typical glacial landscape characterized

by rugged towering peaks, cirque glaciers and moranic deposits. There are also thick and

extensive alluvial fans. At the higher reaches of the valley, the thickness of colluvium cover

varies from a few meter to 10 meter but in the lower portions it could be even up to ±20 to

30m in a few stretches. These tributaries show sub dendritic to trellis pattern of drainage.

The higher reaches of the slopes on either side of the Chandra Bhaga or Chenab River have

a number of glaciers which forms the perennial source of discharge in tributaries. About 200

glaciers have been identified in the Chenab basin in Himachal Pradesh of which 43 lies on

its southern side in Pir Panjal range and 157 on the northern side. As per Dobhal and Kumar

(1966), the ratio between basin area and glaciated area is 4.22:1.

6.3 REGIONAL GEOLOGY OF THE AREA

The project area constitutes a part of great Himalayan range, older folded cover sequence

and crystalline complex overprinted by Himalayan fold-thrust movement, covering a stretch

of Chandra-Bhaga valley. The topography of the area is rugged and characterized by sharp

crested ridges and deep cut valleys.

The valley slopes in the area are characterized by the stretches of unusually abundant

debris. These could have been formed due to the fractured or weathered rocks transported


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in abundance by snow, avalanche and landslides to the lower elevations on the banks of the

river.

The rock at and around this stretch of the area are represented by dark grey phyllitic

quartzites and quartzites with thin carbonaceous and pelitic bands. They belong to Haimanta

group of Proterozoic age and the geological succession worked out by Prashara et al (1986-

87) and Prashara (1992) is given in Table-6.2. The Regional Geology is depicted in Figure-

6.1.

Table-6.2: Geological succession of the Area

GROUP AGE FORMATION LITHOLOGY Haimanta Proterozoic Kunzum La Greenish grey siltstone, shale

& dolomite Batal Quartzite, phyllite, Carbonaceous

and pyritous. (It also includes Manjir and Katarigali Formations)

Lahaul or Chola Thach Garnetiferous schist and quartzite Rohtang Gneissic Gufa Granite gneiss, migmatite and

meta sediments Group

Damphung Matamorphites with subordinate gneiss and migmatite

Kulti Granite gneiss, migmatites with high grade Granite, gneiss, migmatites with high grade Granite, gneiss, migmatites with high grade metamorphites

Source: DPR

Haimanta Group of rocks has been divided into Batal and Kunzum- La Formations. In the

south-eastern part of the Lahaul i.e. in the valley of Chenab or Chandra-Bhaga, the Batal

Formation of this group is regarded to be represented by Manjir and Katarigali Formations of

Vaikrita Group of Chamba area. Here Rapa & Gadhoke (1984) mapped two formations i.e.

Bagotu and Dunai which were regarded equivalents of Manjir and Salooni Formations of

Chamba area. Subsequently un-fossiliferous part of Salooni Formation was renamed as

Bharmour Formation and correlated with Katarigali Formation of Jammu & Kashmir. These

formations have not been defined in the rest of Lahaul area except that the pelites

underlying the Tandi Group were correlated with Salooni and conglomerate exposed at

Chobia and Trilokinath with Manjir Formation by Raina and Prashara (1973).


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Figure-6.1: Regional Geology of the Area

6.4 STRUCTURE, TECTONICS AND METAMORPHISM

Many authors (e.g. Prasbra, K. C and Rapa, D.A., 1977; Nanda, M.M and Singh, M.P., 1977;

Srikantia, S.V. and Bhargava, 0.N., 1979; Steck , A., et al., 1999; Searle, M, et al., 1988;

Fuchs, G., and Linner, M., 1995; Frank W., M., Purtscheller, F., 1997; Robyr, M., 2002 and

references therein) have already worked in the upper Lahaul, Chamba and Zanskar area in

order to resolve the rather complex tectonic evolution of these regions. These studies,

although sometimes contradictory have allowed laying the bases of the tectono-


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metamorphic evolution of this part of the Himalayan range. It comes out from these previous

works that the Himalayan structures are dominated by SW-directed thrusting and folding.

However, in the Spiti and the Chenab Valley area, early NE-directed verging structures have

also been described. Following these works, four major tectonic events are considered to

explain the tectonic evolution of the Chamba, Zanskar and Lahaul area.

Phase D1: The NE-directed Shikar Beh Nappe

The early NE-directed Shikar Beh Nappe was proposed for the first time by Steck et al. (1993).

Their arguments are based on the regional distribution of the metamorphic facies in the

lower part of the Chandra Valley, near Khoksar. In this area, the metamorphic grade

reaches the amphibolites facies conditions and decreases gradually northward, in the direction

of the frontal part of the North Himalayan nappes. This decrease in metamorphic conditions

likely results from the overthrusting of a pile of nappes from the SW towards the NE. Other

arguments for an early NE-directed nappe are based on the unusual vergence of the Tandi

Syncline. Although the enigmatic character of this syncline was already recognized by several

authors. Lyddecker (1883) recognized this structure as a syncline. A detailed analysis

(Powell and Connaghan 1973) showed the polyphase nature of this structure and they

demonstrated that the Tandi syncline is associated with a first phase of deformation.

Nevertheless, they interpreted it as an antiform closing to the NE. Frank et al. (1973) and

Srikantia and Bhargava (1976 and 1979) recognized the NE-directed vergence of the Tandi

Syncline. This unusual NE-vergence only represents a local perturbation of the SW-

directed folding associated with the SW-directed thrusting along the Main Central Thrust. In

recent years, the detailed structural analysis of the Tandi Syncline confirmed that this structure

corresponds to a NE verging fold (Steck et al; 1993) and are associated this phase with an

early NE-directed nappe referred to as the Shikar Beh Nappe. However, the existence of such

nappe is still debatable among various other workers (Frank et al 1995).

Phase D2: The SW-directed Nyimaling-Tsarap Nappe

In the northern part of the Indian Himalaya, in the Zanskar and Ladakh area, the first phase of

folding is associated with the SW-directed North Himalayan nappes emplacement

though, nappe tectonics in the northern part of the Himalaya is still debated by Fuchs and

Linner (1995). For these authors, the term of nappe is not appropriate to describe the

tectonics in the Zanskar region. They consider that prevalent tectonics in Zanskar only consists of

folds and imbricated structures. On the basis of a two-dimensional shear model, Steck et al.

(1993) calculated a total crustal shortening of about 87 Km within the Tethyan Himalaya of

Zanskar and concluded that the geometry and the kinematic of the Tethyan Himalaya in the

Zanskar is comparable with the tectonic style of Alpine nappes.


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The North Himalayan nappes emplacement is responsible for the main phase of

deformation affecting the sedimentary sequences of the Tethyan Himalaya in the northern

part of the range. The name of Nyimaling-Tsarap nappe was introduced by Steck et al (1993)

for the whole thrust pile of sedimentary rocks located between the Indus Suture Zone to the

north and the Baralacha La to the south. The internal structure of this nappe stack is

characterized by a progressive change in style of deformation. The northern part of the range,

close to the suture zone, corresponds to the root zone of the Nyimaling-Tsarap nappe. In this

region, the deformation is primarily accommodated by ductile shearing and folding. In

contrast, in the frontal part of the nappe, the deformation becomes more and more brittle and

is characterized by the development of imbricate structures.

Phase D3: The SW-directed High Himalayan Nappe

In the Lahaul and Spiti area, the early NE directed structures of the Shikar Bah nappe (DI)

are overprinted by SW-directed folding. These D3 structures are observed in the central

and southern part of the upper Lahaul, and intensity of deformation increases from NE to

SW, whereas no D3 large scale structures was highlighted in Chenab valley area. This

D3 phase is, on the other hand, responsible for the spectacular SW-directed Kalath fold

in the Kullu Valley (Thoni, 1977). On the, basis of its vergence, its style and its location, this

D3 phase is interpreted as related to the SW-directed folding and thrusting of the High

Himalayan nappe along the Main Central Thrust (e.g. Crystalline nappe; Frank et al; 1977).

This SW-directed nappe is generally formed of the metamorphic core zone of the

Himalayan Orogen. In numerous sections along the range, the crystalline nappe is

separated from the low-grade metamorphic sediments of the Tethyan Himalaya by the

extensional Zanskar Shear Zone (Dezes et al; 1999) considered as a local equivalent of

the south Tibetan Detachment System.

Phase D4: The doming phase

In the central and eastern part of the Himalaya, the metamorphic core zone of the range

corresponds to a 5-40 km thick, NE-dipping monoclonal slab. In contrast, in the

northwestern part of the Himalaya of India, the high-grade metamorphic rocks are

mainly exposed in a more internal part of the orogen. A major characteristic of this

high-grade metamorphic zone in the Zanskar area is the presence of several large-scale

dome structures, cored by Cambro-Ordovician granitic gneisses and/or tertiary migmatites

and leucogranites. This particular setting implies that the exhumation of high-grade rocks in

this part of the range was for a large part controlled by doming. The exhumation of these

rocks back to the surface and the mechanism of dome formation are a complicated and still

debated problem.


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6.5 TECHTONIC SETUP OF THE PROJECT AREA

The proposed Sach Khas hydroelectric project is situated in between MCT and STDS in broad

tectonic framework of the Tethyan Himalayas and Central Crystalline sequences. In NW

Himalayas the Main Central Thrust is disposed as window and Klippe structures. The Kishtwar

Window is located towards NW of the project area, while Kullu-LargiRampur Window in SE

direction. Towards south in Chamba region, the MCT run more or less parallel to MBT in NW-SE

direction. The Shimla Klippe is significant adjunct to this thrust. Other tectonic element like

MBT and HFT lies further south of MCT while STDS and Zanskar shear zone towards north

of the project area. The some of the important local thrust/fault are Miyar thrust also refer by

some authors (e.g. Thakur, V.C, 2002) as Chenab Normal Fault, Salgaron thrust, Sarchu fault,

Panjal thrust and significant shear zone such as Killar-Miyar shear zone, Kanjhar shear zone

and Zanskar shear zone disposed in the north of the project area.

A review of the published maps suggest that the nearest Tectonic elements such as Miyar and

Salgarom thrust and located more than 50 km away and other fault such as Sundarnagar and

Kistwar faults are located more than 70km away from the Sach Khas project area and no

tectonic implications are foreseen.

6.6 SEISMO-TECTONICS AND SEISMICITY

The Himalayas is the product of the collision of the Indian plate with the Eurasian plate,

where Indian plate is underthrusting beneath the Eurasian plate. The collision tectonics

resulting in progressive progradation of thrust sheets like the Main Central Thrust (MCT),

Main Boundary Thrust (MBT) and the Himalayan Frontal Thrust (HFT). The

contemporary deformation styles and the seismicity in the Himalaya are related to this

continued collision tectonics resulting in strain builds up along discrete tectonic surfaces

and transverse features causing segmented blocks. On the basis of well constrained focal

depths of many moderate earthquakes in the tectonic domain between the MBT and MCT,

the focal mechanism of discrete events and neotectonic adjustments, many workers

have postulated that in the Main Himalayan seismic belt, the events are related to the

thrust type of faults.

Two seismo-tectonic models, one Steady State Model proposed by Seeber and

Armbruster, (1981) and another, the Evolutionary Model proposed by Ni and Barazangi,

(1984) and minor modifications, have been in use to explain the high seismic status of the

Himalaya. Seeber and Armbruster, (1981) have identified two separate seismogenic

domains. One related to the interplate detachment surface, dipping at low angles

towards north beneath the Tethyan slab, and the source for the Great Himalayan

Earthquakes like the Kangra event of 1905. The other domain is the thrust type of


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deformation style located between the MCT and MBT, the Basement Thrust Front (BTF). It

has also been postulated that the Detachment surface and the MCT and related thrust

surfaces, which are steeper than the detachment surface merge beneath the Great

Himalayan Range.

The most referred conceptual tectonic model of the Himalayan Seismic Belt (HSB), the

seismic zone within the MBT and MCT, suggests that below the Main Central Thrust

(MCT) lies the Basement Thrust Front (BTF), a ramp. The ramp is a geometrical asperity

on the plane of detachment, which accumulates the stress due to collision tectonics in

the Himalaya, and it was suggested that the great earthquakes occurred on the plane of

detachment. The plane of detachment separates the Indian shield and the Himalayan

sedimentary wedge; some authors named it Main Himalayan Thrust (MHT).

The Himalayan Seismic Belt generated several large and great earthquakes based on

which a conceptual tectonic model was envisaged. The Himalayan tectonic model fits

fairly well with the Western Himalayan seismicity to the north of MBT, where earthquakes

occur on the MHT at shallower (<20 km) depth. The four great earthquakes that

occurred to the south of MBT, however, do not fit into this model. It is argued that these

events are not on the MHT, each occurred at a deeper depth in different tectonic

domains.

The upper Chenab valley area encompassing the proposed Sach Khas Hydroelectric

project is located in highly seismic Central Himalayas. Tectonically, the region is located

in Main Himalayan Tectonic Belt bounded by Indus Suture Zone (ISZ) in the north and

Main Boundary Fault—(MBF-1) in south. Most important tectonic plane within this belt is

Main Central Thrust (MCT). However, its position in the area between the rivers Beas and

Chenab has not been clearly demarcated. The other feature of tectonic importance in this

belt is the Vaikrita Thrust. The tectonic zone south of Main Himalayan Belt is Frontal Fold

Belt demarcated in north by MBF1 and in south by Foot Hill Thrust (FHT). The important

tectonic surfaces in this zone include MBF-II, Jwalamukhi Thrust and MBF-III apart from

several transverse faults. From seismotectonic point of view, the project area falls on the

western margin of Kangra Seismic Block of Narula (1991) which is demarcated by Ravi

Tear in west and Sunder Nagar Fault in east. The earthquake catalogue of IMD indicates

that the concentration of magnitude >4<5 earthquakes is maximum in 'the area, being

71% of total recorded events between latitude 32°-3 4°and longitude 75°- 78°. The

catalogue also indicates that after 1964, when worldwide seismic network was

established, a total of 83 earthquakes were recorded up to March, 1995 in the above

mentioned area. The percentage of earthquakes with magnitude >4<5 was 75, those with

magnitude >5<6 were 14% and rest of the events had greater magnitude.


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Figure 6.2 Seismotectonic domain of NW Himalayas

Figure 6.3 Seismotectonic domain of NW Himalayas


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Major earthquakes of the region include Kangra-1905 (M=8); Chamba-1945, 1947, 1950

(M=6.5, 6.2, & 5.5); Dharamshala 1978, 1986 (M= 5 & 5.7) and Kathua-1980 (M=5.3). As

per Zoning Map of India Showing Seismic Zones (IS: 1893-2002 (Part-1)), the project

area lies in Zone-V i.e. highest seismic zone in Western Himalayas. (Refer Figure-6.2 &

6.3). Therefore, it is recommended that suitable seismic coefficient to commensurate with

the seismic status of the area may be evolved based on detailed seismo-tectonic and

seismological studies and incorporated in the design of various appurtenant structures of the

scheme.

6.7 GEO-TECHNICAL APPRAISAL OF THE COMPONENT STRUCTURES

DAM

The Sach Khas dam site is of heterogeneous both in terms of lithological assemblage as

well as structural conditions. Grey color, hard, compact quartzite with phyllite and phyllitic

quartzite partings forms the foundation of dam and spillways. These lithologies are traversed

by multiple sets of discontinuities. These in association with foliation discontinuities and

foliation parallel shear seams and variable degree of weathering (mostly W-II) have rendered

the rock mass further heterogeneous. However, the core recovery (70 to 90%) and RQD

(>70) and lugeon values (2 to 10) with local shattered zones varying in thickness from 10cm

to 30cm indicates the fair to good quality of rock mass foundation.

POWER HOUSE

The underground power house cavern has been located in the North-South ridge, about

300m downstream of the dam axis. The underground cavern will be located in grey quartzite,

diamictite and phyllitic quartzite bands. The foliation trends N40oW – S40oE with 35o-40o dips

towards SW i.e. downstream.

The proposed power house cavern is likely to encounter fresh and hard quartzite (55% to

60%), diamictite and phyllitic quartzite (30% to 35%) in 80 to 85% reach, phyllite in 10%

reach and sheared and shattered rock mass in 5% reach.

PRESSURE SHAFTS

The water from the reservoir will be carried through three, 5.8m diameter (finished diameter)

and approx. 300m long pressure shafts embedded partly in dam body (EL±2150m) and

partly in the toe of north south trending ridge at an invert level of EL 2140.40m on the right

bank of river Chenab.

The pressure shafts will roughly pass through 45% in quartzite, 25% in diamictite and 30% in

phyllite and phyllitic quartzite rock mass. The rock quality index ‘Q’ probably varies from 7.8

to 3.6 whereas, the shear seams and shattered rock mass may have ‘Q’ values of 1.6 to

<0.5.


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DIVERSION TUNNEL

The proposed diversion arrangement consists of a 10m dia. and 780.0m long tunnel and is

located on the left flank of the Chenab River in a North South trending ridge. The inlet portal

of the Diversion Tunnel is located 280m upstream of the Sach Khas dam axis whereas outlet

portal is located 350m downstream of the dam axis.

The diversion tunnel roughly passes through 52% in quartzite, 28% in diamictite and 20% in

phyllitic quartzite and phyllite interbands. The rock quality index ‘Q’ will probably vary from

3.2 to 7.4 for moderately jointed and competent quartzite diamictite; the values for thinly

foliated phyllite and phyllitic quartzite may be of the order of 1.2 to 4.1 whereas soft rock

units, shear seams and shattered zones may have a Q values of 0.15 to 0.04.

COFFER DAM

For construction requirement, two coffer dams, 200m upstream and 290m downstream of

the Sach Khas dam axis have been proposed with top level fixed at EL 2172m and EL

2162m respectively.The grey color, fresh and hard quartzite with phyllitic quartzite and

phyllite interbands are exposed on both the abutments of the upstream Coffer Dams.

TAIL RACE TUNNEL The Tail Race Tunnel (Tunnel) in say from power house cavern run in N350W-S350E

direction. The tunnel would negotiate fresh, hard and competent quartzite, diamictite, phyllitic

quartzite and phyllite inter bands in its entire reach.

The TRT will encounter fair to poor rock mass and the ‘Q’-values varying from 6.3 to 1.6 for

the quartzite, phyllitic quartzite and diamictite inter bands. The ‘Q’-values will be 1.1 to <0.1

for the phyllite and sheared rock mass.

AUXILIARY POWER HOUSE

The auxiliary power house 30.5 x 10.0 m (L x W) aligned in N660W-S660E direction has

been located on the left flank of river Chenab on a rock cut terrace at EL 2160m, at the foot

of dam. Hard and massive quartzite with phyllite inter bands are exposed along the river

bank and uphill slopes. The terrace is covered with thin overburden comprising slope wash

material.The power house will be founded on hard and fresh rock mass. However, the

surface runoff and stream lets may have to be diverted by parabolic drainage, thus,

preventing erosional matter coming into the area of pit.


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CONSTRUCTION ADITS MAIN ACCESS TUNNEL (MAT)

A 220m long and 8.0m dia. ‘D’ shaped MAT to power house cavern has been planned at an

invert level of 2163.0m with a down grade of 13.9:1, upstream of the Bambal Nala. The MAT

will have a vertical cover of 5-7m in the initial reach to more than 100m in the cavern area.

The MAT will encounter moderately fresh to fresh quartzite and phyllitic quartzite at the

portal with a W=II weathering and stained joints in the initial reaches followed by hard and

fresh grey color quartzite (50%) diamictite (20%), phyllitic quartzite (20%) and phyllite

interbands and shear seams 10%. The general trend of foliation is N550W-S550E with 760 to

800 southwesterly dips.

The Q-values generally varies from 3.4 to 1.6 for the quartzite, phyllitic quartzite & diamictite

and 1.1 to 0.01 for phyllictic and sheared rock mass in the reach between 0m to 80m length.

It is followed by Q= 7.8 to 1.6 for quartzite & diamictite and 3.2 to <0.5 for phyllitic quartzite

and phyllite for the rock mass between 80m to 220m length.

CONSTRUCTION ADIT TO POWER HOUSE CAVERN

A 200m long construction adit for the excavation of the top of power house cavern has been

planned at an invert level of 2163.0m upstream of the MAT. The adit will subsequently be

used as ventilation tunnel in the power house cavern area.

Hard and fresh quartzite with diamictite, phyllitic quartzite and phyllite interbands are

expected to encounter in the adit. The percentage of rock mass will be of the order of 50%,

20%, 20% and 10% respectively. The general trend of foliation is N550W-S550E with

760southwesterly dips. For the initial 60.0m reach, the rock mass quality index Q generally

varies from 6.4 to 1.6 for quartzite, diamictite & phyllitic quartzite inter bands and 1.1 to <0.1

for phyllitic quartzite & sheared rock mass whereas from 60.0m to 200.0m length of adit Q-

values will be of the order of 7.8 to 1.6 for quartzite & diamictite and 3.2 to <0.5 for phyllitic

quartzite, phyllite and sheared rock mass.

CONSTRUCTION ADIT TO PRESSURE SHAFTS

A construction adit at an invert level of 2141.40m has been planned to excavate the three

pressure shafts. The D-shaped adit will have a length of 140m and diameter of 7.0m in 10:1

down grade excavation slope.

The adit is expected to encounter quartzite (40%) diamictite 30%, phyllitic quartzite 10% and

phyllite and sheared rock mass (20%). The general trend of foliation is N550W-S550E with

760 southwesterly dips. For the initial 55m length of adit, the Q-values varies from 4.2 to 1.6


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for quartzite & diamictite and 1.1 to <0.1 for weathered phyllitic quartzite, phyllite & sheared

rock mass. The reach between 55m to 155m length is likely to encounter Q-values ranging

from 6.8 to 3.2 for quartzite & diamictite and 1.6 to <0.5 for weathered phyllite & sheared

zone material.

RESERVOIR AREA

A detailed assessment of the reservoir area has been made and in principle, it is qualitative

and is largely based on the observations of geomorphology, vegetation and geology backed

by approximate measurements of the slide features. The 90.0m high, Sach Khas dam with

FRL 2219.0m will have water way of about 8.4km and extend 400m upstream of the Purthi

Bridge.

The topography of the reservoir area comprises of steep slopes along the right and left bank

of the reservoir in a broad ‘U’ shaped valley. The lower elevations comprise glacial drifts,

glacio-fluvial deposits; colluvial / slope wash material, riverine material with exposures of

rocks.

The rock exposed in reservoir area is mainly quartzite with diamictite, quartzite phyllite and

phyllite interbands, trending N300-750W – S300-750E with 400 to 850 south westerly dips. The

rocks are highly folded and crenulated. In addition to the foliation joints, the rock mass is

traversed by four prominent sets of joints i.e. (a) East –West / 200 to 450 northerly southerly

dips (b) North-South/ 500 to 800 Easterly southerly dips (c) N450W-S450E/ 600 to 700

Northerly easterly and (d) N450E-S450W/ 300 to 700 North Westerly dips.

CHAPTER-7

BASELINE SETTING FOR

PHYSICO-CHEMICAL ASPECTS


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CHAPTER-7

BASELINE SETTING FOR PHYSICO-CHEMICAL ASPECTS

7.1 GENERAL

Before start of any Environmental Impact Assessment study, it is necessary to identify the

baseline levels of relevant environmental parameters which are likely to be affected as a result

of the construction and operation of the proposed project. A similar approach has been adopted

for conducting the CEIA study for the proposed Sach khas hydroelectric Project. A Scoping

Matrix as outlined in Chapter-4 was formulated to identify various issues likely to be affected as

a result of the proposed project. Based on the specific inputs likely to accrue in the proposed

project, aspects to be covered in the EIA study were identified. The other issues as outlined in

the Scoping Matrix were then discarded. Thus, planning of baseline survey commenced with

the shortlisting of impacts and identification of parameters for which the data needs to be

collected. The baseline setting for physico-chemical aspects have been covered in this

Chapter.

7.2 METEOROLOGY

Temperature

Temperature variation in the project area ranges from extreme cold in winter to moderate

temperatures in summer. During winter season, upper reaches of most part of the project

area is covered with snow and temperature remains much below the freezing point

throughout winter season. Cold season precipitation is observed from December to March.

The storms from Iran and Baluchistan side are mainly responsible for heavy snowfall during

winter season in the area. The catchment area is by and large snow bound for about two

months during winter season. For the remaining months, the lower reaches of the drainage

area is free from the snow cover.

For a major part of the year, the basin is under the effect of cold weather systems; viz.

Western Disturbances. The Dhauladhar, the Pir Panjal and the Zanskar ranges of the

Himalayas impart distinct climatological features to the Chenab basin.

Temperature data is not available within the catchment up to Sach Khas. However, daily

maximum and minimum temperature data observed by IMD are available in the downstream

of Sach Khas dam site viz. at Badarwah and Banihal falling in J&K. The data availability is

shown in Table-7.1.


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Table-7.1 : Temperature data availability in Chenab Basin

S.No. Name of Station Elevat ion Period of data availability 1 Badarwah EL 1643 m 1977-2009 2 Banihal EL 1630 m 1972-2009

Source: DPR

Monthly snowline elevations

It is observed that the temporary snowline reaches about EL 2600 in the Pangi Valley of the

Chenab basin where Sach Khas dam site is proposed, during winter season. The permanent

snowline is commonly taken as EL 4500 m in these areas. Further, the snow cover is

maximum in September-October and minimum in March-April. Accordingly, the monthly

snowline elevations are assumed and the areas above snowline are calculated from the

hypsometric data and are given in Table-7.2

Table-7.2: Snowline elevations and areas Month Assumed snowline Elevation (m) Area above Snowline (m) January 3500 5843 February 3000 6317 March 2600 6503 April 2700 6410 May 2900 6379 June 3200 6142 July 3400 5949 August 3700 5605 September 4000 5142 October 4500 3973 November 4200 4731 December 3800 5476

Source: DPR

Average monthly temperatures in the project catchment.

It can be observed that temperature data obtained from both Badarwah and Banihal stations

are in close agreement, indicating consistency of the temperature data. Further, it comes out

that the average minimum temperature of the project catchment area in the month of

January are of the order of -60C, while the average maximum temperatures are in the month

of July , which is around 110C. The monthly average temperatures in the project catchment

are depicted graphically in Figure-7.1.


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Figure-7.1: Monthly average temperatures in project catchment

PRECIPITATION CHARACTERISTICS

There are a few raingauge stations in the project catchment maintained by India

Meteorological Department (IMD). The details are given in Table-7.3.

Table-7.3: Details of raingauges in Project catchment maintained by IMD S.No. Name of Station Elevation (m) Period of data availability 1 Gondla EL 3144 1970-2002 2 Keylong EL 3166 1970-2003 3 Koksar EL 3204 1970-2005 4 Udaipur EL 2641 2001-2003

Source: DPR

The rainfall data of Udaipur is for a very less period for inclusion in any catchment-wide

analysis. The other three stations viz. Gondla, Keylong and Koksar are very close to each

other in comparison to the catchment spread. Further, all the three stations are located at

similar elevations denying a representative catchment rainfall estimate. Nevertheless, an

analysis has been carried out in the DPR with the daily rainfall data available for the stations.

A summary of the results of the analysis is presented in Table-7.4.


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Table-7.4: Summary results of analysis Description Gondla Keylong Koksar Udaipur Average annual rainfall

932.1 mm 494.78 mm 923.58 mm The data availability period is too less for analysis.

Maximum annual rainfall

1656.6 mm in 1972

1193.5 mm in 1994

2127.0 mm in 1988

Minimum annual rainfall

457.5 mm in 2000

120.9 mm in 1973

360.0 mm in 1973

Maximum daily rainfall

82.6 mm on 11.03.1975

85.0 mm in 08.08.1972

120.0 mm in 27.02.1988

Source: DPR

The Thiessen Polygon Analysis was carried out to assign weights to the station rainfalls of

Gondla, Keylong and Koksar. The Thiessen map is shown in Figure-7.2 . The weights

assigned to various stations as per Theissen Polygon Analysis is given in Table-7.5.

Table-7.5: Weights assigned to rainfall stations in Catchment Area Station Thiessen weights Gondla 0.13 Keylong 0.485 Koksar 0.385 Source: DPR

Figure-7.2: Thiessen Map of Sach Khas project catchment

The monthly average rainfalls in the project catchment based on the weights above is

estimated as 798 mm. The monthwise rainfall is given in Table-7.6.


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Table-7.6: Monthly average rainfall in the catchment area of Sach Khas HEP

Month Average Rainfall (mm) January 80.30 February 111.57 March 126.78 April 78.31 May 60.65 June 33.68 July 76.01 August 71.67 September 56.74 October 21.41 November 25.81 December 54.85 Total 797.77 say 798 mm

Source: DPR

The monthly average rainfall at Gondla, Keylong and Koksar is shown in Figure-7.3. The

monthly average weighted rainfall in the catchment area of Sach Khas HEP is depicted in

Figure-7.4.

Figure-7.3 Monthly average rainfall at Gondla, Keylong & Koksar


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Figure-7.4: Monthly weighted average rainfall in project catchment

From the above analysis, a few important features of the precipitation pattern emerges –

1. There are two distinct rainfall cycles – one from November to May and the other from

June to October. Rainfall in the winter season is attributed to Western Disturbances

moving from West to East in westerly wind regime that normally prevails over the

Himalayan latitudes. From July to October, the basin is normally under the influence

of southwest monsoons.

2. The amount of rainfall in winter due to Western Disturbances is more than that in

summer due to Monsoon. From the results of the analysis carried out, it comes out

that out of the total annual rainfall, rainfall in the period November to May is 67%

against 33% rainfall in the period June to October. It may be mentioned here that the

flood producing area is however quite diminished in the winter season and therefore,

the extreme flood events are always experienced in the monsoon season.

3. Based on the available data the average annual rainfall in the project catchment is

797.77 mm. It may be mentioned that this not the representative of the catchment, as

most of the catchment area remains snow-covered and snowfall data is not available.

7.3 SOILS

Soil is the product of geological, chemical and biological interactions. The soils in the region

vary according to altitude and climate. The soil in the project area and study area are young

like any other region of Himalayas. The vegetal cover is one of the most important

influencing factors characterizing the soil types in a region. Soil on the slope above 30o, due

to erosion and mass wasting processing, are generally shallow and usually have very thin


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surface horizons. Such soils have medium to coarse texture. Residual soils are well

developed on level summits of lesser Himalayas, Sub-soil are deep and heavily textured.

As a part of field studies, soil depth at various locations in the catchment area ranged from

20 to 50 cm. has been collected during summer, post-monsoon and winter seasons and

were analyzed. The sampling stations are shown in Figure- 7.5. The results of the analysis

of soil sampling conducted for Monsoon, winter and pre-monsoon seasons are given in

Tables-7.7 to 7.9 respectively.

Table-7.7: Results of soil sampling analysis of study area (Monsoon season)

Parameter Unit S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 pH - 7.2 7.6 7.8 7.5 7.5 7.2 7.2 7.5 7.0 7.3 Electrical Conductivity

micro mhos/ cm

17.1 18.4 27.4 20.8 24.6 16.9 26.2 18.4 20.7 27.1

Organic Matter

% 1.0 0.8 1.0 1.1 1.0 1.7 1.4 1.4 1.6 1.2

Available Phosphorous (as P2O5)

Kg/ha 11 16 15 13 15 13 16 16 12 15

Available Potassium (as K2O)

Kg/ha 140 180 140 150 130 170 150 120 130 140

Available Nitrogen (as N)

Kg/ha 294 310 317 294 290 350 280 250 320 245

Cation Exchange

meq/ 100gm

11.2 12.7 11.9 13.1 11.5 13.7 11.8 12.6 11.9 12.0


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Parameter Unit S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 Capacity Particle Size Distribution

%w/w

>0.25mm %w/w 24.1 25.1 18.4 21.2 23.7 25.1 20.4 21.8 21.5 17.9

0.25 to 0.149mm

%w/w 26.2 26.0 27.1 24.2 21.4 27.1 26.2 25.1 27.0 24.4

0.149 to0.088mm

%w/w 27.4 24.1 14.2 15.6 18.4 27.8 27.0 25.1 27.1 27.1

0.088 to 0.074mm

%w/w 8.4 9.2 9.1 7.3 11.7 11.9 9.9 7.4 9.6 11.4

0.074 to 0.0625mm

%w/w 1.2 0.8 1.7 1.8 2.1 1.7 1.3 2.1 1.9 1.5

0.0625 to 0.053mm

%w/w 1.4 0.7 1.8 1.4 1.5 1.5 1.4 2.0 1.5 1.2

<0.053mm %w/w - - - - - - - - - - Source: Field Studies

Table-7.8: Results of soil sampling analysis of study area (winter season) Parameter Unit S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 pH - 7.3 7.5 7.6 7.4 7.4 7.1 7.1 7.3 7.0 7.2 Electrical Conductivity

micro mhos/ cm

17.0 18.4 25.2 20.2 23.7 16.0 26.2 18.4 20.7 27.1

Organic Matter

% 0.8 0.7 0.8 1.0 1.1 1.5 1.2 1.1 1.2 1.0


kg/ha 10 15 14 12 14 12 14 14 10 13


kg/ha 130 160 120 130 120 150 140 110 120 130


kg/ha 282 305 312 287 280 340 276 241 310 240

Cation Exchange Capacity

meq/ 100gm

11.4 12.0 11.5 12.2 11.2 12.8 11.6 12.0 11.5 11.2

Particle Size Distribution

%w/w

>0.25mm %w/w 24.1 25.1 18.4 21.2 23.7 25.1 20.4 21.8 21.5 17.9

0.25 to 0.149mm

%w/w 26.2 26.0 27.1 24.2 21.4 27.1 26.2 25.1 27.0 24.4

0.149 to0.088mm

%w/w 27.4 24.1 14.2 15.6 18.4 27.8 27.0 25.1 27.1 27.1

0.088 to 0.074mm

%w/w 8.4 9.2 9.1 7.3 11.7 11.9 9.9 7.4 9.6 11.4

0.074 to 0.0625mm

%w/w 1.2 0.8 1.7 1.8 2.1 1.7 1.3 2.1 1.9 1.5

0.0625 to 0.053mm

%w/w 1.4 0.7 1.8 1.4 1.5 1.5 1.4 2.0 1.5 1.2



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Table-7.9: Results of soil sampling analysis of study area (summer season)

Parameter Unit S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 pH - 7.2 7.4 7.5 7.4 7.4 7.2 7.1 7.2 7.1 7.1 Electrical Conductivity

micro mhos/ cm

17.2 18.5 25.3 20.4 23.78

16.2 26.24

18.5 20.9 27.2

Organic Matter

% 0.9 0.7 0.9 1.2 1.4 1.6 1.2 1.4 1.2 1.2


kg/ha 10 14 14 12 13 12 14 12 10 12


kg/ha 125 154 110 128 119 147 138 108 117 128


kg/ha 274 302 306 270 264 325 270 235 308 236

Cation Exchange Capacity

meq/ 100gm

11.2 11.8 11.4 12.0 11.0 12.3 11.2 11.7 11.2 11.1

Particle Size Distribution

%w/w

>0.25mm %w/w 24.1 25.1 18.4 21.2 23.7 25.1 20.4 21.8 21.5 17.9

0.25 to 0.149mm

%w/w 26.2 26.0 27.1 24.2 21.4 27.1 26.2 25.1 27.0 24.4

0.149 to0.088mm

%w/w 27.4 24.1 14.2 15.6 18.4 27.8 27.0 25.1 27.1 27.1

0.088 to 0.074mm

%w/w 8.4 9.2 9.1 7.3 11.7 11.9 9.9 7.4 9.6 11.4

0.074 to 0.0625mm

%w/w 1.2 0.8 1.7 1.8 2.1 1.7 1.3 2.1 1.9 1.5

0.0625 to 0.053mm

%w/w 1.4 0.7 1.8 1.4 1.5 1.5 1.4 2.0 1.5 1.2


The pH of soil at various sites lies within neutral range. The levels of NPK indicate moderate

soil productivity. The CEC levels do not indicate any potential for soil salinization or adverse

impacts on soil productivity

In a hydroelectric project, no significant impact on soil quality is expected barring, soil

pollution at local level due to disposal of construction waste. For amelioration of such

impacts appropriate management measures are recommended.

7.4 WATER QUALITY

There are no major sources of organic pollution loading in the basin. The Catchment

intercepted at the project site has low population density with low cropping intensity. The low

cropping intensity coupled with low agro-chemical dosing also means that the pollution load

due to agro-chemicals is quite low. The absence of industries implies that there is no


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pollution load from this source as well.

As a part of the field studies, water samples were collected at various locations in the study

area. The water sampling results for three seasons (summer, monsoon and winter) covered

as a part of the field studies are given in Tables-7.10 to 7.12. The locations of various

sampling stations as shown in Figure-7.6 and are listed as below:

W1 - At dam site W2 - 1 km upstream of dam site W3 - 1 km downstream of dam site W4 - 3 km downstream of the dam site W5 - Power house site.

The drinking water quality standards are given in Table-7.13.

Table-7.10: Water quality in the study area (Monsoon season) Parameter Unit Sampling stations

W1 W2 W3 W4 W5 pH - 7.1 7.2 7.3 7.4 7.5 TDS mg/l 76 78 80 74 80 Sulphates mg/l <1.0 <1.0 <1.0 <1.0 <1.0 Nitrates mg/l 3.1 4.0 3.5 3.2 2.9 Phosphates mg/l 0.2 0.2 0.2 0.2 0.2 Chlorides mg/l 8 7 7 7 8 Sodium mg/l 11 9 11 11 9


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Parameter Unit Sampling stations W1 W2 W3 W4 W5

Potassium mg/l 3.1 3.0 4.1 3.0 3.9 Calcium mg/l 14 16 16 14 14 Magnesium mg/l 2.7 2.7 2.6 2.2 2.1 Copper mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Mercury mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Lead mg/l <0.001 <0.001 <0.001 <0.001 <0.001 Iron mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Zinc mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Cyanides mg/l <0.01 <0.01 <0.01 <0.01 <0.01 Cadmium mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Chromium mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Manganese mg/l <0.1 <0.1 <0.1 <0.1 <0.1 DO mg/l 8.6 8.9 8.6 8.7 8.9 BOD mg/l 1.1 1.2 1.2 1.2 1.1 COD mg/l 2.1 2.3 2.4 2.3 2.2 Hardness mg/l 46 51 51 44 44 Electrical Conductivity

µS/cm 104 107 109 101 109

Total Coliform MPN/100 ml Nil Nil Nil Nil Nil Source: Field Studies

Table-7.11: Water quality in the study area (winter season) Parameter UNIT Sampling stations

W1 W2 W3 W4 W5

pH - 7.1 7.1 7.2 7.4 7.5 TDS mg/l 80 84 82 78 84 Sulphates mg/l <1.0 <1.0 <1.0 <1.0 <1.0 Nitrates mg/l 3.6 4.1 3.8 3.4 3.0 Phosphates mg/l 0.4 0.5 0.3 0.4 0.4 Chlorides mg/l 10 10 9 10 12 Sodium mg/l 14 12 14 13 12 Potassium mg/l 3.5 3.5 4.4 3.2 4.3 Calcium mg/l 16 18 17 15 17 Magnesium mg/l 2.8 2.8 2.8 2.4 2.4 Copper mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Mercury mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Lead mg/l <0.001 <0.001 <0.001 <0.001 <0.001 Iron mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Zinc mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Cyanides mg/l <0.01 <0.01 <0.01 <0.01 <0.01 Cadmium mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Chromium mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Manganese mg/l <0.1 <0.1 <0.1 <0.1 <0.1 DO mg/l 8.7 8.9 8.7 8.8 8.9 BOD mg/l 1.1 1.2 1.2 1.2 1.3 COD mg/l 2.3 2.4 2.3 2.4 2.5 Hardness mg/l 52 57 54 47 52 Electrical µS/cm 110 115 112 107 115


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Parameter UNIT Sampling stations W1 W2 W3 W4 W5

Conductivity Total Coliform MPN/100 ml Nil Nil Nil Nil Nil Source: Field Studies

Table-7.12: Water quality in the study area (summer season)

Parameter UNIT Sampling stations W1 W2 W3 W4 W5

pH - 7.1 7.1 7.1 7.3 7.3 TDS mg/l 76 80 77 72 76 Sulphates mg/l <1.0 <1.0 <1.0 <1.0 <1.0 Nitrates mg/l 3.2 3.4 3.4 3.2 2.9 Phosphates mg/l 0.4 0.4 0.3 0.3 0.4 Chlorides mg/l 8 8 6 7 10 Sodium mg/l 11 11 10 12 10 Potassium mg/l 3.2 3.4 4.1 3.0 4.0 Calcium mg/l 14 16 14 14 16 Magnesium mg/l 2.6 2.5 2.6 2.0 2.1 Copper mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Mercury mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Lead mg/l <0.001 <0.001 <0.001 <0.001 <0.001 Iron mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Zinc mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Cyanides mg/l <0.01 <0.01 <0.01 <0.01 <0.01 Cadmium mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Chromium mg/l <0.1 <0.1 <0.1 <0.1 <0.1 Manganese mg/l <0.1 <0.1 <0.1 <0.1 <0.1 DO mg/l 8.6 8.8 8.6 8.7 8.8 BOD mg/l 1.0 1.1 1.1 1.1 1.1 COD mg/l 2.0 2.2 2.1 2.1 2.2 Hardness mg/l 46 50 45 43 49 Electrical Conductivity

µS/cm 101 110 102 97 102

Total Coliform MPN/100 ml Nil Nil Nil Nil Nil Source: Field Studies

Table-7.13: Drinking water quality standards (Specified by Central Public Health and Environment Engineering Organisation (CPHEEO) Characteristics *Acceptable **Cause for

Rejection Turbidity (units on JTU scale) 2.5 10 Colour (Units on platinum cobalt scale) 5.0 25 Taste and Odour Unobjectionable Unobjectionable PH 7.0 to 8.5 <6.5 or >9.2 Total Dissolved Solids (mg/l) 500 1500 Total hardness (mg/l) (as CaCO3) 200 600 Chlorides as CD (mg/l) 200 1000 Sulphates (as SO4) 200 400


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Characteristics *Acceptable **Cause for Rejection

Fluorides (as F) (mg/l) 1.0 1.5 Nitrates (as NO3) (mg/l) 45 45 Calcium (as Ca) (mg/l) 75 200 Magnesium (as Mg) (mg/l) If there are 250 mg/l of sulphates, Mg content can be increased to a maximum of 125 mg/l with the reduction of sulphates at the rate of 1 unit per every 2.5 units of sulphates

30 150

Iron (as Fe) (mg/l) 0.1 1.0 Manganese (as Mn) (mg/l) 0.05 0.5 Copper (as Cu) (mg/l) 0.05 1.5 Zinc (as Zn) (mg/l) 5.0 15.0 Phenolic compounds (as phenol) (mg/l) 0.001 0.002 Anionic detergents (as MBAS) (mg/l) 0.2 1.0 Mineral Oil (mg/l) 0.01 0.3 Toxic materials Arsenic (as As) (mg/l) 0.05 0.05 Cadmium (as Cd) (mg/l) 0.01 0.01 Chromium (as hexaalent Cr) (mg/l) 0.05 0.05 Cyanides (as CN) (mg/l) 0.05 0.05 Lead (as Pb) (mg/l) 0.1 0.1 Selenium (as Se) (mg/l) 0.01 0.01 Mercury (total as Hg) (mg/l) 0.001 0.001 Polynuclear aromatic hydrocarbons (PAH) 0.2 µg/l 0.2 µg/l Notes: *1. The figures indicated under the column `Acceptable’ are the limits upto which water is generally

acceptable to the consumers **2 Figures in excess of those mentioned under `Acceptable render the water not acceptable, but still may

be tolerated in the absence of alternative and better source but upto the limits indicated under column “Cause for Rejection” above which are supply will have to be rejected.

The total hardness in water samples ranged from 44-51 mg/l and 47 to 57 mg/l in monsoon and

winter season respectively. In summer season, Hardness level ranged from 43 to 50 mg/l. The

low hardness level can be attributed low calcium and magnesium levels, which are responsible

for soft nature of water. The low EC and TDS values indicate the lower concentration of cations

and anions. The concentration of TDS level ranged from 72 to 84 mg/l in various seasons,

which is much lower than the permissible limit of 500 mg/l specified for domestic use (Refer

Table-7.13). This is also reflected by the fact that the concentration of most of the cations and

anions are well within the permissible limit.

The BOD values are well within the permissible limits, which indicate the absence of organic

pollution loading. This is mainly due to the low population density and absence of industries in

the area. The low COD values also indicate the absence of chemical pollution loading in the

area. The marginal quantity of pollution load, which enters river Chenab, gets diluted. In fact,

even for the minimum flow, there is more than adequate water available for dilution. The heavy

metal concentration in the study area is below the permissible limit used for drinking purposes.


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Total Coliform count is nil in the study area. It can be concluded that water quality was

observed to be quite good, as various parameters are well below the permissible limit specified

for meeting domestic requirements.

7.5 NOISE ENVIRONMENT

Baseline noise data has been measured using a weighted sound pressure level meter. The

survey was carried out in calm surrounding. Sound Pressure Level (SPL) measurement in

the outside environment was made using sound pressure level meter. Hourly noise meter

readings were taken at different sites. The survey for monsoon season was conducted in

August 2010. The location of various noise monitoring stations is shown in Figure-7.7. The

noise levels were monitored continuously from 6 AM to 9 PM at each location and hourly

equivalent noise level was measured. Sound Pressure Level (SPL) measurement in the

ambient environment was made using sound pressure level meter. The hourly ambient noise

levels monitored for various seasons are given in Tables-7.14 to 7.16. The noise standards

for various categories are given in Table-7.17 . The day time equivalent noise levels

estimated are given in Table-7.18.


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Table-7.14: Hourly equivalent noise levels-Monsoon Season Location Dam site (N1) Submergence

Area (N2) Power house site (N3)

Village Shin

6-7 AM 35 36 36 35 7-8 AM 38 36 37 36 8-9 AM 39 39 39 40 9-10 AM 41 40 41 40 10-11 AM 42 42 42 42 11-12 Noon 44 44 42 41 12 noon – 1 PM 40 41 42 42 1-2 PM 42 41 41 42 2-3 PM 42 42 42 40 3-4 PM 40 42 40 40 4-5 PM 42 42 42 41 5-6 PM 41 40 41 40 6-7 PM 40 39 38 39 7-8 PM 39 37 37 38 8-9 PM 38 37 37 37

Source: Field Studies

Table-7.15: Hourly equivalent noise levels-Winter Season Location Dam site -1

(N1) Submergence Area (N2)

Power house site (N3)

Village Shin

6-7 AM 37 37 38 38 7-8 AM 40 39 40 39 8-9 AM 41 41 41 42 9-10 AM 42 43 42 42 10-11 AM 44 44 43 42 11-12 Noon 45 44 40 42 12 noon – 1 PM 42 43 44 44 1-2 PM 42 42 43 44 2-3 PM 43 43 43 42 3-4 PM 42 42 42 42 4-5 PM 41 41 43 42 5-6 PM 40 40 42 42 6-7 PM 40 40 40 40 7-8 PM 39 39 39 39 8-9 PM 38 38 38 38


Table-7.16: Hourly equivalent noise levels-Summer Season Location Dam site -1

(N1) Submergence Area (N2)

Power hous e site (N3)

Village Shin

6-7 AM 38 39 39 40 7-8 AM 41 40 42 42 8-9 AM 42 43 42 44 9-10 AM 43 44 43 44 10-11 AM 45 45 45 45 11-12 Noon 45 46 45 46 12 Noon – 1 PM 44 47 46 47 1-2 PM 44 45 45 46 2-3 PM 44 44 45 46 3-4 PM 44 44 45 44 4-5 PM 43 43 43 42


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Location Dam site -1 (N1)

Submergence Area (N2)

Power hous e site (N3)

Village Shin

5-6 PM 41 42 42 42 6-7 PM 42 41 41 41 7-8 PM 39 40 40 40 8-9 PM 39 39 39 39

Source : Field Studies

Table-7.17 : Ambient Noise Standards ---------------------------------------------------------------------------------------------------------------------- Area Category Limits in dB(A)Leq Code of Area ----------------------------------------------------------- Day time Night time ---------------------------------------------------------------------------------------------------------------------- A. Industrial Area 75 70 B. Commercial Area 65 55 C. Residential Area 55 45 D. Silence Zone 50 40 ---------------------------------------------------------------------------------------------------------------------- Notes:

• Day time 6 A.M. and 9 P.M. • Night time is 9 P.M. and 6 A.M. • Silence zone is defined as areas upto 100 meters around such • Premises as hospitals, educational institutions and courts. The silence zones are to be

declared by competent authority. Use of vehicular horns, loudspeakers and bursting of crackers shall be banned in these zones.

• Environment (Protection) Third Amendment Rules, 2000 Gazette notification, Government of India, date 14.2.2000.

Table-7.18: Day time Equivalent noise levels S. No. Location Zone Value (dB(A))

Monsoon Winter Summer 1. Dam site-1 Residential 40.0 41.55 42.75 2. Submergence Area Residential 40.5 41.54 43.46 3. Power house site Residential 40.3 41.58 42.34 4. Village Shin Residential 40.7 41.57 43.86

The day time equivalent noise level at various sampling stations ranged from 40.0 to 40.7

dB(A) and 41.5 to 41.6 dB(A) and 42.3 to 43.9 dB(A) in monsoon, winter and summer

seasons respectively. The noise levels were observed to be well within permissible limits

specified for residential area (Refer Table-7.17 ).

7.6 AMBIENT AIR QUALITY

The ambient air quality with respect to the study area around the proposed site forms the

baseline information. The study area represents rural environment. The sources of air

pollution in the region are vehicular traffic, dust arising from unpaved roads and domestic

fuel burning. The prime objective of the baseline air quality study was to establish the


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existing ambient air quality of the area. This section describes the identification of sampling

locations, methodology adopted for monitoring, and frequency of sampling.

Selection of Sampling Locations

The baseline status of the ambient air quality has been established through a scientifically

designed ambient air quality monitoring network and is based on the following

considerations:

• Meteorological conditions on synoptic scale; • Representatives of regional background air quality for obtaining baseline status • Representation of likely affected area.

Three Ambient Air Quality Monitoring (AAQM) locations were selected taking care of above-

mentioned points. The following stations have been monitored:

• Near dam site • Near power house site • Village Shin

The location of Ambient Air Quality Monitoring stations are shown in Figure-7.8 .

Frequency and Parameters for Sampling

Ambient air quality monitoring has been carried out with a frequency of two samples per

week for four consecutive weeks at various locations.The baseline data of ambient air

environment has been generated for the mentioned parameters as given below:


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• Respirable Particulate Matter (RPM) • Sulphur dioxide (SO2) • Nitrogen dioxide (NO2).

The findings of ambient air quality monitoring in various seasons are given in Table-7.19.

The ambient air quality standards are given in Table-7.20.

Table-7.19: Findings of ambient air quality monitoring in various seasons Parameter Average (µg/m 3) Maximum (µg/m 3) Minimum (µg/m 3) Particulate Matter less than 10 microns (PM10)

44.8 – 51.9 49 – 56 42 – 49

Sulphur dioxide (SO2)

6.4 – 7.2 7.0 – 7.6 BDL

Nitrogen dioxide (NO2)

8.7 – 11.8 10.4 – 13.2 7.6 – 8.9

Table-7.20: National Ambient Air quality Standards (NAAQS) S. No.

Pollutant Time Weighted Average

Concentration of Ambient Air Industrial, Residential Rural and other area

Ecologically Sensitive area (notified by

Central Government) 1 Sulphur Dioxide

(SO2) , µg/m3

Annual* 24 hours **

50

80

20

80 2 Nitrogen

Dioxide (NO2) , µg/m3

Annual* 24 hours **

40

80

30

80 3 Particulate

Matter (Size less than 10, µm) or PM10 , µg/m3

Annual* 24 hours **

60

100

60

100

Notes: • Annual arithmetic mean of minimum 104 measurements in a year at a particular site

taken twice a week 24 hourly at uniform intervals. • 24 hourly or 08 hourly or 01 hourly monitored values, as applicable, shall be

complied with 98% of the time in a year. 2% of the time, they may exceed the limits but not on two consecutive days of monitoring.

Observations on ambient RPM levels

The average RPM levels as observed at various stations in the study area ranged from 44.8

to 51.9 µg/m3. The highest RPM value was recorded as 56 µg/m3 at power house site. The

RPM values monitored during the field survey were well below the permissible limit of 100

µg/m3 for residential and rural areas (Refer Table-7.20 ).

Observation on ambient SO 2 levels

The highest average SO2 values of 7.2 µg/m3 was observed at dam site in winter season.

The highest value of 7.6 µg/m3 too was also observed at the same station in winter season.


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The SO2 level was Below Detectable Limit BDL) of 6 µg/m3 at some stations covered in

ambient air quality monitoring programme. The SO2 level observed at various sampling

stations was much lower than the permissible limit of 80 µg/m3 for residential and rural areas

are given in Table-7.20.

Observations on NO 2 levels

The highest average NO2 values of 11.8 µg/m3 was observed at power house site in winter

season. The highest value of 13.2 µg/m3 too was also observed at the same station in winter

season. The NO2 level observed at various sampling stations was much lower than the

permissible limit of 80 µg/m3 for residential and rural areas are given in Table-7.20.

7.7 LAND USE PATTERN

Landuse describes how a patch of land is used (e.g. for agriculture, settlement, forest),

whereas land cover describes the materials (such as vegetation, rocks or buildings) that are

present on the surface. Accurate land use and land cover identification is the key to most of

the planning processes.

The land use pattern of the study area has been studied through digital satellite imagery

data. Digital IRS-P6, LISS-III satellite imagery (Path: 095, Row: 048) dated 9th May,2007

was procured from National Remote Sensing Agency (NRSA), Hyderabad. The data was

processed through ERDAS software package available with WAPCOS.

Multi-variate statistics have been used for the analysis of multi-spectral data. As a first step,

clustering algorithms was established to a set of multi-variate class statistics against which

each pixel measurement vector in the scene was compared. Then a classification decision

rule, such as the probability of maximum likelihood that the pixel belongs to a particular class

amongst the statistics set was calculated and the pixel was assigned to the particular class.

The information classes most often considered include both cover type or community type

descriptors as well as limited structural categories, such as crown cover and size class: of

the trees.

Although two different approaches to the development of the multi-variate statistics are

used, unsupervised and supervised, their combination gives better results. In the

unsupervised classification, the radiance values of the image data set were submitted to

clustering algorithms that generate statistics until the stopping rule i.e. minimum number of

points per cluster was reached and the minimum distance between clusters and separability

measure was established. Another approach is to 'seed' spectral space with starting points

to establish candidate mean value for clusters, and then iterate the clustering procedure until

minimization criteria is achieved. In the supervised method, training sites with known

properties were used to extract spectral statistics from the image data by interactively


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identifying the sites in the imagery. Ground truthing was done for site identification. In the

unsupervised method, identification of the cluster was done after completing the

classification by comparing the spatial distribution of the mapped classes with ground

reference data.

The wide geographic distribution and the range of sites and climates occupied by forests

complicates the understanding of the interaction of forests with solar radiation. Many forests

grow in uneven mountainous terrain. The terrain relief produces large variations in how solar

radiation reaches the forests and produces land form shadows. Terrain relief also generates

large micro-climate variations in temperature, precipitation, and soil properties that produce

large differences in forest composition and activity over elatively small geographic areas.

Vegetation indices are an aid for obtaining accurate results. The DN values of different

bands can be combined mathematically to create output images that can be used

extensively in forest analysis to bring out small differences between vegetation classes.

These mathematical combinations are called indices and if chosen judiciously, they highlight

and enhance differences, which cannot be observed in the display of original color bands.

Indices also help in minimizing shadow effects in satellite multi-spectral images. Ground

truth studies were conducted in the area to validate various signals in the satellite images

and correlate them with different land use domains. The image obtained after the vegetation

index, enhancement becomes a single band data Le. The grey set. The grey set was

merged with the colored False Color Composite (FCC). This image was then classified using

the prominent signatures extracted based on the past experience. However, this is only a

preliminary classification which will be refined further. The classified image of the study area

is given as Figure-7.9 . The landuse pattern of the study area is given in Table-7.21 .

Table 7.21: Land use pattern of the study area of Sach Khas HE project based on satellite data

S.No Category Area(ha) Area(%)

1 River 15 0.03 2 Dense Vegetation 18443 38.79 3 Open Vegetation 12956 27.25 4 Agricultural Land 4903 10.31 5 Scrubs 404 0.85 6 Snow 6919 14.55 7 Degraded/Barren Land 3758 7.90 8 Settlements 152 0.32

Total 47550 100.00 Source: Satellite Data

The major landuse category in the study area of Sach Khas HE project is dense vegetation,

as it accounts for about 38.79% of the study area followed by open vegetation (27.25%).


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Snow covered area accounts about 14.55% of the study area. The area under Agricultural

Land is 10.31% of the study area. Barren land accounts for about 7.9% of the study area.

Settlements account for about 0.32% of the study area. The area under scrub and water

bodies is 0.85% and 0.03% of the study area.

42L & T Himachal Hydropower Limited

Figure-7.9: Classified Image of the Study Area

CHAPTER-8

BASELINE SETTING FOR

ECOLOGICAL ASPECTS


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CHAPTER-8

BASELINE SETTING FOR ECOLOGICAL ASPECTS

8.1 GENERAL

Before start of any Environmental Impact Assessment study, it is necessary to identify the

baseline levels of relevant environmental parameters which are likely to be affected as a result

of the construction and operation of the proposed project. A similar approach has been adopted

for conducting the CEIA study for the proposed Sach Khas hydroelectric Project. The baseline

setting for Ecologcal aspects have been covered in this Chapter.

8.2 FORESTS & FOREST TYPES

The Pangi valley is spread over an area of about 1176 sq miles. Out of which, 602 sq miles

falls under grass land, 93 sq miles under forest and 3 sq miles under cultivation (Minakshi

Chaudhary, 1998). The forest predominates with mixed broad leaves to conifer on the

downslopes. Among broad leaves birch and maples are common, however, oak is absent.

Among confers deodar is pre-dominant species followed by pine, spruces and firs. Forest

area of pangi valley valley consist of 8009 Ha RF, 4795 Ha PF, 97503 ha Unclassified forest

and the remaing under others as alpine scrubs, respectively.

The floristic accounts of the Indian cold deserts Lahaul & Spiti including Pangi Valley also

forms a part of Cold Desert of Himalayas, have been largely described under „Western

Himalayas by the early Phytogeographers (Hooker, 1906 and Chatterjee, 1939). Various

authors have described the vegetation of this region as Caragana-Lonicera-Artemisia

formation (Osmaston, 1922); Zone of Dry bushes (Nako, 1955); Alpine Steppe

(Schweinfurth, 1957); Dry alpine scrub (Champion and Seth, 1968) and Alpine stony deserts

(Puri et al., 1989). The vegetation in Cold Deserts, infact, varies from semi-desertic to

desertic, depending upon the prevailing bio-climate.

The Study area has no eco-sensitive area nearby to project vicinity any declared protected

or Reserved Forests under Forest Protection Act -1927, Wildlife Protection Act (1972) and

Biodiversity Conservation Act (2001) is present 10 km radius from project boundary. Mostly,

the unclassified forest including Alpine pasture has been reported on hill slopes above

3500m msl which is far away from project impacted zone located at deep in river bed of

about 2145 to 2220m, msl. No National park or’ Wildlife Sanctuary is reported within 10 km

from the proposed boundary as far as sensitivity is concern for special conditions of EIA

Notification 2006 & 2009.

Therefore, based on the primary survey as well as secondary data sources, the predominate

Forest Types include Broad Leaved and Coniferous Forest, Lower Western Himalayan

Temperate, Moist Alpine Scrubs and Dry Alpine Forests in the study area. However, the


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major forest types assessed during field survey according to the classification of Champion

and Seth (1968) are:

Type 16/C1 Dry alpine scrub Type 16/E1 Dwarf juniper scrub

Type 15/C3 Alpine Pastures Type 13/C5 West Himalayan Dry Juniper Forests Type 13/C1 Broad leaved and Coniferous Forests Type 12/C1 Dry Temperate Mixed Evergreen Forest Type 12/C2 Dry Coniferous Forest

Type 12/C1c: Moist Deodar Forests Type 12/C1d: Western Mixed Coniferous Forests Type 12/C1f: Low level Blue pine type Type 12/1s1: Alder Forests 8.3 REMOTE SENSING ASSESSMENT OF FLORA

Application of remote sensing in biodiversity assessment and characterization is limited in

the literature. Remote sensing technique has been used to demarcate the biotype of a

region so far. However, the dream of species characterization in biodiversity assessment

using remote sensing is yet to be achieved (Turner et al., 2003). The major problem with the

use of remote sensing in biodiversity characterization is the identification species, as we

could see only the crown in the air borne/space borne data. Even satellite data with 0.5 m

pixel resolution are not able to identify individual species (Biging et al., 1995). Datasets from

IRS 1C/1D LISS III for the distribution maps of Podophyllum heterophyllum, Artemisia

maritime, Thymus linearis and other important species such as Hippophae rhamnoides and

stratification of Ephedra gerardiana from the cold desrts of western Himalayas (Porwal et al.,

2003). The other study in genus level mapping of Pinus and Abies by White et al. (1995),

has achieved only 63% accuracy. However, they have just demarcated the species

occurrence not the biodiversity value of that species. Hence, the details such as the species

composition and stand density of forests could be obtained only through field floristic

sampling studies.

During present investigation Remont Sensing data has been used for authentication of

presence of major biotype in the area. The probable project site is well marked in the

Figure-8.1 . The secondary data from the species distribution map of zone IV of HP which

comprises of 3 distircts (Kinnaur, Lahul & Spiti and Chamba-Pangi valley) has been

completed by the state forest department. In Pangi valley (H.P.), to observe the land use

patterns, the state department has ans assess the livelihood pattern the area was mapped

through Remot Sensing Techniques. The pangi valley has spread on area of approximity

1,600 square kilometer. Therefore, major LSEs types of the region were mapped using IRS

1D LISS III satellite image (Path 094, Row 047) and the results revealed that 21.96% of

Pangi is occupied by forests ). Out of this, maximum area was occupied by mixed broad


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leaved forest (36.08%) followed by Cedrus deodara (26.94%), Betula utilis (18.07%), Pinus

wallichiana (11.26%), Corylus jacquemontii (7.30%) and Pinus gerardiana (0.35%) forests.

These species were also found present during the study period conducted in vicinity of Sach

Khas project.

The depicted floral cover is broadly described with dominant groups, however is not able to

give complete account. Therefore, this data has been used as secondary data base where

predominant groups are almost in line with the satellite imager data along with other

supportive communities.

The description of sampling sites w.r.t. Project appurtenances is given in Table-8.1. The

sampling location map is enclosed as Figure-8.2 .

Table-8.1: Description of Sampling Sites w.r.t. Project appurtenances Sampling sites

Location Distance from Dam site

Longitude E

Latitude N

Submergence area -Catchment U/S Dam Site Site1 (T1) Chenab river –

Catchment Area-Submergnece zone

Near Mujar chow confluence with chenab (5.0-10.0 km)

320 55’24” 076027’30”

Dam Site to Power House Area Site 2 (T2) Dam site (Plate 1) Left &

Right Banks Diversion Structure 0.0km

320 57’57” 076025’15”

Site 3 (T3) Power House Site ~ 300m d/s Dam site

Project Influence d Area D/S Dam Site Site 4 (T4) Mindhal and Sach Khas

village up to Shin village Cherry Bangla & Mindhal Bridge Site iimage (~3km)

330 00’05” 076026’02”

Site 5 (T5) Influenced Zone d/s towards Findru Village

Approx 6-7km d/s along Chenab river


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Figure -8.1 : Remote Sensing Map- Satellite Imagery of Pangi Valley with proposed Sach Khas Project vicinity (H.P.)


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U/S Veiw of Sach Khas HEP (Ref. By Mr. Shakher Damle)

D/S Veiw of Sach Khas HEP (Ref. By Mr. Shakher Damle)


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L&T 260 MW Sach Khas HEP Dam Axis Left Bank Drift

Bridge across Chenab River for Mindhal village d/s

Catchment-Submergence, Project site and Influence zone on Chandrabhaga river, Pangi Valley HP

8.4 METHODOLOGY

Floral Study

The present report on the plants of project area is based on field survey of the area. The

seasonal study has been conducted during pre-monsoon (summer), monsoon and winter

seasons. The whole area of the valley was divided into four altitudes i.e. from river bed 2200

to 3000 m, 3000-3500 m, 3500-4000 m, and 4000-4500 m for having an holistic view of

phyto-sociological aspects. The number of quadrats laid in the study area is given in Table-

8.2.

Table-8.2: Number of Quadrats laid in the Study Area Sampling Location

Trees (10x10) m 2

Shrubs (5x5) m 2

Herbs (1x1) m 2 Winter Pre

Monsoon Monsoon

Site I 14 20 15 24 18 Site II 15 20 15 19 22 Site III 15 20 15 17 17 Site IV 12 20 15 21 15 Site V 20 20 15 21 18

To understand community structure, quadrat sampling mode was followed. The vegetation

sampling was done at seven locations. Sampling was carried out by randomly placing

quadrats of 10m x 10m size for trees, 5m x 5m size for shrubs and 1m x 1m for herbs. The

size and number of quadrats needed were determined using the species area curve (Misra,

1968).

Species diversity and evenness index is calculated by using the Shannon-Wiener Diversity

Index formula and Evenness Index formula, respectively.

Shannon-Wiener Diversity Index (H) = - Σ pi ln (pi)


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Where, pi is the pr oportion of total number of species made up of the ith species.

Evenness index (E): H/ log S

Where, H is Shannon Wiener index of general diversity and S is number of species

A nested quadrates technique was used for sampling the vegetation. The size and number

of quadrates needed were determined using species area curve (Mishra, 1968) and the

runnings mean method (Kershaw, 1973). To study the phytosociological attributes quadrates

of 10 m × 10 m size for trees, 5 m x 5 m. size for shrubs and 1m x 1m size for herbs and

grasses were randomly laid out at each site at different elevations. Total 10 number of

quadrats were laid at study sites which are representation of from the left and right banks

river Chenab, where each 5 quadrats laid both banks to the uppermost possible slopes. The

terrain is tough nd steep up to the tree lines on Left bank from the Pir Panjal range whereas

right banks at higher elevation has comparately moderate slopes from the Zanskar range.

The enumeration of vegetation in each of the quadrat was done.

The vegetation data collected for phyto-sociological information was quantitatively analyzed

for density and frequency of each species according to the method developed by Curtis and

McIntosh (1950). The size and number of quadrats needed were determined using the

species area curve (Misra, 1968).

The tree species diversity for each stand in different forest types was determined using

Shannon Wiener information function (Shannon and Wiener, 1963) and Evenness Index

formula, respectively.

8.5 FINDINGS OF THE FIELD STUDIES

To understand the community in the proposed project area, the sampling was carried out at

five locations. The results indicate that Deodar (Cedrus deodara) is the dominant species

alongwith Kail (Pinus wallichiana), Fir and Spruce fringe at side slopes of high altitudes in

river course area in the project vicinity. The dominating deciduous trees are Corylus colurna,

Aesculus indica, Juglans regia, and Fraxinus sp. near the river banks. Higher slopes are

dominated by Birches and Mapples with fever patches of pinus gerdiana. These forests

perform protective function, by preventing snow slides and avalanches. The upper fringes

form by Juniperous and alpine scrubs. The undergrowth mainly comprises of Rumax sp,

Rosa sp, Berberis spp. Juniperus communis, J. recurva. The ground flora comprises of

mainly of Artemisia sp., and Polygonum sp.. The prominent feature in vast stretch of nutrition

grasses-alpine pasture during summers followed with patches of alpine scrub, principally

birch, Juniperus spp. The study area also has a variety of medicinal herbs and flowers, e.g.,

Dhup (Jurinea macrocephala), Patis (Aconitum heterophyllum), Karu (Picrorrhiza kurrooa),

Kala Jira (Bunium persicum) are commonly occurring and extracted for commercial


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proposes. The details of density and frequency of various trees and shrubs for the sampling

sites is given in Tables-8.3 and 8.4. The details of density and herbs species in summer,

monsoon and winter seasons is given in Tables-8.5 and 8.6 respectively.

Site I: Catchment Area –submergence zone

Catchment area of the project is characterized by Deodar Forest on both banks alongwith

Kail (Pinus wallichiana), Fir and Spruce fringe at high altitudes. The dominant tree species in

catchment area are Deodars and at higher elevations is Bitula utilis followed by maples and

above the fringes by Juniperous spp and Juglus regia spp. Downslopes patch also has

fewever ash and walnut trees. Shrub layer is dominated by Juniperus communis and

Lonicera sp. Shrubs are represented by sixteen species among them predominate at hill

slopes are Rosa sp., Berberis sp, Rumux sp. and Salix sp. The community thus formed is

represented by mainly deaodar, Junipers, Juglans, Prunus as top story followed by Barberis,

Rosa as shrubs as understory vegetation. The details of density and frequency of various

trees and shrubs is given in Tables-8.3 and 8.4. The alpine scrubs (3200-3500m), meadows

(>3500m) and pastures-grass land (>4500m) are present above the fringe zone of birch and

junifers starting from the downward of snow scree slopes. In general grassi meadows mixed

with chilgosa are observed. There was not much variation in occurrence of vegetation at

Power house, dam site and catchment area however the pattern changes d/s power house

area that might be related to decrease in elevation along the river bed slopes.

The herbs are rich in diversity and represented by several of grasses and flowering plants of

seasonal and periinnial nature from the dry scrub land, moistures wet land alpine area varies

along the hill slopes from deep river bed. The group is represented by about 47 species.

Herbs like compositeae and asteraceae are the common herbs in winter on both the bank of

Chenab river. There are 14 taxon of perennial herbs reported with some seasonal herbs

from the family Ranunculaseae, Apeaceae, and Scrofulariaceae etc. Monsoon seasons

shows variation in species composition, the common species recorded from downstream

area are Fabaecae (Trifolium pretense, Oxytropis humifusa), Asteraceae (Anthemis cotula

and Taraxacum officianale), taxon from the family Poaceae and polygoneaceae. The details

of density and frequency of herbs in monsoon, winter and summer seasons is given through

Tables-8.5 and 8.6 respectively.

Site II: Dam Site

The dominant tree species at this site is Deodar (Cedrus deodara) alongwith Kail (Pinus

wallichiana), Fir and Spruce fringe at high altitudes. The higher slopes are dominanted by

Birches and maples followed by junipers. These forests perform protective function, by

preventing snow slides and avalanches. The undergrowth comprises of Berberis vulgaris,

Lonicera sp., Rosa sp, Juniperus at upper fringe in the Birch patches. The ground flora


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comprises of mainly of Artemisia sp. and Polygonum sp. etc. The study area shows the

absent of river bank riparian vegetation due to steep slopes. The cover starts about 3-4

meter above the left banks however at much higher side on the right banks. The river flows

through a confined and narrow valley. The dense patch of deodar has been noticed. Other

vegetation is varied along the side slope to tope hills following a general pattern of

distribution i.e. grassi-pasture land (>4000m), alpine meadows (>3500m), alpine scrubs

(3200-3500m), broad leaves forest-Birches and maples (3000-3200m) and downward

Conifers. The area is reperesned by rich diversity of herbal group. These groups are almost

absent along the river bank at dam site except the members of apeaceae, however, at side

slopes are quite frequent. The density and frequency of taxon observed are given through

Tables-8.3 to 8.6 respectively.

Site III: Power House Site

The power house side is located 300m downstream of dam site where the river takes a bend

while flowing through almost same river morphology. Therefore, the same type of vegetation

is present in the power house site. The dominant species along river bank slopes is deodar

followed by Pinus wallichiana, Picea smithiana and Juniperus recurva. The shrub layer

formed is mainly represented by Rosa sp, Berberis sp, A Artemeissia sp, Aesculus sp, and

Salix sp. The dominating deciduous trees are present near to river banks Corylus colurna,

Juglans regia and Fraxinus sp. followed by Aesculus sp and Salix spp of shrubs. Among

herbs apeaceae are dominant group followed by the poaceae and polygoneacae. Details of

floral accounts are given through Tables-8.3 to 8.6 respectively.

Site IV: Downstream of Power house site near Mindhal Bridge

The river downstream of power house flows comparatively open valley and joined by three

side streams i.e. Chheni nalla, Mokha nala and downward of Mindhal bridge Saichu nalla.

The vegetation also reflecting the impact of comparatively open valley, though the dominant

species is the deodaor only however inbetween the deaodar and river banks many variety of

trees and shrubs has taken place. The trees followed by Pinus spp (Blue Pines), Picea sp,

Abies sp and near river bank growth of thangi trees i.e. corylus spp and shrubs of Asculus

sp, Salix spp and others as Rosa and Berberis spp. However the higher tree line is mainly

predominate by Birches which are located at far higher places. Further the birch fringe

followed by Juniperous and aboive the line alpine scrubs of Pinus geardiana are commonly

occurring. Near the Birch tree line towards alpine meadows Aconitum sp also occurring

commonly. The dominant deciduous trees are present close to river banks Corylus colurna,

Juglans regia, Fraxinus sp. and Aesculus indica. The details of density and frequency of

trees, shrubs and herbs for this sampling site located are given in Tables-8.3 to 8.6

respectively.


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Site V: Influenced Area d/s towards Findru village

After confluence of Saichi nall on right bank Pinus wallichiana, and Juniperus the

chandrabhaga river- Chenab river again enters to the narrow and confined valley however

the river bed level decrease from 2145 at power house site to 2120 d/s confluence. The

river banks are near and after confluence are having interference of dense thangi trees

followed by walnuts, ash, elm, hazelnut with willow growth and above by other conifers as

Abies sp, Blue pine, Spruce and Fir. At higher slopes Deodar dominate which are at its

fringe line have Birch and Mapples. Thus, the downwards along river Chenab showing

influences of other vegetation of lower elevation supporting the western mixed conifer forest

types, alder forest type and low blue pine forest type. The area downstream will not

anticipate any impact as the river flow will not be alter and bankful flow will be available as

usual.

The details of density and frequency of various trees, shrubs and seasonal variation among

herbs for the sampling site located towards Findru village 4-5 km downstream of Power

house Site is given through Tables-8.3 to 8.6 respectively.

Table-8.3 : Density and frequency of trees in the study area

Tree Species

Site 1 Site 2 Site 3 Site 4 Site 5 d

Nos./ha % R. Freq

d Nos./ha

% R. Freq

d Nos./ha

% R. Freq

d Nos./ha

% R. Freq

d Nos./ha

% R. Freq

Abies pindrow 0 0.0 0 0.0 0 0.0 10 1.6 40 3.7 Cedrus deodara 160 23.5 190 25.0 170 26.3 120 17.5 210 19.5 Pinus gerardiana 20 2.0 50 1.9 30 1.8 20 1.6 40 1.2 Pinus wallichiana 50 7.8 60 9.6 60 8.8 50 9.5 120 12.2 Picea smithiana 20 3.9 40 3.8 40 1.8 60 6.3 70 7.3 Alnus nitida 0 0.0 0 0.0 0 0.0 30 3.2 50 2.4 Betula utilis 80 13.7 90 15.4 100 15.8 40 6.3 80 7.3 Corylus colurna 40 5.9 20 1.9 40 1.8 20 3.2 70 3.7 Corylus cornuta 30 3.9 20 1.9 30 1.8 30 3.2 50 2.4 Corylus jacquemontii 50 7.8 50 7.7 60 7.0 90 9.5 100 8.5 Acer acuminatum 40 5.9 50 7.7 30 5.3 30 3.2 30 3.7 Juglans regia 90 2.0 50 3.8 60 10.5 40 1.6 60 1.2 Juniperus recurva 80 3.9 60 5.8 20 1.8 40 3.2 40 2.4 Juniperus communis 80 3.9 60 3.8 70 5.3 60 3.2 20 1.2 J.macropoda 20 2.0 30 1.9 20 1.8 0 0.0 0 0.0 Podophyllum hexandrum 0 0.0 0 0.0 0 0.0 30 3.2 20 1.2 Populus caspica 30 3.9 30 1.9 30 3.5 80 6.3 40 2.4 Ulmus wallichiana 0 0.0 0 0.0 0 0.0 40 3.2 90 4.9 Prunus padus 0 0.0 20 1.9 20 1.8 40 3.2 50 4.9 Prunus cornuta 40 5.9 50 3.8 30 1.8 60 4.8 60 6.1 Fraxinus floribunda 20 3.9 20 1.9 20 1.8 30 4.8 20 2.4 Robinia pseudoacacia 0 0.0 0 0.0 30 1.8 10 1.6 10 1.2 Total Trees 850 100 890 100 860 100 930 100.0 1270 100.0

Table-8.4 : Density (no./ha) of Shrubs in the Study Area

Shrubs


Nos./ha % R. Freq

d Nos./ha

% R. Freq

d Nos./ha

% R. Freq

d Nos./ha

% R. Freq

d Nos./ha

% R. Freq

Berberis jaeschkeana 560 13.6 720 15.1 520 17.0 400 12.9 320 7.7

B.aristata 120 3.0 320 5.7 200 9.4 120 4.8 360 13.5


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Shrubs


Nos./ha % R. Freq

d Nos./ha

% R. Freq

d Nos./ha

% R. Freq

d Nos./ha

% R. Freq

d Nos./ha

% R. Freq

Salix eleganse 160 4.5 120 3.8 200 5.7 240 8.1 120 3.8

S. fragilis 80 3.0 80 1.9 160 3.8 320 8.1 240 5.8

Aesculus indica 280 6.1 160 5.7 120 5.7 160 4.8 160 9.6

Lonicera spinosa 400 12.1 400 15.1 360 11.3 360 9.7 320 3.8

Rosa webbiana 520 15.2 480 15.1 400 13.2 480 11.3 400 13.5

Hipophae rhamnoids 120 3.0 120 1.9 80 1.9 0 0.0 0 0.0

Hipophae tibetiana 80 1.5 80 3.8 40 1.9 80 1.6 0 0.0

Artemesia maritima 120 1.5 0 0.0 0 0.0 160 3.2 0 0.0

Artemisia nilagirica 360 10.6 320 9.4 200 5.7 200 6.5 360 11.5

Artemisia brevifolia 120 3.0 0 0.0 160 5.7 120 1.6 0 0.0

Rumex hastatus 440 10.6 240 9.4 400 9.4 360 9.7 400 13.5

Skimmia laureola 160 4.5 200 5.7 0 0.0 80 3.2 0 0.0

Medicago falcata 80 3.0 120 1.9 120 3.8 120 3.2 200 3.8

Ephedra gerardiana 120 4.5 160 3.8 200 3.8 280 8.1 240 11.5

E. intermediata 0 0.0 80 1.9 80 1.9 80 3.2 120 1.9

Total Shrubs 3720 100 3600 100 3240 100.0 3560 100.0 3240 100 Table-8.5 (A) : Density (no./ha) of herbs in the Study Area Scientific Name Site 1 Site 2 Site 3

S M W S M W S M W

Artemisia dracunculus-- prnl 0.12 0.10 0.20 0.03 0.05 0.20 0.03 0.13 0.33

Bromus inermis 0.25 1.05 0.15 0.67 0.85 0.60 0.27 0.67 0.40

Bunium persicum 0.08 0.35 0.58 0.35 0.07 0.42

Bupleurum falcatum 0.50 0.05 0.17 0.35 0.08 0.08

Chaerophyllum reflexum 0.17 0.14 0.20 0.05 0.07

Anthemis cotula 0.14 0.55 0.20 0.17

Saussurea costus 0.05 0.08 0.32 0.70 0.02 0.40

Taraxacum officianale 0.25 0.65 0.21 0.17 0.10 0.20 0.55 0.20 0.17

Cynoglossum sp. 0.75 0.05 0.60 0.42 0.10 0.30 0.02 0.08 0.33

Eritrichium canum 0.15 0.52 0.08 0.15 0.28 0.10

Sisymbrium orientale 0.35 0.14 0.08 0.30 0.50 0.05

Cirsium wallichii 0.58 1.20 0.92 1.05 0.03 0.35

Dianthus orientalis 0.58 0.10 0.08 0.40 0.12 0.17

Aconitum heterophyllum-- prnl 0.67 0.10 0.60 0.92 0.05 0.30 0.47 0.27 0.23

A.deinorrhizum 0.08 0.90 0.30 0.50 0.15 0.10 0.05 0.22 0.23

A.violaceum 0.08 0.14 0.10 0.23 0.20 0.20 0.08 0.38 0.43

Impatiens sulcata 0.21 0.38 0.20 0.42 0.05 0.40 0.22 0.17 0.23

Draba spp (D.Himachalensis)--prnl 0.32 0.10 0.40 0.17 0.20 0.10 0.23 0.15 0.13

Scabiosa speciosa 0.03 0.10 0.10 0.42 0.20 0.10 0.20 0.13 0.40

Oxytropis humifusa 0.55 0.38 0.30 0.32 0.60 0.70 0.17 0.67 0.43

Trofolium pratense 0.72 0.40 0.25 0.30 0.42 0.12

Poa alpine (meadow grass) 0.95 0.69 0.40 0.67 0.60 0.20 0.27 0.38 0.30

Geranium wallichinum --Prnl 0.18 0.52 0.50 0.30 0.40 0.50 0.07 0.17 0.08

Nepeta spicata 0.40 0.19 0.58 0.25 0.08 0.17

Thymus linearis 0.20 0.24 0.25 0.30 0.07 0.08

Jurinea dolomiaea --prnl 0.21 0.05 0.10 0.33 0.50 0.60 0.08 0.20 0.37

Cichorium intybus --prnl 0.22 0.49 0.20 0.25 0.50 0.20 0.02 0.08 0.20


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Scientific Name Site 1 Site 2 Site 3 S M W S M W S M W

Polygonum macrophyllum --prnl 0.18 0.33 0.20 0.87 0.10 0.50 0.05 0.10 0.38

Polygonum spp 0.23 1.03 0.20 0.38 0.20 0.45 0.62 0.48 1.22

Polygonum affine --prnl 0.58 1.20 0.24 0.17 0.40 0.36 0.65 0.47 0.35

Arthraxon lancifolius 0.95 0.21 0.75 0.25 0.27 0.43

Stipa roylei 0.18 0.14 0.20 0.08 0.16 0.36 0.12 0.22 0.32

Lolium perenne 0.65 0.33 0.68 0.19 0.07 0.38

Kraschennini koviaceratoides 0.05 0.14 0.10 0.20 0.05 0.17

Viola spp 0.10 0.19 0.10 0.30 0.15 0.07 0.08 0.15 0.40

Angelica glauca 0.20 0.19 0.11 0.40 0.15 0.08 0.22 0.35 0.10

Valeriana jatamansi 0.40 0.05 0.02 0.40 0.70 0.07 0.23 0.18 0.47

Ferula asafoetida-- prnl 0.04 0.05 0.01 0.05 0.07 0.04 0.02 0.03 0.02

F. jaeschkeana --prnl 0.01 0.01 0.02 0.03 0.03 0.02 0.07 0.08 0.02

Arnebia benthami 0.05 0.40 0.05 0.15 0.47

A.euchroma 0.05 0.40 0.05 0.15 0.20

Pedicularis pectinata 0.22 0.05 0.50 0.09 0.10 0.18 0.45 0.15

Picrorhiza kurruoa-- prnl 0.05 0.05 0.04 0.04 0.06 0.05 0.12 0.17 0.25

Gentiana kurroo --prnl 0.01 0.03 0.02 0.05 0.05 0.04 0.17 0.57 0.17

Crocus sativus --- prnl 0.09 0.05 0.02 0.03 0.04 0.02 0.13 0.13 0.13

Humulus lupulus ---prnl 0.08 0.05 0.03 0.07 0.05 0.04 0.32 0.38 0.38

Primula minutesiita 0.12 0.76 0.08 0.05 0.15 0.32

Saxifraga sibirica 0.28 0.03 0.05 Note: prnl: Parrenial nature Table-8.5 (B) : Density (no./ha) of herbs in the Study Area

Scientific Name Site 4 Site 5

S M W S M W Artemisia dracunculus --prnl 0.23 0.12 0.07 0.07 0.25 0.06 Bromus inermis 0.40 0.95 0.60 0.31 1.10 0.29 Bunium persicum 0.10 0.20

0.10 0.30

Bupleurum falcatum 0.13 0.50 0.60 0.05 Chaerophyllum reflexum

0.07 0.75 Anthemis cotula 0.44 0.56 0.30 0.20 Saussurea costus 0.03 0.13 0.10 0.10 Taraxacum officianale 0.63 0.40 0.03 0.11 0.05 0.03 Cynoglossum sp. 0.50 0.20 0.00 0.32 0.34 0.30 Eritrichium canum 0.27 0.20 0.10 0.11 Sisymbrium orientale 0.07 0.15 0.06 0.13 Cirsium wallichii 0.07 0.08 ------- 0.15 0.40 Dianthus orientalis 0.07 0.12 0.31 0.15 Aconitum heterophyllum -- prnl 0.52 0.14 0.23 0.19 0.22 0.19 A.deinorrhizum 0.10 0.45 0.21 0.07 0.15 0.10 A.violaceum 0.47 0.20 0.36 0.60 0.30 0.30 Impatiens sulcata 0.47 1.10 0.01 0.67 0.05 0.10 Draba spp (D.Himachalensis) --prnl 0.23 1.50 0.04 0.33 3.30 0.20 Scabiosa speciosa 0.09 0.10 0.06 0.07 0.75 0.90 Oxytropis humifusa 0.71 1.02 0.28 0.23 0.43 0.10 Trofolium pratense

0.67 0.35 0.46 0.40 Poa alpine (meadow grass) 0.45 0.90 0.30 0.35 0.12 0.60 Geranium wallichinum -- prnl 0.18 0.21 0.19 0.25 0.20 0.90 Nepeta spicata 0.18 0.22 0.20 0.17 Thymus linearis 0.31 0.35

0.20 0.25

Jurinea dolomiaea-- prnl 0.20 0.60 0.05 Cichorium intybus -- prnl 0.18 0.20 0.03 0.32 0.35 0.31 Polygonum macrophyllum --prnl 0.58 0.82 0.06 0.27 0.32 0.20 Polygonum spp 0.85 0.20 0.14 0.47 0.20 0.10 Polygonum affine -- prnl 1.02 0.95 0.11 0.60 0.15 0.10 Arthraxon lancifolius

0.20 0.23 0.15 0.27


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Scientific Name Site 4 Site 5

S M W S M W Stipa roylei 0.42 0.10 0.01 0.33 0.65 0.60 Lolium perenne 0.18 0.20

0.45 0.15

Kraschennini koviaceratoides 0.13 0.40 1.25 0.15 Viola spp 0.12 0.20 0.05 0.05 0.15 0.30 Angelica glauca 0.25 0.10 0.03 0.75 0.30 0.50 Valeriana jatamansi 0.35 0.20 0.01 0.10 0.05 0.90 Ferula asafetida -- prnl 0.03 0.20 0.07 0.05 0.10 0.02 F. jaeschkeana -- prnl 0.02 0.40 0.02 0.01 0.10 0.01 Arnebia benthami

1.20 0.05 A.euchroma

0.30 0.10 Pedicularis pectinata 0.43 0.20 0.30 0.40 Picrorhiza kurruoa --prnl 0.32 0.60 0.00 0.65 1.10 0.10 Gentiana kurroo -- Prnl 0.30 0.10 0.02 0.30 1.55 0.30 Crocus sativus -- prnl 0.23 2.10 0.07 0.45 1.80 0.30 Humulus lupulus -- prnl 0.20 0.20 0.00 0.23 0.15 0.50 Primula minutessita 0.25 0.40 0.10 0.25 Saxifraga sibirica 0.30 0.28

Note: prnl: Parrenial nature Vegetational Profile & Status

A total 84 species of flowering plants are observed in the study area. Out of which, 22

species are from trees, 16 from shrubs and 46 from herbs. However, no species from

twiners and climbers are present in the area that may be due to dry semi arid to arid climatic

conditions (Table-8.6) . Similarly none of the species among pteridophytes and bryophytes

has been found in the area during study period along the slopes of river Chenab that may be

due to dry climatic conditions. Though, the presence of bryophytes in the wet moist alpine

meados has shown presence of bryophyte that may be the marchantia or seleginella group

due to its survival in the wet soil surface at an elevation above 4000 m. However, 11 species

of Lichens and Fungi are reported from the area mainly mashrooms and authenticated with

the secondary data. There are 11 plant species are belong to the Gymnosperm group

whereas the remaining trees, shrubs and herbs are belongs to Angiosperms group.

Table-8.6: Vegetation observed in the study area S. No

Scientific Name Local Name Family Habit

1. Abies pindrow Fir Pinaceae Tree 2. Cedrus deodara Deodar Pinaceae Tree 3. Pinus gerardiana Chilgoza pine Pinaceae Tree 4. Pinus wallichiana Kail Pinaceae Tree 5. Picea smithiana Spruce Pinaceae Tree 6. Alnus nitida Alder Betulaceae Tree 7. Betula utilis Bhojpatra Burj Betulaceae Tree 8. Corylus colurna Thangi, Pinakooni Betulaceae Tree 9. Corylus cornuta hazelnut Betulaceae Tree 10. Corylus jacquemontii Virin Betulaceae Tree 11. Acer acuminatum Mapple, Snakebark Aceraceae Tree 12. Juglans regia Akhrut- walnut Juglandaceae Tree 13. Juniperus recurva - Cupressaceae Tree 14. Juniperus communis Bithal Cupressaceae Tree 15. J.macropoda Dhupi /shurgh Cupressaceae Tree


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S. No


16. Podophyllum hexandrum Bankakri Berberidaceae Tree 17. Populus caspica Popular Salicaceae Tree 18. Ulmus wallichiana Elm tree Ulmaceae Tree 19. Prunus padus Taranizum,Birdcherry Rosaceae Tree 20. Prunus cornuta Taranizum,Birdcherry Rosaceae Tree 21. Fraxinus floribunda Himalayan ash Oleaceae Tree 22. Salix eleganse Bashal Salicaceae Shrub 23. S. fragilis & alba Willow Salicaceae Shrub 24. Aesculus indica Indian Horse Chestnut Sapindaceae Shrub 25. Berberis jaeschkeana -------- Berberidaceae Shrub 26. Berberis aristata -------- Berberidaceae Shrub 27. Lonicera spinosa -Honeysuckel Caprifoliaceae Shrub 28. Rosa webbiana Chua, Susli Rosaceae Shrub 29. Hipophae rhamnoids Sea Buckthorn Elaeagnaceae shrub 30. Hipophae tibetiana Sea Buckthorn Elaeagnaceae shrub 31. Artemesia maritima aromatic Asteraceae Shrub 32. Artemisia nilagirica aromatic Asteraceae Shrub 33. Artemisia brevifolia Nureha Asteraceae Shrub 34. Rumex hastatus Churki buti, dry rocks Polygonaceae Shrub 35. Skimmia laureola Pattidhup-Ornamtnl Rutaceae Shrub 36. Medicago falcata Yellow lucerne Fabaecae Shrub 37. Ephedra gerardiana Somalata Ephedraceae Shrub 38. E. intermediata Somalata Ephedraceae Shrub 39. Primula minutessita ----- Primulaceae Herb 40. Bunium persicum Kala Zira, Apiaceae Herb 41. Bupleurum falcatum Sickle leafs Apiaecae Herb 42. Chaerophyllum reflexum Kashmir Chervil Apiaceae Herb 43. Artemisia dracunculus (Prnl) Tarragon Asteraceae Herb 44. Anthemis cotula Chigar weed Asteraceae Herb 45. Saussurea costus kuth Asteraceae Herb 46. Taraxacum officianale ----- Asteraceae Herb 47. Cynoglossum sp. Gypsy flower Boraginaecae Herb 48. Sisymbrium orientale Hedgemustard Brrassicaceae Herb 49. Cirsium wallichii Kateli Compositae Herb 50. Dianthus orientalis ----- Caryophyllaeca

e Herb

51. Aconitum heterophyllum Patish or Atish Ranunculaceae Herb 52. A.deinorrhizum Patish Ranunculaceae Herb 53. A.violaceum Meethapatish Ranunculaceae Herb 54. Impatiens sulcata ----- Balsaminaceae Herb 55. Draba spp (D.himachalensis) Yellow drabas Brassicaceae Herb 56. Scabiosa speciosa ------ Dipsaeaecae Herb 57. Oxytropis humifusa ------ Fabaecae Herb 58. Trofolium pratense Wild Red Clover Fabaecae Herb 59. Poa alpine (meadow grass) Alpine bluegrass Gentianaceae Herb 60. Geranium wallichinum Geraniaceae Herb 61. Nepeta spicata Lamiaecae Herb 62. Thymus linearis Wild ajwain Lamiaceae Herb 63. Jurinea dolomiaea jhari dhoop 3200-

3800m Compositae Herb


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S. No


64. Cichorium intybus chicory Asteraceae Herb 65. Polygonum macrophyllum - Polygonacae Herb 66. Polygonum verticilatum Polygonacae Herb 67. Polygonum aviculare Lowgrass,buckwheat Polygonacae Herb 68. Polygonum affine PRNL Border jawel- Polygonacae Herb 69. Arthraxon lancifolius Kangulya (Hindi). Poaceae Grass 70. Stipa roylei grass Poaceae Herb 71. Lolium perenne grass Poaceae Herb 72. Kraschennini koviaceratoides Chenopodiacea

e Herb

73. Viola spp - Violaceae Herb 74. Angelica glauca Taskarh-Canda Apiaceae Herb 75. Valeriana jatamansi Jatamansi Valerianaceae Herb 76. Ferula asafetida PRNL Hing Apiaceae Herb 77. F. jaeschkeana PRNL Wild hing Apiaceae Herb 78. Arnebia benthami Rattan jot Boraginaceae Herb 79. A.euchroma Rattanjot Boraginaceae Herb 80. Pedicularis pectinata Marsh lousewort Scrophulariaec

ae Herb

81. Picrorhiza kurruoa Karoo -- Scrofulariaceae Herb 82. Gentiana kurroo Karu Scrofulariaceae Herb 83. Crocus sativus Kesarj,alpine tundra Iridaceae Herb 84. Humulus lupuluL hops Cannabaceae Herb

8.6 LICHENS & FUNGI

Numerous patches of ashy blue and yellow coloured Crustose lichens were observed over

the big boulders at the dam site attached. A good growth of music, liverworts, and hornworts

were also recorded in places of rocky and boulders along the river. No macrophytes

attached to the rocks, boulders, stones, etc. are found in the area as being dry and cold

climatic conditions.

VAM fungi as viewed from literature-secondary data are present in association with some

endemic plants. These are well know for their close association with plants and plays very

important role in the plant growth and soil conservation. Among them are Pinus gerardiana

and Sea buck thorn Hippophae rhamnoides, a multipurpose shrub and native of higher

Himalayas which are also known as cold desert gold due to its high potential as a bio

resource for wetland reclamation, soil erosion, food, medicinal and cosmetic industries.

Pinus gerardian has association with mycorrhizal fungi- Basidiomycetous mycelium and B.

hyphae. The literature for scientific study on microbial associates with Sea buck thoran plant

revealed the presence of 26 fungal species in its rhizosphere. Among them, three fungal

entophytes (e.g. Aspergillus niger, Morteirella minutessima and sterile mycelium) and four

species of VAM spores (i.e. Globus albidum, Globus fasciculatum, Globus macrocarpum,

and Gigaspora margariata) has also been isolated from different plant parts (Root, stem ,

leaves and barks) and soil samples respectively [ (Shiv Kumar & Anand Kumar, 2007,


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Ref.Enclosed : The low plant species richness at lower slopes could also be attributed to soil

erosion, for pastoralists uproot plants such as Krascheninnikovia ceratoides and Caragana

versicolor from these slopes (Rawat and Adhikari 2005b). Some other plants e.g. Caragana,

though it was not observed in the study area however it is reported in the pir panjal and

zanskar range- a leguminous plant is known to enhance soil fertility as its root-nodules have

nitrogen-fixing bacteria (Lu et al. 2009), and it also helps in retaining moisture in the soil

Cladonia carneola (Fr.) Entoloma (Fr.) P. Kumm. Lecidea Ach.

Lichen P. Micheli Lichen P. Micheli Lichen P. Micheli

Lycoperdon Pers. Pluteus Fr. Stropharia (Fr.) Quél.

Rhizoplaca taxon Rhizoplaca taxon Scutellinia Lambotte

**Reference : Mushroom Observer Species List Lichens & fungi of Pangi, Valley, Himachal, India (219).htm. Pangi Valley, Himachal Pradesh, India: Alok Mahendroo (alok): 2011-07-28

Rhizocarpon geographicum

Lichen & Fungi Species & their Images**


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8.7 ECONOMICALLY IMPORTANT PLANT SPEICES

Vegetation in the study area is dominated by temperate conifers like Juniperus sp., Pinus

sp., Cedrus sp. including broadleaved species of Betula sp., Populus sp. and shrubs like

Hippophae sp. and Rosa sp. Most of the vegetation present in the area are having limited

distribution due to climatic conditions prevailing in the area however locally they are present

in abundance. Numerous herbs species are having economic and medicinal importance and

are being used in ayrveda and yunani medicince by local vaids and even supplied out side

places. The trees are also having importance varies from timber, fodder, fuel wood to

medicinal values.

On the basis of ethanobotanical importance the floral groups are further described under

different heads as follows.

Medicinal Plants

The list of medicinal plants were recorded from the study area are given in Table-8.7.

Table-8.7 : Medicinal Plants in the Study Area Family & scientific name

Local name

URSV (Mode of preparation and ailments cured)

IMP( Kirtikar and Basu, 1976), DIFME (Jain 1991), ECDT (Sood etal 2001) & Medicincal plants of HP by N.K.Chohaun and Bharmaur Area by Dutt etal 2011

ASTERACEAE or Compositae Artemisia brevifolia

Nureha

Juice of fresh roots used

Stomachic disorders, aphrodisiac, . Laxative, anthelminitic, alexiteric, cures scorpion sting, toothache, gripping, ophthalmia, inflammation (Yunani) & acts as blood purifier

ASTERACEAE Artemisia dracunculus

Tarragon Dried leaves and seeds are crushed to make paste.

Purgative, controls ear pain, smoke cures burns, and toothaches.

ELAEAGNACEAE Hippophae rhamnoides

Cherma

Fruits as berries used for various purposes.

Cures eruptions and lung complaints and tuberculosis. As aphrodisiac, pickle and herbal tea. Also cures jaundice and helps in blood purification*

Hippophae tibetana

Chhr-Tuan

Dried berries processed for various used

Stomach disorders, cough, congestion, jaundice and as blood purifier*, commonly as Herbal Tea

ASTERACEAE Saussurea ccostus

kuth

Fresh juice of leaves and flowers used

Antidote against food poisoning. Dried powder as cooling agent*

EPHEDERACEAE Ephedra gerardiana Wall.ex Stapf. Ephedra intermedia

Somalata

Extract of young and fresh shoots is used in joint pains

Diaphoretic, antipyretic, astringent, stimulant, jaundice, cures rheumatism, syphilis, respiratory troubles, asthmatic paroxysms, heart failure, cardiac problems ans acts as blood purifier


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Family & scientific name

Local name

URSV (Mode of preparation and ailments cured)

IMP( Kirtikar and Basu, 1976), DIFME (Jain 1991), ECDT (Sood etal 2001) & Medicincal plants of HP by N.K.Chohaun and Bharmaur Area by Dutt etal 2011

FABACEAE Oxytropis spp

Chhushin Darm

Whole plant is boiled in water and the water is applied

POLYGONACEAE Rumex spp

Shomang

Extract & Juice of fresh leaves

To cure burns and other skin problems

Polygonum spp Plant powder used

Also considered as cooling agent and taken orally with water to cure jaundice* Stomach disorders

ROSACEAE Rosa webbiana

T-siya, Seva

Flower and fruit juice useful

Cures hepatitis, jaundice & stomach pain & juice as tonic to vigour vitality

Apiaceae Bunium persicum

Kala zira Seeds are useful Stomach Disorder and add flavours to foods.

Apiaceae Ferula asafoetida F.jaeschkeana

Hing

Gum resins In remedy of whooping cough, pneumonia, bronchitis in children and asthma

Boraginaceae Arnebia benthami

Rattan jot Rhizomes Anti HIV activity

Ranunculaceae Aconitum spp

Pettish meetha-patish

Grounded roots to relieve stomach pain.

Compositae Jurinea dolomiaea

Gugal dhoop Jhari dhoop As dhuni

Fabaecae Trifolium pratense

Red flower Asthma

Gentianaceae Gentiana kurroo

Kaud Leaves to relieve fever.

Scrophulariaceae Picrorhiza kurroa

Kaud Leaves Antipyretic. As insecticides in wheat fields

Violaceae Species of Viola

Banakshan Flowers Cough & Cold treatment

Asteraceae Saussurea costus

Kuth Roots, leaves, flowes

To relieve from Arthrites, dhuni for bed evil spirits, Relief in pregnancy etc.

Economically Important Plants

In study area the local people are depends on the forest for their lively hood such as fruits,

timber, fuel wood, dyes and fodder. The list of plants used for the various purposes are

given in Table-8.8.

Table-8.8: Other Economically Important Plants in the Study Area Family Scientific Name Local

Name Use

Berberidaceae Berberis jaeschkeana Dye Betulaceae Betula utilis Bhiy Timber, Furniture Caprifoliaceae Lonicear sp. Fuel Cupressaceae Juniperus communis Fuel


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Family Scientific Name Local Name

Use

Ephedraceae Ephedra gerardiana Toothbrush Fabaceae Trifolium pretens Fodder and food Leguminaceae Robinia pseudo-acacia Timber Pinaceae Cedrus deodara Diyar Kleu Timber Pinaceae Pinus wallichiana Kail Timber, Furniture Rosaceae Prunus armeniaca Jammu Cultivated for Fruits Salicaceae Salix denticulata Timber, Fuel, Fodder Salicaceae Salix alba Timber, Fuel, Fodder Salicaceae Salix fragilis Timber, Fuel, Fodder Salicaceae Populus caspica Safeda Timber, Fodder,

Furniture, Fuel Agriculture practices including Horticulure

The habitation area also following agricultural practice. As per the data available, about 3 sq

miles of Pangi Valley area has agricultural practices. Some of agricultural field are also present

in Shin, Mindhal, Sach khas and Findue village in the locality. The major crops grown are

categorized in to vegetables, grasses, pulses, and fruits. The details of vegetation under

cultivation practices are given through Tables 8.9 to 8.11.

Table-8.9: Agriculture crops /grass grown in the Area Crop species English name Local name Allium cepa Onion Pyaz Brassica juncea Indian Mustard Sarson Cannabis sativa Hemp Bhang Chenopodium album Goose foot Bathu Fagopyrum esculentum Buckwheat Oggal-Bharesh Fagopyrum tataricum Buckwheat Papher-Bharesh Lens esculenta Lentils masoor Phaseolus vulgaris Kidney bean Rajmah Pisum sativum Pea Dal matar Setaria italica Foxtail millet Kagni, kauni Solanum tuberosum potato aloo Triticum aestivum wheat gehun Zea mays Maize makki

Table-8.10: Vegetables grown in the area Botanical Name Common Name Common Name Brassica oleracea var. capitata Cabbage Band Gobhi B. oleracea var. botrytis Cauliflower Phulgobhi B. campestris var. rapa Turnip Shaljam Raphanus sativus Radish Muli Beta vulgaris var. bengalensis Spinach Palak Spinacia oleracea Spinach Vilayati Palak Chenopodium album Bathua Pisum sativum Pea Matar Phaseolus vulgaris French bean Fransebean Solanum tuberosum Potato Alu Lycopersicon esculentum Tomato Tamatar Capsicum annuum Green chilli Shimla mirch


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Botanical Name Common Name Common Name C. frutescens Chilli Lal mirch Daucus carota Carrot Gajar Solanum melongena var. esculentum Aubergine Baingan

Table-8. 11 : Fruit Plants grown in the area or naturally occurring in the area Malus pumila Apple Prunus armeniaca Apricot P. avium Cherry P. amygdalus Almonds Juglans regia Walnut Corylus colurna Hazelnut (wild) Castanea vulgaris Chestnut (wild and cultivated) Pinus gerardiana Chilgoza, Neoza (wild)

8.8 RET SPEICES

During the field survey one rare species (Eremurus himalaicus, Family: Liliaceae) is recorded

from the study area (Red Data Book Plants of India (Nayar & Sastry 1987-88). Eremurus

himalaicus is endemic to Western Himalaya. The plant is observed in the study area in

monsoon season.

8.9 FAUNA

The fauna of the study area consists mostly of species with zoo-geographic affinities of

palaearctic, Indo-Malayan and indigenous variably. However, to gain an insight in the

following respects for species of carnivore, ungulates, non-human primates, mammals,

birds/butterflies, reptiles and other fauna, the survey was conducted in the study area up to

10km radius from the project appurtenances in catchment-submergence zone, dam site,

power house site and d/s power house site upto 5km river reach length.

Ground surveys was carried out by trekking the impact zone for identification of faunal

species inhabiting the area along the riverbanks, adjoining forest on the slopes, nullahs, hill

top and agricultural fields. Apart from direct sightings and primary data generated through

transects and trails, we have also collected secondary data from literatures published, forest

department and other sources like citing of animals by the locals in the study area. The

sighting of wild animals and other faunal groups were carried out during study period though

being tough terrain and hill peaks remain covered in snow most of the period, the possible

accounts are taxed in this section. The general methodology followed is described below as:

• For sampling butterflies the standard ‘Pollard Walk’ methodology was used by recording

all the species that were encountered while trekking along the foot trails between these

two sites, daily. Photographs of specimens of species were taken in the field for

identification purpose. Sampling was done for 1 hour in a stretch on each transect(n=4).


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• For sampling birds ‘point sampling’ along the fixed transects (foot trails) was carried out

to record all the species of birds observed with the help of binoculars; field guides and

photography for 1 hour on each transect(n=4).

• For sampling mammals, ‘direct count on open width (20 m) transect’ was used on the

same transects (n=4) for 1 hour in each transect. Besides, information on recent

sightings / records of mammals by the villagers and locals was also collected form

these areas.

• ‘Reptiles’ mainly lizards were sampled by ‘direct count on open width transects’ (n = 4)

for 1 hour in each transect.

8.9.1 Mammals

The study area reported occurrence of a total of 19 species of wild mammal mosly

aclimatised of dry temperate climates as per the secondary information collected. These 19

species belong to 17 Genra, 11 families and 5 Order of mammals as confirmed from Pangi

Valley Area (ZSI 2011). Most of the animals are present in the Sechu Tuan Nalla Wildlife

Sanctuary which is located beyond 10km of the study area. This is a high altitude (2550 m -

6072m asl) wildlife sanctuary which is spread over an area of 10,295 ha. Therefore, the

presence in the Zanskar might be viewd from the presence of pasture land zone. These

species are widely distributed in the trans -himalayan zone.

The direct sighting of most of these species in the demarcated study area up to 10km radius

has not found and the presence is only supported from secondary data. The other factor of

not able to direct sighting may be the area is having habitation of few villages and rugged

terrain of Chenab deep cut valley. However, during present assessment in the study area

the possible presence of 18 species are also made out with the information supplied by the

locals and available literatures which belongs to 18 genera and 9 families. About 8 species

are carnivorous in nature and belong to the family Ursidae, Canidae, Mustelidae and

Felidae. These species are found in the forest area and towards snow covered hill peaks,

however, fewever times species of ursidae and canidae also cited near to agricutral field at

the fringes of forests in human habitation for searching the food as per the information

provided by the locals. Some of the common mammals found in the area are Himalayan

brown bear (Ursus arctos), Himalayan black bear (Selenarctos thibetanus), Fox (Vulpes

montana), Goral (Naemorhedus goral), Ibex (Capra sibirica) and Yellow throated marten

(Martes flavigula). Other mammals which are generally remain at higher altitude peaks and

alpine pature land are Musk Deer, Snow Leopards, Jungle Cat, Goral, Bharal--Blue Sheep,

Common Langur, Markhor, Himalayan Mouse-Hare, Serow, Himalayan Tahr, Marmot etc.

The list of mammal species reported in the Study Area and their conservation status is given

in Table-8.12.


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As per survey conducted and information retrieved from the locals, presence of Tahr, Gharal

and deers on pasture and alpine meadow slopes below snow scree mountain peaks

(>4000m asl) on left bank Pir Panjal range and right bank Zanskar range, which are located

far away places from the deep river bed project side (2145m, asl) and will not anticipate any

impacts. The maximum submergence level will reaches up to 2220m, asl.

Table-8.12: The mammalian species reported from the Study Area with their status S. No.

Family / Species common name

Scientific name IUCN 2013 WPA (1972) Remarks#

A Mustelidae 1 Himalayan Yellow-

throated Marten Martes flavigula Least Concern Schedule II Indirect

evidence* 2 Himalayan Weasel

Mustela sibirica Schedule II Indirect

evidence* B Canidae 3 Fox Vulpes monntana Data deficient Schedule II Direct sightings C Cercopithecidae 4 Hanuman Langur Semnopithecus

entellus Least Concern Schedule II Direct sightings

D Bovidae 5 Himalayan Tahr

Hemitragus jemlachicus

Vulnerable Schedule I Direct sightings

6 Ghoral

Naemorhedus goral Near Threatened

Schedule III Direct sightings

7 Bharal-Himalayan Blue Sheep

Pseudois nayar Endangered Schedule I Indirect Evidence

8 Musk Deer

Moschus chrysogaster Vulnerable Schedule I Indirect evidence

9 Wild goat –Jungli bakri Capra ibex Endangered Schedule I Indirect evidence

10 Markhor--Large Wild Goat Capra falconeri Endangered Schedule I Indierct evidence

11 The Himalayan serow Capricornis thar Near Threatened

Schedule I Indirect evidence

E Felidae

12 Snow Leopard

Uncia uncial / Panthera uncia

Endangered Schedule I Indirect evidence

13 Cat jungle Felis chaus Least Concern Schedule II Indirect evidence

F Ursidae 14 Himalayan Black Bear

Salenarctos thibetanous

Vulnerable Schedule II Indirect evidence

15 Himalayan Brown Bear,

Ursus arctos

Vulnerable Schedule II Indirect evidence

G Sciuridae 16 Himalayan marmot-the

largest ground squirl - Marmota himalayana Least Concern Schedule II Direct Sighting

H Ochotonidae 17 The Himalayan Mouse

hare or Royle's Pika Ochotona roylei Least

Conceren Schedule IV Direct

evidence I Vespertilionidae (Fruit

Bats)


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S. No.

Family / Species common name

Scientific name IUCN 2013 WPA (1972) Remarks#

18 Coromandel Pipistrelle

Pipistrellus coromandra

Least Concern Schedule V Indirect evidence

* Information from the locals, Secondary data from literature & of forest & wildlife division ** The information of other domesticated animals and livestocks present in the area are also

collected. These animals are mainly mammals and enlisted in the study area are as given in

Table-8.13.

Table-8.13: List of Domestic Fauna in the Study Area S. No. Zoological Name Common Name

1 Bos grunniens Yak 2 Bos indicus Cow 3 Cains familieris Dog

4 Capra hircus Goat 5 Equus cabilus Horse

6 Equus hermionus Ass 7 Felis domesticus Cat

8 Ovius polic Sheep 8.9.2 Avi-Fauna As many as 38 birds species belonging to 18 families were observed in the study area. The

list is enclosed as Table-8.14. Most of the species of birds are protected as their respective

families have been listed under Schedule IV of Indian Wildlife (Protection) Act 1972. On the

basis of their sighting the species are divided into common, rare and categories occasional.

The bird includes the monal and koklas, pheasants, Himalayan tragopan, snow pigeon and

the chukor. Little Forktail, Koklass Pheasant were among the uncommon or rarely sighted

species, whereas Himalayan Monal was reported from high altitude nearby area by the local

inhabitants.

Most of the bird species to be affected in this zone prefer aquatic fresh water habitat, but

these are of common occurrence and distributed all over the Chandrabhaga River e.g.

White-capped Red start, Plumbeous Water Redstart, Brown Dipper, Little Forktail, and

Citrine Wagtail. Similarly, among the species of butterflies and mammals none of the

species is totally dependant or restricted to the submergence area.

There is a paucity of published records on the birds of this Area. However, Singh et al.

(1990) has provided a preliminary list of 16 bird recored in the Sechu Sanctuary Zone

located about 12km distance from the project site. Among them the common species are as

Western Tragopan Tragopan melanocephalus (Globally Threatened), Snowcock

Tetraogallus himalayensis, Himalayan or Impeyan Monal Lophophorus impejanus and

Koklass Pheasant Pucrasia macrolopha are found here but data on general bird life is


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lacking. The site is considered Data Deficient till we have more information on avifauna.

Later on studies in the Pangi valley was conducted by the ZSI (2011) and they have

reported presence of 75 species of Avi fauna. During present studies the species

encountered are illustrated in the Table8.14 .

Table-8.14: List of avi-faunal recorded from the Study Area Common Name Scientific Name Family Abundance

Himalayan Bulbul Pycnonotus leucogenys Pycnonotidae Common

Red vented Bulbul Pycnonotus cafer Pycnonotidae Common

House Sparrow Passer domesticus Passeridae Common

Rock Bunting Emberiza fucata Fringillidae Common

White-capped Bunting Emberiza stewarti Fringillidae

European Goldfinch Carduelis carduelis Fringillidae Common

*Alpine Accentor Prunella collaris Fringillidae Uncommon-

Common Hoopoe Upupa epops Upupidae Occasional

Yellow browed Tit Silvyparus modestus Paridae Common

Rufous-vented Tit Parus rubidiventris Paridae Common

Simla Crested tit Parus rufonuchalis Paridae Occasional

Green-backed Tit Parus monticolus Paridae Ocassional

Ashy Drongo Dicrurus leucophaeus Dicrurinae Common

Western Crowned Warbler Phylloscopus occipitalis Phylloscopidae Common

White-throated Fantail Rhipidera albicollis Rhipiduridae Common

Grey Bushchat Saxicola ferrea Muscicapidae Common

Plumbeous Water Redstart Rhyacornis fuliginosus Muscicapidae Common

White capped Water Redstart Chaimarrornis leucocephalus Muscicapidae Common

Little Forktail Enicurrus scouleri Muscicapidae Uncommon

Brown Dipper Cinclus pallasii Cinclidae Fairly common

Blue Whistling Thrush Myophonus caeruleus Turdidae Common

Streaked laughing Thrush Garrulax lineatus Timaliidae Common

Variegated Laughing thrush Garrulax variegatus Timaliidae Common

Oriental White eye Zosterops palpebrosus Zosteropidae Uncommon

Oriental Turtle Dove Streptopelia orientalis Columbidae Common

Spotted Dove Streptopelia chinensis Columbidae Common

Snow Pigeon Columba leuconota Columbidae Fairly common

Rock pigeon Columba livia Columbidae Ocassional

Himalayan Griffon Gyps himalayensis Accipitridae Common

Yellow-billed Chough Pyrrhocorax graculus Corvidae Common

Red billed Chough Pyrrhocorax pyrrhocorax Corvidae Common

*Himalayan snow cock Tetraogallus himalayensis Phasianidae Fairly common

Chukar Alectoris gracea /chukar Phasianidae Fairly common

Himalayan Monal Lophophorus impejanus Phasianidae Fairly Common

*Koklass Pheasant Pucrasia macrolopha Phasianidae Uncommom

Citrine Wagtail Motacilla citreola Motacillidae Common


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Common Name Scientific Name Family Abundance *Western Tragopan Tragopan melanocephalus Phasianidae Uncommon

*Snow Partridge Lewra lewra Phasianidae Uncommon

*Not sighted in the study area however present at higher elevation in Pangi Valley.

8.9.3 Herpetofauna- Reptiles

Total 7 species of reptiles has been recorded from the area. However, only two species of

herpetofauna i.e. Ladakhi Rock Skink (Asymblepharus ladacensis) and Kashmir Rock

Agama (Laudakia tuberculata) were sighted during the survey. Besides that no any

herpetofauna species was encountered however, description is given based on secondary

information. The information was also collected from secondary source to find out

occurrence of reptiles of Kashmir Himalayas from the locals & from the literature

(Biodiversity of the Kashmir Himalayas by GH. Dar et al. 2002) and from recent studies of

ZSI (2011)on flora and fauna of Pangi Vaalley, which show the presence of 7 reptile species

in the area. However, during priamary survey, no such species was encountered except the

rock agama and skinks. Similarly, presence of pit vipor is also supported from the research

evidence, which shows presence of Himalayan Pit Viper upto Ladakh Himalayas 4800m, asl.

The occurrence of common species of reptiles are enlisted in Table-8.15 .

Table-8.15: List of Reptiles in the study area S.No. Common Name Scientific Name Lizards

1 Common Garden Lizard Calotes versicolor 2 Kashmir Rock Agamid Laudakia tuberculata 3 Skinks or Ladakhi Rock Skink Lygosoma himalayana or Asymblepharus

ladacensis Snakes

1 Himalayan pit viper Agkistrodon himalayanus 2. Mountain keel back Amphiesoma platycips 3. Himalayan trinket snake Elaphe hodgsoni 4. Rat snake Ptyes mucosus

*Based on secondary data

8.9.4 Insects

Among Insects, species of Butterfly and Moths were study. Seondary information with

respect to the occurrence in the study area has also been collected though the area has

paucity of data. Some data from the Pangi Valley is available. The project site is located

within the Pangi valley. Therefore, the secondary information was used for supporting of the

primary data.


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8.9.5 Butterflies

During the survey, a total of 16 species of insects were sighted in the study period. Some of

the butterflies like Small copper (Lycaena phlaeas), Satyr (Aulocera sps.), Indian tortoise

shell (Aglais cachmirensis), Indian cabbage white (Pieris canidia indica) and Clouded yellow

(Colias sp.) were common and found throughout the study area. On the basis of their

sighting the species are divided into common, uncommon and occasional categories. The

list of butterflies recorded from the study area is given at Table -8.16. The alpine zone

Himalayas are typical habitat for Appollo butterflies. The ZSI has reported 16 oriental

species and 17 palearctic species of butterflyies from the Pangi Valley. These species are

reported in the moist alpine meadows and pasture land areas however presence of some

the species in the mixed forest area has also been reported. However, during present

investigation total 16 species are observed where presence of Palearctic species (S.No.11-

16) and remaining Oriental species are viewed from the ZSI report and remaining are

sighted in the field.

Table-8.16: Insects found in the Project Area

S.No. Common name Scientific name Family Abundance 1 Common Emigrant Catopsilia pomona Pieridae Uncommon 2 Indian Cabbage White Pieris canidia indica Pieridae Common 3 Cabbage butterfly Pieris brassicae Pieridae Common 4 Small Copper Lycaena phlaeas Lycaenidae Fairly Common 5 Common Satyr Aulocera swaha swaha Nymphalidae Common 6 Indian Tortoiseshell Aglais cachmirensis Nymphalidae Very Common 7 Indian Red Admiral Vanessa indica Nymphalidae common 8 Painted Lady Vanessa cardui Nymphalidae common 9 Clouded Yellow Colias fieldii Pieridae Uncommon 10 Walnut Blue Chaetoprocta odata Lycaenidae Common 11 The Tailed Cupid Everes huegelii Lycaenidae Common 12 Pearl white Euchloe daphalis Pieridae Common 13 Violet Meadow Blue Polyommatus icarus* Lycaenidae Common 14 Common meadow blue Polyommatus eros* Lycaenidae Common 15 Silvery Meadow Blue Polyommatus florenciae* Lycaenidae Common 16 Large green underwing Albulina galathea* Lycaenidae Common 17 Mountain Apollos Parnassius spp**. Papilionidae Common

*Ref ZSI 2011 ** Apollo –alpine meadows(Threatened Category IUCN)

The occurrence of butterflies has shown interaction with some of the flowering plant species.

Mostly are occurring in the moist alpine meadows area located much higher elevation

(>3500m) beyond the submergence and influenced zone of the proposed project. Some of

the species are also found in the deadar site. The list of community intraction with plant

species has been shown in Table-8.17 (Ref. ZSI 2011).


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Table-8.17: Nectar food plants of Butterflies from Pangi Valley (ZSI, 2011) Plants Plant Family Butterfly species Saussurea costus (Falc.) Lipschitz Asteraecae Aulocera swaha Oxytropis spp. Fabaecae Albulina galathea Anthemis cotula Linnaeus Asteracae Colias fieldii Medicago falcata Linnaeus Fabaecae Colias fieldii Scabiosa speciosa Dipsaeaecae Pieris brassicae Trofolium repens Linnaeus Fabaecae Polyommatus eros,

P.astrarche Nepeta spicata Benth. Limiaecae Pieris brassicae Pedicularis pectinata Scrophulariaecae Albulina galathea Bupleurum falcatum Apiaecae Albulina galathea Cynoglossum sp. Boraginaecae Polyommatus icarus Nepeta spicata benth. Lamiaecae Aulocera swaha Anthemis cotula Linnaeus Asteracae Colias fieldii Dianthus orientalis Caryophyllaecae A. galathea, P. icarus Oxytropis sp. Fabaecae Polyommatus icarus Trifolium pretense (Linnaeus) Fabaecae Colias fieldii Chaerophyllum reflexum Lindl. Apiaceae Chaetoprocta odata Taraxacum sp. Asteraceae Colias fieldii Thymus linearis Benth. Lamiaceae Lycaena phaleas Sisymbrium orientale Brrassicaceae Pieris brassicae Cirsium wallichii Compositae Vanessa cardui

Maniola pulchra sitting at Deodar tree

Parage eversmanni –lives in habitat of deodar

Blue cupid Aglais kaschmirensis


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Ref.Faunal Diversity of Pangi Valley, 2011(Dr.Kamal Saini and Dr. Avtar Kaur Sidhu), High Altitude Regional Centre, Zoological Survey Of India, Solan

Polyommatus icarus Butterflies reported in the study area –Pangi Valley

8.9.6 Protected Areas and Corridors for wild animals

There is no Wildlife sanctuary, National park or Biosphere Reserve present within the study

area. The project area does not come under any wildlife corridor. The pattern of occurrences

of fauna much above the submergence area reflects that no direct impacts is anticipated on

the occurrence and distribution of faunal diversity.

8.10 AQUATIC ECOLOGY

8.10.1 Sampling Details

The river Chenab in project vicinity flows in the northern direction with a slight inclination

towards the east. The Cheni nala confluences with the Chenab river on its left bank about

downstream of 1.1 km near the Shin village of proposed dam. Further about 2.5 km

downstream one more stream joins the Chenb river namely by the Mokha Nala and about

200m downwords of confluence point, the river takes a westward bend. The right bank

stream Saichu nallah also confluence Chenab near the tail water discharge site.

Therefore, the complete area is divided in to three zones of having an holistic view of river

ecology i.e. Submergence zone, Dam site to powerhouse site, and downstream influence

zone covering about 20 km longitudinal length of the river in line of 10km radius approach

based on project appurtenances. The details of sampling sites are given in Table and Plates.

Samples were made during Pre monsoon (summer), monsoon and winter seasons during

the study period. The details of the study area to assess the aquatic fauna are given in

Table-8.18 and Figure-8.3.

Table-8.18: Description of study sites selected on river Chenab and its tributaries in the project impact zone

Sampling sites


Elevation covered (amsl)

Longitude E

Latitude N

Submergence area U/S Dam Site Site 1 Chenab river –

Submergence zone,

River Reach length u/s 2-10 km from dam site to Mujar (Chow)

2200 +40m 320 55’24” 076027’30”


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Sampling sites


Elevation covered (amsl)

Longitude E

Latitude N

U/s dam site view (Fig -8.2)

stream confluence with Chenab

Dam Site to Power House Area Site 2 -Dam site

River Chandrabhaga Dam site image(Fig-8.2)

1.5 km dam site to power house area upto confluence of Saichu Nallah

2150+16m 320 57’57” 076025’15”

Project Influenced Area D/S Dam Site Site 3 Saichu nallah

confluence to Mokha nallah confluence with river Chenab up to Fintru village

~8.0 km of river reach length of Chenab up to Fintru Village Mindhal Bridge Site Image (Fig-8.2)

2130+20m 330 00’05” 076026’02”



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Figure -8.3: River Chandrabhaga Project Influenced Area --through Pangi valley

8.10.2 Methodology

The river /stream morphology is determined to ascertain the type of habitats, substratum and

covers (aquatic vegetation, substratum, large woody debris, Particulate as clay, silt, sand,

gravel, pebble, cobble, boulder, bedrock etc.), bank conditions, flow pattern, and type of

valleys following flood prone area and riparian covers etc has been assessed based on the

criteria described by Rosgen (1996) and habitat inventory described by Armontrout (1998),

Myers and Swanson (1992) and Rosgen (1996). Stream order classification was based on

Horton’s (1954) approach as modified by Strahler (1954, 1957). In this system all ultimate

headwaters are called first order streams. Stream formed by union of two such streams are

designated second order and whenever two streams of a particular order join they form next

order and so on. Habitat structures were observed in the river stretches from down stream

to upstream at a fixed point including longitudinal survey of submergence, dam site and

influence zones of toe dam projects with onsite visual estimation.

Plankton samples were collected using a tericot ring net of a 20 µm net to make. For

enumeration of phytoplankton population, 100 l composite water samples were collected

from the river surface up to 60 cm depth and were filtered through a 20 µm net to make 1 l of


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bulk sample. The bulk samples so collected were preserved in 2% formalin solution and

were brought to the laboratory for analysis. Ten replicate water samples each of 15 ml were

made out of the preserved 1 l bulk sample and were centrifuged at 1500 rpm for 10 minutes.

After centrifuging, the volume of aliquot concentrate was measured. 0.1 ml of aliquot

concentrate was used for enumeration of phytoplankton population in each replicate. A

plankton chamber of 0.1 ml capacity was used for counting of plankton under a light

microscope. Periphyton-Epilithic phytobenthos were obtained by scrapping the surface of

rocks and boulders (4 x 4 cm2) with the help of a hard brush and preserved in 3% formalin

solution for further analyses.

For the quantification of zooplankton and phytoplankton 100 liters of water for each

community was filtered at each site by using plankton net made up of fine silk cloth (mesh

size 25 µm). The filtrate collected for the study of phytoplankton was preserved in Lugol’s

solution, while a part of the unpreserved samples for the study of zooplankton was brought

to the laboratory.

Benthic macro-invertebrates were collected from the pebbles, cobbles and gravels form the

surface collected up to 15 cm sediment depth at different elevations with the help of sieve of

a mesh size of 100 µm.

All collected specimens–organisms of planktons, periphytons, benthoses etc were preserved

in 3 % formalin solution or 70 % alcohol and were identified by using keys formulated by

different workers such as Pennak (1953), Edmondson (1959), Ward and Whipple (1959),

Needham and Needham (1962), Trivedy and Goel (1984), Sarod and Kamat (1984), Hustedt

and Jensen (1985), Battish (1992), Edington and Holdren (1995) and APHA (1992, 1998).

The density of the plankton and benthic samples was estimated by using drop count method

(Bhatt et al., 2005) and standards methods of APHA (1992, 1998).

Fishes occurrence were determined by visual method and by collecting samples using

different fishing gears like cast net, scoop net, hand net, hook-line, pot and open local

devices methods. Fishes were identified up to the species level with the help of keys of

Jayaram (1981), Menon (1987) and Talwar and Jhingran (1997). IUCN Red Data List (2008)

was compared to assess threatened, endangered and vulnerable species in the study area.

Conservation Assessment Management Plan of Biodiversity Conservation Prioritization

Project Workshop (CAMP-BCPP, 1997) was followed to understand the threats and

conservation status of Indian fish species.

The total number of planktons present in a litre of water sample was calculated using the

following formula:

N = (n x v x 100)/ V

Where, N= Number of plankton per litre n = average number of plankton cells in 0.1 ml of aliquot concentrate


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v = volume of plankton concentrate (aliquot) V= volume of water from bulk sample centrifuged

The species diversity index was calculated using Shannon’s species diversity index (H)

formula taking the density values of each species into consideration.

Shannon index of general diversity (H): - ΣPi log Pi

Where ni = density value for each species

N = total density value Pi = density probability for each species = ni /N

8.10.3 River Morphology & Habitat Structure

The Chenab river is mainly snow fed. The main drainage channel of the basin is Chenab

river, which is named after the confluence of two streams namely Chandra and Bhaga river

near Tandi (2,573 meters) in the districts of Lahaul & Spiti (H.P.). Chandra river rises in the

snows lying lake of Chandra Tal, located in the southeast slope of the Baralacha La pass

and turns abruptly west after traveling 48-km to flow another 64-km to meet with the Bhaga

River at Tandi in the Lahaul and Spiti district. The Bhaga River rises in a small tarn called

Suraj Tal. The river pursues a southwesterly course for about 64-km and joins Chandra at

Tandi The united stream, called the Chandrabhaga, flowing northwesterly for 46 kms is

joined on its right bank by the Miyar Nala near Udaipur. The latter negotiates a total river

course of 80 km with an average fall of about 24 m/km. The Chandrabhaga, after flowing in

general northwest direction almost parallel to the Pir Panjal range, crosses at El. 1838 masl

the Pangi valley of Himachal Pradesh to enter Padder block of district Kishtwar of J&K.

After sweeping the Lahul and Spiti valley it enters in the Pangi Valley of Chamba district at

Karunalla confluence point (~2400m, asl) downward of Udaipur and leaves the Pangi valley

after confluence of Sansari Nallah to Kishatwar area of J& K (Figure below). Here, the river

is sandwiched between two sub-systems of the Himalayas the Zaskar and the Pir Panjal. It

flows in from Lahaul and passing through the length, it divides Pangi into two unequal parts

while the cliffs sometimes rise vertically to a height of a couple of thousand feet. The

mountains are surroundings the valley range between 5,400 and 6,700 meters. The tiny

villages of this verdant pocket lie between 2,100 and 3,000 meters. On the right bank of the

river Chanderbhaga, the growing settlement of Kilar (2,590 mtrs), is the administrative

headquarter. Thus hill peaks are ranging from river bed 2100m to 6707m. There are many

passes located on the Pir Panjal range which takes to Pangi valley like Cheni Pass, Drati,

Chobia, Kugdi and Sach Pass (4268m to 5300m). At project site, Mindhal village is on the

left bank whereas Sach khas is on the rightbank of river Chenab. At this point, valley spread

out (comparatively open type though V-shaped) and river flows in NW direction to reach

Killar and Dharawas as shown in Figure below. The several streams born on Zanskar range

and feed the Chenab on right banks. These are mainly Karu nallah, Saichu, Parmar, Kiryani,


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Mahlu, Lujai, and the Sansari nallah (the last one in HP) near killer are noticeable. On the

left bank , the Cheni nallah near Mindhal, and Sach Khas nallah near Killar are noticeable.

At project site, hills are showing cover of overhanging snow clad peaks overawe. Vegetation

becomes sparse or even devoid of vegetation except few patches of deodar trees. The river

flows here through deep gorges cutting through the stable and rocky hills of high mountains

in the project site. Thus flows through narrow valley. The river flows through a narrow gorge

exposing bedrock on both the abutments where the diversion site is planned immediately

near to the sharp bend in river. Also immediately downstream of the proposed location the

river width broadens and again constricts to a narrow width at a location where the tailrace

tunnel outlet is planned.

The tract lies in a semi arid zone of inner Himalayas. The climate varies from dry temperate

to alpinetypes. The area remains snow covered for almost six month period where

temperature ranges between –20 oC to +27 oC. The rock system is very fragileand liable to

erosion which is often accentuated by the rigrous of severe winters, avalanches and the

strong winds that accompany them. The valley is surrounded by high mountain peaks and

deep river bed i.e. stable and confined valley (‘U to V’ shapes Plate-8.1). The aspects of the

hills in the area are steep to highly steep. The Pir Panjal range on left bank has much higher

steep slope than the right bank side Zanskar range. The vegetation is sparse and river bank

is devoid of riparian cover. The substratum is rocky which constitute large rocks, boulders

with lesser amount of cobbles, pebbles and absence of sand at banks. River has torrent

flow with bubble formation where rapids and cascade habitat is occur quite frequently. Some

place scour pools, side and pocket pools also formed by the presence of rocks and

boulders. Thus, the river has high gradient at dam site (4-10%) and fluvial morphology. At

dam site and power house sites, rapids habitat dominant whereas no frequent run, pool and

scour pools habitat observed in the river course. The streams are first order category and

consits fall and cascade habitats with torrent flow. The glacial melt water is flowing in the

Chenab and its streams where velocity is found >4m/sec (torrent flow) due to steep slope.

All the streams falling in the influenced area and river Chenab are claasified A-type as per

Rosgen’s (1996) criterion developed for river morphology. The detail geomorphology of the

river Chenab and its streams falling in the project submergence zone and influenced zone is

depicted in Table-8.20.


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Table-8.20: River Morphology and Habitat Structures of Chenab & its streams in the Project Impact Zone

Sites River/Stream Gradient (% Slope) & Stream type

Substratum with stream/river morphology

Habitats

U/S dam Site -Submergence Zone I Chenab-Snow

Fed < 4% and Category A

Rocks, Boulders, Banks stable and rocky hills, No riparian cover (V-U shape)

Rapids. Confined morphology with stable rocky hills

Dam site to Power House Zone II River

Chandrabhaga (Chenab)-Snow Fed

< 4%, and Category A

Rocks, Boulders, Banks stable and rocky hills, No riparian cover, Valley Narrow and confined (V-U shape)

Rapids. Confined morphology with stable rocky hills.

Influnced Zone D/s dam site III River Chenab

& side streams -Snow Fed

2-4% river Chenab and streams above 10% slope- Category A

Rocks, Boulders, Banks stable and rocky hills, No riparian cover, Valley Narrow and confined (V-shape)

Rapids in Chenab whereas cascade, fall and lesser pools in steams. Confined morphology.

Biotic resources study involved the assessment of status of phytoplankton, zooplankton,

phytobenthos, benthos and macro-invertebrates, macrophytes, fishes and other aquatic

fauna. Biotic resources are divided into two groups i.e. autotrophs and heterotrophs.

Autotroph constitutes the aquatic flora whereas heterotrophs constitutes of aquatic fauna.

Aquatic flora comprises of algae in suspended form (plankton) and benthic form (phyto-

benthos). Aquatic fauna includes zooplankton, micro- invertebrates and fish & fisheries.

Aquatic flora includes microflora as phytoplankton, phytobenthos, and periphytons and

macroflora consist of aquatic plants.

8.10.4 Phytoplanktons

Micro flora is comprised of Chlorophyceae (green algae), Cynophyceae (blue green algae)

and Bacillarionphyceae (ditoms) (Table-8.21). The stream being a freshwater body, the

presence of Chlorophyceae was more prominent. Chlorophyceae included Ulothrix,

Spirogyra, Zygnema and Cladophora as filamentous algae forming sheets on the river /

streams edges. Other green algae found predominate are chlorella, scenedesmus and

closterium with other flagellates. Blue green algae are represented by Oscillatoria,

Phormidium and Schizothrix taxon. After green algae, diatoms (Bacillariophyceae) are found

in abundance. At most of the sampling sites Achnanthes, Cocconeis, Fragilaria and

Gomphonema taxon were the most common species in river Chenab and its tributaries

recorded during study period. The trend of aquatic flora is reflecting the local climatic

conditions. However, the occurrence was quite low that may be attributed to the glacial melt


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water of oligotropic nature. Thus, the variation in occurrence of phytoplankton taxa is the

reflection of prevailing the water quality, channel morphology, elevation, geomorphology that

occur in the project site in river Chandrabhaga and its tributaries.

Table-8.21: Phytoplankton Species Observed in the project impact zone Phytoplankton Taxon (cells/l or sq cm) Submergence

Zone (u/s dam site)

Dam Site to Power house Area

Influenced Zone (D/s Power house area)

PM M W PM M W PM M W Blue Green Algae Cyanophyceae Oscillatoria tinues 8 10 12 8 6 14 12 O. limnosa 4 6 8 9 6 8 11 8 Phormidium autumnale 4 4 6 2 8 12 8 Schizothrix fasciculata 8 4 4 8 6 Green Algae-Cholorphyceae Zygnema himalayense 8 12 26 6 8 12 14 8 18 Spirogyra porticalis 6 12 6 8 18 4 14 Ulothrix zonata 6 8 4 10 4 14 Cladophora glomerata 4 10 9 12 8 8 18 Scenedesmus ellipticus 8 10 14 6 12 16 10 24 Chlorella vulgaris 4 6 14 8 6 8 10 Chlamydomonas moewusii 4 6 16 6 12 10 16 Closterium leibleinii 2 12 12 12 10 14 16

Microspora amoena 3 5 9 4 6 10 8 12 12 Diatoms-Bacillariophyceae

Tabellaria fenestrate 22 26 32 12 18 30 16 22 46 Cocconeis placentula 18 20 16 26 16 26 26 Diatoma hiemale 8 12 12 6 12 24 32 24 42 Flagellaria .pinnata 12 12 18 8 16 20 32 40 40 F. inflata 10 12 12 12 16 30 40 Synedra ulna 10 16 8 12 12 16 20 34 Synedra mediocontracta 6 8 10 6 12 18 20 26 38 Achnanthes linearis 8 6 8 14 24 Achnanthes minutissima 10 12 14 8 12 20 18 26 24 Stauroneis phoenicenteron 8 12 20 14 16 26 20 36 Nitzschia linearis 12 16 14 10 16 16 20 20 Navicula radiosa 22 36 18 12 14 20 22 18 Cymbella affinis 14 32 16 10 18 28 12 16 22

Hannaea arcus 12 8 8 14 14 12 16 24 Gomphoneis herculeana 10 8 18 28 12 18 20 G.geminatum 10 10 8 10 20 16 14 20 28 Amphora ovalis/bitumida 16 8 6 8 16 10 14 24 Meridion circulare 10 16 6 10 24 8 16 32

PM= Pre Monsoon, M= Monsoon, W= Winter Source: Field Studies


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The river waters shows low occurrence /density and diversity that represented by

phytoplankton (56– 432 cells/l), phytobenthos (54 – 406 cells/cm2) and zooplanktons (14-

284 cells/L). Cholorophyceae accounted for the majority of the biotic communities followed

by Bacillariophyceae and Cyanophycae.

8.10.5 Macroflora/ Macrophytes

No growth of macrophytes seen in the area that may be due to rapid currents and fall habitat

which has river wash affects. However, macrophytes that remain attached to the rocks,

boulders; stones, etc. belong to various genera of bryophytes (mosses). These mosses grow

on stone and boulders that protrude a few centimeters above the surface of water

sometimes growth reaches in the flowing water edges stones.

8.10.6 Zooplanktons

Zooplanktons are represented by protozoa, rotifer and crustaceans (Refer Table-8.22) .

Among protozoans Arcella, Peridinium, and Ceratium taxon are commonly observed.

Rotifers are represented by Keratella, Brachionus and Philodina taxon. Copepod consists of

Cyclopes species whereas cladocerans are represented by Daphnia and Bosmina sp. The

occurrence are mainly from the edge pools of side stream and river banks, however, the

group in totality is poorly represented due to climate conditions followed by long winters and

torrential flow. The low occurrence is also linked to rapid habitat and rocky substratum in the

deep gorge narrow valley.

Table-8.22: Zooplankton observed in the Project Impact Zone (~10km radius) Zooplanktons (Cells/L) Submergence

Zone (u/s dam site)

Dam Site-Project Site

Influenced Zone (Power house site)

PM M W PM M W PM M W Protozoan Peridinium cinctum 4 8 3 6 4 12 14 Arcella crenulata 4 8 10 6 8 6 14 20 Ceratium furca 3 4 4 6 10 14 Rotifers Keratella quadrata 8 6 6 14 28 Asplanchna priodonta 10 8 8 12 26 Philodena roseola 6 10 6 4 8 12 8 18 12 Brachionus bidenta 12 6 6 12 24 Polyarthra vulgaris 4 18 10 6 10 14 10 16 14 Trichocerca longiseta 6 12 8 4 7 12 8 15 10 Cladoceran Bosmina longirostris 12 20 6 12 14 20 34 Daphnia pulax 16 12 8 14 16 22 40 Copepods Cyclops scutifer 4 6 8 4 8 8 14 26 Cyclops glacialis 2 4 8 6 8 16 22



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8.10.7 Macro-invertebrates (Zoo benthos)

Macro-invertebrate fauna of river Chenab are comprised by Heptageniidae, Baetidae,

Ephemerellidae, Perlidae, Hydropsychidae, Hydroptilidae, Chironomidae, Simulidae,

Elmiade, Blepharoceridae and Amphizoidae families. The details are given in Table-8.23.

The density of macro- invertebrates ranged from 16 to 304 individuals/m2. Among them

Ephemeropterans are observed as the dominant group which is followed by Placopteran and

dipterans. Species of genera Stenonema, Epeorus, Baetis, Ephemeralla, Rhycophila and

Chironimds are observed in the region. The distribution and occurrence is directly related to

the habitat structure and substratum of Chenab river and its tributaries. The poor occurrence

of benthos during study period could be due to low water temperature, high turbidity, torrent

flow and rocky substratum in river and its tributaries.

Table-8.23: Macro-invertebrates composition in proposed project impact area Invertebrates Taxon (ind./m2)

Submergence Zone (u/s dam site)

Dam Site -Project Site


PM M W PM M W PM M W Heptageniidae Epeorus lauhalensis 2 4 8 10 12 18 36 Baetidae Baetis chandra 8 2 6 6 8 10 16 18 Baetis himalayana 2 10 14 2 4 10 15 19 26 Ephemerellidae Ephemeralla major 6 8 4 12 8 12 20 Stenonema tripunctatum 2 10 6 12 8 14 24 Perlidae Isoperla montana 2 8 7 8 6 8 16 Perla marginata 6 4 12 4 10 14 10 14 18 Choloroperlatorrentium 8 6 12 4 10 12 4 8 20 Tipulidae Ameletus primitius 6 8 14 6 8 6 8 12 22 Hydropsychidae Rhyacophila fuscula 8 4 9 6 6 8 Hydroptilidae Ochrotrichia susanae 16 12 12 20 18 Chironomidae Chironemous sp 12 16 10 8 14 16 20 16 Dipter a -Simulidae Simulium pictipus 16 8 10 14 12 Athericidae Atherix sp (Snipe fly larvae) 14 4 12 12 26 Blepharoceridae Bibiocephalle sp 8 12 4 6 18 22 14 Elmidae Narpus sp larvae 6 10 2 4 6 12 6 Elmid sp larvae 6 8 4 8 2 Amphizoidae (trout beetel) 4 8 2 4 4 8 2 Amphizoa sp. 2 4 8 10 12 18 36



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8.10.8 Diversity index

The diversity index is given in Table-8.24.

Table-8.24: Species Diversity Index and density of different biotic communities

Biota -Groups Submergence Zone (u/s dam site)

Dam Site -Project Site


PM M W PM M W PM M W Phytoplanktons Shannon H' Log Base 10. 1.033 1.17 1.259 0.889 1.154 1.235 1.235 1.254 1.241 Shannon Hmax Log Base 10. 1.114 1.23 1.279 0.903 1.176 1.279 1.279 1.279 1.279 Shannon J' 0.928 0.951 0.984 0.985 0.981 0.966 0.966 0.981 0.97 Periphytons -Epiphytes Shannon H' Log Base 10. 0.695 1.02 1.093 0.822 1.059 1.02 1.089 1.064 1.079 Shannon Hmax Log Base 10. 0.778 1.114 1.146 0.845 1.114 1.079 1.146 1.146 1.146 Shannon J' 0.893 0.916 0.954 0.973 0.951 0.945 0.95 0.929 0.941 Zooplankton Shannon H' Log Base 10. 0.755 0.937 1.084 0.469 0.879 1.084 1.084 1.104 1.08 Shannon Hmax Log Base 10. 0.778 1 1.114 0.477 0.903 1.114 1.114 1.114 1.114 Shannon J' 0.97 0.937 0.973 0.982 0.973 0.973 0.973 0.991 0.97 Macro -Invertebrates Shannon H' Log Base 10. 0.734 1.065 1.233 0.574 1.103 1.2 1.215 1.228 1.191 Shannon Hmax Log Base 10. 0.778 1.146 1.255 0.602 1.146 1.23 1.255 1.255 1.255 Shannon J' 0.944 0.929 0.982 0.953 0.962 0.975 0.968 0.978 0.949 Densities / Occurrences Zooplankton (cells/I) 26 93 124 14 52 116 108 195 284 Phytoplankton (cells/I) 101 203 241 56 179 274 274 329 432 Phytobenthos (cells/cm2) 63 147 191 54 135 182 172 210 306 Macro-invertebrates (ind./m2) 42 82 190 16 83 153 169 243 304


8.11 FISH COMPOSITION AND STATUS

The region has a diverse Ichthyofauna with the fish species of upper and middle reaches

showing great affinity with Western Himalayan elements. The river of Himachal Pradesh

show a longitudinal and latitudinal variation in the fish diversity, abundance, species

composition and assemblages. However, water bodies located across Tran’s himalyan zone

are virgin in oligotropic in nature. Therefore, the state department has made efforts to

restore such virgin rivers, stream and lakes through introduction of trous like rainbow and

brown trouts and the new stock of Arctic char. Earliar the efforts were made by the

Britishers. Due to this, Chandrabhaga river in the Lauhal valley area between Udaipur to

Tandi and Tandi to Darch and Tandi to Khoksar occurrence of trouts has been reported.

However, the terrain of Chandrabhaga in Pangi Valley is altogether different and very few

patch are observed suitable for future fisheries, which still to be explored.

The present study is limited to project impact zone maximal longitudinalreach length of 15-

20km river basin and very little secondary data is available so the most of the data is based


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on the primary survey collected during field survey carried out in the river Chenab and its

tributaries between 2125 to 2250 m.

Fish species adapted to cold water conditions approx 100C or subzero water temperature

are found in the region. Among 3 species of fish, 1 has been classified under the vulnerable

category on the basis of CAMP criterion. Schizothorax richardsonii. Rainbow, brown and

golden trout are exotic species and introduced by the State Fishery Department. The area

has been found devoid of crucial spawning requiste riffle habitat in the dam site and

upstream zone except d/s areas near to side stream confluence. The d/s area will remain

unaltered and will coninuosly receive environmental flow and tail water flow for lower stream

habitat requirement. Table-8.25 depicts the composition and conservation status of fishes

based on available literature and primary survey. Cultural fishery is absent and there are no

fish farms and hatcheries for the fishery development in this region.

Table-8.25: Fish species composition of Chenab River and their conservation status S. No

Zoological name Common name Family IUCN Status

1 Schizothorax richardsonii Snow tourt Cyprinidae Vulnerable

2 S. gairdnerii gairdnerii Rainbow trout Salmonidae Least Concerned

3 Salmo trutta fario Brown trout Salmonidae Least Concerned


Out of the reported 3 fish species, Schizothorax richardsonii of Cyprinidae family is the only

species which falls in vulnerable category, though none of the species are found present in

the project area. The remaining species are declared as common or exotic in introduction.

Though, the endemic trout species is widely distributed throughout Indian Himalayan region.

Endemic trout is considered migratory in nature within the river stretch which mostly

localized in nature.

CHAPTER-9

PREDICTION OF IMPACTS


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CHAPTER-9

PREDICTION OF IMPACTS

9.1 GENERAL

Based on the project details and the baseline environmental status, potential impacts as a

result of the construction and operation of the proposed Sach Khas hydroelectric project

have been identified. This Chapter addresses the basic concepts and methodological

approach for conducting a scientifically based analysis of the potential impacts likely to

accrue as a result of the proposed project. The Environmental Impact Assessment (EIA) for

quite a few disciplines is subjective in nature and cannot be quantified. Wherever possible,

the impacts have been quantified and otherwise, qualitative assessment has been

undertaken. This Chapter deals with the anticipated positive as well as negative impacts due

to construction and operation of the proposed project. The construction and operation phase

comprises of various activities each of which is likely to have an impact on environment.

Thus, it is important to understand and analyze each activity so as to assess its impact on

environment. The key activities have been categorized for construction and operation

phases.

Construction Phase Activities

• Site preparation • Earthwork and excavation including controlled blasting and drilling • Construction of a concrete dam of 77 m height • Intake, Pressure shaft, Power house for underground power house for main power

house • Intake, Pressure Shaft, Surface Power house for secondary power house • Underground manpower house to generate (3x86.7) 260 MW of power • Surface secondary power house to generate (2x7) 14 MW. • Tail Race Tunnel of length 99.75 m, 113.13 n and 132.35 m • Construction of new roads and upgradation of existing roads • Construction of a bridge on river downstream of tail race tunnel • Project headquarter, offices and colonies • Disposal of muck and construction wastes • Transportation of construction material • Operation and maintenance of construction equipment • Civil and mechanical fabrication works for construction of various project

components. • Operation of DG sets • Disposal of pollutants from workshops, etc. • Disposal of effluents and solid waste from labour camps and colonies

Operation Phase Activities

• Diversion of water from river Chenab for hydropower generation • Equipment maintenance and equipment restoration • Sewage and solid waste generation from project colonies


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The various project activities and associated potential environmental impacts on various

environmental parameters have been identified and summarized in a matrix and the same is

outlined in Table-9.1 .


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TABLE-9.1

Matrix for various project activities and associated potential Environmental Impact on various Environmental Parameters S. No.

Project Activities Soil & Land

Geology

Hydrology

Water quality

Air quality

Noise Flora/ Fauna

Employment Socio -culture

A. Construction Phase 1. Sire preparation including tree cutting √ √ √ √ 2. Earthwork and excavation including

blasting and drilling √ √ √ √ √ √ √

3. Construction of concrete dam over river Chenab

√ √ √ √ √

4. Construction of primary and secondary surge shafts

√ √ √

5. Construction of primary and secondary intakes

√ √ √

6. Widening of approach roads √ √ √ √ √ 7. Disposal of muck and construction

wastes √ √ √ √

8. Transportation of construction materials

√ √ √ √

9. Operation and maintenance of construction equipment

√ √ √ √

10. Disposal of sewage and solid waste from labor camps

√ √

11. Acquisition of forest land √ √ √ 12. Acquisition of labor population √ √ √ √ √ √ √ B. Operation Phase Activities 1. Diversion of water for hydropower

generation √ √ √

2. Equipment maintenance √ √ √ √ 3. Disposal of sewage and solid waste

from project colony √ √

4. Mushrooming of allied activities √ √ √ √ √ √


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The impacts which have been covered in the present Chapter are categorized as below:

- Impacts on Water Environment - Impacts on Air Environment - Impacts on Noise Environment - Impacts on Land Environment - Impacts on Biological Environment - Impacts on Socio-Economic Environment

9.2 IMPACTS ON WATER ENVIRONMENT

The various aspects covered under water environment are:

- Water quality - Sediments - Water resources and downstream users

9.2.1 Water quality

a) Construction phase

The major sources of surface water pollution during project construction phase are as

follows:

• Sewage from labour camps/colonies • Effluent from crushers • Pollution due to muck disposal • Effluents from other sources

i) Sewage from labour camps

The project construction is likely to last for a period of 9.5 years. The peak labour strength

likely to be employed during project construction phase is about 1000 workers and 200

technical staff. The employment opportunities in the area are limited. Thus, during the

project construction phase, some of the locals may get employment. It has been observed

during construction phase of many of the projects; the major works are contracted out, who

bring their own skilled labour. However, it is only in the unskilled category, that locals get

employment.

The construction phase, also leads to mushrooming of various allied activities to meet the

demands of the immigrant labour population in the project area.

The following assumptions have been made for assessing the emigrating population in the

area:

• 80% of workers and technical staff emigrating into the area are married. • In 80% of the family of workers both the husband and wife will work. • In 100% of the family of technical staff, only husband will work. • 2% of total migrating population has been assumed as service providers. • 50% of service providers will have families. • Family size has been assumed as 5.


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Based on these assumptions the peak migrant population has been calculated as 6200

persons (Table-9.2 ). This population is expected to reside in the project area at any given

time.

Table- 9.2: increase in population due to migration of labour and technical staff during construction phase A. Migrant Population of Laborers Total labor force 1000 Married laborers (80% of 1000) 800 Single laborers (20% of 1000) 200 Husband and wife both working Labour (80% of 800) 640 Number of families where both husband and wife work (640/2) 320 Number of families where only husband work (20% of 1000) 200 Total number of laborers families (320+200) 529 Total Migrant Population of Laborers (520 x 5 + 200) 2800 B. Migrant Population of Technical Staff Total technical staff 400 Married technical staff 200 Single technical staff 200 Total migrant population of technical staff (100 x 5 + 100) 600 Migrant Workforce (Labor plus Technical) 3400 C. Service Prov iders Total service providers (2% of total migrant workforce) 68 Married service providers (50 % as assumed) 34 Single service providers 34 Total migrant population of service providers (34 x 5 + 34) 204

Total Migrant Population 3604, say 3600

Immigration of such a large population for a long duration in remote area can cause serious

impact on various environmental resources including socio-economic profile of local

population. The congregation of large number of construction workers during the peak

construction phase is likely to create problems of sewage disposal, solid waste

management, tree cutting to meet fuel requirement, etc. Appropriate mitigating measures

have been suggested in EMP, which needs to be implemented to minimize such impacts.

The domestic water requirement has been estimated as 70 lpcd. Thus, total water

requirements work out to 0.25 mld. It is assumed that about 80% of the water supplied will

be generated as sewage. Thus, total quantum of sewage generated is expected to be of the

order of 0.20 mld. The BOD load contributed by domestic sources will be about 162 kg/day.

It is assumed that the sewage is discharged without any treatment for which, the minimum

flow required for dilution of sewage is about 2.4 cumec.

Detailed DO modelling was done using Streeter Phelp’s model. The D.O. level was

estimated using the following equation:


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K1LA [10-K1t – 10-K2t ] Dt = ------------------------------- + DA 10-K2t

K2 – K1 Dt = D.O. deficit downstream at time t. K1 = Deoxygenation rate K2 = Reaeration rate LA = Ultimate upstream BOD DA = D.O. deficit upstream t = Time of stream flow upstream to point at which D.O. level is to be estimated

The D.O. level in the river Chenab was taken as 8.0 mg/l. The minimum flow in the river

Chenab was taken as 8.7 cumec (minimum flow estimated for 90% dependable year in the

month of February). The results of D.O. model are summarized in Table-9.3.

Table-9.3: Results of D.O. Modeling due to disposal of sewage from labour camps in River Chenab

Distance from outfall (km) D.O. (mg/l) 0.1 8.0 0.2 8.0 0.3 8.0 0.4 8.1 0.5 8.1 1.0 8.2

It can be observed from Table-9.3 , that no impact is anticipated on river water quality, as a

result of disposal of sewage from labour camps. Even though no impact is envisaged on

water quality of river Chenab, as a result of disposal of untreated sewage, it is recommended

to provide adequate treatment for the sewage generated from labour camps.

ii) Effluent from crushers

During construction phase, at least two crusher will be commissioned at the quarry site by

the contractor involved in construction activities. It is proposed only crushed material would

be brought at construction site. The total capacities of the two crushers are likely to be of the

order of 120-150 tph. Water is required to wash the boulders and to lower the temperature of

the crushing edge. About 0.1 m3 of water is required per ton of material crushed. The

effluent from the crusher would contain high-suspended solids. About 12-15 m3/hr of

wastewater is expected to be generated from each crusher. The effluent, if disposed without

treatment can lead to marginal increase in the turbidity levels in the receiving water bodies.

The natural slope in the area is such that, the effluent from the crushers will ultimately find its

way in river Chenab. This amounts to a discharge of 0.0033 to 0.0042 cumec. Even the

lowest 10 day minimum flow in river Chenab is 8.7 cumec. The effluent from crusher will

have suspended solids level of 3000-4000 mg/l. On the other hand, suspended solids as

observed at various sampling locations, during water quality monitoring studies was


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observed to be <0.1 mg/l. The composite value of suspended solids would increase by 0.07

mg/l, which is insignificant. Thus, no adverse impacts are anticipated due to small quantity of

effluent and large volume of water available in river Chenab for dilution. Even then, it is

proposed to treat the effluent from crushers in settling tank before disposal so as to

ameliorate even the marginal impacts likely to accrue on this account.

iii) Pollution due to muck disposal

The major impact on the water quality arises when the muck is disposed along the river bank.

The project authorities have identified suitable muck disposal sites which are located near the

river channel. The muck will essentially come from the road-building activity, tunneling and

other excavation works. The muck out falling into the river channel will greatly contribute to the

turbidity of water continuously for long time periods. The high turbidity is known to reduce the

photosynthetic efficiency of primary producers in the river and as a result, the biological

productivity will be greatly reduced. Therefore, the prolonged turbid conditions would have

negative impact on the aquatic life. Therefore, muck disposal has to be done in line with the

Muck Disposal Plan given in EMP to avoid any adverse impact.

iv) Effluent from other sources

Substantial quantities of water would be used in the construction activities. With regard to

water quality, waste water from construction activities and runoff from construction site would

mostly contain suspended impurities. Adequate care needs to be taken so that excess

suspended solids in the wastewater are removed before discharge into water body. The

effluent is proposed to be treated by collecting the waste water and runoff from construction

sites and treating the same in settling tanks.

b) Operation phase

The major sources of water pollution during project operation phase include:

• Effluent from project colony. • Impacts on reservoir water quality. • Eutrophication risks • Sediments

i) Effluent from project colony

During project operation phase, due to absence of any large-scale construction activity, the

cause and source of water pollution will be much different. Since, only a small number of

O&M staff will reside in the area in a well-designed colony with sewage treatment plant and

other infrastructure facilities, the problems of water pollution due to disposal of sewage are

not anticipated. In the operation phase, about 50 families (total population of 250) will be

residing in the project colony proposed to be developed. The details are given in Table-9.4.


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Table-9.4: Details of project colonies and officers in operation phase

S.No. Type Plinth Area (m 2) 1 Main Office 800 2. Staff colony 3600 Source: D PR

About 37.5 m3/day of sewage will be generated. The total BOD loading will be order of 11

kg/day. It is proposed to provide septic tank to treat the sewage generated from project

colony. The BOD loading will reduce to 3 to 4 kg/day. The sewage treatment for septic tank

will be discharged into nearby water body. The quantum of sewage so generated will be so

small that no major adverse impact is anticipated as a result of disposal of effluents from the

project colony.

ii) Impacts on reservoir water quality

The flooding of previously forest land in the submergence area will increase the availability

of nutrients resulting from decomposition of vegetative matter. Phytoplankton productivity

can supersaturate the euphotic zone with oxygen before contributing to the accommodation

of organic matter in the sediments. Enrichment of impounded water with organic and

inorganic nutrients will be the main water quality problem immediately on commencement of

the operation. However, this phenomenon is likely to last for a short duration of few years

from the filling up of the reservoir. In the proposed project, most of the land coming under

reservoir submergence is barren, with few patches of trees. These trees too are likely to be

cleared before filling up of the reservoir. The proposed project is envisaged as a runoff the

river scheme, with significant diurnal variations in reservoir water level. In such a scenario,

significant re-aeration from natural atmosphere takes place, which maintains Dissolved

Oxygen in the water body. Thus, in the proposed project, no significant reduction in D.O.

level in reservoir water is anticipated.

iii) Eutrophication risks

Another significant impact observed in the reservoir is the problem of eutrophication, which

occurs mainly due to the disposal of nutrient rich effluents from the agricultural fields.

However, in the present case, fertilizer use in the project area is negligible, hence, the runoff

at present does not contain significant amount of nutrients. Even in the post-project phase,

use of fertilizers in the project catchment area is not expected to rise significantly. Another

factor to be considered that the proposed project is envisaged as a run off the river scheme,

with significant diurnal variations in reservoir water level. Thus, residence time would be of

the order of few days, which is too small to cause any eutrophication. Thus, in project


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operation phase, problems of eutrophication, which is primarily caused by enrichment of

nutrients in water, are not anticipated.

9.2.2 Sediments

When a river flows along a steep gradient, it could carry a significant amount of sediment

load, depending on the degradation status of the catchment. When a hydraulic structure is

built across the river, it creates a reservoir, which tends to accumulate the sediment, as the

suspended load settles down due to decrease in flow velocity. The proposed project is

envisaged as a runoff the river scheme, with a barrage at regular intervals, the gates of the

barrage shall be opened to flush out the sediments. Thus, in the proposed project,

sedimentation problems are not anticipated.

9.2.3 Water resources and downstream users

The Sach Khas Hydro Electric Project is a run of river scheme project on river Chenab.

Since, it is a dam toe power house, not diversion of water for hydropower generation will

lead to drying or reduction of flow river stretch in monsoon season. The lean season, it will

lead to drying of river stretch to store water for MDDL to FRL for peaking power generation.

There are no major users of water in the intervening stretches, as the river stretch flows

through a gorge. As a result, there are no major users of water of river Chenab in the

intervening stretch. Thus, no major adverse impacts are anticipated on downstream water

users. This can lead to adverse impacts on riverine ecology, which needs to be ameliorated

through the release of minimum flow. The number of hours for which Peaking is available in

Sach Khas HEP is given in Table-9.5.

Table-9.5: Number of hours of peaking available in 90% dependable year for Sach Khas HEP Month Discharge in 90%

Dependable year (cumec)

Rated discharge (cumec)

Time available for peaking power (hrs.)

June

I 339.77 428.1 19.0 II 525.26 428.1 24.0 III 510.65 428.1 24.0

July

I 722.12 428.1 24.0 II 724.46 428.1 24.0 III 502.94 428.1 24.0

August

I 552.68 428.1 24.0 II 443.77 428.1 24.0 III 522.50 428.1 24.0

September

I 396.95 428.1 22.3 II 274.44 428.1 15.4 III 223.06 428.1 12.5

October

I 145.25 428.1 8.1 II 120.17 428.1 6.7


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Month Discharge in 90% Dependable year (cumec)

Rated discharge (cumec)

Time available for peaking power (hrs.)

III 89.18 428.1 5.0 November

I 85.72 428.1 4.8 II 88.84 428.1 5.0 III 82.49 428.1 4.6

December

I 20.4 428.1 1.1 II 27.7 428.1 1.6 III 25.9 428.1 1.5

January

I 10.4 428.1 0.6 II 9.3 428.1 0.5 III 9.6 428.1 0.5

February

I 8.7 428.1 0.5 II 9.3 428.1 0.5 III 10.7 428.1 0.6

March

I 17.3 428.1 1.0 II 17.6 428.1 1.0 III 30.5 428.1 1.7

April

I 76.02 428.1 4.3 II 76.02 428.1 4.3 III 97.76 428.1 5.5

May I 128.53 428.1 7.2 II 149.60 428.1 8.4 III 216.36 428.1 12.1

Source: D PR

It can be seen from Table-9.5 that number of hours for which peaking power will be

available, in 90% dependable year shall range from 12.5 to 24 hours in monsoon season

from June to September. In the period from October to November and April to May, peaking

will be available for a period of 4.6 to 8.1 hours and 4.3 to 12.1 hours respectively.

In lean season, from December to March peaking will be available for a period of 0.5 to 1.7

hours in 90% dependable year. It can be observed that in lean season, river water will be

stored for a period of 22 to 23.5 hours. As a result, downstream stretch of river from the dam

site will be remain dry for a period of 22 to 23.5 hours, which will be followed by a continuous

flow equal to rated discharge of 428.1 cumec for a period of 0.5 to 2 hours.

The modification of downstream river flow characteristics (regime) by an impoundment shall

have adverse effects upon fish species. These include impact on migration, spawning

grounds, survival of eggs & juveniles, food production etc.

Regulation of stream flow during the migratory period can alter the seasonal and daily

dynamics of migration. Regulation of a river can lead to decrease in a migratory population.

In Sach Khas hydroelectric project, the discharge for 90% dependable year is higher than


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the rated discharge (428.1 cumec) for a period about 70 days from 11th June to 31st August.

The project envisages generation of 260 MW of hydropower using 3 turbines of 86.57 MW

capacity each. Thus, in monsoon months, all of the three turbines can be operated and pre-

project level of discharge will be maintained in river Chenab downstream of Sach Khas

hydro-electric project.

In lean season, i.e. from December to March, the discharge is less and even one turbine

cannot run at 10% capacity. If peaking power is to be generated then the reservoir needs to

be filled up to FRL. This can result in drying of river stretch downstream of dam site of Sach

Khas hydroelectric project for a stretch of 6.0 km, i.e. upto tail end of reservoir of Dugar

hydroelectric project. The drying of river stretch to fill the reservoir upto FRL for peaking

power will last even upto 23.5 hours, after which there will continuous flow equivalent to

rated discharge of 428.1 cumec for 0.5 to 2 hours. Even, if peaking power is not attained and

turbines operate at lower capacity (based on optimization of power generation with respect

to cost) can result in drying up of river stretch followed by continuous flow of rated discharge.

The rated discharge could be 9 to 10 times the lean season flow in a 90% dependable year.

9.3 IMPACTS ON AIR ENVIRONMENT

In a water resources project, air pollution occurs mainly during project construction phase. The

major sources of air pollution during construction phase are:

• Pollution due to fuel combustion in various equipment • Emission from various crushers • Fugitive emissions from various sources. • Blasting Operations • Pollution due to increased vehicular movement • Dust emission from muck disposal • Pollution due to DG sets

Pollution due to fuel combustion in various equipment

The operation of various construction equipment’s requires combustion of fuel. Normally, diesel

is used in such equipment. The major pollutant which gets emitted as a result of combustion of

diesel is SO2. The SPM emissions are minimal due to low ash content in diesel. The short-term

increase in SO2, even assuming that all the equipment are operating at a common point, is

quite low, i.e. of the order of less than 1µg/m3. Hence, no major impact is anticipated on this

account on ambient air quality.

Emissions from crushers

The operation of the crusher during the construction phase is likely to generate fugitive

emissions, which can move even up to 1 km in predominant wind direction. During construction

phase, one crusher each is likely to be commissioned near proposed dam and proposed power


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house sites. During crushing operations, fugitive emissions comprising mainly the suspended

particulate will be generated. Since, there are no major settlements close to the dam and power

house; hence, no major adverse impacts on this account are anticipated. However, during the

layout design, care should be taken to ensure that the labour camps, colonies, etc. are located

on the leeward side and outside the impact zone (say about 2 km on the wind direction) of the

crushers.

Fugitive Emissions from various sources

During construction phase, there will be increased vehicular movement. Lot of construction

material like sand, fine aggregate are stored at various sites, during the project construction

phase. Normally, due to blowing of winds, especially when the environment is dry, some of the

stored material can get entrained in the atmosphere. However, such impacts are visible only in

and around the storage sites. The impacts on this account are generally, insignificant in nature.

Blasting Operations

Blasting will result in vibration, which shall propagate through the rocks to various degrees

and may cause loosening of rocks/boulders. The overall impact due to blasting operations

will be restricted well below the surface and no major impacts are envisaged at the ground

level. During various blasting operations, dust will be generated, ID blowers will be provided

with dust handling system to capture and generated dust. The dust will settle on vegetation,

in the predominant down wind direction. Appropriate control measures have been

recommended to minimize the adverse impacts on this account.

Pollution due to increased vehicular movement

During construction phase, there will be increased vehicular movement for transportation of

various construction materials to the project site. Similarly, these will be increased traffic

movement on account of disposal of muck or construction waste at the dumping site. The

maximum increase in vehicle is expected to 50 vehicles per hour. Large quantity of dust is

likely to be entrained due to the movement of trucks and other heavy vehicles. Similarly,

marginal increase in Hydrocarbons, SO2 and NOx levels are anticipated for a short duration.

Modeling studies for hydrocarbon emissions were conducted and the results are given in

Table-9.6.

Table-9.6: Increase in hydrocarbon concentration due to vehicular movement Distance (m) Increase in HC concentration (µg/m 3) 10 5 20 2.50 30 1.67 40 1.25 50 1.00


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Distance (m) Increase in HC concentration (µg/m 3) 60 0.83 70 0.71 80 0.63 90 0.56 100 0.50 The increase in vehicular density is not expected to significant. In addition, these ground

level emissions do not travel for long distances. Thus, no major adverse impacts are

anticipated on this account.

Dust emission from muck disposal

The loading and unloading of muck is one of the source of dust generation. Since, muck will be

mainly in form of small rock pieces, stone, etc., with very little dust particles. Significant amount

of dust is not expected to be generated on this account. Thus, adverse impacts due to dust

generation during muck disposal are not expected.

Pollution due to operation of DG sets

Construction power would not be available for the project from any resources in the state.

The requirement would have to be met by two sources 3.5MW Chhoo Hydroelectric Project

and through diesel generating sets. The requirement of construction power would vary at

each individual site depending upon the equipment deployed. The operation of DG sets

would lead to air pollution. The capacity of DG sets would be estimated during project

construction phase. The fuel consumed shall be LDO. The major emission LDO combustion

shall be SO2. The particulate matter emissions shall be marginal, due to low ash content in

LDO. Appropriate management measures to reduce emission level from the incinerator shall

be commissioned to reduce the impacts on ambient air quality.

9.4 IMPACTS ON NOISE ENVIRONMENT


In a water resource projects, the impacts on ambient noise levels are expected only during the

project construction phase, due to earth moving machinery, etc. Likewise, noise due to

quarrying, blasting, vehicular movement will have some adverse impacts on the ambient noise

levels in the area.

i) Impacts due to operation of construction equipment

The noise level due to operation of various construction equipment’s is given in Table-9.7.


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Table-9.7: Noise level due to operation of various construction equipment’s Equipment Noise level dB(A) Earth moving Compactors 70-72 Loaders and Excavator 72-82 Dumper 72-92 Tractors 76-92 Scrappers, graders 82-92 Pavers 86-88 Truck 84-94 Material handling Concrete mixers 75-85 Movable cranes 82-84 Stationary Pumps 68-70 Generators 72-82 Compressors 75-85 Others Vibrators 69-81 Saws 74-81

Under the worst-case scenario, considered for prediction of noise levels during construction

phase, it has been assumed that all these equipment’s generate noise from a common point.

The increase in noise levels due to operation of various construction equipment’s is given in

Table-9.8.

Table-9.8: Increase in noise levels due to operation of various construction equipment’s

Distanc e (m)

Ambient noise levels dB(A)

Increase in noise level due to construction activities dB(A)

Increased noise level due to construction activities dB(A)

Increase in ambient noise level due to construction activities dB(A)

100 36 45 45 34 200 36 39 39 29 500 36 31 31 25 1000 36 25 25 25 1500 36 21 21 24 2000 36 19 19 24 2500 36 17 17 24 3000 36 15 15 24

It would be worthwhile to mention here that in absence of the data on actual location of various

construction equipment’s, all the equipment have been assumed to operate at a common point.

This assumption leads to over-estimation of the increase in noise levels. Also, it is a known fact

that there is a reduction in noise level as the sound wave passes through a barrier. The

transmission loss values for common construction materials are given in Table-9.9.


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Table-9.9: Transmission loss for common construction materials

Material Thickness of construction material (inches)

Decrease in noise level dB(A)

Light concrete 4 38 6 39

Dense concrete 4 40 Concrete block 4 32

6 36 Brick 4 33 Granite 4 40

Thus, the walls of various houses will attenuate at least 30 dB(A) of noise. In addition there are

attenuation due to the following factors.

• Air absorption • Rain • Atmospheric in homogeneities. • Vegetal cover

Thus, no increase in noise levels is anticipated as a result of various activities, during the

project construction phase. The noise generated due to blasting is not likely to have any effect

on habitations. However, blasting can have adverse impact on wildlife. It would be worthwhile to

mention that no major wildlife is observed in and around the project site. Hence, no significant

impact is expected on this account.

Impacts due to increased vehicular movement

During construction phase, there will be significant increase in vehicular movement for

transportation of construction material. At present, there is no vehicular movement near the

dam site. During construction phase, the increase in vehicular movement is expected to

increase up to a maximum of 5 to 6 trucks/hour.

As a part of EIA study, impact on noise level due to increased vehicular movement was

studied using Federal Highway Administration model. The results of modeling are outlined in

Table-9.10.

Table-9.10: Increase in noise levels due to increased vehicular movement Distance (m) Ambient noise

level dB(A) Increase in noise level due to increased vehicular movement dB(A)

Noise levels due to increased vehicular movement dB(A)

Increase in ambient noise level due to increased vehicular movement dB(A)

10 36 72 72 60 20 36 67 67 55 50 36 61 61 49 100 36 57 57 45


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Distance (m) Ambient noise level dB(A)

Increase in noise level due to increased vehicular movement dB(A)

Noise levels due to increased vehicular movement dB(A)

Increase in ambient noise level due to increased vehicular movement dB(A)

200 36 52 52 40 500 36 46 47 35 1000 36 42 44 31

As mentioned earlier, there will be significant attenuation due to various factors, e.g.

absorption by construction material, air absorption, atmospheric in homogeneties, and

vegetal cover. Thus, no significant impact on this account is anticipated. Appropriate

measures have been suggested as a part of Environmental Management Plan (EMP) report

to minimize impacts on wildlife.

Impacts on labour

The effect of high noise levels on the operating personnel has to be considered as this may

be particularly harmful. It is known that continuous exposures to high noise levels above 90

dB(A) affects the hearing acuity of the workers/operators and hence, should be avoided. To

prevent these effects, it has been recommended by Occupational Safety and Health

Administration (OSHA) that the exposure period of affected persons be limited as per the

maximum exposure period specified in Table-9.11.

Table-9.11: Maximum Exposure Periods specified by OSHA

Maximum equivalent continuous Noise level dB(A)

Unprotected exposure period per day for 8 hrs/day and 5 days/week

90 8 95 4 100 2 105 1 110 ½ 115 ¼ 120 No exposure permitted at or above this level

Noise generated due to drilling

The noise levels monitored at a 10 m distance from the source and operator’s cabin is given

in Table-9.12.

Table-9.12: Noise generated due to drilling

Equipment Noise level at source dB(A) Standing idle (inside cabin) 70-72 Standing idle (10 m radius) 72-74 On load (inside cabin) 78-80 On load (10 m radius) 82-84


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The noise levels during various construction activities have been compared to various

standards prescribed by Occupational Safety and Health Administration (OSHA), which are

being implemented in our country through rules framed under Factories Act. It can be

observed that as per unprotected exposure period specified by OSHA (Refer Table-9.11 )

that for an 8 hour duration, equivalent noise level exposure should be less than 90 dB(A).

The Director General of Mines Safety in its circular no. DG(Tech)/18 of 1975, has prescribed

the noise level in mining operations for workers in 8 hour shift period with unprotected ear as

90 dB(A) or less. Similar norms can be considered for construction phase of the proposed

project as well. The workers who are expected to be exposed to noise levels greater than 90

dB(A), should not work in these areas beyond 6 to 8 hours. In addition, they also need to be

provided with ear plugs. Thus, increased noise levels due to drilling are not expected to

adversely affect the workers operating the drill or involved in other mining activities closely.

Noise generated due to blasting

Noise generated by blasting is instantaneous, site specific and depends on type, quantity of

explosives, dimension of drill hole, degree of compaction of explosives in the hole and rock.

Noise levels generated due to blasting have been monitored at various sites and the results

have been summarized in Table-9.13 .

Table-9.13: Noise generation due to blasting No. of holes Total charge

(kg) Maximum charge/delay (kg)

Distance (m) Noise level dB(A)

15 1500 100 250 76-85 17 1700 100 250 76-86 18 1800 100 250 74-85 19 1900 100 400 70-75 20 2000 100 100 76-80

It can be observed from Table-9.13 , that noise level due to blasting operations are expected

to be of the order of 75-86 dB(A). Since, the nearest settlement are about 0.8 to 1.0 km

away, the incremental noise due to blasting is expected to be 50-60 dB(A). As the blasting is

likely to last for 4 to 5 seconds depending on the charge, noise levels over this time would be

instantaneous and short in duration. Considering attenuation due to various sources, even

the instantaneous increase in noise level is not expected to 60 dB(A). Hence, noise level due

to blasting is not expected to cause any significant adverse impact.


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9.5 IMPACTS ON LAND ENVIRONMENT


The major impacts anticipated on land environment during construction are as follows:

• Quarrying operations • Operation of construction equipment • Soil erosion • Muck disposal • Acquisition of land

Quarrying operations

The total quantities required for the construction of civil components of the Sach Khas HEP

are as follows:

� Concrete and Shotcrete Volume : 7.5 Lakh Cum � Fine Aggregate : 3.5 Lakh Cum � Coarse Aggregate : 8.5 Lakh Cum

The above construction material shall be arranged from the identified quarry sites located at

the confluence of Bakanwal nala with Chenab River, 3.6 Km upstream of dam axis on the left

bank. The quantum of muck generation is 13, 15,000.00 cum, of 3, 94,500.00 cum shall be used

as construction material. Fine aggregate requirement shall be met locally from the river bed

and crushed sand.

River Bed Material for Aggregates

For the construction purpose around 70% material from Quarry site, 20% material from

excavated muck & rest 10% material shall be utilized from River bed.

Opening of the quarries will cause visual impacts because they remove a significant part of

the hills. Other impacts will be the noise generated during aggregate acquisition through

explosive and crushing, which could affect wildlife in the area, dust produced during the

crushing operation to get the aggregates to the appropriate size and transport of the

aggregates, and transport of materials.

The quarrying operations are semi-mechanized in nature. Normally, in a hilly terrain like

Himachal Pradesh, quarrying is normally done by cutting a face of the hill. A permanent scar

is likely to be left, once quarrying activities are over. With the passage of time, the rock from

the exposed face of the quarry under the action of wind and other erosion forces, get slowly

weathered and after some time, they become a potential source of landslide. Thus it is

necessary to implement appropriate slope stabilization measures to prevent the possibility of

soil erosion and landslides in the quarry sites.


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ii) Operation of construction equipment

During construction phase, various types of equipment’s will be brought to the site. These

include crushers, batching plant, drillers, earthmovers, rock bolters, etc. The siting of this

construction equipment’s would require significant amount of space. Similarly, space will be

required for storing of various other construction equipment. In addition, land will also be

temporarily acquired, i.e. for the duration of project construction for storage of quarried

material before crushing, crushed material, cement, rubble, etc. Efforts must be made for

proper siting of these facilities.

Various criteria for selection of these sites would be:

• Proximity to the site of use • Sensitivity of forests in the nearby areas • Proximity from habitations • Proximity to drinking water source Efforts must be made to site the contractor’s working space in such a way that the adverse

impacts on environment are minimal, i.e. to locate the construction equipment, so that an

impact on human and faunal population is minimal.

iii) Soil erosion

The runoff from the construction sites will have a natural tendency to flow towards river

Chenab or its tributaries. For some distance downstream of major construction sites, such as

dam, power house, etc. there is a possibility of increased sediment levels which will lead to

reduction in light penetration, which in turn could reduces the photosynthetic activity to some

extent of the aquatic plants as it depends directly on sunlight. This change is likely to have

an adverse impact on the primary biological productivity of the affected stretch of river

Chenab. Since, river Chenab has significant flow; hence, impacts on this account are not

expected to be significant. However, runoff from construction sites, entering small streams

would have significant adverse impact on their water quality. The runoff would increase the

turbidity levels with corresponding adverse impacts on photosynthetic action and biological

productivity. The impacts on these streams and rivulets thus, would be significant. Adequate

measures need to be implemented as a part of EMP to ameliorate this adverse impact to the

extent possible.

iv) Muck disposal

Total muck from excavation of the project components such as Dam, Power house, TRT, Adits,

Pressure shaft etc. worked out, Component wise muck generation and disposal are given in

Tables-9.14 and 9.15 respectively.


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Table-9.14: Component wise Total Muck Generation

S. No. Particulars Quantity (cum) 1. Diversion Tunnel 1,40,000 2. Dam & Intake 6,00,000 3. Plunge Pool 1,10,000 4. Pressure Shaft 70,000 5. Powerhouse 2,50,000 6. Tail Race Tunnel 20,000 7. Adits 25,000 8. Project Roads 1,00,000 Total 13,15,000

Source: D PR

Table-9.15: Total Muck to be disposed after Considering Swelling Factor

S. No. Description Quantity (cum) 1 Total Excavation 13,15,000.00 2 Common Excavation (considering 40% of Total

Muck) 5,26,000.00

3 Total Rock Excavation = (1) – (2) 7,89,000.00 4 Reusable Quantity as construction material 3,94,500.00 5 Disposable rock muck 3,94,500.00 6 Disposable rock muck after swelling:

(considering 50% swelling factor) 5,91,750.00

7 Back fill/fill quantity 1,90,000.00 8 Disposable common muck = (2) – (7) 3,36,000.00 9 Disposable common muck after swelling

(considering 25% swelling factor) 4,20,000.00

10 Total muck to be disposed = (6 ) + (9) 10,11,750.00 Source: D PR

It is clear from Table-9.15 , that total 1.01 Mm3 of muck needs to be disposed. Most of the

area, identified for dumping is planned on the banks of nearest drainages & away from River

HFL. The identified areas are mostly gradually sloping near river bank. The drainage side

bank of the area will be properly protected and stabilized with Gabions/ Retaining Walls of

suitable designed sections. The details of muck disposal areas and capacities are given in

Table-9.16.

Table-9.16: Muck Disposal Sites and Capacities

S. No.

Disposal Site Area Average road distance from Dam

area

Capacity

(ha) (km) (lakh cum) 1 Area near Bumbal (R/Bank) 5.46 1 2.30 2 Area near Mindhal Bridge

(L/Bank) 0.77 6 0.20


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S. No.

Disposal Site Area Average road distance from Dam

area

Capacity

(ha) (km) (lakh cum) 3 Area near Mindhal Bridge

(L/Bank) 0.66 6 1.10

4 Area near Mindhal Bridge (L/Bank)

3.64 6 6.60

Total 10.53 10.20 Source: D PR

The capacity of various muck disposal sites is 1.02 Mm3. As such, around 1.01 Mm3 muck to

be disposed hence capacity of the dumping area is sufficient to accommodate the muck

generated from the project.

Muck, if not securely transported and dumped at pre-designated sites, can have serious

environmental impacts, such as:

• Muck, if not disposed properly, can be washed away into the main river which can

cause negative impacts on the aquatic ecosystem of the river.

• Muck disposal can lead to impacts on various aspects of environment. Normally,

the land is cleared before muck disposal. During clearing operations, trees are

cut, and undergrowth perishes as a result of muck disposal.

• In many of the sites, muck is stacked without adequate stabilization measures. In

such a scenario, the muck moves along with runoff and creates landslide like

situations. Many a times, boulders/large stone pieces enter the river/water body,

affecting the benthic fauna, fisheries and other components of aquatic biota.

• Normally muck disposal is done at low lying areas, which get filled up due to

stacking of muck. This can sometimes affect the natural drainage pattern of the

area leading to accumulation of water or partial flooding of some area.

The muck disposal sites will be suitably stabilized on completion of the muck disposal. The

details of stabilization of muck disposal sites are outlined in Environmental Management

Plan covered in Volume-II of this Report.

v) Acquisition of land

The total land required for the project is 125.62 ha. A part of this land is required for labour

camps, quarry sites, muck disposal storage of construction material, siting of construction

equipment, which will be required temporarily and returned once the construction phase is

over. Permanent acquisition of land is required for Dam axis, submergence area, Power

House etc. The details of land required for various project appurtenances are given in Table-

9.17. The entire land to be acquired is forest land.


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Table-9.17: Land requirement for Sach Khas hydroelectric project

S. No Project Component/ Activity Area (ha) 1 Submergence Area: a) Forest Land 81.88 b) Non-Forest Land (Private Land) 0.28

Total Area of Submergence 82.16 2 Muck Dumping Area 10.53 3 Quarry 3.03 4 Dam & Power House 9.54 5 Project Site Offices/Job Facilities: 5.25 6 Explosive Magazine 0.23 7 Sub-surface (Underground Works) Area 2.44 8. Approach Roads to explosive magazine,

Project facilities & Quarry 5.32

9. Township & Office (Private land on lease basis)

7.12

Total 125.62 Source: D PR

vi) Impacts due to roads

To execute the various civil works, roads would be made for linking the work site to other

sites and to job facility areas. They would essentially be unpaved and would be constructed

at a workable gradient so that loaded construction equipment does not have to toil hard to go

up slope. An average gradient of 1:15 has been contemplated. These roads would be

connected to the existing roads in the area or to other project roads. The details are given in

Table-9.17 .

Table-9.17: List of new roads to be constructed New roads to be constructed Length (Km) Project Area Bridge to Dam Site (Left Bank of the River) 0.368 Quarry Site to Main Road (SH-26 – Left Bank of the River) 4.139 Project Area Bridge to Main Road (Via Facility Area) 2.995 Dam Top to Main Road (SH-26 – Right Bank of the River) 0.578 Main Road (SH-26) to Dumping Area (Right Bank of the River) 4.00 Total 12.08 Source: D PR

Two bridges are proposed to construct at River Chenab, one at downstream of Tail Race

Tunnel & other on at Ajog Village for the access of Township. The length of the each bridge

shall be in order of 50 m.


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The construction of roads can lead to the following impacts:

• The topography of the project area has steep to precipitatuous slope, which

descends rapidly into narrow valleys. The conditions can give rise to erosion hazards

due to net downhill movement of soil aggregates.

• Removal of trees on slopes and re-working of the slopes in the immediate vicinity of

roads can encourage landslides, erosion gullies, etc. With the removal of vegetal

cover, erosive action of water gets pronounced and accelerates the process of soil

erosion and formation of deep gullies. Consequently, the hill faces are bared of soil

vegetative cover and enormous quantities of soil and rock can move down the rivers,

and in some cases, the road itself may get washed out.

• Construction of new roads increases the accessibility of a hitherto undisturbed areas

resulting in greater human interferences and subsequent adverse impacts on the

ecosystem.

• Increased air pollution during construction phase.

9.6 IMPACTS ON BIOLOGICAL ENVIRONMENT


i) Increased human interferences

During project construction phase, labour population is likely to congregate near various

construction sites. It can be assumed that the technical staff likely to congregate will be of

higher economic status and will live in a more urbanized habitat, and will not use wood as

fuel. However, workers and other population groups residing in the area may use fuel wood

(if no alternate fuel is provided) for whom firewood/coal depot could be provided.

The details of fuel wood requirements are given as below:

* Average fuel wood consumption : 20 kg pcd * Population size over : 3600 Project construction phase * Average consumption per day : 72 t/day or 2232 t/month * For a construction period of 9.5 years : 54448 t or 31060 m3.

One tree produces about 2.5 m3 of wood, thus, about 127,200 trees will be cut to meet the

fuel wood requirements to the labour population, over a construction phase of 9.5 years.

Hence to minimize impacts, it is recommended that the project contractor shall provide

alternate source of fuel be provided to the labour population, so that they do not cut trees to

meet their fuel wood requirements. The details are covered in Environmental Management

Plan covered in Volume-II of this Report.


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The other major impact on the flora in and around the project area would be due to

increased level of human interferences. The workers may also cut trees to meet their

requirements for construction of houses and other needs. Thus, if proper measures are not

undertaken, adverse impacts on terrestrial flora is anticipated. Since, labour camps are

proposed to be constructed by the contractor along with necessary facilities, such impacts

are not envisaged.

During construction of various components of the project, e.g., road, colony, dam axis, muck

disposal, etc. trees will have to be cleared. The tree felling or clearing shall be done by the

Forest Department.

Impacts due to Vehicular movement and blasting

Dust is expected to be generated during blasting, vehicle movement for transportation of

construction material or construction waste. The dust particles shall settle on the foliage of

trees and plants, thereby reduction in amount of sunlight falling on tree foliage. This will

reduce the photosynthetic activity. Based on experience in similar settings, the impact is

expected to be localized up to a maximum of 50 to 100 m from the source. Thus, no

significant impact is expected on this account.

Acquisition of forest land

During project construction phase, land will be required for location of construction

equipment, storage of construction material, muck disposal, widening of existing roads and

construction of new project roads. The total land requirement for the project is 125.62 ha.

The major portion is under riverbed, i.e. submergence area, which is about 82.16 ha. The

balance land is mostly under forest.

The forest in the area has already been degraded due to a large-scale human interference.

The tree density at dam site and submergence area is 126 per ha 151 per ha respectively.

The dominant tree species at dam site are Pinus wallichiana and Juniperus recurva. Shrub

layer is represented by Berberis jaeschkeana, Lonicera sp., Juniperus communis, etc. Pinus

wallichiana, and Juniperus recurva, are the dominant trees recorded from power house site.

The commonly observed shrubs at this site were Rosa sp.and Lonicera sp., Salix sp.

No rare and endangered species are observed in the forest to be acquired for the project.

Thus, no adverse impacts are anticipated on this account.


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9.6.2 Impacts on Terrestrial fauna


Disturbance to wildlife

The total land required for the project is 125.62 ha of which 82.16 ha comes under

submergence, (including river bed). The balance 43.46 ha land is required for other project

appurtenances.

Based on the field survey and interaction with locals, it was confirmed that no major wildlife

is reported in the proposed submergence area. It would be worthwhile to mention here that

most of the submergence lies within the gorge portion. Thus, creation of a reservoir due to

the proposed project is not expected to cause any significant adverse impact on wildlife

movement. The project area and its surroundings are not reported to serve as habitat for

wildlife nor do they lie on any known migratory route of wildlife. Thus, no impacts are

anticipated on this account.

During construction phase, large number of machinery and construction workers shall be

mobilized. The operation of various equipments will generate significant noise, especially

during blasting which will have adverse impact on fauna of the area. The noise may affect

the fauna and in the area. . Likewise, siting of construction plants, workshops, stores, labour

camps etc. could also lead to adverse impact on fauna of the area due to increase human

interfererence.

During construction phase, accessibility to area will lead to influx of workers and the people

associated with the allied activities from outside will also increase. Increase in human

interference could have an impact on terrestrial ecosystem. The other major impact could be

the blasting to be carried out during construction phase. This impact needs to be mitigated

by adopting controlled blasting and strict surveillance regime and the same is proposed to be

used in the project. This will reduce the noise level and vibrations due to blasting to a great

extent. Likewise, siting of construction equipment, godowns, stores, labour camps, etc. may

generally disturb the fauna in the area. However, no large-scale fauna is observed in the

area. Thus, impacts on this account are not expected to be significant. However, few stray

animals sometimes venture in and around the project site. Thus, to minimize any harm due

to poaching activities from immigrant labour population, strict anti-poaching surveillance

measures need to be implemented, especially during project construction phase. The same

have been suggested as a part of the Environmental Management Plan (EMP).


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Impacts on migratory routes

The faunal species observed in the project area are not migratory in nature. The proposed

submergence area is not the migratory route of wild animals. The construction of the

proposed Sach Khas hydroelectric project will form a reservoir of about 82.16 ha, which is

also not reported to be on the migratory route of any major faunal species.

Impacts on avi-fauna

The project area and its surroundings are quite rich in avi-fauna. However, water birds are

not very common in the area. The main reason for this phenomenon is that water birds

generally require quiescent or slow moving water environment. However, in the proposed

project area and its surroundings due to terrain conditions, water flow is swift, which does

not provide suitable habitat for the growth of water birds. With the damming of the river, a

reservoir of an area of about 82.16 ha will be created, with quiescent/tranquil conditions. The

reservoir banks will have wet environment throughout the year which can lead to proliferation

of vegetation e.g. grass, etc. along the reservoir banks. Such conditions are generally ideal

for various kinds of birds, especially, water birds. This is expected to increase the avi-faunal

population of the area.

b) Operation phase

i) Increased accessibility

During the project operation phase, the accessibility to the area will improve due to

construction of roads, which in turn may increase human interferences leading to marginal

adverse impacts on the terrestrial ecosystem. The increased accessibility to the area can

lead to increased human interferences in the form of illegal logging, lopping of trees,

collection of non-timber forest produce, etc. Since significant wildlife population is not found

in the region, adverse impacts of such interferences are likely to be marginal. The details of

measures to improve terrestrial ecology of the area are covered in Volume II of this Report.

9.6.3 Aquatic Flora


During construction phase wastewater mostly from domestic source will be discharged

mostly from various camps of workers actively engaged in the project area. Around 0.49 mld

of water is required for the workers during the peak construction phase out of which 80%

(i.e. about 0.39 mld) will be discharged back to the river as wastes, more or less as a point

sources from various congregation sites where workers will reside. The average minimum

flow during lean season is about 8.7 cumec. However, sufficient water for dilution will be

available in river Chenab to keep the DO of the river to significantly high levels.


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b) Operation phase

The completion of Sach Khas hydroelectric Project would bring about significant changes in

the riverine ecology, as the river transforms from a fast-flowing water system to a quiescent

lacustrine environment. Such an alteration of the habitat would bring changes in physical,

chemical and biotic life. Among the biotic communities, certain species can survive the

transitional phase and can adapt to the changed riverine habitat. There are other species

amongst the biotic communities, which, however, for varied reasons related to feeding and

reproductive characteristics cannot acclimatize to the changed environment, and may

disappear in the early years of impoundment of water. The micro-biotic organisms especially

diatoms, blue-green and green algae before the operation of project, have their habitats

beneath boulders, stones, fallen logs along the river, where depth is such that light

penetration can take place. But with the damming of river, these organisms may perish as a

result of increase in depth.

9.6.4 Impacts on Aquatic Fauna

Construction phase

Impacts due to excavation of construction material from river bed

During the construction phase a large quantity of construction material like stones, pebbles,

gravel and sand would be needed. Significant amount of material is available in the Quarry

and river bed. It is proposed to extract construction material from quarry as well as from the

River bed. The extraction of construction material may affect the river water quality due to

increase in the turbidity levels. This is mainly because the dredged material gets released

during one or all the operations mentioned below:

• Excavation of material from the river bed. • Loss of material during transport to the surface. • Overflow from the dredger while loading • Loss of material from the dredger during transportation.

The cumulative impact of all the above operations is increase in turbidity levels. Good dredging

practices can however, minimize turbidity. It has also been observed that slope collapse is the

major factor responsible for increase in the turbidity levels. If the depth of cut is too high, there

is possibility of slope collapse, which releases a sediment cloud. This will further move outside

the suction radius of dredged head.

In order to avoid this typical situation, the depth of cut be restricted to:

γ H/C < 5.5

Where, γ - Unit weight of the soil H - Depth of soil


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C - Cohesive strength of soil

The dredging and deposition of dredged material may affect the survival and propagation of

benthic organisms. The macro-benthic life which remains attached to the stones, boulders etc.

gets dislodged and is carried away downstream by turbulent flow. The areas from where

construction material is excavated, benthic fauna gets destroyed. In due course of time,

however, the area gets recolonized, with fresh benthic fauna. The density and diversity of

benthic fauna will however, be less as compared with the pre-dredging levels.

The second important impact is on the spawning areas of fishes. Almost all the cold water fish

breed in the flowing waters. The spawning areas of these fish species are found amongst

pebbles, gravel, sand etc. The eggs are sticky in nature and remain embedded in the gravel

and subsequently hatch. Any disturbance of stream bottom will result in adverse impacts on fish

eggs. Even increase in fine solids beyond 25 ppm will result in deposition of silt over the eggs,

which would result in asphyxiation of developing embryo and also choking of gills of young

newly emerged fry. Thus, if adequate precautions during dredging operations are not

undertaken, then significant adverse impacts on aquatic ecology are anticipated.

Impacts due to discharge of sewage from labour camp/colony

The proposed hydro-power project envisages construction of a project colony at Village

Ajog. This would result in emergence of domestic waste water which is usually discharged

into the river. However, it is proposed to commission aseptic tank for treatment of sewage

prior its disposal. Due to perennial nature of river Chenab, it maintains sufficient flow

throughout the year which is sufficient to dilute the treated sewage from residential colonies.

Therefore, as mentioned earlier, no adverse impacts on water quality are anticipated due to

discharge of sewage from labour camp/colony.

Impacts due to human activities

Accumulation of labour force in the project area might result in enhancement in

indiscriminate fishing including use of explosives. The use of explosive material to kill fishes

in the river in the project area would result in complete loss of fishes and other aquatic life

making a river stretch completely barren. Indiscriminate fishing will reduce fish stock

availability for commercial and sport fishermen. These aspects have been adequately

covered in the Environmental Management Plan (EMP) outlined in Volume II of this Report.


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(b) Operation Phase

Impacts due to damming of river

The damming of river Chenab due to the proposed hydroelectric project in creation of 82.16 ha

of submergence area. The dam will change the fast flowing river to a quiescent lacustrine

environment. The creation of a pond will bring about a number of alterations in physical, abiotic

and biotic parameters both in upstream and downstream directions of the proposed dam site.

The micro and macro benthic biota is likely to be most severely affected as a result of the

proposed project.

The positive impact of the project will be the formation of a water body which can be used for

fish stocks on commercial basis to meet the protein requirement of region. The commercial

fishing in the proposed reservoir would be successful, provided all tree stumps and other

undesirable objects are removed before submergence. The existence of tree stumps and other

objects will hinder the operation of deep water nets. The nets will get entangled in the tree

stumps and may be damaged.

The reduction in flow rate of river Chenab in lean season is likely to increase turbidity levels

downstream of the dam. Further reduction in rate of flow may even create condition of semi-

dessication in certain stretches of the river. Since, fisheries are not reported in the project

area, hence, this is not reported to lead to any adverse impacts on riverine fisheries.

Impacts on migratory fish speies

The obstruction created by the dam would hinder migration of species especially Schizothorax

sp. (from upper reaches to the lower reaches). These fish species undertake annual migration

for feeding and breeding. Therefore, fish migration path may be obstructed due to high dam

and fishes are expected to congregate below the dam wall. Under this situation poaching

activities may increase in the area. However, it is proposed that the artificial seed production in

hatchery may be adopted which can be stocked in the river stretches downstream and

upstream of the proposed dam.

9.7 IMPACTS ON SOCIO-ECONOMIC ENVIRONMENT

A project of this magnitude is likely to entail both positive as well as negative impacts on the

socio-cultural fabric of the area. During construction and operation phases, a lot of allied

activities will mushroom in the project area.

9.7.1 Impacts due to influx of labour force

During the construction phase a large labour force, including skilled, semi-skilled and un-

skilled labour force including their families of the order of about 3600 persons, is expected to

immigrate into the project area. It is felt that most of the labour force would come from other

parts of the country. However, some of the locals would also be employed to work in the


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project. The labour force would stay near to the project construction sites.

The project will also lead to certain negative impacts. The most important negative impact

would be during the construction phase. The labour force that would work in the construction

site would settle around the site. They would temporarily reside there. This may lead to filth,

in terms of domestic wastewater, human waste, etc. Besides, other deleterious impacts are

likely to emerge due to inter-mixing of the local communities with the labour force.

Differences in social, cultural and economic conditions among the locals and labour force

could also lead to friction between the migrant labour population and the total population.

9.7.2 Economic impacts of the project

Apart from direct employment, the opportunities for indirect employment will also be

generated which would provide great impetus to the economy of the local area. Various

types of business like shops, food-stall, tea stalls, etc. besides a variety of suppliers, traders,

transporters will concentrate here and benefit immensely as demand will increase

significantly for almost all types of goods and services. The business community as a whole

will be benefited. The locals will avail these opportunities arising from the project and

increase their income levels. With the increase in the income levels, there will be an

improvement in the infrastructure facilities in the area.

9.7.3 Impacts due to land acquisition

Another most important deleterious impact during construction phase will be that, pertaining

to land acquisition. About 125.62 ha of land proposed to be acquired for the proposed Sach

Khas hydro-electric project. Of this about 82.16 ha is under reservoir submergence. The

balance is under forests.

9.7.4 Impacts on cultural/religious/historical monuments

Apart from village temples in the study area, monuments of cultural, religious, historical or

archaeological importance are not reported in the project as well as the study area. Thus, no

impact on such structures is envisaged.

9.8 INCREASED INCIDENCE OF WATER-RELATED DISEASES

9.8.1 Increased incidence of water-related diseases

The construction of a barrage would convert riverine ecosystem into a lacustrine ecosystem.

The vectors of various diseases may breed in shallow parts of the impounded water. The

magnitude of breeding sites for mosquitoes and other vectors in the impounded water is in

direct proportion to the length of the shoreline. Since, this is a run-of river project in a

mountainous region, increase in water spread area will be marginal and it would remain mostly

confined in the gorge of the river, the increase in the incidence of water borne disease is not

expected. Further, mosquitoes are normally observed upto a maximum elevation of about


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2000 m above sea level. The proposed project is located just above this elevation. Hence,

increase in incidence of mosquitoes is not expected at the project site.

9.8.2 Aggregation of labour

About 1200 labourers and technical staff will congregate in the project area during peak

construction phase. The total increase in population is expected to be of the order of 3600.

Most of the labour would come from various parts of the country. The labourer would live in

dormitories provided by the Contractor. Proper sanitary facilities are generally provided. Hence,

a proper surveillance and immunization schedule needs to be developed for the labour

population migrating into the project area.

9.8.3 Inadequate facilities in labour camps

Improperly planned labour camps generally tend to become slums, with inadequate facilities for

potable water supply and sewage treatment and disposal. This could lead to outbreak of

epidemics of water-borne diseases. Adequate measures for supply of potable water and

adequate treatment for sewage has been recommended as a part of Environmental

Management Plan outlined in Volume II of this Report.

ANNEXURES

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ANNEXURE-I

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ANNEXURE-II

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