Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
TABLE OF CONTENTS
CHAPTER
I
DESCRIPTION
Executive Summary
PAGE NO.
1-9
II
Background Information
10-17
III
Project Area
18-25
IV
Topographical & Geo-technical Aspects
26-33
V
Hydrology
34-53
VI
Conceptual Layout and Planning
54-64
VII
Power Potential Studies
65-97
VIII
Power Evacuation
98
IX
Environmental Aspects
99-119
X
Infrastructure
120-123
XI
Construction Planning & Schedule
124-129
XII
Cost Estimate
130-165
XIII
Economic Evaluation
166-173
Plates
Annexures
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
LIST OF DRAWINGS
TITLE
PLATE
No.
Preliminary Ranking Study Layout
1
Cascade Development of Teesta River Basin
2
Layout Plan of Schemes in Upper Part of Teesta Basin
3
Cascade Development of Tolung River Basin
4
Geological Plan of The Project Area
4.1
Vicinity Map
6.1
Project Layout Plan
6.2
Layout Plan-Dam Area
6.3
Layout Plan-Power House Area
6.4
Water Conductor System L-Section
6.5
Dam Upstream Elevation
6.6
Dam: Spillway & Non-Overflow Cross Section
6.7
Typical Cross Section Of Constituents Of Water
Conductor System & Diversion Tunnel
6.8
Single Line Diagram – Power Evacuation
8.1
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
ANNEXURES
TITLE
No.
Geology of the Area Around the Project- By G SI
4.1
Technical Report on Seismic History and
Seismicity- By IMD
4.2
Preliminary Ranking Study Report- By CEA
6.1
Reply on CEA/CWC Comments on Draft PFR
6.2
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – I
EXECUTIVE SUMMARY
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER-I
EXECUTIVE SUMMARY
1.0
INTRODUCTION
The Lingza Hydroelectric Project located in North Sikkim district of Sikkim envisages
utilization of the waters of the river Ringpi a tributary of river Rangyong for power
generation on a run of river type development, harnessing a head of about 746m.
The project with a proposed installation of 120MW (3 x 40MW) would afford an annual
energy generation of 477.51 GWh in a 90% dependable year. The tariff from the project
at present day cost would be Rs2.62 per KW h(levellised).
The diversion site is located at Latitude 27º36’ North, Longitude 88º27’20” East. The
dam site is approachable from Mangan-Lingza road by a footpath of 5km. The dam site is
at a distance of about 7km from Lingza and about 24km from Mangan, the head quarter
of North Sikkim district. The nearest railhead is at New Jalpaiguri and airport at
Bagdogra.
1.1
GENERAL PROJECT FEATURES
The Lingza HE Project envisages construction of :
•
a 75 m high concrete Dam across river Ringpi to provide a live storage of
1.71mcum. with FRL at 1850m and MDDL at 1830m;
•
two intakes and two desilting chambers of
size 95m(L)x5m(W)x7.5m(H) to
remove silt particles of size 0.2mm and above;
•
a 4km long , 3.3m diameter head race tunnel terminating in a surge shaft;
•
a 40m high, 10m dia surge shaft;
•
900m long, 2m dia one pressure shaft;
•
an underground power house having an installation of 3 Pelton turbine generating
units of 40 MW each operating under a net head of 736m; and
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
•
250m long, 3.3m diameter tailrace tunnel to carry the power house release back to
the river;
The power generated from the project would be evacuated through one number 220KV
double circuit line to be connected at the pooling station, which is assumed to come up
near Teesta-III HE Project to feed power to the national grid.
The salient features of the projects are as under:
SALIENT FEATURES
LOCATION
State
Sikkim
District
North Sikkim
River
Ringpi
Location Of Dam Site
U/S Of Ishana Village
Location Of Power House
U/S Of Village Lingza
Nearest Rail Head
New Jalpaiguri
Nearest Airport
Bagdogra
Latitude
27º36’00’’& 27º33’46’’
Longitude
88º27’20’’& 88º26’39’’
HYDROLOGY
Catchment Area
198 Km²
Design Flood (PMF)
940 Cumecs
DIVERSION TUNNEL
Diameter & Shape
6 M, Horse-Shoe
Length
400 M
Diversion Discharge
±300 Cumecs
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Diversion Tunnel Gate
2nos., 3 M X 7.5 M
COFFER DAMS
Type
Rock Fill With U/S Concrete Facing
Max. Ht Of U/S Coffer Dam
20M
Max. Ht Of D/S Coffer Dam
10M
DAM
Type
Concrete Gravity With Central Spillway
Dam Top
EL 1855 M
River Bed Level
EL 1795M
Length At The Top
320 M
Dam Height (Above River Bed 60 M
Level)
Max. Dam Height (Above Deepest 75 M
Fdn. Level)
SPILLWAY
Type
Low Level Orifice Type
Crest Elevation
EL 1810 M
Number & Size OfSpillway Opening
3 Nos, 4 M (W) X 6 M (H)
Design Flood
940 Cumecs
RESERVOIR
Full Reservoir Level (FRL)
EL 1850 M
Min. Draw Down Level (MDDL)
EL 1830 M
Area Under Submergence At FRL
10.75 Ha
Gross Storage
2.64MCM
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Live Storage
1.71 MCM
INTAKE
Invert Level
EL 1820 M
Number Of Intakes
2 NO.
Size Of Each Gate
3 M (W) X 3 M (H)
Design Discharge
22.16 Cumecs
Stoplogs
1 Set Of Stoplog (3 M Wide )
Trash Rack
Steel Trash Rack With M/C
DESILTING CHAMBERS
Type & Numbers
2 No;. Dufour Type
Design Discharge
11.08
Cumecs
Each
(Including
Flushing Discharge)
Particle Size To Be Removed
0.2mm And Above (90% Efficiency)
Size Of Chamber
95 M(L) X 5 M (W) X 7.5M(H)
SILT FLUSHING TUNNEL
Shape & Size
1 M X 1.8 M, D-Shaped
HRT
Shape And Size
Horse-Shoe, 3.3 Dia
Length
4 Km
No. Of Adits
2 (3.3 M Dia, D-Shaped)
SURGE SHAFT
10 M Diameter & 40 M High
PRESSURE SHAFT
Number & Type
One, Inclined
4
20%
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Shape
Circular, Steel Lined
Length
900 M (Inclined)
Diameter
2M
No. Of Adits
(3.3 M Dia D-Shaped)
POWER HOUSE
Type And Location
Under Ground; Left Bank
Design Discharge
18.47 Cumecs
Type Of Turbine
Vertical Pelton
Power House Size
100 M X 17m X 40m
Gross Head
746 M
Rated Net Head
736m
Centre Line Of M/C
1097m
Installed Capacity
120 Mw
TAILRACE TUNNEL
Shape And Size
Horse Shoe, 3.3 M Dia
Length
250 M
Tail Water Level
El.1095 M
SWITCHYARD
Size
200M X 150 M
POWER GENERATION
Installed capacity
120 MW
Annual Energy generation in a 90%
477.51MU
dependable year & 95% machine
availability
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
COST ESTIMATES & FIANANCIAL ASPECTS ( Rs. Crores)
Civil Works
527.68
Electro Mechanical Works
97.36
Sub Total (Generation)
625.04
Transmission Works
5.01
Total (Hard Cost)
630.05 at June,2003 Price Level
Interest During Construction
69.75
Grand Total
699.80
Tariff for first year per KWh
a. with 12% free power
b. without 12% free power
Levellised Tariff per KWh
a. with 12% free power
b. without free power
Rs. 3.24
Rs. 2.85
Rs. 2.62
Rs. 2.31
COSTRUCTION PERIOD
1.2
4 years
STUDIES/INVESTIGATIONS UNDERTAKEN
•
Study of topographic maps and remote sensing imageries
•
Reconnaissance of area for identifying probable alternative sites of projects
components.
•
Study of regional geotechnical features/ seimotectonic aspects.
•
Geological appraisal of proposed project components.
•
Water availability design flood studies based on available meteorological/
hydrological data.
•
Conceptual layout and project planning.
•
Power potential studies.
•
Study of biotic environment, socio -economic environment for prediction of
environmental impacts of the projects.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
1.3
•
Study of existing infrastructure.
•
Cost benefit and economic evaluation.
RESULTS OF STUDIES AND INVESTIGATIONS
1.3.1 Geology
The preliminary geological survey of the locations of all the structures on the ground was
carried out after site visits. The site-specific geological data were got collected and
utilized in the design of various components of the project. The geological survey of the
near by area was also carried out to co-relate the geology of the project area. The dam
location has been fixed after observing the rock exposures on both the banks and in the
riverbed.
1.3.2 Hydrology
The river Ringpi drains a catchment area of about 198sq.km at the proposed dam site.
The water availability for the project has been considered on the basis of 10-daily
discharge series at Lachen for the period from 1976-1997. The water availability at the
Lingza dam site has been derived from the above data on the basis of catchment area
proportion and applying an overall reduction factor of 0.22. The computed inflow series
works out has been utilized for Power Potential Studies. The design flood has been
assessed as 940cumecs.
1.3.3 Power Potential Studies
The computed inflow series for 21 years viz June 1976 to May 97 has been considered in
the assessment of a power benefits from the project. As per GOI notification for tariff the
year 1976-77 corresponds to 90% dependable year. An installation of 120MW
comprising 3 generating units of 40MW has been proposed. The energy availability from
the project in a 90%dependable and an average year has been summarized below:
Annual Energy Generatio n
Annual Energy Generation (GWh)
7
477.51
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Annual Load Factor (%)
47.42
Generation during Lean Flow Season (Sept – JuneI)
Energy Output (GWh)
225.79
Load Factor (%)
28.72
The design energy for tariff at 95% availability in a 90% dependable year has been
worked out at 477.51 GWh.
A pondage of 1.71 mcum has been provided in the diversion dam which would enable the
station to operate as peaking station. The pondage is equivalent to 3086.61 MWh which
sufficient to operate the station for 3 hours.
1.3.4 Power Evacuation Aspects
The power generated from the project would be evacuated through a 220KV, double
circuit line to be connected at the pooling station assumed to come up near Teesta –III
HE Project to feed power to the National Grid.
1.3.5 Environmental Aspects
The project is located in north district of Sikkim. The total land requirement for the
construction of various components is about 112ha. Most of the land falls under the
category of private land. Based on assessment of environmental impacts, management
plans have to be formulated for Catchment Area Treatment, compensatory afforestation
and other environmental issues. These issues would be addressed during the investigation
for DPR.
1.3.6 Estimates Of Cost
The project is estimated to cost Rs. 699.80 crores including IDC at June,2003 price
levels. The preliminary cost estimate of the project has been prepared as per guidelines of
CEA/CWC. The break down of the cost estimate (Rs. Crores) is given below:
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Civil works
:
527.68
Electro Mechanical Works
:
97.36
Sub Total (Generation)
:
625.04
Transmission Works
:
5.01
Total (Hard Cost)
:
630.05
Interest During Construction
:
69.75
Grand Total
:
699.80
1.3.7 Financial Aspects
As indicated above, the Lin gza HE project with an estimated cost of Rs. 699.80crores
(including IDC of Rs. 69.75crores) and design energy of 477.51GWh in a 90%
dependable year is proposed to be completed in a period of 4 years. The tariff has been
worked out considering a debt-equity ratio of 70:30, 16% return on equity, annual interest
rate on loan at 10% and 12% of energy as free power to Home State available after
losses. The tariff for the first year and levellised tariff has been worked out Rs. 3.24/KWh
& Rs. 2.62/KWh respectively.
1.3.8 Conclusion
The Lingza HE project involves simple civil works and could be completed in 4 years.
The project would afford a design energy of 477.51 GWh in a 90% dependable year. The
cost per MW installed work out Rs.5.21Crore. The Preliminary Feasibility Report
indicates that the scheme merit consideration for taking up for Survey & Investigation
and preparation of DPR.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – II
BACKGROUND INFORMATION
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER –II
BACKGROUND INFORMATION
2.1
GENERAL INFORMATION
2.1.1 Introduction
Sikkim has elected to join the Indian Union to become 22nd state in 1975; It is one of the
most picturesque regions of Asia. The bowl like, mountain –girdled state in the eastern
Himalayas bordered on the west by Nepal, on the north by Tibet, on the east by Bhutan
and the south by Darjeeling district of the West Bengal, lies between 27 0 to 280 north
latitude and 880 to 890 east longitudes. The Sikkim is the youngest and small hill state of
India having an area of 7096 Sqkm. Sikkim is surrounded by important mountain ranges.
The chola range of mountains on its east forms the watershed between it and Bhutan on
one side and chumbi valley of Tibet on the other. The well-known singalila ridge is of the
great Himalayas peaks.
Sikkim is divided into four districts. The most populated area is the Eastern district,
which contains the capital town Gangtok followed by Southern and Western districts.
The northern district is sparsely populated because of its inhospitable climate and steep
ridges. Lying along the slopes of Himalayas between Tibet and plain of India, cut off
from the rest of the world by mighty mountains, Sikkim’s scenic beauty has no parallel in
the East Sikkim’s historic past, mystic religion, sublime monasteries and age old rituals
have an attraction hardly to be found anywhere else in the world.
Sikkim is mountainous terrain with cliffs and valleys. Dominating both legend and
landscape is the mighty massif of Kanchendzonga known to the outside world as
Kanchenjunga, it is the third highest peak in the world, towering at 8550 meters.
Sikkim is drained by number of Perennial Rivers. However, the two main river systems
are Teesta and Rangit. The other entire stream eventually joins one or the other. Rangit
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
also joins the Teesta just near the broader between Sikkim and West Bengal at Melli.
Besides the river, there are number of lakes and hot springs which add to the beauty of
the region. The important hot springs are Phut sachu, Raeong sachu, Yumthang and
Momay.
2.1.2 Topography
Geographical area of Sikkim State is about 7300 sq. km. The maximum horizontal length
from north to south is about 112 Km. whereas the maximum width from east to west is 90
Km. The Tibetan Plateau on the north, Nathula and other passes on the north east, Bhutan
on the south east, Darjeeling district of West Bengal on the south and Singalila range of
Nepal from the boundaries of this picturesque Himalayan State. It is a hill state having no
plain area. The altitude above mean sea level varies from 213m in the south to over
8500m in the northwest. The Khangchedzonga, the third highest peak in the world at an
elevation of about 8550m adorns the state with its beautiful range covered with shining
snow. Gangtok, the capital is about 1677m above mean sea level. The northern part of the
state is cut into deep escarpments. The northern part is not populated except in Lachung
and Lachen valleys. Southern Sikkim is, however, more open and fairly well cultivated.
2.1.3 Rivers
The river Teesta is one of the main Himalayan Rivers, which originates in the glaciers of
Sikkim at an elevation of over 8500m above mean sea level. River rises in mountainous
terrain and is formed mainly by the union of two hill streams Lachen Chu and Lachung
Chu at Chungthang in North Sikkim. After the confluence of Lachen Chu and Lachung
chu at Chungthang, the river gradually increases in width and takes a wide flowing down
to Singhik, dropping in elevation from 1550m to 750m. At Singhik, the river receives one
of the its major tributaries, the Talung chu on its right. Tolung Chu originates from the
Talung glaciers, which are the part of the Khangchendzonga range. From Singhik, the
rivers flow towards Dikchu in a very deep valley and drops from 750mto 550m. From
Dikchu the river flows in a big curve again down to the Singtam with a drop of about
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
200m. The Rongnichu, which drains the Changu lake area joins Teesta from left at
Singtam and the river receives Rangpo Chu at Rangpo. After Rangpo, Teesta start
widening rapidly and is joined by the great Rangit at Melli bazar on Sikkim – West
Bengal border.
2.1.4 Communication
By Air
Bagdogra is the nearest airport of Sikkim. There are regular scheduled flights operated by
the Indian airlines and other private airlines between Calcutta, the capital of West Bengal
and Bagdogra and also between New Delhi and Bagdogra. Jeep taxis are available
outsides Bagdogra airport for Gangtok. Gangtok is 124 kms from Bagdogra and the
journey takes about 4 hours by jeep and 5 hours by bus.
By Rail /Road
The two closest railway stations to Gangtok are Siliguri junction, (Meter Gauge) which is
114km away and New Jailpaiguri (Broad Gauge), which is 125km away. A number of
trains are available for Calcutta, Delhi, Guwhati and other important cities of India.
Besides jeep taxis, Sikkim National Transport and other private buses ply regularly
between Sikkim and Siliguri.
2.1.5 The Project
2.1.5.1 Background
In order to exploit vast hydro potential in the country and to achieve the ideal hydro
thermal mix of 40:60, the Honourable Prime Minister of India had launched a hydroelectric initiative on 24th May 2003 to develop 50,000MW hydro power potential in the
country. Accordingly, based on the results of the preliminary ranking studies of Central
Electricity Authority, 162 hydroelectric power schemes with estimated installed capacity
of 50,560MW were selected in 16 states for preparation of Pre Feasibility Reports. The
work of preparation of PFR’s was entrusted by Ministry of Power under overall
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
coordination of CEA to NHPC Ltd, SJVN Ltd, NEEPCO, WAPCOS, KPCL, HPSEB and
UJVN Ltd as consultancy work. NHPC was entrusted a total number of 43 schemes of
21345 MW comprising of 7 schemes in Indus -Jhelam Basin J&K, 25 schemes in DihangDibang-Subansiri Basins Arunachal Pradesh, 1 scheme in Narmada Basin Madhya
Pradesh and 10 schemes in Teesta Basin Sikkim. The Lingza is one of the such scheme
for PFR.
2.1.5.2 About The Project
The project is located on the river Ringpi chu in Dzongu area of North district of
Sikkim. The headquarter of the district North Sikkim is at Mangan. The project involves
construction of a 75m high concrete dam, a 4.0 Km long headrace tunnel and an
underground powerhouse with an installed capacity of 120 MW. The project shall
generate 477 MU of energy in a 90% dependable year. The dam site is located about 5.0
Km u/s of the confluence of river Ringpi Chu and Rangyong Chu.and 6.0Km u/s of
village Lingza. The underground powerhouse is located about 750 m u/s of the
confluence of Ranyong Chu and Ringpi Chu near the place called Chhana. The village
Lingza, nearest to Power house site, is well connected from Mangan by 17 km long state
PWD road.
2.2
POWER SCENARIO AND EXISTING INSTALLATION
2.2.1 Power System In India
The Power System in India has grown from small, isolated stations, serving limited
consumers in and around large cities, into large regional Power Grids. The generating
capacity installed in the country has already grown to 107903.53 MW by March 2003.
For the purpose of system planning and operation the country has been divided into
following five geopolitical regions: Northern, Western, Southern, Eastern and NorthEastern regional power grids and the transmission system are being progressively interconnected for efficient operation of these five regional grids.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
The objective of the system development is to evolve self-sufficient regional grid catering
to the individual regional power demands. It is also aimed at achieving the maximum
benefits from integrated operation, through a proper mix of thermal and hydro generation
and ultimately to tie the five regional grids together to form a strong National Power
Gird, providing even greater reliability.
The proposed Lingza Hydro electric project located in north Sikkim is envisaged to feed
power at a pooling point near Teesta III H.E. Project (Approx 2 Km from Teesta-III) via
one double circuit line.
2.2.2 Power Position in North Sikkim Region.
The total installed capacity in Eastern Region is 16696.68 MW.Out of this only 2459.51
MW is hydel installation. Thus the Hydro-thermal mix is 15:85, which is well below the
national average of 25:75 and desirable ratio of 40:60.
The power supply position for Eastern region during 10th and 11th Five Year Plans is
summarised in Table2.1. The power and energy availability and requirements during and
after 10th Plan period in the Eastern Region is shown in Tables as projected in the 16th
Electric Power Survey, published by CEA.
Even considering the coordinated operation of existing hydro and thermal stations, as
well as benefits from ongoing projects and also from the schemes cleared by CEA, the
Eastern region is expected to face peak power and energy deficits during most of the 10th
five Year Plan. The power situation in the region is dynamic and it is expected that the
power generated from this project shall be cheap and helpful to the region as compared to
thermal and other expensive power in the region.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
2.2.3
Existing Power Installations In Sikkim
First time, a micro hydel station was established in Sikkim on the bank of Ranikhola at
Lower Sichey Busty with an installed capacity of 10 KW on 27th May 1927 for the needs
of the members of the Royal family and Gangtok. Later, Lower Lagyap Hydel Project with
an installed capacity of 12MW was constructed by Govt. of Sikkim and this was a big
boom. Presently following hydel schemes totaling 95.70MW are under operation in the
state.
Sl.
Hydel Schemes
Year of
Installed
Firm
No.
1
2
Completion
3
Capacities
4
Capacity
5
1966
2.10
1.20
1
Jali Power House
2
Rothak Micro Hydel
1971-72
0.20
0.10
3
Rimbi Micro Hydel, Stage -I
1970-71
0.60
0.30
4
Lower Lagyap HEP
1979-80
12.00
5.50
5
Lachen Micro Hydel
1989-90
0.10
0.05
6
Rimbi Stage-II
1989-90
1.00
0.50
7
Rongnichu Micro Hydel-II
1988-89
2.50
1.20
8
Lachung Micro Hydel
1991-92
0.20
0.10
9
Mayongchu
1993-94
4.00
2.00
10
Upper Rongnichu HEP
1994-95
8.00
4.00
11
Kalej Khola
1995-96
2.00
1.00
12
Rangit Hydel Project
1999-00
60.00
20.00
13
Robom Micro Hydel
2003-04
3.0
1.00
I - Total Hydel Power
95.70
36.95
II - Total Diesel Power
2.70
2.70
Total Generation Capacity
98.40
39.65
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
2.2.3 Load Demand & Power Position of Eastern Grid
Table-2.1 shows the power supply position of Eastern grid up to 2011-12.
2.3
NECESSITY OF THE PROJECT AND RELATED ASPECTS
The need for Lingza H.E.Project has been considered in the context of increasing demand
of power in the eastern region. It has been assumed that eastern region will have energy
requirements at the rate 10% per annum rise of each year. This is a run of the river
scheme in Teesta basin in North Sikkim District, Sikkim. It will generate 477.51 MU in
90% dependable year (1976-77) with 95% machine availability.
The proposed Lingza Hydro Electric project located in north Sikkim is envisaged to feed
power at a pooling point near Treesta-III H.E. Project (Approx 2 Km from Teesta III)
through one 220 KV double circuit line.
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Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW)
Table 2.1
POWER SUPPLY POSITION OF EASTERN REGION
WITHOUT LINGZA HE PROJECT (120 MW)
10th Plan
Eastern
2002-03
Region
11th Plan
2003-04
2004-05
2005-06
2006-07
2007-08
2008-09
2009-10
2010-11
2011-12
1
2
3
4
5
6
7
8
9
10
Installed Capacity
MW
16697
17197
18327
20077
21237
22369
23269
24769
25429
26749
Peak availability
Peak requirement
MW
MW
7676
8076
7906
8527
8425
9002
9230
9505
9763
10035
10284
10586
10697
11167
11387
11780
11690
12427
12297
13109
Peak Surplus(Deficit)
MW
-400
-621
-577
-275
-272
-302
-470
-393
-737
-812
Peak Surplus(Deficit)
%
-4.95%
-7.28%
-6.41%
-2.89%
-2.71%
-2.86%
-4.21%
-3.34%
-5.93%
-6.19%
Energy availability
MU
50260
51765
55167
60434
63926
67334
70043
74558
76545
80518
Energy requirement
MU
51653
54484
57469
60619
63941
67400
71046
74890
78941
83212
Energy Surplus (Deficit)
MU
-1393
-2718
-2303
-184
-14
-66
-1003
-331
-2396
-2694
Energy Surplus (Deficit)
%
-2.70%
-4.99%
-4.01%
-0.30%
-0.02%
-0.10%
-1.41%
-0.44%
-3.04%
-3.24%
1. All the data for the year 2002-2003 has been taken from the website www.cea.nic.in.
2. Energy availability for the year 2002-2003 onwards have been estimated on the basis of ratio of Energy availability to Installed capacity for the year 20022003.
3. Peak availability for the year 2002-2003 onwards have been estimated on the basis of ratio of Peak availability to installed capacity for the year 2002-2003.
4. Energy requirement & peak requirement for the year 2002-2003 onwards is based on the annual increments given at page -117 & 118 of "Sixteenth Electric
Power Survey Of India".
5. Micro/mini projects have not been considered for the study.
Note:- This is a statistical analysis based on various publications mentioned above and are meant for study and planning purposes.
17
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – III
PROJECT AREA
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER –III
PROJECT AREA
3.1
DESCRIPTION OF PROJECT INCLUDING RIVER SYSTEM
Lingza H.E. Project is situated in the Dzongu area of north district of Sikkim .The project
envisages construction of 75 m high concrete gravity dam near the place Ishana. and an
under ground powerhouse near the place Chhana. The river water shall be diverted
through a diversion tunnel of 400 m length and 6.0 m dia for construction of dam. A
headrace tunnel of 4.0 km length, 3.3m dia shall carry a discharge of 18.47 cumecs of
water to the powerhouse. Two numbers of desilting chambers of 95mX8mX7.5 m size
shall be constructed to separate the silt particles of 0.2mm size and above from the water.
A surge shaft of 10 m dia and 40m deep along with one inclined pressure shaft of 2.0m
dia 900 m length shall be constructed. A tailrace tunnel of 250m length and 3.3 m dia
shall discharge the water back into the river. A switchyard of 200Mx150m size shall also
be constructed. The powerhouse shall have installed capacity of 120 MW to generate
477.51MU of energy in a 90% dependable year.
The river Ringpi Chu is the tributary of the Rangyong Chu originating in the glaciers of
North Sikkim at an elevation of about 5000 m above mean sea level. he Jumthu Chu,
Dawathang Chu, Kishong Chu, Pegor Chu and Zong Chu are the main tributary of Ringpi
Chu. The Ringpi is the tributary of Rangyong Chu and meets Rangyong Chu upstream of
the confluence of Ringyong Chu and Rangyong Chu. The other tributaries of the
Rangyong Chu /Tolung Chu are Umram Chu, Passaram Chu, Rangyang Chu , Rangli
Chu and Rahi Chu. Both the river Rahi Chu and Rangyong Chu meets Teesta river near
village Singhik . After running about 14 Km from the confluence, the Dikchu River joins
the Teesta River near the village Dikchu. In the downstream the Rongni Chu joins Teesta
River at Singtam, Rangpo Chu at Rangpo and Rangit at Melli.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
3.2
SOCIO-ECONOMIC AND OTHER ASPECTS
3.2.1 Demographic Features
As per the 2001census of India, the total population of the State is 540,493. The overall
density of population in the State is 76 per sq. Km. East district is the most populated
where as North's density only 7 and is the least populated. Sex ratio (females per
thousand male) in 1981 was 835, where as it had improved in 1991 to 878 and in 2001
has shown a declining trend with a value of 875. There are only eight urban towns and
urban population is 9.10% of total population. Literacy rate was 56.94% (19th position)
in 1991 and has increased to 70.65% in 2001. The rural literacy rate in 2001 is 68.59%
whereas the urban literacy rate is 85.80%.
The economy of Sikkim is mainly based on agricultural and animal husbandry.
Approximately 11% of the total geographical area is under agriculture. The work force
participation rate as per 2001 census is 48.52%. The female participation rate in Sikkim is
also much higher than the national average. This is an important aspect of the hill
economy, as productivity is low and hence all the able-bodied people are employed in
agriculture and other activities. Cultivators account for the greater majority of the people
in the State. Animal husbandry is an integral part of the house hold economy of the
region. There are certain household industries also which substantially adds to house hold
incomes. The past one and half decade has witnessed a tremendous upward swing in
various development programme giving a new thrust to the Sikkim economy. This
process has increased wage employment opportunities. The area in the vicinity of the
project is populated. The human settlements are scattered and the human population as
per the 1991 census up to different aerial distances from the project are given in below.
Table 3.1: Human settlement and Population around the project vicinity
Item
Up to 2 km from
Up to 2-5 km
Up to 5-10 km
Population
Nil
527
2369
Households
Nil
118
448
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
3.2.2 Ethnographic details (Details of the tribals in the area)
In Sikkim various communities with their own customs, religion and culture intermingle
freely
to constitute a homogeneous blend. The predominant communities are the
Lepchas, Bhutias and Sherpas. Lepchas , Bhutias, Sherpas are categorized as Scheduled
tribes. The Lapchas are the original inhabitants of the state. Compared to other ethnic
groups, the Lapchas still maintain many of their traditional ways. The Bhutias comprise,
the sikkimese Bhutia and Bhutia from Bhutan and Tibet. The Sherpas are a marginal
ethnic group in the state. Over 80% population consists of Nepalese. Many people from
the plains have also settled, espically in urban areas.
3.2.3 Health & Education
There are 4 district hospitals, Gyalshing, Namchi, Singtam & Mangan and one Central
Referral Hospital at Gangtok, besides 25 Primary health centers 150 Primary health sub centre, 9 Veterinary hospitals and 25 Veterinary dispensaries. There is a blood bank at
Gangtok. There are 1234 doctors. Small pox and Kalzor have been eliminated from the
state and many schemes for the provision of safe drinking water to the villages and
bazars have been implemented. Sikkim has 700 Pre-nursery schools, 531Primary schools,
122 Middle schools, 64 Secondary schools, and 28 Higher secondary schools 2 Public
schools. There is a Training Institute for primary teachers, a Law college, a B.Ed. college,
2 Degree colleges, one Industrial Training Institution, a Medical and an Engineering
college.
3.2.4 Religion
Hinduism and Buddhism are the two main religions prevalent in Sikkim. Hindus and
Buddhists constitute 99 percent of the population; Christians, Muslims, Jains and Sikhs
together are less than one per cent.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
3.2.5 Trade & Industry
Sikkim has a State Industrial Development Investment Corporation, which is encouraging
establishment of industrial units in Sikkim. The Industrial Training Institute located at
Rangpo is providing necessary expertise to the younger people for self- independence in
the trade and the know-how. Sikkim has two distilleries , one tannery, and other ancillary
units. Rangpo area has been declared as an industrial Zone. A Brewery is located at
Melli, South Sikkim. and another at Rangpo, East Sikkim. There is also a fruit
preservation factory at Singtam. The Sikkim Mining Corporation mines copper, zinc, lead
etc in the state. The Sikkim Time Corporation a watch- manufacturing factory is located at
Gangtok, which is producing one of the latest watches in India. There is a jewel factory
located at Gangtok. Besides the above a good number of entrepreneurs have recently
proposed to set up new factories. Some of the units are manufacturing leather goods,
safety matches, local crafts, carpet weaving, handmade paper, woodcarving and similar
works. The Sikkim State Tea Board has also been established for quality tea production.
3.2.6 Natural Resources
Sikkim is gifted with abundant natural resources. The resources can be grouped into a
biotic & biotic both of which can be renewable and non-renewable. Biotic resources
include agricultural crops, forests etc. The entire Himalayan region is endowed with
natural flora and fauna and is a natural paradise for nature lovers, conservationists,
botanists, zoo lists and environmentalists. There are 4500 species of flowering plants, 300
species of primulas, 20 species of bamboos etc., 45 species of rhododendrons and around
450 species of orchids.
The State is very rich in fauna also. There are 144 species of mammals, 500-600 species
of birds, over 400 species of butterflies and moths and many species of reptiles are
available. Sikkim is rich in medicinal plants/herbs and also important shrubs are found in
low and high altitude areas. The State is endowed with water resources, tourism,
hydroelectric potential etc. Under economic geology minerals like copper, iron, lime,
dolomite, limestone, coal, quartzite, silicate & graphite are available in the state. As per
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
the available data around 60% of cardamom production in India is from Sikkim. There is
a vast potential for hydroelectric power generation. Tourism development deserves
considerable attention to add to the economy of the region.
3.2.7
Hydropower Potential
The Teesta and Rangit are the two main rivers of Sikkim where considerable hydro
potential is available. Sikkim have developed 95.7 MW of hydropower potential so far by
constructing mini & micro hydel projects and about 600 MW hydel potential is under
development in different stages. The details of hydropower potential identified is as
under:
Teesta Basin :
According to the preliminary reconnaissance survey, the river could be harnessed under a
cascade development for hydropower generation is six stages as under :
i) Teesta Stage-I
It is possible to diver the water of Teesta river d/s of confluence Chento chu near
Shacham and d/s of confluence Lhonak chu and Poke chu by constructing diversion
structures at EL ± 3330 and interconnecting tunnels discharging the Tail water at an EL ±
2623 near the place Zema. The scheme will have installed capacity of about 320 MW.
ii) Teesta Stage-II
Under this scheme, a diversion dam of 83 m high is proposed near Bonsoi to divert the
tail water of Teesta Stage-I and the power house at Chungthang. The scheme shall
generate 330 MW.
iii) Teesta Stage-III
The schemes involve construction of Teesta River and Lachung chu near Chungthang and
a Power house near Singhik. The scheme shall have the installed capacity of 1200 MW .
iv) Teesta Stage-IV
A diversion dam is proposed just d/s of confluence of Teesta and Tolung chu near the
place called Sanklan and power house near the village Dikchu. The scheme shall have
installed capacity of 495 MW.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
v) Teesta Stage-V
A diversion dam has been proposed d/s of confluence of Dikchu chu and Teesta river and
a power house near the village Sherwani. The scheme shall have installed capacity of 510
MW.
vi)Teesta Stage-VI
Power Potential of Rangit Basin It envisages construction of a 76 m high concrete dam
near Khanitar d/s of the confluence of the Teesta and Rongni chu in East Sikkim and the
power house near the village Namthang/Tarkhola in South Sikkim with installed capacity
of 360 MW.
Rangit Basin
The hydropower development of Rangit river was identified in four stages as under :
i) Rangit HE Project Stage –I
The Rathong chu, a major perennial tributary of Rangit river has a very steep bad slop.
The river takes a big loop near Yoksum. It is proposed to divert the water of Rathong chu
at an elevation of about 2300 m U/S of Yoksum to elevation of 100 m near village
Thingtom. The scheme shall generate 47 MW of power at 60 % load factor.
ii) Rangit HE Project Stage-II
It is proposed to divert the water of Rimbhi chu near Sigglitem and allow the water to
drop through 425 m near Lingchum on Kalet chu to generate 10 MW of power at 60%
load factor.
iii) Rangit HE Project Stage –III
A dam has been constructed just d/s of confluence of Rathong chu and Rangit river and a
power house near the village Mongbru. The installed capacity of the scheme is 60 MW.
The project has been commissioned by NHPC in the year 1999 and is in operation.
iv) Rangit HE Project Stage-IV
The scheme shall utilize a drop of 110 m from an elevation of 440 m to 355 m in Reshi
loop. The scheme shall generate 18 MW of power at 60 % load factor.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Schemes For PFR in Teesta Basin
The Cenrtral Elecrtricity authority entrusted 10 schemes with total installed capacity of
1569 MW for preparation of prefeasibility reports as per details given below:
Sl.
No.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Name of Scheme
Dikchu
Rongni
Namlum
Panan
Lingza
Rangyong
Ringpi
Rukel
Jedang
Teesta Stage-I
Installed
Capacity (MW)
105
195
160
200
160
141
70
33
185
320
Name of
River
Bakchachu/Dikchu chu
Rongni chu
Rangit
Tolung chu
Ringpi
Rangyong/ Umramchu
Ringpi
Rukel/Rangyong
Jhonak chu
Teesta & Zemu chu
District
East
East
South
North
North
North
North
North
North
North
OTHER SCHEMES IDENTIFIED BY CEA AND SIKKIM
The CEA in the preliminary ranking studies and Sikkim in the preliminary studies
identified the fallowing schemes:
Sl.
No.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13
Name of Scheme
KalepHE Project
Talem HE Scheme
Serum HE Scheme
Lachung HE Scheme
Chhota Pathing/Rolep
Chuzachen
Suntalitar HE Scheme
Mana
Gompa
Rammam Stage -I
Rammam Stage -II
Rammam Stage -III
Chakhung Chu hydel
Installed Capacity
(MW)
40
65
50
30
55
13
25
37
46
70
85
100
30
24
Name of River
Teesta
Teesta
Lachung Chu
Lachung
Chu/Sebokong
Rangpo
Chu Chu
Rangpo Chu
Rangpo Chu
Rangit
Rangit
Rammam
Rammam
Rammam
Chakhung Chu
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
In addition to above schemes, the Govt. of Sikkim have identified about 40 mini/micro/
small schemes for hydropower development in the region.
25
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – IV
TOPOGRAPHICAL &
GEO-TECHNICAL ASPECTS
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER-IV
TOPOGRAPHIC AND GEOTECHNICAL ASPECTS
4.1
INTRODUCTION
Central Electricity Authority proposed construction of Lingza hydroelectric scheme on
Ringpi Chu near Ishana in order to generate hydroelectricity from its water potential. The
scheme envisaged construction of a diversion structure upstream of Ishana, a water
conductor system in the left bank of Ringpi Chhu and a powerhouse downstream of
confluence of Ringpi Chu and Rangyong Chu. The scheme was expected to generate
approximately 160 MW of power. The task of preparation of pre- feasibility report was
assigned to NHPC. As per the MOU, GSI reports and site visits of experts would form
major in puts for topographic and geotechnical aspects. The present appraisal is based on
study of topographic sheet 78 A/6 and reconnaissance traverse that was undertaken by
mid October.
A study of the area was undertaken and a few modifications were made in layout of the
project, because of Panan scheme, which has been proposed in the downstream. Now, a
diversion structure shall be constructed approximately 700m upstream of Ishana, a 4 km
long water conductor system in the right hill and an underground powerhouse upstream
of confluence of Ringpi and Rangyong Chhu. The tail water shall be discharged above
the FRL of Panan Scheme. The geological report from GSI has been received and placed
as annexure 4.1.
4.2
REGIONAL TOPOGRAPHIC AND GEOTECHNICAL FEATURES
River Teesta in Sikkim is a major river originating from Zemeu glaciers and generally
flows in north-south direction, at a steeper gradient. The river is joined by several
tributaries major amongst them being Yumthang Chu, Zemu Chu, Talung Chu, Dik Chu
and Rangpo Chu, apart from others join the river. The river valleys in this region are ushaped while, as the tributaries had developed deep gorges, which are bound by steep
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
slopes. A thick vegetal cover occupies the hill slopes. These hill slopes are generally used
for cultivation of cardamom.
A brief of regional geological aspect of this area has been provided. The Eastern
Himalaya covers the Sikkim- Darjeeling-Bhutan and Arunachal Pradesh sectors,
extending from the eastern Nepal to western Burma. The higher Himalaya is a zone of
crystalline rocks dividing two distinct lithofacies association in the south and the north. It
is designated as the Axial belt. The northern zone comprising the Tethyan PalaeoMesozoic sedimentary sequence forms the Trans -Axial belt. To the south of the Axial
belt occurs the Inner belt, comprising thrust sheets of Proterozoic-Upper Palaeozoic
formations, while the foothill belt is represented by para-autochthonous Siwaliks. This
scheme is valid for the entire Eastern Himalaya, upto the Lohit District of Arunachal
Pradesh, where the geological picture does not conform to this general scheme. The
stratigraphic sequence provided by GSI report on Ringpi Hydroelectric Scheme has been
brought out hereunder for the purpose of regional geological setup of the area. According
to this report the region from south to north is occupied
by Gondwana, Daling,
Chungthang and Central Crystalline Gneissic group of rocks.
Group
Gondwana
Lithology
Grits, pebble cum boulder beds and carbonaceous shale with
occasional coal seams, pegmatite, quartzite (Tourmaline bearing)
Daling
Chungthang
•
Interbedded quartzite and chlorite sericite phyllite / schist
•
Lingza Granite
•
Quartzite/ Biotite schist
•
Interbedded quartzite and garnetiferous quart biotite
schist.
•
Calc-silicate rock/marble.
•
Garnet-Kyanite-sillimanite-biotite-quartz-schist.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Central Crystalline
Gneissic Complex
Banded gneiss with augen gneiss and quart-biotite gneiss.
Augen gneiss.
Rock types belonging to Central Crystallines of Higher Himalaya occupy the area.
4.3
TOPOGRAPHIC AND GEOTECHNICAL ASPECTS OF COMPONENT
STRUCTURES
The region is thickly vegetated and falls within Tolung Reserve Forest. From the peruse
of topographic sheet 78 A/6 Jumthul Chhu an E-W flowing nala originating from Jumthul
glacier meets Dwathang Chhu near Tolung and thus give rise to Ringpi Chhu. Beyond
this confluence Ringpi Chhu flows almost N-S with occasional easterly and westerly
swings. Upstream of Ishana the nala takes a southwesterly direction till it meets
Rangyong Chu. Beyond the confluence of jhumthul Chhu and Dwathang Chhu near
Tolung the nala is joined by few tributaries namely Ludul Chhu, Pegor Chhu, Kangcha
Chhu and Zong Chhu all left bank tributaries. The area is bound by ridges, which
generally trend NE-SW and follow the general strike of formations. The river flows in a
steep gradient. The project area is occupied by Central Crystallines of Higher Himalaya.
Ringpi Chhu almost flows along the strike of the formations. Entire area has a highly
rugged terrain with elevation in vicinity varying from 1600 M to 6000 M. Near Shobrung
and Ishana the topography is approximate as indicated in the topographic map.
The area is approachable by a fair weather road upto Lingza beyond which a foot track
reaches Tolung. In general the valley slopes are occupied by slope wash material, while
rock fromations are exposed as steep ridges.
4.3.1 Diversion Structure
The proposed diversion structure is located approximately 700m upstream of Ishana.
Here, Ringpi takes a westerly swing and flows southwesterly to southerly. The area was
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
studied in detail to assess the proposed alignment and any possible alternative alignment.
During the study it was observed that in vicinity of Ishana the river has carved a wide
valley with gentle to moderate side slopes. From upstream of Ishana and upto Shobrung
the river flows in a gentler gradient and has deposited a wider terrace, however,
downstream of Shobrung the nala flows in a steeper gradient. Also, upstream of the
proposed location the nala flows in cascades within a steep gradient. Further upstream the
nala section is inaccessible, however it is observed that a thick pile of debris material
(approximately 15m) comprising boulders, cobbles and pebbles in a silty/sandy matrix
occupies the riverbed section (Photo-1). The river valley is approximately 300m wide. A
thick pile of slope wash material occupies both the right and left bank slopes and the
same is under a thick vegetal cover. The slopes are comparatively steeper while the right
bank slopes are moderate and become steep towards higher elevation, which show rock
exposure. The area is under a thick vegetal cover. The right bank slopes are being used
for cardamom cultivation. The area is occupied by rock exposures of gneisses, which are
strong to very strong. The rock formations trend NE-SW dipping northwesterly (Plate4.1). Occasional warping in rock types is noticed. Downstream of place Be a massive
band of yellowish quartzite is noticed. The area is required to be investigated in detail to
assess the bedrock depth and abutment conditions.
4.3.2 Water Conductor System
A 4 Km long head race tunnel has been proposed in the left hill. A recci traverse from
lingza along the foot track in left bank of Ringpi was undertaken upto place Be. After
crossing the nala at place Be a traverse was undertaken from place Be to Ishana. The area
is bound by steep rid ges, which trend NE-SW. The slopes along the foot track are
occupied by a pile of slope wash material. Nevertheless, a few intermittent reaches show
rock exposures. Also rock exposures are observed towards higher elevations. From a
study of the topographic map it is seen that the water conductor system is crossed by
several small drainages. Mostly these drainages are dry. During the field visit a nala
downstream of Be was seen to carry a little discharge.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
This water conductor system shall be housed within the rock types of gneisses with
occasional bands of augen gneisses. A thick band of quartzite was observed in vicinity of
place Be. This band appears to be 150-200m thick. Since the contact between the two is
under a debris its nature could not be ascertained. The gneisses and quartzites are strong
to very strong and are expected to offer a good tunneling media. The rock types trend
NE-SW dipping 40-65º towards NW (Plate-4.1). Sufficient superincumbent cover is
available above the tunnel. Prima-facie no major drainage appears to have deeply incised
the proposed tunnel alignment.
4.3.3 Powerhouse
The powerhouse location was fixed keeping in view the FRL of Panan Scheme.
Accordingly, it was proposed to keep the tail water above the FRL of Panan Scheme. A
foot track runs above the proposed powerhouse location and the present appraisal is
based on the observations made along this foot track. At the proposed powerhouse
location the formation are exposed as steep rocky escarpments. A thick pile of slope wash
material occupies the area along the foot track. An underground powerhouse has been
contemplated since steep ridges bind the area. The underground powerhouse area shall be
housed within gneisses, which occupy the area. These trend NE-SW dipping towards NW
(P late-1). Fair to good rock media is expected during powerhouse excavation. Sufficient
superincumbent cover is available above the proposed powerhouse cavern. The
orientation of powerhouse shall be suitably aligned with respect to principal
discontinuity.
4.4
SEISMICITY
The site lies within Zone-IV of seismic zoning map of India IS 1893 (Part-I) 2002.
Technical report on seismic history and seismicity of the teesta basin of sikkim covering
proposed sites for hydroelectric schemes has been collected from IMD and enclosed as
annexure 4.2. The report contains a list of earthquake events that have occurred within
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
the region. The Seismic data for the region covering longitude 86-90º and 25-29º has
been analyzed. The probable intensity of earthquake within seismic zone-IV corresponds
to intensity VIII on Modified Mercali Scale. Notable earthquakes that have occurred
close to this area are Cachar 1869 (M 7.5), Great Assam Earthquake 1897 (M 8.7),
Dhubri 1930 (M 7.1), Bihar-Nepal Earthquake 1934 (M 8.3), Assam Earthquake 1950 (M
8.5) and Nepal-India border earthquake 1988 (M 6.4). The maximum intensity
experienced in Sikkim region during Great Assam Earthquake, 1897 was VIII (MMI) and
during Bihar-Nepal border earthquake, 1934 was VII (MMI).
Two major tectonic features occur in the area namely MBT (Main Boundary Thrust) and
MCT (Main Central Thrust) besides other minor features. Many past occurrences of
earthquakes have been associated with these major lineaments.
4.5 GEO-PHYSICAL SURVEY
The area at dam site is covered by heavy boulders and the opposite bank was not
accessable and is connected by 5 km long hilly footpath. Hence the geophysical survey
was not feasible at dam location. The rock is fully exposed in the power house area,
therefore geo-physical survey was not required.
4.6 CONSTRUCTION MATERIAL SURVEY
The availability of river shoals may not suffice the requirement of construction material.
Hence, the alternative arrangements for construction material have to be explored. The
area is bound by steep rocky ridges, therefore the quarries for construction material can
be developed.
4.7 RECOMMENDATIONS
•
At the dam axis and powerhouse area, few drill holes are required to assess
overburden thickness and its amenability for construction of various structures.
•
Detailed geological mapping of the project components need to be carried out.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
•
Availability of construction material may be assessed after detailed survey of the
quarries and may be got tested for their suitability at FR/PFR stage.
32
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Photo-1 Riverbed at Proposed Dam Site
33
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – V
HYDROLOGY
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER –V
HYDROLOGY
5.1
GENERAL
Lingza scheme is a run of the river scheme, proposed on Ringpi Chu, one of the
tributaries of Ryong Chu/Tolung Chu, which is a major right bank tributary of river
Teesta. The project envisages construction of a 75 m high diversion structure on Ringpi
Chu with a gross storage capacity of about 2.64 Mcum and area of submergence as 10.75
Ha at EL 1850 m. The hydrological investigations and analysis have been carried out for
Lingza Project with a view to:
•
Assess the availability of water for power generation by establishing a
series of average 10-daily discharges for the project site.
•
Establish the spillway design flood
•
Determine the capacity of the reservoir and the area of submergence at
different levels including FRL and MD DL.
•
5.2
Reservoir sedimentation.
RIVER SYSTEM AND BASIN CHARACTERISTICS
Ringpi Chu is one of the major tributary of Talung chu river which in turn is one of the
major tributary of river Teesta and meets Teesta at Singhik on its right bank. Ringpi Chu
intercepts a substantial catchment area and is formed by two streams originating at high
elevations having snow catchment in their upper reaches. The river has substantial flows
and a steep gradient. Talung Chu originates from the Talung glacier, which is a part of
the Kanchanjunga range. The river is known by different names in different reaches. In
the upper reach it is known as Rukel Chu, further downstream it is called Rangyong Chu
and in the lower reaches it is known as Tolung Chu. Tolung Chu is fed by a number of
tributaries having large drainage areas at their confluence.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
The river Teesta is one of the main Himalayan Rivers, which originates in the glaciers of
Sikkim at an elevation of over 8500m above mean sea level. It is being snow fed by the
glaciers Zemu, Changame Khanpu, Talung etc. It is an international river, which flows
through the states of Sikkim and West Bengal in Indian Territory and then to Bangladesh.
The river rises in mountainous terrain and is formed mainly by the union of two hill
streams Lachen Chu and Lachung Chu at Chunthang in North Sikkim. The river upto this
reach generally flows in a very steep gradient and the slope of the Teesta river upto the
confluence of Lachen chu and Lachung chu is about 1 in 20. After the confluence of
Lachen chu and Lachung chu at Chungthang the river gradually increases in width and
takes a wide loop flowing down to Singhik dropping in elevation from EL 1550 m to EL
750 m. It is here after traversing about 20 Km that the river confluences with Tolung
Chu.
The area has a rugged terrain with the surrounding peaks reaching a maximum elevation
of approximately 4000m. The nallah joins Teesta river almost perpendicularly. The
terrain hosts a rich growth of vegetation. In general the river flows in southeasterly
direction. Numerous valleys are seen in the area, which are occupied by cultivated
terraces. Few high level terraces have been observed in this area especially in vicinity of
Lingza and Kayem village.
5.2.1 Cascade Development In Teesta Basin
The river Teesta has tremendous potential for development of hydro power, as the river
descends from an elevation of about 3600m to about 300m over a distance of about 175
Km. According to the preliminary reconnaissance survey by Central water and power
Commission in 1974, the river could be harnessed under a cascade development for
hydro power generation. The cascade development proposed at that stage consisted of
power generation in six stages on river Teesta. Out of these schemes, NHPC had
submitted a DPR for Teesta H.E project, Stage -III in 1990. The diversion structure for
Teesta-III was proposed to be constructed at Chungthang, which lies downstream of the
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
confluence of Lachen Chu and Lachung Chu. Another project under Teesta Basin
development, which is under execution by NHPC, is Teesta Stage-V having an installed
capacity of 510 MW, where a diversion structure is being built at Dikchu, about 2 Km
downstream of confluence of Dikchu with Teesta. About 70km downstream of Teesta-V,
NHPC has been entrusted two projects namely, Teesta Low Dam H.E projects, Stage-III
& IV, having an installed capacity of 132 MW and 160 MW respectively.
5.2.2 Catchment Area
The catchment area of the proposed scheme lies between Longitude 88o16′00” E to
88o 32′00” E and Latitude 27o 35′00” N to 27o 45’00” N. The catchment area upto the
proposed dam site is about 198 Sq.km. The catchment is both snowfed as well as rainfed.
The proposed diversion structure lies at Longitude 88 o 28′00” E and latitude 27 o 36′00” N.
The catchment Plan is shown in Plate-5.1.
The catchment plan has been prepared from 1:50000, Survey of India toposheets. The
entire catchment is covered in toposheets no. 78A/6, and 78A/2. The area above
EL4600m is about 74 Sq.km and has been assumed to be the snowfed area in the
catchment. Thus the rainfed and snowfed area in the catchment are 124 Sq.km and 74
Sq.km respectively.
5.2.3.1
Temperature And Humidity
The climate in the region is fairly humid and moist. The abrupt variation in altitude is
chiefly responsible for abrupt changes in the climatic conditions and aided by the
complex orography, the area experiences frequent rainfall of varying intensity and
duration. The maximum and minimum temperature varies from 390 C in summer to 60 C
in winter and the relative humidity varies from 80% to 100%. Temperature and relative
humidity observations are being made in the basin at Dikchu site where Teesta-V H.E
project is being constructed by NHPC and at TLDP-III and TLDP-IV sites, as a part of
cascade development on Teesta river. The monthly maximum, minimum temperatutre
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
and relative humidity at Dikchu from Jan 1998 to Dec 2001 is enclosed as Annexure -5.1
and annual maximum and minimum temperature from 1998 to 2001 is given in Table
5.1.
Table 5-1
Temperature And Humidity Data At Dikchu
Min.
Month
& Year
Maximum
Minimum Temp
o
Temp C
o
C
Max. Relative
Relative
Humidity %
Humidity
%
1998
38.0
7.0
99.0
89.0
1999
39.0
6.0
99.0
90.0
2000
39.0
7.0
97.0
85.0
2001
31.0
11.0
97.0
90.0
Overall
39.0
6.0
99.0
85.0
5.2.4 Precipitation Characterstics
In the Teesta basin the southwest monsoon normally sets in the third week of May and
withdraws in the second week of October. The major portion of the catchment being hilly
and the river flowing in steep gradient, heavy rains in the upper and middle catchments
has an immediate effect of rendering the plains to flash floods.
Sh. B.Biswas and C.V.V Bhadram in their paper titled “A study of major rainstorms of
Teesta Basin” and published in Mausam (1984), have studied the rainfall distribution,
major rainstorms and their associated synoptic situations over the catchment based on 22
years data (1960-81). The entire Teesta catchment extending from its origin in north upto
the Indo Bangladesh border has been considered. On the basis of the rainfall distrib ution,
the Teesta catchment has been divided into three parts viz. upper, middle & lower. The
average annual rainfall is 1328 mm, 2619 mm & 3289 mm for the upper, middle and
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
lower parts respectively. The monthly breakup of the annual rainfall of the basin is given
in Table 5.2 .
Table 5.2
Average Monthly Rainfall (mm) of Teesta Basin
Month
Catchment
Upper
Middle
Lower
Jan
21
23
6
Feb
41
32
16
Mar
73
66
30
Apr
72
147
144
May
142
274
315
Jun
245
463
547
Jul
236
621
866
Aug
222
512
645
Sep
171
338
495
Oct
77
112
191
Nov
15
19
21
Dec
13
12
13
Annual
1328
2619
3289
From the table it is clear that July is the wettest month followed by August and June. The
upper, middle and lower catchments receive 71.6%, 78.1% and 83.4% of the annual
rainfall respectively due to southwest monsoon. The catchment area upto the present
proposed scheme comprises the upper and middle portions only.
The authors have considered 53 rainstorms of duration ranging from one to three days in
the study. The selection of storms is based on isohyetal analysis of daily rainfall values.
Out of the 53 rain storms 40 were of 1 day, 11 were of 2 day and only 2 were of 3-day
duration. It was concluded that 1-day duration storm are more frequent, a fact which is
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
also supported by the narrow width of the catchment for which the effect of any system
lasts for a shorter duration. No storm of longer duration than 3 day is reported. Majority
of the storms have been reported in July & August. It has also been concluded that rain
storms over this catchment occur in association with any of the following synoptic
situations:
(i) Break monsoon conditions i.e. shifting of the axis of trough close to the
foothills of the Himalayas.
(ii) Eastern end of monsoon trough lying north of Latitude 240 N.
(iii)Movement of trough in west lies across the eastern Himalayas ; and
(iv) Low pressure system lying over or to the west of the catchment.
Many of the rainstorms studied by the authors were seen to occur due to either of the first
two synoptic situations in July & August. A combination of first three synoptic situations
is also a common feature over the area, giving rise to heavy precipitation.
5.2.4.1 Rain Gauge Network
As per the paper of Sh. B.Biswas and C.V.V Bhadram, the network density of rain
gauges in the basin works out to be one raingauge per 300 Sq.km of the basin area. The
data used by them is of 42 raingauge stations working under Indian Meteorology
Department (IMD) and Central Water Commision (CWC), 24 of which are equipped with
self recording raingauges. The rainfall data availability status of the raingauge stations in
the catchment upto Teesta-V H.E project, with NHPC, is shown in Table 5.3.
Table 5.3
Data Availability Status Of Raingauge Stations Upto Teesta-V
S.No
1.
Name of station
Lachung
Period of data availability
Jul 57 to Dec 58, 1960 to 1964,1970 to 1981,
Feb 91 to Dec 97
2.
Chunthang
Apr 57 to Dec 58, 1960 to 1964,1970 to Jul 85,
1991 to 1997
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
3.
Lachen
Jan 57 to Dec 58, Jan 60 to Apr64, 1971, Sep
77 to Jan 78, Jun 92 to Dec 97
4.
Yumthang
Jul 57 to Oct 57, 1958, 1960 to 1964, Jan 70 to
Sep 82, Jan 83 to Apr 85
5.
Singhik
Sep 75 to Sep 85, 1991 to 1993
6.
Thangu
Jan 57 to Dec 58, 1960 to 1964, 1970 to 1974,
Jan to Apr 83
7.
Dikchu (near Teesta- 1992 to 1997, 2001 to Feb 03
V dam site)
8.
Gayzing
1978 to 1988
9.
Yoksam
1978 to 1988
10
Rangit dam site
1991 to 1997
11.
Pelling
May 93 to Dec 96
At all the above raingauge sites, data for few months is missing in between. Raingauge
sites have also been established near Teesta Low dam projects, Stage-III & IV and are
operational since August 2000. Lot of efforts has been made to collect all available
rainfall data in the basin but only rainfall data of 11 stations mentioned above is available
at present. None of the above rainfall stations lie in the catchment of the proposed project
so this data has not been used in the hydrological analysis.
5.3
WATER AVAILABILITY STUDY
5.3.1 Stream flow and River gauges
Since Teesta River offers ideal conditions for cascade development of hydroelectric
schemes, the discharge passing through the river is measured at various sites by CWC.
Recently NHPC has also established its various G&D sites on Teesta river since a
number of projects have been entrusted to NHPC as a part of cascade development on the
river. These include Teesta-V, and Teesta Low Dam projects, Stage -III & IV. However,
no G&D data is available on Ringpi Chu, at or near the proposed dam site of Lingza H.E
40
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
project. The various G&D sites and period of data availability in Teesta Basin is shown in
Table 5.4.
Table 5.4
Data Availability Status Of G&D Sites In Teesta Basin
S.No Name of site
River
Period of availabilty
Catchment
Area
(Sq.km)
1.
Chunthang
(before Lachen
Jan 75 to Aug 85
1919.25
Jan 75 to Jun 86
2786.8
Tolung
Jan 75 to Aug 85, Apr
731.25
Chu
90 to Apr 98
Lachung
Lachung
May 76 to Aug 85
634.50
Chuba
Chu
Yumtha
Jan 78 to Aug 85
355.5
Zema
ng Chu
Zema
Jan 79 to Aug 85
900.0
confluence of Lachung Chu
2.
& Lachung Chu)
Chungthang
(after Teesta
confluence of Lachung
& Lachung Chu)
3.
4.
5.
6.
Third Mile
Chu
7.
Sankalang
Teesta
Dec 89 to May 98
8.
Dikchu (near Teesta-V Teesta
Jan 84 to Oct 91,
damsite)
Nov91 to Mar97, Jan
00to Oct01, Sep02 to
Feb 03
9.
10.
Sirwani (Power house
Teesta
May 84 to Mar 97,
site-TeestaV)
2000
Legship (near Rangit Rangit
Jan 77 to Dec 79, Apr
41
4307
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
damsite)
87 to Dec 87, Jan 90
to Dec 91
11.
Teesta Bazar
Teesta
1972 to 1994
12.
Samco Ropeway
Teesta
Aug 2000 till date
7755
13.
Coronation Bridge
Teesta
1972 to 1994, Aug
8065
2000 till date
14.
Domohoni
Teesta
1972 to 2000
5.3.2 Present Study
No daily G&D data was available on Ringpi Chu, on which the present project is
proposed. For the pre feasibility study, water availability for the proposed project has
been computed based on the following methodologies:
(i) Based on observed discharges at Tolung Chu (Jan 75 to Aug 85, Apr 90 to Apr
98)
The proposed diversion structure for Lingza project is located on Ringpi Chu, which is a
tributary of Tolung Chu. Daily G&D data is available on Tolung Chu from Jan 75 to Aug
85 and Apr 90 to Apr 98. The site lies downstream of the proposed project on Tolung
Chu, having a catchment area of 731 Sq.km. Average 10-daily series has been prepared
based on this observed data and reduced to dam site using catchment area proportion,
using a reduction factor of 0.21.
(ii) Based on discharge series of Teesta-III H.E project (1976-1984)
Average10-daily series recommended for Teesta-III H.E project by CWC at Chungthang
has been converted at proposed site using catchment area reduction (catchment reduction
factor – 0.15). Thus a series for the period 1976 to 1984 has been obtained.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
(iii) Based on observed G&D data at Lachen (1976-1997)
G&D data observed at Lachen has been converted at proposed site using catchment area
reduction (catchment reduction factor – 0.22). Thus a series for the period 1976 to 1997
has been obtained. Data at Lachen is missing for the years 1986-1988, i.e for 3 years.
This missing data has been filled from the observed data at Dikchu G&D site (Teesta-V)
using catchment area reduction.
(iv) Based on discharge series of Teesta-V H.E project (1976-Feb 2003)
The 10-daily series at Teesta-V H.E project for the period 1976- Feb 2003 has been
converted at proposed damsite using catchment area reduction (catchment reduction
factor – 0.03). The series from 1976-1996 is the approved series by CWC for Teesa-V
and from 1997 to Feb 2003 is the observed data at Dikchu where observations are being
taken by NHPC.
Average 10-daily discharge for all the above four series developed is worked out and
compared. The plot showing this comparison of average 10-daily discharge at Lingza is
enclosed at Figure -5.1. From the plot it is obvious that the average 10-daily of the series
obtained on the basis of G&D data observed on Tolung Chu is on a much higher side as
compared to other three series. Rainfall-runoff relationship could not be established for
the observed data on Tolung Chu as no rainfall data in the catchment of the proposed
project was available. Hence, for pre- feasibility study, the series so obtained on the basis
of Tolung Chu data cannot be adopted as such, it comparatively being on a higher side.
Average 10-daily obtained from other three approaches are almost comparable so need
for further statistical checks is not fe lt necessary. For pre- feasibility stage, the average
10-daily obtained from G&D data at Lachen is recommended for Lingza H.E project.
Though the catchment area reduction factor is very low for all three series, this series has
been adopted as Lachen G&D site has a smaller catchment area as compared to
Chungthang and Teesta-V. After estabilishing G&D site near proposed dam axis and
obtaining more rainfall data in the catchment, detailed water availability study need be
43
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
done during feasibility/DPR stage. The final 10-daily series at Lingza is enclosed as
Annexure -5.2.
5.4
RESERVOIR ELEVATION AREA CAPACITY CURVE
The reservoir elevation-area-capacity curve for Lingza H.E project has been prepared
from 1:50000 Survey of India toposheets. The contours are available at an interval of
40m the minimum contour being of 1800m. The area enclosed within the contours has
been found using Autocad. Area has been found from elevation 1800m to 1960m at an
interval of 40m. The volume between any two elevations is calculated using the conical
formula :
V = H/3 * (A1 +A2 +√A1 A2 )
Where
V = Volume between two contours
H = Contour interval
A1 = Area at level of first contour
A2 = Area at level of second contour
The incremental volumes thus computed are added up to obtain cumulative volume. The
resultant area capacity curve is enclosed as Figure -5.2. The curve may be improved after
receiving toposheets in scale of 1:25000. The gross capacity at FRL 1850 m is 2.64
Mcum and submergence area is 10.75 Ha.
5.5
DESIGN FLOOD
Design Flood for a project can be estimated by following approaches:
(i)
Deterministic approach using Unit Hydrograph technique.
(ii)
Statistical approach using Flood frequency analysis
(iii)
Empirical methods
44
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
•
Unit Hydrograph technique
Due to non-availability of G&D data and hourly gauges, design storm values in the
proposed catchment, rating curves and observed flood hydrographs could not be
developed for computing the Unit Hydrograph and Design Flood hydrograph.
•
Flood Frequency analysis
Due to non-availability of long term, consistent G&D data near the proposed scheme,
frequency analysis could not be done to estimate the design flood.
•
Empirical Methods
The following empirical relationships have been used to estimate the design flood peak:
(i) Dicken’s formula
Q = CA 3/4
Where C = Dickens constant with value between 11-14 for North- Indian Hilly
catchment. A value of 14 has been adopted in present study.
A = Catchment area in sq.km
Therefore, Q = 14 x 198 3/4
= 739 cumec
(ii) Ali Nawab Jung formula
Q = C(0.386A)(0.925-1/14logA)
Where C = 49 to 60 (55 used)
Q = 55* (0.386*198)(0.925-1/14log(198))
= 1694 cumec
(iii) Computation of Design Flood from Design Flood at Teetsa-III using Dicken’s
formula
The design flood recommended for Teesta H.E project, Stage-III was 4572 cumec. The
total catchment area upto Stage-III dam site is 2786 Sq.km. Lingza H.E project is located
45
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
on Ringpi Chu river which is a tributary of Tolung Chu, which in turn is a major tributary
of Teesta river and both the catchments can be assumed to be hydrologically and hydrometeorologically similar. Therefore, it seems logical to transpose the design flood value
of Teesta-III to proposed dam at Lingza. This transposition has been done by Dicken’s
formula using a conversion factor of 0.138.
Q 1 = CA 1 n
Q 2 = CA 2 n
Where,A 1 = Catchment area of Lingza project
A 2 = Catchment area of Teesta-III project
Q 1 = Design Flood for Lingza project
Q 2 = Design Flood for Teesta-III project
C = Dicken’s constant
n= 0.75
Q Lingza = Q Teesta-III * (A Lingza /A T eesta-III ) 0.75
= 629 cumec
(iv) Computation of Design Flood from Design Flood at Teetsa-V using Dicken’s
formula
The design flood for Lingza project has also been estimated by transposing the design
flood at Teesta-V H.E project using Dicken’s formula. The design flood recommended
for Teesta-V H.E project, having a catchment area of 4307 Sq.km is 9500 cumec. The
conversion factor for converting it at Lingza project, having a catchment area of 198
Sq.km comes out to be 0.099.
Q Lingza = Q Teesta-V * (A Lingza/A Teesta-V) 0.75
= 943 cumec
A comparativ study of flood peak
computed from various methods is placed as Table
5.5.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Table 5. 5
Comparison Of Various Flood Values
SSS.No
Method used
Design Flood (cumec)
1.
Dickens Formula
739
2.
Ali Nawaz Jung Formula
1694
3.
Transposition of Teesta-III Flood peak
629
on the basis of Dickens formula.
4.
Transposition of Teesta-V Flood peak
943
on the basis of Dickens formula.
For pre-feasibility stage study, a design flood of 940 cumec has been recommended at
proposed dam site.
On availability of more data/information, design flood will have to be estimated by
deterministic approach using unit hydrograph technique and probabilistic approach using
flood frequency analysis in feasibility stage. Also, design flood has been worked out on
the basis of design flood at Teesta-III and Teesta-V, which has been computed using both
unit hydrograph technique and flood frequency analysis.
5.6
SEDIMENTATION
A rate of sedimentation of 0.1385 Ham/Sq.km/Year has been worked out for Teesta-V
H.E project based on suspended sediment observations at Dikchu. In the absence of
sediment data at or near the proposed dam site, the same silt rate of Dikchu may be
adopted for Lingza H.E project too.
The necessity of Detailed sedimentation study is not felt during PFR stage and the same
need be done during feasibility/DPR stage with more observed data at the proposed site
using a suitable method.
47
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW)
TEESTA BASIN PROJECTS
Annexure 5.1
Maximum, Minimum monthly temperature and Relative humidity at Dikchu (Teesta-V dam site)
Month
1998
TEMPERATURE
Max O C
Min OC
Jan
25
7
Feb
27
Mar
1999
RELATIVE
HUMIDITY
(%)
TEMPERATURE
Max O C
Min OC
92
23
6
8
90
24
30
10
92
Apr
36
12
May
38
Jun
2000
RELATIVE
HUMIDITY
(%)
TEMPERATURE
Max O C
Min OC
90
22
9
7
92
24
28
9
91
89
34
16
14
91
35
36
20
98
Jul
35
20
Aug
36
Sep
RELATIVE
HUMIDITY
(%)
2001
TEMPERATURE
RELATIVE
HUMIDITY
(%)
Max O C
Min OC
90
20
11
96
7
92
22
14
93
N.A
N.A
N.A
24
15
91
94
32
22
90
29
20
92
18
93
36
17
87
29
19
91
37
20
99
38
20
89
31
22
93
99
39
21
96
39
22
90
31
20
90
21
93
38
20
96
36
21
89
30
22
97
35
20
93
34
16
97
35
20
89
28
22
95
Oct
31
16
93
30
15
96
35
16
85
27
19
96
Nov
29
14
92
28
13
91
31
14
90
25
16
95
Dec
24
9
92
23
9
91
25
10
97
N.A
N.A
N.A
48
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW)
Annexure-5.2
AVERAGE 10-DAILY DISCHARGE
YEAR/MONTH
1976
1977
1978
1979
1980
1981
1982
1983
I
II
III
I
II
III
I
II
III
I
II
III
I
II
III
I
II
III
I
II
III
I
II
III
JAN
4.85
4.64
4.42
2.62
2.49
2.38
3.74
3.35
3.43
3.99
3.69
3.62
6.57
6.32
6.26
6.50
6.09
6.01
4.94
5.50
5.42
5.65
5.03
3.53
FEB
4.50
4.42
4.61
4.39
4.28
2.56
3.47
3.39
3.12
3.30
3.29
3.58
6.01
6.30
6.72
5.59
5.75
6.95
5.38
5.58
5.43
3.21
3.19
4.44
MAR
5.27
5.65
6.13
2.43
3.46
3.21
3.16
3.38
3.74
3.67
3.85
4.74
6.91
7.09
9.57
6.88
7.28
8.60
5.66
6.33
7.54
4.77
6.11
5.51
APR
7.15
7.83
9.15
4.66
4.37
4.65
4.50
5.76
6.83
6.99
6.95
8.73
10.75
13.78
15.71
8.61
10.90
12.84
9.48
9.46
10.49
8.11
6.63
8.30
MAY
8.46
6.70
9.40
5.08
6.28
8.95
7.78
15.94
18.62
13.09
16.69
12.77
14.98
12.81
13.66
15.77
17.03
16.52
13.16
14.78
14.36
13.36
16.01
21.31
49
JUN
13.44
26.23
19.03
14.46
25.65
18.65
21.35
22.41
28.33
15.21
18.20
26.10
20.94
27.87
31.19
18.19
21.75
29.53
25.34
27.91
30.86
26.79
26.00
36.28
JUL
24.33
23.19
17.65
21.32
25.08
30.04
24.87
26.66
25.73
27.11
25.93
29.04
33.01
33.79
35.40
37.72
32.35
30.43
27.09
30.35
35.80
41.55
35.35
35.07
AUG
20.57
22.43
23.98
24.53
20.64
24.10
30.46
25.74
19.32
26.84
21.19
22.48
35.77
39.28
32.72
29.67
31.31
30.44
24.06
22.78
26.73
28.71
30.44
35.56
SEP
21.84
12.60
9.20
16.83
13.76
11.48
16.03
20.87
15.69
22.11
19.29
14.15
31.26
24.50
19.83
29.13
24.97
19.90
20.56
29.74
19.51
28.58
32.14
37.07
OCT
7.79
6.15
6.21
14.01
8.83
7.05
15.09
11.77
10.03
23.58
16.09
12.07
15.51
13.33
12.42
18.25
16.89
14.76
13.81
11.60
11.17
26.07
25.70
17.52
NOV
6.18
5.12
4.57
7.31
6.67
5.04
8.04
5.99
5.90
12.03
9.80
9.22
10.49
9.55
8.79
12.58
10.04
8.31
8.75
7.63
7.39
14.32
13.16
10.84
DEC
3.72
3.18
2.94
4.55
4.81
5.44
5.69
4.82
4.33
8.79
7.24
6.97
8.17
7.42
6.74
7.63
6.86
5.38
6.53
6.02
5.70
9.04
8.47
7.60
AVG
10.38
10.34
12.20
13.12
16.71
16.04
14.52
17.82
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW)
YEAR/MONTH
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
I
II
III
I
II
III
I
II
III
I
II
III
I
II
III
I
II
III
I
II
III
I
II
III
I
II
III
I
II
III
JAN
6.78
6.67
5.94
11.12
10.56
9.14
4.93
4.90
4.64
3.88
3.65
3.43
3.65
3.65
3.61
2.77
2.69
2.67
2.91
2.70
2.44
2.64
2.59
2.56
2.79
2.31
2.36
2.54
2.57
2.41
FEB
5.72
5.94
5.71
9.99
9.13
11.05
4.69
4.82
5.52
3.25
3.22
3.53
3.54
3.71
4.12
2.97
2.71
2.89
2.40
2.26
2.18
2.48
2.36
2.38
2.50
2.41
2.31
2.33
2.48
2.39
MAR
12.60
14.08
13.83
14.04
15.21
14.16
5.89
6.41
6.58
3.30
3.91
4.91
4.27
6.33
6.51
3.28
3.35
3.44
1.99
1.63
1.65
2.54
2.90
3.06
2.47
2.49
2.56
3.91
3.90
4.08
APR
14.54
15.50
15.51
17.05
20.57
24.29
6.47
8.37
9.39
8.96
6.26
8.27
7.44
8.40
9.77
3.58
4.28
5.14
1.71
2.82
3.50
8.03
4.58
4.84
3.03
4.25
3.89
4.15
4.53
5.43
MAY
17.60
25.72
36.54
17.48
20.29
28.26
8.80
9.36
9.86
9.35
10.40
12.20
9.99
14.97
19.84
9.02
9.32
22.70
5.16
9.09
10.46
8.13
9.91
10.96
3.81
4.43
4.46
6.89
6.20
6.28
50
JUN
37.97
45.66
41.00
18.13
22.64
64.15
11.98
20.32
30.12
20.25
29.40
24.68
16.00
23.15
25.36
20.16
33.39
35.32
22.09
21.58
25.24
11.73
18.52
17.03
4.92
7.02
13.60
8.06
10.30
13.25
JUL
47.19
47.35
50.05
50.58
66.00
55.50
26.08
32.59
29.31
28.31
27.07
30.26
39.42
30.96
34.12
35.96
35.37
32.92
27.82
35.46
30.35
19.45
18.95
20.66
11.69
11.82
13.43
27.74
27.74
32.53
AUG
45.14
45.26
47.38
44.85
47.31
57.92
26.02
22.36
24.76
28.66
31.26
20.90
33.87
31.09
47.16
28.57
22.41
21.99
25.85
26.26
23.30
23.69
27.29
22.55
14.70
14.76
16.05
36.49
34.59
33.13
SEP
48.80
46.57
36.94
23.62
22.57
18.91
21.74
27.00
21.98
37.59
20.11
27.58
22.52
15.19
16.99
21.32
19.31
19.18
22.37
21.42
14.92
22.72
24.00
18.59
14.08
13.85
11.47
34.86
29.36
27.76
OCT
31.12
39.47
30.41
16.25
14.25
11.74
17.72
13.25
10.35
17.13
12.76
10.91
14.34
9.51
7.65
15.15
12.89
10.49
12.50
12.73
10.47
14.84
11.77
9.66
8.66
6.21
5.29
24.67
18.30
15.69
NOV
22.66
19.58
17.41
9.53
8.28
7.34
9.51
8.47
7.31
8.85
5.40
4.75
6.31
5.70
5.31
6.52
5.29
4.81
6.41
4.79
4.00
8.00
7.08
5.40
3.90
3.47
3.16
13.02
11.47
10.52
DEC
11.16
10.98
11.02
6.25
5.65
5.20
6.54
6.03
4.44
4.48
4.09
3.74
5.04
4.78
4.52
4.20
3.64
3.19
3.66
3.02
2.61
4.54
3.48
3.06
3.13
2.71
2.50
10.26
9.43
7.75
AVG
25.99
22.47
13.29
13.52
14.13
13.14
11.38
10.64
6.46
13.80
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW)
YEAR/MONTH
1994
1995
1996
1997
AVG
Note :
I
II
III
I
II
III
I
II
III
I
II
III
I
II
III
JAN
7.30
6.80
6.87
4.80
4.85
4.79
3.81
3.79
4.01
5.88
5.59
5.69
4.76
4.57
4.35
FEB
6.77
6.48
6.94
4.75
4.73
4.76
4.15
3.69
4.04
5.67
5.65
5.59
4.41
4.35
4.58
MAR
6.40
5.77
7.30
4.33
4.10
5.65
4.11
4.75
5.07
5.72
6.01
6.55
5.16
5.64
6.11
APR
7.09
8.87
8.14
5.53
6.85
9.99
4.66
4.53
10.07
6.28
6.25
6.43
7.22
7.81
9.15
MAY
9.12
9.40
11.57
14.58
22.51
21.75
12.28
10.76
14.89
7.50
8.63
8.91
10.52
12.60
15.19
1) All discharge data is in cumec.
2) Total no. of years -19
51
JUN
16.70
22.10
25.66
25.25
27.01
27.36
13.97
11.83
21.13
9.85
14.04
17.29
17.85
22.86
27.32
JUL
21.94
23.26
23.71
34.72
29.13
22.39
23.47
25.27
22.50
21.61
18.71
15.63
29.68
30.11
29.66
AUG
21.79
21.28
22.89
24.46
24.68
21.92
21.51
20.06
20.21
17.91
21.85
14.35
27.91
27.47
27.72
SEP
19.41
19.44
16.80
19.78
17.71
17.04
20.18
19.26
16.75
15.35
17.39
14.07
24.12
22.32
19.35
OCT
13.14
11.68
10.70
12.59
12.25
9.57
14.72
13.49
12.06
11.07
7.26
5.73
16.27
13.92
11.45
NOV
8.80
7.26
6.06
6.23
7.11
7.15
10.97
10.20
9.07
5.25
4.85
4.39
9.35
8.04
7.12
DEC
5.85
5.35
5.06
5.35
4.76
4.42
6.25
5.65
5.20
3.96
3.87
3.65
6.13
5.56
5.07
AVG
12.32
13.47
11.62
9.57
13.77
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – VI
CONCEPTUAL LAYOUT &
PLANNING
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHPAPER-VI
CONCEPTUAL PLANNING AND LAYOUT
6.1
INTRODUCTION
The Lingza H.E. project is located in the North district of Sikkim state near village
Ishana. It is a run of the river scheme proposed to harness hydel potential of the Ringpi
Chu, a tributary of river Teesta.
The available maximum gross head of 746 m is
proposed to be utilised for generating 120 MW of Power. A small reservoir of adequate
capacity has been provided as an operating pool to meet diurnal peaking load demands.
6.2
PROJECT COMPONENTS
•
6 m diameter, 400 m long Diversion Tunnel with u/s & d/s coffer dam
•
75 m high & 320m long concrete Dam with a central spillway
•
Intake Structure leading to 2 Nos. 3 m dia D-shaped intake tunnels.
•
Two Nos. Underground Desilting Chambers of size 95m (L) X 5m (W) X 7.5 m (H).
•
One 3.3m diameter horseshoe shaped concrete lined and 4 kms long Head Race
Tunnel with three adits.
•
One 10 m diameter & approx. 40 m high semi-Underground Surge Shaft.
•
One circular inclined Pressure Shaft of 2m diameters, 900 m long each further
bifurcating into 3 numbers steel lined circular penstocks of 1.1 m diameter and length
50 m each up to Power House.
•
Underground Power House of size 100m x 17m x 40m consisting of 3 Pelton units of
40 MW each.
•
One no.3.3m diameter Horseshoe shaped tailrace tunnel of about 250 m length.
The conceptual planning and lay-out of project components have been worked out based
on S.O.I toposheets of 1:50000 scale (toposheet no. 78A/6) with contour intervals 40 m.
54
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
6.2.1 Conceptual Layout
The choice of location and type of the dam has been made keeping in view the
topography, geology and water availability at various locations of the diversion structure
near the one suggested earlier by CEA. The location of the powerhouse has been fixed
keeping the tailrace outlet at EL 1095 m. This level has been kept same as FRL of the
proposed Panan H E Project.
The location of major component of the project, riverbed levels at dam site, TRT outlet
site and generation capacity of the project as identified in the ranking study undertaken
by CEA in 1990 have been considered during the preparation of this report. The
upcoming hydroelectric projects on Ringpi Chu have been considered in the conceptual
planning of the project.
The layout plan of the project and brief write up as envisaged by CEA have been
enclosed as plate-1 and annexure 6.1 respectively. The cascade development schemes on
the Teesta River as prepared by CEA is enclosed as plate-2 and of Tolung River basin as
plate 3 and 4.
Based on the hydrological and topographical study, reconnaissance survey of the site and
input data of ranking study, a conceptual layout plan of the project was prepared and
discussed in CEA for vetting during sept’03.
6.2.2 Dam and River diversion works
Construction of a 75m high concrete Dam has been proposed across river Ringpi Chu.
The reservoir formed by construction of Dam has a gross storage pre-sedimentation
capacity of 2.64 M.cum and live storage capacity of 1.71 M cum. After sedimentation,
the reservoir is likely to have a live storage of adequate capacity for running the power
station at full capacity for 3-4 hours in a day during the period of lean flows.
55
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Width of the valley at Dam site varies from 50 m at riverbed level to 320 m at EL 1855
m, which is suitable for a concrete dam. Average bed level at Dam site is EL 1795 m.
FRL is proposed to be fixed at EL 1850 and MDDL at El.1830 m keeping in view the
inflow of water in Ringpi Chu during lean period. The top of the dam has been proposed
to be kept at EL 1855 m and seat of the dam at EL 1780 m after removal of approx. 15.0
m thick overburden. Near the dam axis, right bank is steep, however left bank rises
moderately and becomes steeper at higher elevation. The area is thickly forested and the
slopes are covered by slope wash material. No rock exposure is seen in the dam area.
However on the basis of exposure in the vicinity. It appears that the rock type expected to
be encountered shall be gneiss, which is suitable for founding the dam and housing the
underground structures. The availability of construction material for the dam, cofferdam
and its suitability has been discussed elsewhere in the report.
The overflow section is 30 m long and Non –overflow section is 290 m comprising 165
m on right abutment and 125 m on left abutment. The spillway has three bays each of size
4 m X 6 m with 3.0 m wide piers. The spillway is designed to pass a probable maximum
flood of 940 cumecs with one gate inoperative. The crest of spillway has been kept at
EL1810 m. The low-level orifice type spillway has been provided to flush out the
sediment accumulated in the reservoir to maintain the live storage capacity of the
reservoir. The top width of non-overflow has been fixed as 8 m. The d/s slope of the
Non-overflow section has been proposed as 0.8H: 1V and u/s slope as 0.1H: 1V. The
project area falls within Zone -IV of seismic zoning map.
One no. Concrete lined 6 m dia 400 m long diversion tunnel has been proposed on the left
bank of the river to divert a flood of approx. 300 cumecs of Ringpi chu The design
diversion discharge has been decided based on the experience of various ongoing NHPC
projects in Teesta valley and fast track completion of the project. This data shall however
need to be firmed up during the preparation of detailed project report with the availability
of more hydrological data & experience gained in the basin e.g.: during the construction
56
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
of Teesta-V project. In order to divert the river during construction of the dam, an u/s
cofferdam of approx. height 20m and d/s cofferdam of 10 m height is proposed.
6.2.3 Power Intake & Desilting Chambers
The proposed power intake system is on the Left side of the river and consists of two no.
intake and two no. D-shaped intake tunnels of dia 3 m each. Two no intakes are proposed
to keep the desilting chambers dimension within the manageable limits and to put either
of the desilting chambers to inspection and maintenance while the other is in operation.
The intake structures are designed to pass 22.16 cumecs, which is about 20% excess of
turbine discharge of 18.47 cumecs. The invert level of the intake structure has been kept
at El. 1820m taking into consideration the water seal requirement to prevent the vortex
formation and air entrainment. Also, this level being 10m higher than the spillway crest,
the sediment entry in the water conductor system shall be checked. The intake structure
shall be provided with the trash racks to prevent the entry of trash in the water conductor
system. The gross area of the trash racks shall be determined to give a velocity of not
more than 1.5m/s. A mechanical raking machine operated from El.1855m shall clean the
racks.
For the efficient, trouble free and continuous operation of turbines with least possible
wearing and erosion damages due to silt, it is necessary to remove 90% of the sediments
larger than 0.2mm-particle size. Two nos. 5 m wide Dufour type Desilting chambers with
height 7.5 m shall be provided to remove 90% of particles having size greater than or
equal to 0.2m. Two separate intakes lead the water to two independent desilting chambers
95 m long spaced at 30 m c/c, through 25 m long upstream transition which will
gradually reduce the velocity of water in the chamber to 0.25m /sec. The chambers have
been provided with central gutter with holes to facilitate the flushing of settled silt
particles through the flushing tunnel.
A silt flushing conduit at the bottom of each
chamber runs along the length and two flushing tunnels join to form a single silt flushing
tunnel of size 1 m x 1.8 m D -shaped and 500 m length which will discharge the sediment
57
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
back into the river d/s of the dam. Thus practically silt free water will be led into the
headrace tunnel. The requirement of desilting chambers is being foreseen, as the TeestaV project, which is d/s of this project, has been provided with the desilting chambers. The
size, alignment, orientation of the chambers can be optimized after more geo-logical,
topo-graphical and sedimentation data becomes available.
.
6.2.4 Head Race Tunnel, Surge Shaft, and Pressure Shaft
The proposed 3.3 m diameter concrete lined horse- shoe shaped headrace tunnel of 4 km
length, and having a slope of 1 in 300 is designed to carry a design discharge of 18.47
cumec. The diameter of the headrace tunnel has been fixed from the minimum working
area requirements. The Invert level of headrace tunnel is fixed at EL. 1820 m near intake.
The rock cover above headrace tunnel generally varies from +100 m to +400 m. The low
cover reaches are confined to prominent nalla crossings. The HRT shall be aligned with
in the rock type of quartzite and gneiss. Three nos. constructions Adits are proposed to
facilitate excavation of headrace tunnel within the scheduled completion time. The length
of tunnel between 300 m long adit-1 & 300 m long adit-2 is 2.5 Km. The tunnel is
proposed to be lined with 225 mm thick plain M-20 concrete. The rock support treatment
shall consist of grouted rock bolts/anchors and shotcrete with or without wire mesh as per
geological conditions encountered. In rock class of IV & V steel ribs supports is
envisaged.
A vertical, restricted orifice type semi- underground surge shaft of 10 m finished dia and
about 40 m height has been proposed with its top opening into a platform at elevation EL
+1860 m. Surge shaft is proposed to be concrete lined with 0.75 m thick R.C.C. Its
bottom is kept at EL 1815 m at the HRT and surge shaft junction. The transient studies
shall be required to be done to work out the maximum and minimum levels for the worst
conditions and optimize the surge sha ft dimensions. During excavation, rock shall be
supported with grouted rock bolts/anchors with wire mesh as per geological conditions.
58
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Two no. Steel lined inclined circular Pressure Shaft of 2m diameter and 900 m length
takes off from the surge shaft each further bifurcating at two points into 3 numbers
underground steel lined circular penstocks of 1.1 m diameter and 50 m length ach upto
Power House which will feed water to three units of Pelton turbines each of 40 MW.
6.2.5 Power House Complex & Tail Race Channel
The underground Power House is located on the Left bank of Ringpi Chu u/s of Panan
dam. It will have an installed capacity of 120 MW (3 generating units of 40 MW each).
The rock type expected to be encountered is gneiss and the support system shall comprise
of rock bolts and Shotcrete. The centerline of the turbines is proposed at
EL 1097m.
One number electrically operated overhead traveling crane (E.O.T) shall be provided for
handling the electrical and mechanical equipment. The Main inlet valve chamber is
proposed on the u/s of the powerhouse. A lift shall be provided near the service bay for
the transportation of men and material. The overall dimensions of the Power House are
100m x 17m x 40m. A Control block area shall be located on one end of machine hall.
The transformer cavern cum gate shaft is proposed 30m d/s of powerhouse cavern. The
approx. size is of the transformer cavern is 90mx 14m x 15m.
A cable tunnel of size 2.0 m x 3.0 m will take off from transformer area and shall carry
cables to a surface switchyard. The Switchyard measuring approx. 200 m x 150 m shall
be formed in cutting/filling.
Water from the turbines is discharged through four concrete lined tailrace tunnels, which
merge into a single tailrace tunnel of diameter 3.3- m & discharge in the Ringpi Chu. This
tunnel is 3.3 m diameter horseshoe and about 250m long with invert at EL.1095 at
tailrace outlet. The tailrace outlet level has been kept at El. 1095 m in conformity with the
FRL of proposed Panan H E Project so as to use the entire available potential. The
reservoir of Panan H.E. Project shall extend beyond the junction of the Tolung Chu and
Ringpi Chu on the u/s side.
59
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
6.3
FURTHER STUDIES
6.3.1 Topographical Studies
1. Topographical contour Survey of the dam area and Power House area in 1:5000
scales with 5m contour intervals.
2. Survey in 1:1000 scale for locating the adits of the HRT.
3. The riverbed survey including the cross sections at Dam axis and tailrace outlet shall
be undertaken to firm up the power potential of the project.
6.3.2 Geological and Geo-technical investigations
1. Geological/ geotechnical investigations including surface mapping and subsurface
explorations like exploratory drilling and seismic profiling at the dam and
powerhouse area.
2. Rock mechanic lab tests shall be required for finding out the properties of the rock
material.
3. Construction material survey shall be required to be undertaken involving drifts, pits,
and topographical surveys of the borrow/quarry areas.
4. Site-specific studies for earthquake design parameters shall also be required to be
undertaken.
6.3.3 Design Studies
1. Hydraulic design of various structures like spillway, power intake, desilting
chambers, transient studies of surge shaft shall be required for firming up the
dimensions.
2. Stability analysis of non-overflow and overflow sections shall have to be done taking
into account the approved seismic parameters.
3. Hydraulic model studies for reservoir and Dam spillway shall be required for the
confirmation of design parameters.
60
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
4. Sedimentation analysis for working out the post sedimentation storage capacity of the
reservoir.
5. Alternative studies for location, type and layout of main components based on
detailed topographical and geological studies.
6. Alternative studies for diversion structure i.e. possibility of other types of dam.
6.4
HYDRO- MECHENICAL EQUIPMENT
6.4.1 Diversion Tunnel Gates And Hoists
After the construction of the dam, for the purpose of plugging the diversion tunnel, two
numbers fixed wheel type gates will be provided at the inlet of tunnel. The gate shall be
operated by means of electrically operated rope drum hoist located on the hoist platform
installed over the trestle above deck level. The gate is meant for one time closure, just
before plugging of the tunnel. Height of the cofferdam is 20m and gate is designed for
operation against 24m water head.
6.4.2 Spillway Radial Gates, Hoists, Emergency Bulkhead Gate And Gantry Crane
For flushing and to regulate the water level in the reservoir, three numbers submerged
type spillway radial gates have been provided. Each gate shall be operated by means of
suitable capacity hydraulic hoist from a power pack and two double acting cylinders (one
on each end of the gate) having a provision of 25% pushing force.
One trolley mounted mobile gasoline engine operated power pack capable of operating
one gate at 25% of the normal rated speed is envisaged for emergency operation of
spillway radial gates.
One portable oil filter unit for filtration, dehydration & degasification of hydraulic oil is
also being provided.
61
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
One number slide type bulkhead gate has been envisaged to cater to the maintenance
requirement of three nos. spillway radial gates. The bulkhead gate shall be shall be
operated under balanced head condition by means of a suitable capacity gantry crane with
the help of a lifting beam.
6.4.3 Trash Rack And Trash Rack Cleaning Machine
Upstream face of the intake shall be provided with the trash rack screen, which will be
cleaned by means of a trash rack-cleaning machine.
6.4.4 Intake Gates, Intake Bulkhead Gates And Hoists
Two number fixed wheel type gates shall be provided at the intake. The intake gate is to
be designed for self- lowering against upstream water level corresponding to FRL. The
gate shall be operated by means of electrically operated rope drum hoist of suitable
capacity.
For maintenance and inspection of intake gates and embedded parts, two numbers
vertical slide gates have been proposed on the upstream of the intake gates. The slide
gates shall be operated by means of electrically operated rope drum hoist under balanced
head condition.
6.4.5 Desilting Chamber Gate & Hoist
One number slide type gate shall be provided at the outlet of desilting chamber for the
maintenance requireme nt of two nos. desilting chambers. The gate shall be lowered /
raised under balanced head condition by means of suitable capacity EOT Crane.
6.4.6 Flushing Tunnel Gates & Hoists
In two silt- flushing tunnels, each tunnel is provided with a set of two slide (Emergency &
Service) gates for regulating the discharge through flushing tunnels. Both the (Emergency
& Service) gates shall be operated by means of hydraulic hoists. The gate grooves are
62
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
provided with bonnet structures embedded in the concrete and a watertight bonnet cover
at the top of the groove.
6.4.7 Surge Shaft Gate And Hoist
The intake of pressure shaft is provided with one number slide type gate. The gate shall
be operated under balanced head condition by means of an electrically operated rope
drum hoist.
6.4.8 Tail Race Gate And Hoist
To isolate powerhouse from the river during flood, one number fixed wheel type tailrace
gate has been envisaged. The gate shall be operated under balanced head conditions by
suitable capacity electrically operated monorail hoist placed in the transformer cavern.
6.4.9 Adit Inspection Gates
Three nos. adits shall be provided with manually operated hinged type gates in the
concrete plug at the HRT to give access to the head race tunnel in the event of any
inspection, repair and maintenance.
6.4.10 Pressure Shaft Steel Liner
One no. Pressure Shaft of dia. 2000 mm fully steel lined will take off from Surge Shaft to
feed the turbines placed in the powerhouse. It comprises horizontal & inclined ferules, 2
nos. vertical bends, 2 nos. plan bends, 2 nos. bifurcations and branch pipes for feeding
three nos. turbines.
The material of Pressure Shaft liner shall conform to ASTM A537 Class - I. However, for
bifurcation material shall conform to ASTM A517 Gr. F.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
6.4.11 Instrument And Remote Control
Gates shall be provided with PLC based remote control system for Control and operation
of gates and automatic control of the reservoir level.
6.4.12 Diesel Generating Set
One diesel generating set complete with all accessories will be provided for emergency
operation of gates and hoists.
64
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – VII
POWER POTENTIAL STUDIES
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER-VII
POWER POTENTIAL STUDIES
7.1
GENERAL
The Power potential studies of Lingza HE Project has been made for 90% dependable
year based on 21 hydrological years, from 1976-77 (June) to 1996-97 (May) as given in
table 7.1. The salient features of the project are as follows:
FRL (EL)
=1850 m
MDDL (EL)
=1830 m
TWL
= EL 1095 m
Centre line of M/C
=EL 1097 m
Rated net head
= 736 m
Type of turbine
= Vertical Pelton
Rated Discharge of Plant
=18.47 cumecs
Proposed Plant Capacity
=120 MW (3x40 MW)
Design Energy
=477.51 MU in the 90% dependable year with
95% machine availability
Minimum Peaking (Hrs)
= 3 hrs (approx.)
Gross Storage
=
2.64MCM
MWhr
=
4765.31
Live storage
=
1.71 MCM
MWHr
=
3086.61
7.2
AVAILABLE FLOW
The discharge data for the 90% dependable hydrological year is given in table 7.3 and
power potential in 90% dependable year with 95% machine availability has also been
shown in this table. For carrying out the power potential and optimisation studies, the
following statistics have been computed.
65
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Year:
Each 10-daily period of the year represents the average of the flow recorded for the
corresponding period of each year.
90% Dependable Year:
This is the lower decile of the series of the corresponding 10-daily period of the record
i.e. (N+1) x 0.9th year where N is the years for which continuous hydrological data are
available. The 90% dependable year comes out to be 1976-77 whose calculations are
shown in table 7.2.
7.3
Definition Of Terms
Annual Energy
This is the yearly energy provided during the 90% dependable hydrological year with
95% machine availability.
Firm Power
This is the power capacity, which can be guaranteed continuously during the lean period
in 90% dependable year. Here no reservoir capacity has been selected in order to have
minimum environmental impact. During lean inflow period (winter season) the firm
power comes out to be 15.50 MW calculations for this has been shown in table 7.3.
7.4
FULL RESERVOIR LEVEL (FRL) AND MINIMUM DRAW DOWN
LEVEL (MDDL)
FRL and MDDL have been fixed at EL 1850m & EL 1830 m respectively based on civil
consideration. Justification for FRL, MDDL and TWL has been presented in chapter VI
“Conceptual Planning and layout”. This project is envisaged as a run of the river scheme.
7.5
OPERATING HEAD AND HEAD LOSSES
The net operating head for turbines has been derived from the following formula where
head losses are taken as 10 m.
66
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Net operating head =MDDL+2/3 (FRL-MDDL)-TCL-Head losses
The net operating head comes out to 736 m.
7.6
INSTALLED CAPACITY
Installed capacity of 120 MW has been selected based on power potential studies, water
availability and results arrived as per table 7.4(a).The studies for power output and annual
energy gener ation for the 90% dependable year restricted to various MW has been given
in table 7.4.
7.7
SIZE OF GENERATING UNITS
The power load demand in India is increasing at a very rapid rate and both hydroelectric
and thermal (including nuclear) Power potential in the country are being developed not
only to meet the overall requirements, but stimulatingly also to provide a proper mix of
hydro and thermal power for optimum operation of the system. Keeping this in view
current practice is to opt for largest size hydro units permissible within the parameters of
economy, operating efficiency, maintenance, optimum utilization of available water,
transport limitation etc. It is therefore proposed to install 3 units with capacity each of 40
MW with Pelton turbine as prime mover has been envisaged. However detailed
optimization studies for fixation of installed capacity would have to be done at FR/DPR
stage.
7.8
ENERGY GENERATION
The energy generation in the 90% dependable year (1976-77) indicating lean inflow
period and high inflow period is shown in table 7.5 (A). It may be seen from table 7.3
that the total unrestricted energy generation is 543.04 MU. Total energy restricted to 120
MW comes out to be 489.35MU. Annual energy generation at 120 MW (in 90%
dependable year and 95% machine availability) comes out to be 477.51 MU. Incremental
benefits have been shown in table 7.4a which comes out to be 1.79 for this year. Also
annual energy generation unrestricted has been indicated in table 7.7(A) to 7.7(U) for 21
67
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
hydrological years. Energy available at bus bar shall be 471.79 MU after allowing
auxiliary consumption of 0.7% and transformer losses of 0.5% respectively.
A table giving the summary of studies indicating yearly inflows, annual energy
generation, load factor of operation during monsoon and lean flow period has been
presented in studies as per Table 7.5 Annex-B.
68
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW)
TABLE 7.1
HYDROLOGICAL SERIES
Month
1-10
JUNE
19871988
19881989
19891990
19901991
19911992
19921993
19931994
19941995
19951996
19961997
20.94
18.19
25.34
26.79
37.97
18.13
11.98
20.25
16.00
20.16
22.09
11.73
4.92
8.06
16.70
25.25
13.97
27.87
21.75
27.91
26.00
45.66
22.64
20.32
29.40
23.15
33.39
21.58
18.52
7.02
10.30
22.10
27.01
11.83
21-30
2
19.03
18.65
28.33
26.10
31.19
29.53
30.86
36.28
41.00
64.15
30.12
24.68
25.36
35.32
25.24
17.03
13.60
13.25
25.66
27.36
21.13
Jan-00
24.33
21.32
24.87
27.11
33.01
37.72
27.09
41.55
47.19
50.58
26.08
28.31
39.42
35.96
27.82
19.45
11.69
27.74
21.94
34.72
23.47
11-20
4
23.19
25.08
26.66
25.93
33.79
32.35
30.35
35.35
47.35
66.00
32.59
27.07
30.96
35.37
35.46
18.95
11.82
27.74
23.26
29.13
25.27
21-31
5
17.65
30.04
25.73
29.04
35.40
30.43
35.80
35.07
50.05
55.50
29.31
30.26
34.12
32.92
30.35
20.66
13.43
32.53
23.71
22.39
22.50
Jan-00
20.57
24.53
30.46
26.84
35.77
29.67
24.06
28.71
45.14
44.85
26.02
28.66
33.87
28.57
25.85
23.69
14.70
36.49
21.79
24.46
21.51
11-20
7
22.43
20.64
25.74
21.19
39.28
31.31
22.78
30.44
45.26
47.31
22.36
31.26
31.09
22.41
26.26
27.29
14.76
34.59
21.28
24.68
20.06
21-31
8
23.98
24.10
19.32
22.48
32.72
30.44
26.73
35.56
47.38
57.92
24.76
20.90
47.16
21.99
23.30
22.55
16.05
33.13
22.89
21.92
20.21
Jan-00
21.84
16.83
16.03
22.11
31.26
29.13
20.56
28.58
48.80
23.62
21.74
37.59
22.52
21.32
22.37
22.72
14.08
34.86
19.41
19.78
20.18
11-20
10
12.60
13.76
20.87
19.29
24.50
24.97
29.74
32.14
46.57
22.57
27.00
20.11
15.19
19.31
21.42
24.00
13.85
29.36
19.44
17.71
19.26
21-30
11
9.20
11.48
15.69
14.15
19.83
19.90
19.51
37.07
36.94
18.91
21.98
27.58
16.99
19.18
14.92
18.59
11.47
27.76
16.80
17.04
16.75
Jan-00
7.79
14.01
15.09
23.58
15.51
18.25
13.81
26.07
31.12
16.25
17.72
17.13
14.34
15.15
12.50
14.84
8.66
24.67
13.14
12.59
14.72
11-20
13
6.15
8.83
11.77
16.09
13.33
16.89
11.60
25.70
39.47
14.25
13.25
12.76
9.51
12.89
12.73
11.77
6.21
18.30
11.68
12.25
13.49
21-31
14
6.21
7.05
10.03
12.07
12.42
14.76
11.17
17.52
30.41
11.74
10.35
10.91
7.65
10.49
10.47
9.66
5.29
15.69
10.70
9.57
12.06
Jan-00
6.18
7.31
8.04
12.03
10.49
12.58
8.75
14.32
22.66
9.53
9.51
8.85
6.31
6.52
6.41
8.00
3.90
13.02
8.80
6.23
10.97
11-20
16
5.12
6.67
5.99
9.80
9.55
10.04
7.63
13.16
19.58
8.28
8.47
5.40
5.70
5.29
4.79
7.08
3.47
11.47
7.26
7.11
10.20
21-30
17
4.57
5.04
5.90
9.22
8.79
8.31
7.39
10.84
17.41
7.34
7.31
4.75
5.31
4.81
4.00
5.40
3.16
10.52
6.06
7.15
9.07
Jan-00
3.72
4.55
5.69
8.79
8.17
7.63
6.53
9.04
11.16
6.25
6.54
4.48
5.04
4.20
3.66
4.54
3.13
10.26
5.85
5.35
6.25
11-20
19
3.18
4.81
4.82
7.24
7.42
6.86
6.02
8.47
10.98
5.65
6.03
4.09
4.78
3.64
3.02
3.48
2.71
9.43
5.35
4.76
5.65
21-31
20
2.94
5.44
4.33
6.97
6.74
5.38
5.70
7.60
11.02
5.20
4.44
3.74
4.52
3.19
2.61
3.06
2.50
7.75
5.06
4.42
5.20
Jan-00
2.62
3.74
3.99
6.57
6.50
4.94
5.65
6.78
11.12
4.93
3.88
3.65
2.77
2.91
2.64
2.79
2.54
7.30
4.80
3.81
5.88
11-20
22
2.49
3.35
3.69
6.32
6.09
5.50
5.03
6.67
10.56
4.90
3.65
3.65
2.69
2.70
2.59
2.31
2.57
6.80
4.85
3.79
5.59
21-31
23
2.38
3.43
3.62
6.26
6.01
5.42
3.53
5.94
9.14
4.64
3.43
3.61
2.67
2.44
2.56
2.36
2.41
6.87
4.79
4.01
5.69
Jan-00
4.39
3.47
3.30
6.01
5.59
5.38
3.21
5.72
9.99
4.69
3.25
3.54
2.97
2.40
2.48
2.50
2.33
6.77
4.75
4.15
5.67
11-20
25
4.28
3.39
3.29
6.30
5.75
5.58
3.19
5.94
9.13
4.82
3.22
3.71
2.71
2.26
2.36
2.41
2.48
6.48
4.73
3.69
5.65
21-28
26
2.56
3.12
3.58
6.72
6.95
5.43
4.44
5.71
11.05
5.52
3.53
4.12
2.89
2.18
2.38
2.31
2.39
6.94
4.76
4.04
5.59
Jan-00
2.43
3.16
3.67
6.91
6.88
5.66
4.77
12.60
14.04
5.89
3.30
4.27
3.28
1.99
2.54
2.47
3.91
6.40
4.33
4.11
5.72
11-20
28
3.46
3.38
3.85
7.09
7.28
6.33
6.11
14.08
15.21
6.41
3.91
6.33
3.35
1.63
2.90
2.49
3.90
5.77
4.10
4.75
6.01
21-31
29
3.21
3.74
4.74
9.57
8.60
7.54
5.51
13.83
14.16
6.58
4.91
6.51
3.44
1.65
3.06
2.56
4.08
7.30
5.65
5.07
6.55
Jan-00
4.66
4.50
6.99
10.75
8.61
9.48
8.11
14.54
17.05
6.47
8.96
7.44
3.58
1.71
8.03
3.03
4.15
7.09
5.53
4.66
6.28
11-20
31
4.37
5.76
6.95
13.78
10.90
9.46
6.63
15.50
20.57
8.37
6.26
8.40
4.28
2.82
4.58
4.25
4.53
8.87
6.85
4.53
6.25
21-30
32
4.65
6.83
8.73
15.71
12.84
10.49
8.30
15.51
24.29
9.39
8.27
9.77
5.14
3.50
4.84
3.89
5.43
8.14
9.99
10.07
6.43
1-10
MAY
19861987
18.20
1-10
APRIL
19851986
15.21
1-10
MARCH
19841985
22.41
1-10
FEBRUARY
19831984
21.35
1-10
JANUARY
19821983
25.65
1-10
DECEMBER
19811982
14.46
1-10
NOVEMBER
19801981
26.23
1-10
OCTOBER
19791980
13.44
1-10
SEPTEMBER
19781979
1
1-10
AUGUST
19771978
11-20
1-10
JULY
19761977
Feb-00
5.08
7.78
13.09
14.98
15.77
13.16
13.36
17.60
17.48
8.80
9.35
9.99
9.02
5.16
8.13
3.81
6.89
9.12
14.58
12.28
7.50
11-20
34
6.28
15.94
16.69
12.81
17.03
14.78
16.01
25.72
20.29
9.36
10.40
14.97
9.32
9.09
9.91
4.43
6.20
9.40
22.51
10.76
8.63
21-31
35
8.95
18.62
12.77
13.66
16.52
14.36
21.31
36.54
28.26
9.86
12.20
19.84
22.70
10.46
10.96
4.46
6.28
11.57
21.75
14.89
8.91
68
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
TABLE NO.-7.2
CALCULATION OF 90% DEPENDABLE YEAR
YEAR
UNRESTRIC
TED
ENERGY IN
DESCENDIN
G ORDER
RANK
OF
THE
YEAR
UNRESTRICTED
ENERGY
GENERATION
MU
YEAR
1976-1977
543.04
1984-1985
1531.95
1
1977-1978
637.97
1983-1984
1159.62
2
1978-1979
710.22
1985-1986
1078.12
3
1979-1980
820.67
1980-1981
951.00
4
1980-1981
951.00
1981-1982
887.89
5
1981-1982
887.89
1993-1994
876.18
6
1982-1983
818.15
1979-1980
820.67
7
1983-1984
1159.62
1982-1983
818.15
8
1984-1985
1531.95
1987-1988
806.52
9
1985-1986
1078.12
1988-1989
766.48
10
1986-1987
740.20
1986-1987
740.20
11
1987-1988
806.52
1995-1996
722.59
12
1988-1989
766.48
1994-1995
719.50
13
1989-1990
706.28
1978-1979
710.22
14
1990-1991
677.88
1989-1990
706.28
15
1991-1992
569.80
1990-1991
677.88
16
1992-1993
391.47
1996-1997
666.10
17
1993-1994
876.18
1977-1978
637.97
18
1994-1995
719.50
1991-1992
569.80
19
1995-1996
722.59
1976-1977
543.04
20
1996-1997
666.10
1992-1993
391.47
21
69
CALCULATION OF 90%
DEPENDABLE YEAR
N= No. of year
90% Dependable Year
=(N+1)*0.9th year
=(21+1)*0.9th year
=19.8th year
=20th year (say)
90% Dependable year is
1976-1977
90% Dependable energy
(unrestricted)
is543.04MU
90% Dependable energy
whenpower is restricted
to 120 MW is 489.35MU
90% DEPENDABLE
YEAR IS 1976-1977
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
TABLE 7.3
POWER POTENTIAL IN 90% DEPENDABLE YEAR WITH 95% m/c AVAILABILITY
Net Head 736 m
Design Discharge
18.47
overall Efficiency 90%
1976-1977
Period
Jun-76
Jul-76
Aug-76
Sep-76
Oct-76
Nov-76
Dec-76
Jan-77
Feb-77
Mar-77
Apr-77
May-77
10
10
10
10
10
11
10
10
11
10
10
10
10
10
11
10
10
10
10
10
11
10
10
11
10
10
8
10
10
11
10
10
10
10
10
11
365
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
RESTRICTED MW 120
Inflow
Cumecs
Unrestricted Power
Potential Mw
Unrestricted
Energy(Mu)
Restricted
Energy (Mu)
95% M/C
Availability
13.44
26.23
19.03
24.33
23.19
17.65
20.57
22.43
23.98
21.84
12.60
9.20
7.79
6.15
6.21
6.18
5.12
4.57
3.72
3.18
2.94
2.62
2.49
2.38
4.39
4.28
2.56
2.43
3.46
3.21
4.66
4.37
4.65
5.08
6.28
8.95
87.34
170.46
123.69
158.12
150.68
114.69
133.70
145.74
155.81
141.94
81.85
59.76
50.63
39.99
40.37
40.15
33.24
29.72
24.16
20.66
19.09
17.03
16.19
15.50
28.54
27.81
16.66
15.76
22.50
20.89
30.29
28.43
30.21
33.03
40.79
58.13
20.96
40.91
29.68
37.95
36.16
30.28
32.09
34.98
41.13
34.06
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
543.04
20.96
28.80
28.80
28.80
28.80
30.28
28.80
28.80
31.68
28.80
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
489.35
20.96
27.36
27.36
27.36
27.36
30.10
27.36
27.36
30.10
27.36
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
477.51
Restricted Energy generated in 90% dependable year with 95% machine availability with installed
capicity of 120 MW =
%
477.51 MU
MU
Auxiliary consumptions
Transformer losses
0.7
0.5
0.007
0.005
Energy available at Bus
471.79
MU
70
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW)
TABLE 7.4
POWER POTENTIAL IN 90% Dependable Year
1976-1977
Net Head
Period
Jun-76
Jul-76
Aug-76
Sep-76
Oct-76
Nov-76
Dec-76
Jan-77
Feb-77
Mar-77
Apr-77
May-77
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
10
Incremental Steps
736.00
Overall Efficiency
90%
ENERGY GENERATION IN MU RESTRICTED TO VARIOUS MW
Inflow
(Cumecs)
Power Potential
(MW)
Unrestricted Energy
Generation (MU)
80
90
100
110
120
130
140
150
160
170
180
13.44
26.23
19.03
24.33
23.19
17.65
20.57
22.43
23.98
21.84
12.60
9.20
7.79
6.15
6.21
6.18
5.12
4.57
3.72
3.18
2.94
2.62
2.49
2.38
4.39
4.28
2.56
2.43
3.46
3.21
4.66
4.37
4.65
5.08
6.28
8.95
87.34
170.46
123.69
158.12
150.68
114.69
133.70
145.74
155.81
141.94
81.85
59.76
50.63
39.99
40.37
40.15
33.24
29.72
24.16
20.66
19.09
17.03
16.19
15.50
28.54
27.81
16.66
15.76
22.50
20.89
30.29
28.43
30.21
33.03
40.79
58.13
20.96
40.91
29.68
37.95
36.16
30.28
32.09
34.98
41.13
34.06
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
19.20
19.20
19.20
19.20
19.20
21.12
19.20
19.20
21.12
19.20
19.20
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
20.96
21.60
21.60
21.60
21.60
23.76
21.60
21.60
23.76
21.60
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
20.96
24.00
24.00
24.00
24.00
26.40
24.00
24.00
26.40
24.00
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
20.96
26.40
26.40
26.40
26.40
29.04
26.40
26.40
29.04
26.40
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
20.96
28.80
28.80
28.80
28.80
30.28
28.80
28.80
31.68
28.80
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
20.96
31.20
29.68
31.20
31.20
30.28
31.20
31.20
34.32
31.20
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
20.96
33.60
29.68
33.60
33.60
30.28
32.09
33.60
36.96
33.60
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
20.96
36.00
29.68
36.00
36.00
30.28
32.09
34.98
39.60
34.06
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
20.96
38.40
29.68
37.95
36.16
30.28
32.09
34.98
41.13
34.06
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
20.96
40.80
29.68
37.95
36.16
30.28
32.09
34.98
41.13
34.06
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
20.96
40.91
29.68
37.95
36.16
30.28
32.09
34.98
41.13
34.06
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
543.04
400.23
424.51
71
446.59
468.67
489.35
507.28
522.80
534.49
540.53
542.93
543.04
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
TABLE 7.4a
AVAILABILITY OF UNITS IN KWH/KW FOR INCREMENTAL INSTALLATION IN 90%
DEPENDABLE YEAR
1976-1977
S.
No.
1
2
3
4
5
6
7
8
9
10
11
Overall
Efficiency
Net Head
736.00
Installed
Capacity
Mw
Annual
Energy Mu
Load
Factor %
80
400.23
57.11%
90
100
110
120
130
140
150
160
170
180
424.51
446.59
468.67
489.35
507.28
522.80
534.49
540.53
542.93
543.04
90%
Incremental
Energy Mu
Incremental
Energy
Kwh/Kw
Load Factor
For
Additional
Capacity %
24.29
2428.74
27.73%
22.08
2208.00
25.21%
22.08
2208.00
25.21%
20.68
2067.79
23.60%
17.92
1792.49
20.46%
15.53
1552.70
17.72%
11.68
1168.24
13.34%
6.05
604.55
6.90%
2.40
240.00
2.74%
0.11
11.06
0.13%
53.84%
50.98%
48.64%
46.55%
44.54%
42.63%
40.68%
38.57%
36.46%
34.44%
72
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Table 7.5(A)
1976-1977
Net Head 736 m
Period
Jun-76
Jul-76
Aug-76
Sep-76
Oct -76
Nov-76
Dec-76
Jan-77
Feb-77
Mar-77
Apr-77
May-77
10
10
10
10
10
11
10
10
11
10
10
10
10
10
11
10
10
10
10
10
11
10
10
11
10
10
8
10
10
11
10
10
10
10
10
11
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
Restricted MW
120
Overall Efficiency
90%
Inflow
(Cume
cs)
Head
(M)
Unrestr
icted
Power
(Mw )
Unrestrict
ed
Energy
(Mu)
Power
Restricted
To
120mw
Restricted
Energy At
120 Mw
(Mu)
Restricted
Energy at 120
MW With 95%
m/c availability
Energy
during
high
inflow
period
Energy
during
lean
inflow
period
13.44
26.23
19.03
24.33
23.19
17.65
20.57
22.43
23.98
21.84
12.60
9.20
7.79
6.15
6.21
6.18
5.12
4.57
3.72
3.18
2.94
2.62
2.49
2.38
4.39
4.28
2.56
2.43
3.46
3.21
4.66
4.37
4.65
5.08
6.28
8.95
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
736.00
87.34
170.46
123.69
158.12
150.68
114.69
133.70
145.74
155.81
141.94
81.85
59.76
50.63
39.99
40.37
40.15
33.24
29.72
24.16
20.66
19.09
17.03
16.19
15.50
28.54
27.81
16.66
15.76
22.50
20.89
30.29
28.43
30.21
33.03
40.79
58.13
20.96
40.91
29.68
37.95
36.16
30.28
32.09
34.98
41.13
34.06
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
87.34
120.00
120.00
120.00
120.00
114.69
120.00
120.00
120.00
120.00
81.85
59.76
50.63
39.99
40.37
40.15
33.24
29.72
24.16
20.66
19.09
17.03
16.19
15.50
28.54
27.81
16.66
15.76
22.50
20.89
30.29
28.43
30.21
33.03
40.79
58.13
20.96
28.80
28.80
28.80
28.80
30.28
28.80
28.80
31.68
28.80
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
20.96
27.36
27.36
27.36
27.36
30.10
27.36
27.36
30.10
27.36
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
0.00
27.36
27.36
27.36
27.36
30.10
27.36
27.36
30.10
27.36
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
20.96
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
489.35
477.51
45.42
251.71
95.00
225.79
28.72
Energy obtained on 95% machine availibility
LOAD FACTOR
73
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Annexure-B
Table 7.5
Period
Yearly
inflow
(M Cum)
Annual
Energy
Generation
(MU)
Annual
Load Factor
(%)
Load Factor
during high in
flow period
(%)
Load Factor during
lean inflow period
(%)
1976-1977
300.85
477.51
45.42
95.00
28.72
1977-1978
353.44
555.73
52.87
93.89
34.47
1978-1979
393.47
599.02
56.98
92.45
34.40
1979-1980
454.65
711.68
67.70
92.32
50.13
1980-1981
526.86
704.05
66.98
93.19
45.82
1981-1982
491.90
690.15
65.65
94.26
45.24
1982-1983
453.26
635.53
60.46
94.42
38.58
1983-1984
642.43
797.29
75.85
93.92
52.94
1984-1985
848.71
882.95
83.99
94.35
60.29
1985-1986
597.28
627.60
59.70
94.71
39.87
1986-1987
410.07
597.98
56.89
95.08
37.71
1987-1988
446.82
619.88
58.97
93.94
33.73
1988-1989
424.63
548.05
52.14
93.19
28.60
1989-1990
391.28
523.25
49.78
94.02
24.71
1990-1991
375.55
536.56
51.04
93.83
29.56
1991-1992
315.67
504.63
48.01
93.57
25.13
1992-1993
216.88
391.47
37.24
86.90
35.70
1993-1994
485.41
663.31
63.10
94.44
47.17
1994-1995
398.60
630.92
60.02
94.40
37.88
1995-1996
400.32
594.40
56.54
93.68
35.26
1996-1997
369.02
609.25
57.96
94.58
43.75
74
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
TABLE 7.6
POWER GENERATION IN 90% DEPENDABLE YEAR (1976-77)
Power In Mw
Period
1
Jun-76
Jul-76
Aug76
Sep-76
Oct -76
Nov76
Dec-76
Jan-77
Feb-77
Mar77
Apr-77
May77
10
10
10
10
10
11
10
10
11
10
10
10
10
10
11
10
10
10
10
10
11
10
10
11
10
10
8
10
10
11
10
10
10
10
10
11
365
2
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
Energy In Mu
90%
Dependable
Inflow
Cumecs
Unrestricted
Power Potential
Mw
Restrictedto
Installed
Capacity
3
13.44
26.23
19.03
24.33
23.19
17.65
20.57
22.43
23.98
21.84
12.60
9.20
7.79
6.15
6.21
6.18
5.12
4.57
3.72
3.18
2.94
2.62
2.49
2.38
4.39
4.28
2.56
2.43
3.46
3.21
4.66
4.37
4.65
5.08
6.28
8.95
4
87.34
170.46
123.69
158.12
150.68
114.69
133.70
145.74
155.81
141.94
81.85
59.76
50.63
39.99
40.37
40.15
33.24
29.72
24.16
20.66
19.09
17.03
16.19
15.50
28.54
27.81
16.66
15.76
22.50
20.89
30.29
28.43
30.21
33.03
40.79
58.13
5
89.36
120.00
120.00
120.00
120.00
117.34
120.00
120.00
120.00
120.00
83.75
61.14
51.80
40.92
41.31
41.08
34.01
30.40
24.72
21.14
19.53
17.42
16.56
15.86
29.20
28.45
17.05
16.13
23.02
21.37
30.99
29.08
30.91
33.79
41.74
59.47
Unrestricted
Energy(Mu)
Restricted
Energy
(Mu)
6
20.96
40.91
29.68
37.95
36.16
30.28
32.09
34.98
41.13
34.06
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
543.04
NOTE : The energy is calculated taking into consideration 95% machine availability
75
7
20.96
28.80
28.80
28.80
28.80
30.28
28.80
28.80
31.68
28.80
19.65
14.34
12.15
9.60
10.66
9.64
7.98
7.13
5.80
4.96
5.04
4.09
3.88
4.09
6.85
6.67
3.20
3.78
5.40
5.51
7.27
6.82
7.25
7.93
9.79
15.35
489.35
Monthly
Energy In
Gwh
8
78.56
87.88
89.28
62.79
32.41
24.75
15.80
12.06
16.72
14.70
21.34
33.06
#REF!
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW)
INCREMENTAL BENEFIT FOR 90% DEPENDABLE
YEAR(1976-1977)
2.50
2.43
2.21
2.21
2.07
INCREMENTAL MW?MU/?MW
2.00
1.79
1.55
1.50
1.17
1.00
0.60
0.50
0.24
0.01
0.00
80
90
100
110
120
130
CAPACITY(MW)
76
140
150
160
170
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7(A)
ENERGY GENERATION IN YEAR
1976-1977
UNRISTRICTED
ENERGY
PERIOD
FLOW
MONTH
CUMECS
MU
1-10
13.44
20.96
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
26.23
40.91
19.03
29.68
24.33
37.95
23.19
36.16
17.65
30.28
20.57
32.09
22.43
34.98
23.98
41.13
1-10
21.84
34.06
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
12.60
19.65
9.20
14.34
7.79
12.15
6.15
9.60
6.21
10.66
6.18
9.64
5.12
7.98
4.57
7.13
3.72
5.80
3.18
4.96
2.94
5.04
2.62
4.09
2.49
3.88
2.38
4.09
4.39
6.85
4.28
6.67
2.56
3.20
2.43
3.78
3.46
5.40
3.21
5.51
4.66
7.27
4.37
6.82
4.65
7.25
5.08
7.93
6.28
9.79
8.95
15.35
543.04
77
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7(B)
ENERGY GENERATION IN YEAR
1977-1978
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED
ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
14.46
22.55
25.65
40.00
18.65
29.09
21.32
33.24
25.08
39.11
30.04
51.53
24.53
38.25
20.64
32.19
24.10
41.34
1-10
16.83
26.25
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
13.76
21.46
11.48
17.90
14.01
21.84
8.83
13.77
7.05
12.10
7.31
11.41
6.67
10.41
5.04
7.86
4.55
7.10
4.81
7.51
5.44
9.34
3.74
5.84
3.35
5.23
3.43
5.88
3.47
5.41
3.39
5.29
3.12
3.89
3.16
4.93
3.38
5.27
3.74
6.42
4.50
7.02
5.76
8.99
6.83
10.65
7.78
12.13
15.94
24.86
18.62
31.93
637.97
78
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 ( C )
ENERGY GENERATION IN YEAR
1978-1979
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICT ED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
21.35
33.30
22.41
34.94
28.33
44.18
24.87
38.79
26.66
41.58
25.73
44.14
30.46
47.50
25.74
40.14
19.32
33.15
1-10
16.03
25.00
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
20.87
32.55
15.69
24.47
15.09
23.53
11.77
18.35
10.03
17.21
8.04
12.53
5.99
9.35
5.90
9.20
5.69
8.87
4.82
7.52
4.33
7.43
3.99
6.23
3.69
5.75
3.62
6.21
3.30
5.14
3.29
5.13
3.58
4.47
3.67
5.73
3.85
6.00
4.74
8.12
6.99
10.91
6.95
10.85
8.73
13.61
13.09
20.42
16.69
26.03
12.77
21.90
710.22
79
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE7.7 (D)
ENERGY GENERATION IN YEAR
1979-1980
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
15.21
23.73
18.20
28.39
26.10
40.71
27.11
42.27
25.93
40.44
29.04
49.83
26.84
41.86
21.19
33.05
22.48
38.56
1-10
22.11
34.48
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-29
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
19.29
30.09
14.15
22.07
23.58
36.78
16.09
25.10
12.07
20.71
12.03
18.77
9.80
15.28
9.22
14.39
8.79
13.70
7.24
11.29
6.97
11.95
6.57
10.24
6.32
9.86
6.26
10.75
6.01
9.38
6.30
9.83
6.72
9.43
6.91
10.78
7.09
11.05
9.57
16.41
10.75
16.76
13.78
21.50
15.71
24.49
14.98
23.36
12.81
19.98
13.66
23.43
820.67
80
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 (E)
ENERGY GENERATION IN YEAR
1980-1981
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
20.94
32.66
27.87
43.46
31.19
48.64
33.01
51.48
33.79
52.70
35.40
60.73
35.77
55.79
39.28
61.27
32.72
56.13
1-10
31.26
48.75
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
24.50
38.21
19.83
30.93
15.51
24.19
13.33
20.79
12.42
21.31
10.49
16.36
9.55
14.90
8.79
13.72
8.17
12.74
7.42
11.58
6.74
11.57
6.50
10.13
6.09
9.50
6.01
10.31
5.59
8.72
5.75
8.97
6.95
8.68
6.88
10.72
7.28
11.36
8.60
14.75
8.61
13.43
10.90
17.00
12.84
20.03
15.77
24.60
17.03
26.57
16.52
28.34
951.00
81
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 (F)
ENERGY GENERATION IN YEAR
1981-1982
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
18.19
28.36
21.75
33.92
29.53
46.05
37.72
58.83
32.35
50.45
30.43
52.20
29.67
46.27
31.31
48.83
30.44
52.21
1-10
29.13
45.44
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
24.97
38.94
19.90
31.04
18.25
28.46
16.89
26.34
14.76
25.32
12.58
19.62
10.04
15.65
8.31
12.96
7.63
11.90
6.86
10.70
5.38
9.23
4.94
7.71
5.50
8.58
5.42
9.30
5.38
8.39
5.58
8.71
5.43
6.77
5.66
8.82
6.33
9.87
7.54
12.94
9.48
14.78
9.46
14.76
10.49
16.37
13.16
20.52
14.78
23.04
14.36
24.63
887.89
82
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE7.7 (G)
ENERGY GENERATION IN YEAR
1982-1983
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
25.34
39.53
27.91
43.53
30.86
48.12
27.09
42.25
30.35
47.34
35.80
61.42
24.06
37.52
22.78
35.52
26.73
45.85
1-10
20.56
32.07
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
29.74
46.38
19.51
30.43
13.81
21.54
11.60
18.09
11.17
19.16
8.75
13.64
7.63
11.90
7.39
11.53
6.53
10.18
6.02
9.39
5.70
9.78
5.65
8.81
5.03
7.85
3.53
6.05
3.21
5.01
3.19
4.97
4.44
5.54
4.77
7.44
6.11
9.53
5.51
9.46
8.11
12.65
6.63
10.34
8.30
12.95
13.36
20.84
16.01
24.97
21.31
36.55
818.15
83
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE7.7 (H)
ENERGY GENERATION IN YEAR
1983-1984
PERI OD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
26.79
41.78
26.00
40.55
36.28
56.59
41.55
64.80
35.35
55.13
35.07
60.17
28.71
44.77
30.44
47.47
35.56
61.01
1-10
28.58
44.58
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-29
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
32.14
50.12
37.07
57.82
26.07
40.65
25.70
40.08
17.52
30.05
14.32
22.33
13.16
20.52
10.84
16.90
9.04
14.10
8.47
13.22
7.60
13.03
6.78
10.57
6.67
10.40
5.94
10.18
5.72
8.92
5.94
9.26
5.71
8.01
12.60
19.65
14.08
21.96
13.83
23.73
14.54
22.68
15.50
24.18
15.51
24.18
17.60
27.44
25.72
40.11
36.54
62.68
1159.62
84
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE7.7 (I)
ENERGY GENERATION IN YEAR
1984-1985
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
37.97
59.21
45.66
71.20
41.00
63.94
47.19
73.60
47.35
73.84
50.05
85.87
45.14
70.40
45.26
70.59
47.38
81.28
1-10
48.80
76.11
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
46.57
72.63
36.94
57.61
31.12
48.53
39.47
61.56
30.41
52.17
22.66
35.34
19.58
30.54
17.41
27.14
11.16
17.40
10.98
17.12
11.02
18.91
11.12
17.34
10.56
16.47
9.14
15.68
9.99
15.58
9.13
14.24
11.05
13.79
14.04
21.90
15.21
23.72
14.16
24.30
17.05
26.59
20.57
32.08
24.29
37.89
17.48
27.27
20.29
31.64
28.26
48.48
1531.95
85
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE7.7 (J)
ENERGY GENERATION IN YEAR
1985-1986
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
18.13
28.28
22.64
35.30
64.15
100.04
50.58
78.88
66.00
102.93
55.50
95.20
44.85
69.94
47.31
73.78
57.92
99.36
1-10
23.62
36.84
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
22.57
35.19
18.91
29.49
16.25
25.35
14.25
22.22
11.74
20.14
9.53
14.86
8.28
12.91
7.34
11.44
6.25
9.75
5.65
8.81
5.20
8.92
4.93
7.69
4.90
7.65
4.64
7.96
4.69
7.31
4.82
7.52
5.52
6.89
5.89
9.18
6.41
9.99
6.58
11.29
6.47
10.09
8.37
13.05
9.39
14.64
8.80
13.72
9.36
14.59
9.86
16.91
1078.12
86
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE7.7 (K)
ENERGY GENERATION IN YEAR
1986-1987
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
11.98
18.69
20.32
31.70
30.12
46.97
26.08
40.68
32.59
50.83
29.31
50.28
26.02
40.57
22.36
34.88
24.76
42.47
1-10
21.74
33.90
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
27.00
42.10
21.98
34.27
17.72
27.64
13.25
20.67
10.35
17.76
9.51
14.84
8.47
13.20
7.31
11.40
6.54
10.21
6.03
9.40
4.44
7.62
3.88
6.05
3.65
5.70
3.43
5.88
3.25
5.06
3.22
5.02
3.53
4.40
3.30
5.14
3.91
6.10
4.91
8.42
8.96
13.97
6.26
9.76
8.27
12.90
9.35
14.58
10.40
16.22
12.20
20.94
740.20
87
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 (L)
ENERGY GENERATION IN YEAR
1987-1988
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
1-10
FLOW
CUMECS
20.25
29.40
24.68
28.31
27.07
30.26
28.66
31.26
20.90
37.59
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-29
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
20.11
27.58
17.13
12.76
10.91
8.85
5.40
4.75
4.48
4.09
3.74
3.65
3.65
3.61
3.54
3.71
4.12
4.27
6.33
6.51
7.44
8.40
9.77
9.99
14.97
19.84
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
UNRISTRICTED ENERGY
MU
31.57
45.86
38.49
44.15
42.21
51.92
44.69
48.76
35.85
58.63
31.36
43.01
26.71
19.89
18.71
13.80
8.42
7.40
6.98
6.39
6.42
5.70
5.70
6.19
5.52
5.78
5.78
6.66
9.87
11.16
11.60
13.11
15.24
15.59
23.35
34.04
806.52
88
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 (M)
ENERGY GENERATION IN YEAR
1988-1989
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
16.00
24.96
23.15
36.11
25.36
39.56
39.42
61.47
30.96
48.29
34.12
58.54
33.87
52.82
31.09
48.48
47.16
80.91
1-10
22.52
35.12
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
15.19
23.68
16.99
26.49
14.34
22.36
9.51
14.84
7.65
13.13
6.31
9.84
5.70
8.88
5.31
8.28
5.04
7.86
4.78
7.46
4.52
7.76
2.77
4.32
2.69
4.20
2.67
4.58
2.97
4.63
2.71
4.23
2.89
3.61
3.28
5.12
3.35
5.22
3.44
5.90
3.58
5.58
4.28
6.68
5.14
8.01
9.02
14.07
9.32
14.53
22.70
38.95
766.48
89
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 (N)
ENERGY GENERATION IN YEAR
1989-1990
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
UNRISTRICTED
ENERGY
MU
FLOW
CUMECS
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
20.16
31.44
33.39
52.08
35.32
55.08
35.96
56.08
35.37
55.16
32.92
56.48
28.57
44.56
22.41
34.96
21.99
37.73
1-10
21.32
33.24
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
19.31
30.11
19.18
29.91
15.15
23.63
12.89
20.11
10.49
17.99
6.52
10.17
5.29
8.26
4.81
7.51
4.20
6.55
3.64
5.68
3.19
5.47
2.91
4.54
2.70
4.20
2.44
4.19
2.40
3.74
2.26
3.52
2.18
2.72
1.99
3.10
1.63
2.53
1.65
2.84
1.71
2.67
2.82
4.40
3.50
5.45
5.16
8.05
9.09
14.18
10.46
17.95
706.28
90
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 (O)
ENERGY GENERATION IN YEAR
1990-1991
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
22.09
34.46
21.58
33.66
25.24
39.36
27.82
43.38
35.46
55.30
30.35
52.06
25.85
40.31
26.26
40.96
23.30
39.98
1-10
22.37
34.88
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
21.42
33.40
14.92
23.26
12.50
19.49
12.73
19.85
10.47
17.97
6.41
10.00
4.79
7.47
4.00
6.24
3.66
5.71
3.02
4.71
2.61
4.47
2.64
4.12
2.59
4.04
2.56
4.40
2.48
3.87
2.36
3.68
2.38
2.97
2.54
3.97
2.90
4.52
3.06
5.25
8.03
12.52
4.58
7.14
4.84
7.55
8.13
12.68
9.91
15.45
10.96
18.80
677.88
91
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 (P)
ENERGY GENERATION IN YEAR
1991-1992
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
11.73
18.29
18.52
28.88
17.03
26.56
19.45
30.34
18.95
29.56
20.66
35.44
23.69
36.94
27.29
42.56
22.55
38.68
1-10
22.72
35.43
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-29
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
24.00
37.43
18.59
28.99
14.84
23.14
11.77
18.35
9.66
16.57
8.00
12.48
7.08
11.04
5.40
8.42
4.54
7.08
3.48
5.43
3.06
5.25
2.79
4.35
2.31
3.61
2.36
4.05
2.50
3.89
2.41
3.75
2.31
3.24
2.47
3.86
2.49
3.89
2.56
4.39
3.03
4.72
4.25
6.63
3.89
6.06
3.81
5.94
4.43
6.92
4.46
7.65
569.80
92
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 (Q)
ENERGY GENERATION IN YEAR
1992-1993
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
UNRISTRICTED ENERGY
MU
4.92
7.68
7.02
10.95
13.60
21.21
11.69
18.22
11.82
18.44
13.43
23.04
14.70
22.93
14.76
23.02
16.05
27.53
1-10
14.08
21.95
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
13.85
21.61
11.47
17.89
8.66
13.51
6.21
9.69
5.29
9.07
3.90
6.09
3.47
5.41
3.16
4.93
3.13
4.88
2.71
4.22
2.50
4.29
2.54
3.96
2.57
4.00
2.41
4.13
2.33
3.63
2.48
3.86
2.39
2.98
3.91
6.10
3.90
6.08
4.08
7.00
4.15
6.46
4.53
7.07
5.43
8.46
6.89
10.74
6.20
9.67
6.28
10.77
391.47
93
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 (R)
ENERGY GENERATION IN YEAR
1993-1994
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
UNRISTRICTED ENERG Y
MU
8.06
12.57
10.30
16.06
13.25
20.66
27.74
43.27
27.74
43.27
32.53
55.81
36.49
56.90
34.59
53.95
33.13
56.84
1-10
34.86
54.36
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
29.36
45.78
27.76
43.29
24.67
38.47
18.30
28.54
15.69
26.91
13.02
20.30
11.47
17.89
10.52
16.40
10.26
16.01
9.43
14.71
7.75
13.29
7.30
11.38
6.80
10.60
6.87
11.78
6.77
10.56
6.48
10.10
6.94
8.66
6.40
9.97
5.77
9.00
7.30
12.52
7.09
11.06
8.87
13.83
8.14
12.69
9.12
14.23
9.40
14.66
11.57
19.84
876.18
94
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 (S)
ENERGY GENERATION IN YEAR
1994-1995
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
16.70
26.04
22.10
34.47
25.66
40.01
21.94
34.22
23.26
36.28
23.71
40.67
21.79
33.98
21.28
33.19
22.89
39.26
1-10
19.41
30.28
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
19.44
30.32
16.80
26.20
13.14
20.49
11.68
18.22
10.70
18.35
8.80
13.73
7.26
11.32
6.06
9.46
5.85
9.12
5.35
8.34
5.06
8.68
4.80
7.48
4.85
7.56
4.79
8.22
4.75
7.41
4.73
7.38
4.76
5.94
4.33
6.75
4.10
6.40
5.65
9.70
5.53
8.62
6.85
10.68
9.99
15.59
14.58
22.74
22.51
35.10
21.75
37.31
719.50
95
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 (T)
ENERGY GENERATION IN YEAR
1995-1996
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
FLOW
CUMECS
UNRISTRICTED ENERGY
MU
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
25.25
39.39
27.01
42.12
27.36
42.67
34.72
54.15
29.13
45.43
22.39
38.41
24.46
38.15
24.68
38.49
21.92
37.61
1-10
19.78
30.85
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-29
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
17.71
27.63
17.04
26.58
12.59
19.63
12.25
19.11
9.57
16.42
6.23
9.71
7.11
11.09
7.15
11.15
5.35
8.34
4.76
7.43
4.42
7.59
3.81
5.95
3.79
5.91
4.01
6.87
4.15
6.47
3.69
5.76
4.04
5.68
4.11
6.40
4.75
7.41
5.07
8.69
4.66
7.27
4.53
7.06
10.07
15.70
12.28
19.14
10.76
16.78
14.89
25.55
722.59
96
Preliminary Feasibility Report
Lingza HE Project, (3 x 40 MW )
TABLE 7.7 (U)
ENERGY GENERATION IN YEAR
1996-1997
PERIOD
MONTH
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER
JANUARY
FEBRUARY
MARCH
APRIL
MAY
UNRISTRICTED
ENERGY
MU
FLOW
CUMECS
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
13.97
21.78
11.83
18.45
21.13
32.95
23.47
36.61
25.27
39.42
22.50
38.60
21.51
33.54
20.06
31.28
20.21
34.68
1-10
20.18
31.47
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
1-10
11-20
21-31
1-10
11-20
21-28
1-10
11-20
21-31
1-10
11-20
21-30
1-10
11-20
21-31
19.26
30.03
16.75
26.12
14.72
22.96
13.49
21.04
12.06
20.69
10.97
17.11
10.20
15.91
9.07
14.15
6.25
9.75
5.65
8.81
5.20
8.92
5.88
9.17
5.59
8.72
5.69
9.75
5.67
8.85
5.65
8.82
5.59
6.97
5.72
8.93
6.01
9.37
6.55
11.24
6.28
9.80
6.25
9.74
6.43
10.03
7.50
11.70
8.63
13.46
8.91
15.29
666.10
97
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – VIII
POWER EVACUATION
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER-VIII
POWER EVACUATION
8.1
GENERAL
This chapter contains data regarding existing Power network of the Eastern region and
the power evacuation arrangement required, consequent upon power generation at the
proposed Lingza Hydro Electric Project.
8.2
Appraisal of Existing Power Evacuation facilities
The nearest pooling point being proposed is a new 400/220 KV substation at Siliguri
(New Jalpaiguri) where power from Tala H.E.P and Teesta stages is expected to be
pooled. Adjoining to this is also a new substation of 220/132 KV level being created by
WBSEB. Hence power evacuation with respect to development of national grid and
consumption by the state can be considered as assured for the present project. Underlying
220/132 KV 200 MVA PGCIL and 132 KV network in the entire area is available to
cater for local loads.
8.3
Proposed evacuation arrangement to the nearest facility
After study of existing power evacuation facilities, it emerges that evacuation of power
generated at Lingza Hydro Electric Project can be done through one no. 220 kV double
circuit line to be connected at the pooling point which can be assumed to come up near (2
km from Teesta –III H E Project) Teesta III H.E.P. Teesta – III H.E.P. is situated in the
close vicinity of Lingza Hydro Electric Project. The length of this 220 kV double circuit
line would be approximately 15 km.
98
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – IX
ENVIRONMENTAL ASPECTS
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
.CHAPTER - IX
ENVIRONMENTAL ASPECTS
9.1
INTRODUCTION
9.1.1 General
The State of Sikkim has abundant snow and monsoon fed rivers with immense hydro
potential. The proposed run-of-the-river Lingza Hydroelectric Power Scheme involves
construction of diversion structures immediately downstream of Ringpi Power Station at
a riverbed elevation of about 1795 m on river Ringpi chu (fig. 9.1). Ringpi chu is a
tributary of Toulong chu which is a major right bank tributary of river Teesta. The water
from the diversion structure shall be conveyed to the powerhouse through a 4 km long
headrace tunnel situated on the bank of main Tolung chu. The riverbed elevation at the
tailrace shall be about 1095 m and would utilise a net head of 736 m. The proposed
project is envisaged to have generation capacity of about 120 MW.
9.1.2 Location
The proposed project is located on Ringpi Chhu in the North district of Sikkim between
longitude 88°27’20’’E & 88° 26’ 39’’ and latitude 27°36’00’’N & 27° 33’ 46’’, just u/s of
Panan reservoir. New Jalpaiguri is the nearest railhead and Bagdogra is the nearest
airport. The dam site is to be located near the Myong village under Lingza-Tolung
Revenue Block about 4.9 km upstream of the confluence of Rangyong Chhu and Ringpi
Chhu (Fig. 9.2).
9.2
PHYSICAL ENVIRONMENT
9.2.1 Climate/Meteorology
For most of the period in the year, the climate is cold and humid. The region experiences
a cold winter from November to February and monsoons from May to mid- October. The
rainfall in the project area varies from 300-360 cm in most parts of valley. Snowfall is
seen at higher altitudes of the catchment area from November to April. The area enjoys
99
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
sub tropical to alpine conditions. Temperature varies with altitude and slope. Fog is a
common feature in the area especially from September to February.
9.2.2 Topography
Sikkim encompasses the Lesser Himalaya, Central Himalaya, and the Tethys Himalaya.
It is essentially a mountainous State without flat piece of land of any extent anywhere.
The mountains rise in elevation northward. The northern portion of the State is deeply cut
into steep escarpments. South Sikkim is lower, more open, and fairly well cultivated.
This configuration of the State is partly due to the direction of the main drainage, which
is towards the south. The trend of the mountain system is generally in east-west direction.
The Rangit and the Teesta, which form the main channels of drainage, run nearly north
south. The valleys cut by these rivers and their feeders are very deep and are rather open
towards the top, but usually attain a steep gorge like structure as they approach the bed of
the rivers.
9.2.3 Soils
The soil depth varies from 100- 150 cm deep in most areas. There are also certain rock
outcrops in the soil. The soil is mainly coarse to fine loam in texture. Some soils have a
gray tint of color and rich in humus in most places. The State of Sikkim enjoys a wide
range of climate, physiography, geology and vegetation which have further influenced
formation of different kinds of soils that are classified under 5 broad physiographic units.
Table 9.1 gives area wise details of these soils. The light textured soil and rocky areas are
prone to sliding. Topso il in most area is rich in humus and organic matter. The water
holding capacity in most area is low and has low cohesiveness. The soil in general is
loamy sand to silty clay loam with a depth of 30 cm to 100 cm and in some cases even
more than 120 cm.
Based on the soil survey conducted by the National Bureau of Soil Survey of India &
Landuse Planning, the State has been classified into 3 main soil groups:
100
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
•
Udalf: High base status soil of humid region.
•
Orthants: Recently formed soil.
•
Odhepts: Shallow blocks, brown and alluvial soil.
Table 9.1: Major physiographic units of soil in Sikkim
Physiographic units
No
Area (ha)
.
% of total geographic
area
1
Summit & Ridge (>30%)
31459.45
4.43
2
Slide slope of hills
2.1 Very steep slope (>50%)
213100.01
30.03
2.2 Escarpments (>50%)
30480.73
4.3
2.3 Steeply sloping (30-50%)
214641.28
30.24
2.4 Moderately sloping (15-30%)
16024.82
2.26
3
Valleys (<30%)
9683.36
1.37
4
Rocky
cliffs
&
precipitous 85700.29
12.08
slope
5
Glacier/Perpetual
1085100.0
15.29
9.2.4 Geology
The upper reaches of this region comprise of glaciers, snow clad peaks, alpine lakes,
moraine and meadows. There is a network of streams feeding the Ringpi Chu River with
many waterfalls. These streams are fast flowing glacier fed rivers originating from the
Great Himalayan Range and its offshoots. Ringpi chu river joins with Tolung chu to
make main stream of Tolung chu. The northern portion of the state is deeply cut into
steep escarpments.
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Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
The physical configuration of Sikkim is partly due to its geological structure. Major
portion of the State is covered by Precambrian rocks and is of much younger age. The
northern, eastern and western portions of the State are constituted of hard massive gneiss
rocks capable of resisting denudation. The rock type in this region belongs to Lesser and
Higher Himalayas, the former being represented by low grade meta-sedimentaries and
granite gneiss whereas the central crystalline in the axial zone of the north Sikkim are
represented by high grade meta-sedimentary and granite intrusive.
The main lithounits exposed in the area include Daling meta- volcano sedimentaries,
Lingtse sheared granite gneisses and high grade Central Crystallines. The Daling Group
of rocks comprises (schistose) metawacke, chlorite-muscovite phyllite intercalated with
chlorite, quartz and their metamorphic equivalents upto garnet-staurolite kyanite grade.
The metawacke units are highly sheared and are found to be associated with Lingtse
gneiss and meta porphyroid bands with bluish pa lescent quartz clasts.
The Central Crystalline Gneiss comprise of mica bearing quartz, feldspar gneiss, banded
gneiss. Migmatite gneiss, garnet bearing psammitic gneiss and higher grade kyanite
sillimannite garnet gneiss are found to crop out in the eastern part of the area. Apart from
these major litho units in the area there are metabasite bodies and some leucogranites
which show pegmatitic character at places. The metabasic rocks occur as concordant
bodies within the country rock. These bands are found to be of varying thickness and are
present both within the gneisses and the Daling meta-sedimentaries.
9.2.5 Seismicity
Sikkim is a part of active Himalayan belt, which is tectonically young. The area has
experienced mild tremors in the recent past. One earthquake of magnitude 6.0 on Richter
scale was recorded on November 20th, 1980. The project area falls in Zone IV of Seismic
Zoning Map of India as per IS 1893 - 1984.
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9.2.6 Catchment Area
The direct draining catchment of the project is 198 sq. km. The catchment is mountainous
with rugged terrain. The tributaries are angular and have dendritic drainage patterns.
Streams have moderate to steep slopes in upper reaches. The natural vegetation consists
of shrubby to alpine in many places at upper reaches and mixed forest at lower
elevations.
9.2.7 River System
Ringpi Chhu rises as Jumthul Chhu from Jumthul Phuk glacier at the base of Siniolchu
peak (6,888 m). Along its eastward course, Jumthul Chhu is joined by Kishong Chhu on its
left bank to form Ringpi C hhu (Fig 9.3). Kishong Chhu rises in the northeastern part of the
catchment and drains Kishong Chho, a glacial lake and contributes significantly to Jumthul
Chhu. Thereafter, up to the proposed dam site Ringpi Chhu receives drainage mainly on its
left bank from a number of streams like Ludui Chhu, Pegor Chhu, Kongcha Chhu and
Zong Chhu. There are a number of small and big glacial lakes in the eastern part of the
catchments, which contribute to the main river through these streams. Ringpi Chhu
descends from an altitude of 4,000 m to 1,800 m within a distance of about 17.5 km with a
gradient of 128 m/km.
9.2.8 Submergence
The proposed project is likely to inundate a 10.75 ha of land, which is confined to the
river valley. The predominant landuse in the submergence area is degraded and open
forest and does not involve inundation of any village or human habitation. Thus no
displacement is anticipated.
9.2.9 Landuse pattern (including land requirement of the project)
The landuse/landcover pattern within the 7 km radius of the proposed Lingza H.E. project
was interpreted and generated from LISS-III scene of Path/Row 107/051 of 19th January,
2000 and PAN D scene of Path/Row 107/051 of 13th January, 2002. LISS and PAN
scenes of area covering 7 km radius of the project site are given in Figures 9.4 & 9.5. The
first level classified landuse/landcover map generated from these two scenes coupled
with ground truthing is given in Figure 9.6. Area covered by various landuse/lancover
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categories is given in Table 9.2 and the percent representation of each of the
landuse/landcover type is shown in Figure 9.7. Based on the data generated from remote
sensing compiled with ground checks, it is clear that Dense Mixed Broadleaf forests
constitute about half (50%) of the total land area, therefore form the predominant landuse
around the proposed project site. The degraded types of forests, which are mostly scrub,
constitute 29% of the area covering about 56.62 ha of land. It is evident from the results
that the area is not significantly disturbed, as the area under human intervention around
the project vicinity (within 7 km radius) comprises only 2% of the cultivation/settlement
area. A sizeable portion of the area is under rocky land and cliffs comprising about 14%
of land area. In addition, some fragile moraines also comprise about 4% land area. Area
under snow is small constituting less than 1% land area. The analysis of the
landuse/landcover indicates that the area is mostly under natural ecosystems with only
limited human intervention. Natural landscape features also include areas under snow and
water bodies. The dense forests in the catchment are present towards north, northeast and
west. These forests are represented by Tolung Reserve Forest in the north and northeast,
Sakyong Reserve Forest in the west and southwest and Lingdem Reserve Forest in the
south and southeast. These forests are mostly broad- leaf forests with occasional
representation of local bamboo species in them, particularly in the warmer areas.
Table 9.2: Area (ha) under different landuse/landcover categories in 7km radius
of Lingza H.E. Scheme
Landuse/landcover
Area (ha)
Dense Mixed Forest
Scrub
Rockyland
Cultivation/Settlements
Moraines
Snow
100.33
56.52
26.69
4.08
8.59
0.01
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14%
2%
4%
1%
29%
50%
Dense Mixed Forest
Scrub
Rockyland
Cultivation/Settlements
Moraines
Snow
Figure 9.7 Percent area under various landuse/landcover categories in 7 km
radius of th proposed Lingza H.E. Scheme.
9.2.10 Infrastructure
The existing facilities in the project area are as follows:
Road communication Network
The project area falls in the North district of Sikkim and the project area is not very easily
accessible. The road is metalled upto Sakkyong and Lingsha. Beyond this there is trek
route to the project site. There is also a well-deve loped trek route up to Toulng Gompa.
Bank
Branches SBI are present at Tolung, Chungthang and Mangan.
Post office
Post and telegraph office exist at Mangan, HQ of North District.
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Educational Facilities
Higher secondary school exists at Tingbong Sec. School, Tingbong. Primary school is
situated at Namprick. Community Information Centre (CIC) is there at Tingbong and
Mangan and provides education in information technology to the students of the school.
For higher education, students go to Sikkim Govt. College, Tadong, Gangtok, Manipal
Institute of Technology Sikkim, Majitar and Sikkim Manipal University of Health
Technology & Medical Sciences, Gangtok.
Communication
The communication network is very poor in the area. However there are telephone
exchange s at locaed far away Gangtok, Phodong and Mangan. Community Information
Centre (CIC) is present in Mangan, which provides internet facilities to the locals.
Government Department
Government department offices exist at block level in the project area. There is a District
centre at Mangan.
Hospitals/ Primary health Centers
Primary health centres are available at Sankalang. Central Referral hospital and Sikkim
Manipal University of Health Technology & Medical Sciences (Referral Hospital) are at
Tadong, Gangtok.
9.3.
BIOTIC ENVIRONMENT
Sikkim stretches from the low lands in the south with tropical climate to the mountainous
regions in the north. The altitude varies right from sea level to mountain peaks covering a
wide spectrum of flora and fauna. Nowhere in the world in such a small area can one find
flora and fauna of all varieties - Tropical to the Alpines. Sikkim's botanical and
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zoological richness is awe- inspiring, boasting of more than 4500 species of flowering
plants. 30% of all the birds in the country are found in Sikkim
.
9.3.1 Vegetation (details of forest types, etc.)
Its extreme altitudinal variation brings in tremendous change in climatic conditions that
in turn supports the biodiversity of different heights. With only 0.22% geographical area
of the country, Sikkim harbors 1/3 rd of the country’s flowering plants. There are 4500
species of flowering plants, 362 species of ferns and its allies, 11 species of oaks, 8
species of tree ferns, 448 species of orchids, 30 species of Primula and 20 species of
bamboos. Many medicinal plants/herbs/and important shrubs are found in low and high
altitude areas.
9.3.2 Flora
The dam site is located in warm temperate hilly terrain and the area of in the vicinity of
the project is mainly comprised of dense mixed fo rests. This area experiences warm and
humid summers and relatively cold winters. There is warm to cool humid climate
throughout the year with a short dry spell during winter months starting from October to
February. Owing to extended spell of humidity and cool to moderate temperatures at
these altitudes the vegetation is constituted mostly by the warm temperate deciduous and
evergreen plant species. In those areas where forests are present these are densely
vegetated by all the physiognomic forms – trees, shrubs and herbaceous flora. The woody
elements in these mixed forests comprises of Albizia lebbek, Alnus nepalensis, Annona
squamosa, Callicarpa arborea, Canarium bengalense, Erythrina arborescens, Ficus spp.,
Lithocarpus sp., Litsea sp., Macaranga denticulata, Rhus wallichii and Toona ciliata.
Shrubby bamboo and some other associates like Abroma anguistifolia, Artemisia
nilagirica, Boehmeria platyphyla , Girardiana diversifolia , Rhamnus virgatus and Rubus
ellipticus form second storey. Cissus repens, Piper sp., Raphidophora decursiva, Rubia
sikkimensis, Smilax sp., Trichosanthes lepiniana, etc. are important climbers in these
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forests.
Herbaceous
flora
is
represented
by Ageratum
conyzoides,
Arenaria
neelagheriensis, Arthraxon hispedus, Begonia spp., Commelina bengalensis, Lecanthus
peduncularis, Oplismenus compositus, Pilea scripta, Polygonum barbadens, Setaria
palmifolia and Thysanolaena latifolia.
9.3.3 Fauna and Wildlife
As the project site falls in the vicinity of dense forests a good presence of wildlife is
expected in and around the project site. The upper part of catchments of Ringpi Chhu and
Rangyong Chhu harbour several faunal species like Hoary-bellied squirrel (Callossciurus
pygerithrus), Orange-bellied squirrel (Dremomys lokhriah), Assamese macaque (Macaca
assamensis), Himalayan palm civet (Paguma larvata), Stone marten (Martes foina ) and
jackals (Canis aureus). These animals are generally found in the vicinity of agricultural
fields. In addition there are also species like Civets (Viverra zibetha), porcupines (Hystrix
brachyura), Grey musk shrew (Suncus murinus), the house mouse (Mus musculus) and
Bandicoot rat (Bandicota bengalensis). The upper reaches, i.e. the alpine areas of the
catchment harbour other mammalian species, which include Nayan, Bha ral, Snow
leopard, Himalaya brown bear, Himalayan tahr, Barking Deer, Himalayan marmot and
pikas. These animals however are rarely seen descending down to lower altitudes like
2,000 m. The avifaunal elements are comprised of bird groups like bulbuls, thrus hes,
eagles, partridges, pigeons, doves, koels, owls, kingfishers, nightjars, woodpeckers,
orioles, drongos, mynas, flycatchers, babblers, robins, etc. Among the reptiles Python
molurus, Naja naja and Dendrelaphis sp. are important species found in the vicinity of
project area.
Among the various faunal species present in the catchment Panthera pardus, Neofelis
nebulosa, Felis bengalensis, Macaca assemensis and Cervus duvaucelli are the
Scheduled as threatened animals of India while Panthera tigris, Selenarctos thibetanus
and Cervus duvaucelli are considered to be globally threatened species.
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9.3.3 Aquatic life
The rivers in Sikkim harbour a variety of fish species. Ichthyofauna in the river
comprised mainly of Balm, Asala, Chepti, Gadela, etc. Snow trouts and other minor
trouts are found at higher elevations. Some of the identified fish species found in the area
are Schizothorax richardsonii, Salmo trutta fario, Labeo pangusia, Noemacheilus
kanjupkhulens, Bagarius bagarius, etc.
9.4.
Existence of any Protected Area/Archaeological Sites
The dam structure and the powerhouse lies within 7km boundary of the of
Kanchendozenga Biosphere reserve. However, there are no sites or monuments of
archaeological or national importance, which would be affected by the project activities
directly or indirectly.
9.5
PREDICTION OF ENVIRONMENTAL IMPACTS
9.5.1. Impacts on Land Environment
Sufficient amount of land will be required for construction of the proposed dam,
powerhouse, colonies & approach roads etc. About 10.75 ha of land would also
come under submergence. All these activities would mean some disturbance in
the soil and change in the landscape. There will be changes in the Landuse of
the area and in its physical composition.
9.5.2 Impacts on Water Environment
The construction of a reservoir replaces the river eco-system by a lacustrine ecosystem.
The vector of various diseases breeds in shallow areas not very far from reservoir
margins. The breeding site for mosquitoes and other vectors in impounded water is in
direct proportion to the length of the shoreline. The construction of the reservoir would
increase the shoreline many times as compared to the pre-project shoreline of various
rivers and tributaries under submergence.
Thus the construction of the proposed
reservoir may enhance the potential breeding sites for various disease vectors.
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9.5.3 Impacts on Air Environment
The construction of the proposed dam would increase dust generation in the area and
some vehicular pollution. However, these would only be limited to the construction
period.
9.5.4 Impacts on Flora/Fauna
9.5.4.1 Impacts on terrestrial flora
About 10.75 ha of land will be inundated due to construction of the proposed dam. The
direct impact of construction activity of a water resources project in a hilly terrain is
generally limited to the vicinity of the construction sites. A large number of labourers
and technical staff and other groups of people are likely to aggregate in the area during
construction phase. In this area majority of forest dwelling rural community depends on
forest for food, fodder and timber. Submergence of forest area in primary impact zone
may reduce the availability of resources for the local people. This would also result in
significant changes at the structural resource level in forest. The acquisition of land for
various project activities would also lead to cutting of vegetation on these lands.
9.5.4.2
Impacts on terrestrial fauna
During the construction phase, a large number of machinery and construction labour will
have to be mobilized.
population.
This activity may cause some disturbance to the wildlife
The operation of various construction equipments is likely to generate
significant noise. Likewise blasting too is likely to generate noise level and vibration
intermittently. The noise may scare the fauna in the region and force them to migrate to
other areas. There might be some impacts due to increased human interference.
9.5.4.3
Impacts on avi-fauna
The construction of the proposed dam will lead to formation of a reservoir, which will
have a fluctuation in the water level, which precisely means the reservoir bank will
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remain wet throughout the year. Due to such reasons grasses may grow along the
reservoir banks. Such conditions are generally ideal for various kinds of birds, especially
water birds. However, because of the presence of a good habitat, it is quite likely that
water birds will flock in this area in a large number. The birds from cold climatic areas
could also use this area during the winter season.
9.5.4.4
Impacts on aquatic ecology:
The major physical change upstream of the proposed dam will be formation of a
lacustrine habitat from a riverine habitat. Whereas below the damsite, there will be
regulated water or very little water in river course. As such there will be some changes in
the aquatic environment in this stretch. For this the water quality analysis shall be
conducted regularly. Moreover, some migratory fish species may get affected due to
construction of the dam.
Also some fish species, which are riverine and are not
accustomed to deep lake environment, may also get replaced.
9.5.5 Impacts on Socio-Economic Environment
Since the submergence area is small and is confined to the river valley, no village will be
submerged. Thus displacement is not anticipated. At present, there are small business
and little employment facilities in the project area. However, with the construction of the
project new business and employment opportunities will open up for the local people
which are likely to improve the economic conditions of the local people. Further, there
will be development of infrastructure facilities as housing, water supply, medical
facilities, schools, transportation and communications. These factors are expected to
bring about positive impact on the socio-economic status of the people living in the
project area. There is possibility of changes in lifestyle and cultural values of local
people due to migrant worker population. However, the impact is expected to be low as
the number of immigrant people will be small for the small project and most of the
labourers employed in the project will be local people.
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As a part of the Environmental Impact Assessment Study, a detailed socio-economic
survey would be carried out to determine the following:
ü Information on various aspects of the affected population viz; demographic
details, socio -economic and cultural characteristics, enumeration of personal
properties of the affected population, education level and occupational profile etc.
ü Enumeration of social infrastructure and community property resources in the
submergence area.
ü Ethnographic assessment of PAFs.
9.6
ENVIRONMENTAL MANAGEMENT PLANS
The objective of the Environmental Management Plan (EMP) is to ameliorate the
negative impacts of a developmental project. The most reliable way to ensure proper
implementation of these management plans is to integrate the same with various
processes involved during project planning, designing, construction and operation phases.
Based on the assessment of environmental impacts, following management plans will be
formulated:
Ø
Catchment Area Treatment
Ø
Compensatory Afforestation
Ø
Wildlife Conservation
Ø
Resettlement and Rehabilitation
Ø
Public Health Management System
Ø
Muck Disposal
Ø
Fishery Management
Ø
Restoration of Construction Area
Ø
Green Belt Development
Ø
Free Fuel Provision
Ø
Disaster Management
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CHAPTER – X
INFRASTRUCTURE
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – X
INFRASTRUCTURE
10.1 EXISTING ACCESS AND INFRASTRUCTURE FACIL ITIES
10.1.1 Road Communication
The road from Mangan to lingza is the approach to the Project . The Power house is
located on the left bank of Ringpi Chu u/s of confluence of Rangyong Chu and Ringpi
Chu near the Place called Chhana about 3.0Km u/s of village Lingza. The Powerhouse is
approachable from Lingza by a road of 2.0 km and a foot path of 1.0km length from the
road. Lingza is 17 Km from Magan, the head quater of North Sikkim District 0f Sikkim,
62 Km from Singtam (NH31A), 162 Km from NJP railway station and 163 Km from
Bagdogra airport. The Lingza village is well connected form Mangan by a PWD road.
The Siliguri-Gangtok (NH-31A) and Singtam-Mangan-Sanklan state highways are being
maintained by BRO. while the Lingza-Sanklan road are being maintained by state PWD.
The dam site is located near the place called Ishana and is approachable by a hilly foot
path of about 5.0 Km length from the end of road. The road is available for a length of
2.0Km beyond Lingza Village.
10.1.2 Housing And Community Facilities
Chhana is the name of the place near to powerhouse and Ishana to Dam site where even
basic facilities of health care, schooling, market, postal and telephone etc. are not
available. It is therefore necessary to plan housing, office, recreation, store etc. for
meeting the requirement of the project.
10.1.3 Power Availability
Sikkim, at present, is dependent mainly its mini and micro hydel power stations for
meeting its power demand. The total installed capacity of state at present is about 95
MW. The state gets some share of power from Chukha Hydel Electric Project in Bhutan,
Farakka Thermal Power Station, West Bengal and Rangit Hydel Power Project of NHPC
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Ltd. Teesta (V) HE Project, 510 MW being executed by NHPC in central sector is also
under advance stage of construction. The existing transmission system of this state
comprises of mainly 66 KV and 11 KV transmission lines. A 132 KV S/C transmission
line is being constructed from Melli border town of Sikkim-West Bengal to Ranipool. A
132 KV sub station is being constructed at Melli. A substation of 2.5MVA, 66/11KV is
located at Phodong near Mangan. Therefore , the necessary construction power shall be
available for the execution of Lingza H.E. Project from some where nearby Mangan but
the exact location may be decided at the time of FR/DPR.
10.2
PROPOSED ACCESS AND INFRASTRUCTURE FACILITIES
Keeping in view the available infrastructure facilities of communication,, housing and
power, the requirement of the same for Lingza H.E. Project has been worked out.
10.2.1 Improvement Of Existing Road And Bridges
The Powerhouse is located on the u/s of confluence of Rangyong Chu and Ringpi
near the village Chhana . The state highway ha ving a length of 17km from Sanklan to
Lingza connects the power house by a foot path of 10 Km and dam site by a foot path of
5.0 Km. Since the Lingza H.E. Project is on u/s of the Panan H.E. Project, therefore it has
been presumed that all the roads and bridges shall be ready upto damsite of Panan H.E.
Project.
10.2.2 Construction Of Roads & Bridges
The power house shall be approached from Mangan - Lingza road from left bank for
which a new project road of 3.0 Km is to be constructed from the dam site of Panan H.E.
Project. The Dam site shall be approached from right bank through a bridge at Vawl.
10.2.3 Accommodation For Residential Purpose
To accommodate the project employees and contractors, land would be required for
construction of suitable residential complexes. The residential colony for Power house
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shall be at Lingza and for dam site at Ishana where suitable land is available. The project
colony would have accommodation for all categories of officials deployed for the
construction. The strength of the officials and staff of various categories required for the
project has been worked out. Each personal would be provided with the accommodation
as per the entitlement. Keeping in view the construction period and subsequent operation
and maintenance of the project, it is proposed to construct about 50% of the buildings as
the permanent and the remaining as temporary. This conclusion has been drawn on the
basis that 50% of the staff strength would be required for maintenance and operation after
the co mpletion of the project.
Requirement of built up accommodation has been worked out to 3960Sq.m of permanent
built up area and 3970 Sq.m of temporary builtup area would be required. Total plinth
area for residential accommodation worked out to be 7930Sq.m,
10.2.4 Accommodation For Non-Residential Purposes
The office complexes are proposed at Lingza and Ishana. Workshops, laboratories, stores,
water supply, fire stations, electrical substations etc would be accommodated in the
project area.. One stockyard is proposed at railhead near new Jalpaiguri Railway station
where construction materials like cement, steel and machinery and equipments would be
store for further transportation to the project site, Batching and mixing plants are to be
commissioned, one near dam site and the other near power house site.
Accommodation required for non residential purposes have been worked out to be 7590
Sq.m of which about 40% would be permanent and rest will be temporary.
10.3
TELECOMMUNICATION FACILITIES
The differ ent work sites of the project, offices, stores, laboratories, workshop and
residences
would
be
connected
through
a
telecommunication
network.
The
telecommunication facilities would also be provided between the projects and outside.
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Therefore, an internal telephone exchange would be provided at the project for
communication within and outside the project. Most parts of Sikkim
are presently
connected with different parts of the world through satellite telecommunication network
for which an earth satellite station with electronic exchange exists. The same network
would be extended to the project area for telecommunication with outstation agencies.
10.4
CONSTRUCTION POWER
The construction power for the project shall be available at the time of constructio n of
the project and it is presumed that till the time some mega projects in the d/s i.e. Teesta
(V), Teesta(III) and Teesta(IV) would have been commissioned and a transmission line
of about 20Km may be required for arranging construction power.
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CHAPTER – XI
CONSRUCTION PLANNING &
SCHEDULE
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER –XI
CONSTRUCTION PLANNING & SCHEDULE
11.1
INTRODUCTION
The Equipment Planning & Construction Methodology of Lingza H.E. Project (3x40
MW) in Teesta Basin Sikkim has been developed on following consideration.
1. The project construction period has been considered as four years after
completion of Stage I & II activities.
2. Available Geological Data at PFR stage.
3. Requirement of Construction Equipment has been planned to handle the quantities
worked out on the basis of preliminary layout.
4. Five months (May to September) rainy season has been considered while
planning surface works.
11.2
Construction Methodology:
11.2.1 Infrastructure Works:
The main infrastructure development is proposed to be carried out in period of 12
months. During infrastructure period Land Acquisition, construction of approach roads,
bridges& culverts, arrangement of construction power will be undertaken. Critical
component of project would be started from 6th month after construction of approach
roads. Platform to accommodate batching plant, stores for construction material, site
workshop, offices and other buildings (residential/ non residential) colonies will also be
developed in infrastructure period.
Crawler Dozer, Loader cum Excavator, Motor
Grader, Air compressor, Road Roller etc. are proposed for deployment during
infrastructure stage.
11.2.2 Diversion of River
The construction of 6.0 m finished diameter, Horse shoe shaped 400 m long diversion
tunnel would be carried out by full face method. Excavation of Diversion Tunnel will be
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carried out with 2 Boom drill jumbo, Air Track/Wagon Drill, Jack hammer, 0.24 cum
skid steer loader &10 T Tippers. However 1.0 cum hyd. excavator would also be required
for portal excavation. Excavation & concreting of diversion tunnel (including portal)
would be completed in 10 months. The concreting equipment proposed are 38 cum
Concrete pump, Transit mixer, shotcrete machine, Grout pump, shutters etc. Concreting
requirement would be catered by the same batching & mixing Pla nt and Aggregate
processing Plant, being proposed for Dam . U/s & D/s Coffer dam would be constructed
immediately after construction of diversion tunnel in 5 months to divert the river.
However river bed excavation would be taken up after completion of Ist stage coffer dam
in three months.
11.2.3 Concrete Dam
Dam abutment stripping is proposed to be carried out in 15 months. The excavation of
river bed & foundation treatment would be carried out in 4 month. Excavated material
will be handled by 1.0 cum Hyd. Excavator and 10T Tippers/20 T Dumpers. Concreting
of Dam & HM work would be carried out in further 18 months. Concreting would be
done by deploying 2 nos. Tower crane (6.9 T at 60 m radius), 1 No. 120 cum/hr
Batching& Mixing plant and 250TPH Aggregate Processing plant.
11.2.4 Intake Structure, Desilting Chamber , Silt Flushing tunnel & HRT
2 nos. Intake structure having gate size of 3 m x3m , 2 Nos. Dufour type Desilting
chambers of size 95m X5mX7.5m each and HRT of 3.3 m dia. would be excavated in 20
months . After excavation of intake structure, 2 nos. intake tunnels of 3m dia would be
excavated by full face method. Excavation of Desilting Chamber would be taken up from
intake tunnel. Intake tunnel would be extended upto full length of Desilting Chamber.
Thereafter it will be expanded side wise to the full width of desilting chamber resulting in
desilting chamber dome. Mucking of excavated material would be done through the
tunnel. After the excavation of desilting chamber, concreting will be carried out.
Excavation of silt flushing tunnel & gate operation chamber would be a parallel activity.
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The equipment to be deployed are Jack hammers, wagon drills, air compressors, skid
steer loader, excavators, tippers, concrete pump, transit mixers etc.
Excavation of 4.0 km long, 3.3 m finished diameter horse shoe shaped Head Race
Tunnel is proposed by full face drilling & blasting method. It will be excavated through 3
nos intermediate adits.
The excavation of adits would be carried out in 5 months.
Excavation would be carried out by deploying three set of equipment i.e 2 boom drill
jumbo, 0.24 cum Skid Steer Loader and 10 T tipper. Concreting will be carried out by
deploying concreting equipment i.e. Concrete pump, Transit Mixer etc. Concreting
requirement would be catered by Batching & Mixing Plant & aggregate processing plant
installed at dam site.
11.2.5 Surge Shaft :
For Construction of 10 m diameter, 40 m high Surge Shaft, an adit to surge shaft bottom
would be excavated in four months. After comple tion of construction adit, pilot shaft of
3.0m dia.(approx.) would be excavated by deploying raise climber, jack hammers from
bottom to top through bottom adit. Thereafter, Pilot hole would be further enlarged to
excavated diameter & shaft will be lowered up to full length of surge shaft with the help
of Wagon Drill, Jack Hammer, crawler dozer etc.. Mucking will be done through the
bottom adit. Concreting would be completed employing 2 m shutter, concrete pump,
Transit Mixer & batching &mixing plant (installed at dam site). Construction of surge
shaft would be completed in 32 months.
11.2.6 Pressure Shaft:
Initially construction of approaches & adit would be done in 8 months. One no. 900 m
long inclined pressure shaft, will be excavated in the same wa y as surge shaft by
deploying Raise climber, Jack hammer etc. However intermediate adit can be used to
handle the muck. Steel liner (2m dia) erection & concreting will be carried out by
125
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
deploying 10/20 t winches, Slipform liner etc. Construction of Pressure shaft would take
around 29 months.
11.2.7 Power House
4 X 30 MW (120 MW) underground power house (100 m X 17 m X 40 m size),
Transformer Cavern & MIV would be excavated in 20 months. For excavation of Power
House, a construction adit would be excava ted up to the crown of power house. Main
access tunnel would also be excavated simultaneously. Construction adit would be
extended up to full length of power House. Thereafter it will be expanded side wise to
the full width of power house resulting in Power House Cavern. Mucking of excavated
material would be done through the Construction adit. From Power House Cavern 4
shafts of 2.0 m diameter would be excavated up to the bottom level of draft tube followed
by benching of Power House cavern up to the bottom of Power House. Mucking will be
carried out through Main access Tunnel/TRT. The equipment to be deployed for
excavation are jack hammers, wagon drills, air compressors, loader, excavators, tippers,
winches etc. Concreting of Powerhouse would be carried out in 24 months with the help
of concrete pump, transit mixer etc.
Concreting requirement would be catered by
deploying 30 cum/hr batching & mixing plant and 50 TPH aggregate processing plant.
Power house Installation & Testing of Machine would be undertaken in such a manner
that Project get commissioned in 48 th month from the start of Project construction.
11.2.8 Tail Race Tunnel
1 Nos. 250m long horse shoe shaped Tail Race Tunnel having 3.3 m finished diameter
will be excavated by full face method. Excavation of Tail Race Tunnel would be carried
out with 2 boom Drill Jumbo, Wagon drill, 0.24 cum skid steer loader , 10 t tipper etc.
The TRT will be excavated from 10th month & will be completed in further 6 month.
After the excavation of power house the TRT will be concreted with the help of concrete
pump, Transit mixer, Batching & mixing plant & aggregate processing plant ( installed at
Power house).
126
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
11.3 CONSTRUCTION SCHEDULE
The schedule for stage I & II activities upto CCEA clearance and construction schedule
has been prepared in the form of bar chart and placed as annexure –11.1 & 11.2
respectively.
127
CONSTRUCTION SCHEDULE
Name of Work
Unit
Quantity
Ist year
IInd year
Ha
Construction of roads & buildings
12
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
M
J
J
A
S
O
N
D
J
F
M
A
M
J
J
A
S
O
N
D
J
J
F
M
A
M
J
J
A
S
O
N
D
J
F
M
A
M
J
J
A
S
O
N
D
J
F
M
LS
5
50,000
9,500
6
4
AWARD OF CONTRACTS
Tendering, Award & Mobilization
DIVERSION TUNNEL
400 m long, 6 m dia horseshoe)
(
3
Excavation
Erection of shutters & Conc. Lining
m
3
m
HM Works
Job
LS
4
Plugging of tunnel
Job
LS
2
m3
Filling-60,000
Conc.-4,500
5
m3
3,46,000
15
m3
Job
Job
5,30,500
16
LS
12
2
Job
LS
5
COFFER DAMS (U/s & D/s)
Const.of Coffer Dams & River Diversion
CONCRETE DAM
m High & 320 m Long at top)
Dam abutments stripping
(60
Excavation and foundation treatment
Mass Concreting
Hyromechanical Works
Reservoir filling
4
Head Race Tunnel of 3.3m dia 4 km long
(including Intakes & Desilting chambers-2 nos. )
Excavation of adits
3
Excavation
m
1,36,500
20
Concrete Lining
m3
38,200
18
Grouting
Job
LS
10
HM Works
Job
LS
15
Cleanning, Adits plugging etc.
Job
LS
1
Water conductor charging
Job
LS
1
POWER HOUSE COMPLEX
Const. of Adits
Job
LS
3
m
1,60,000
20
m3
67,000
24
Job
LS
2
3
Excavation of Power House
Concreting in sub & super structures
Erection of EOT crane
SURGE SHAFT (10 m dia., 40m height)
Const. of approches
Job
LS
4
Excavation
m
65,625
20
Concreting & HM Works
m3
4,200
12
STEEL LINED PRESSURE SHAFT
(2m dia, 900m long inclined ) & PENSTOCKS
Const.of approaches & adit
Job
LS
8
Excavation
m3
14,000
18
Erection of steel liners & Concreting
m3
11,000
15
m3
5,000
6
3
2,000
10
3
TAILRACE TUNNEL
(3.3m dia, 250m long)
Excavation
Concreting & HM Works
m
POT HEAD YARD
Civil & Elect. Works of Pot Head Yard
Job Exc-1,04,000m3
15
Conc-3000m3
ELECTRO-MECHANICAL WORKS
Erection, Testing & Commisioning of all four Units
Job
IVth year
1
8
LS
IIIrd year
A
INFRASTRUCTURE
Acquisition of private & forest land
Annexure-11.2
Schedule of Constructiom
Duration
(months)
28
Note: Since the date of CCEA clearance cannot be anticipated at this stage, the time assumed for various activities is inclusive of the effect of monsoon.
129
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – XII
COST ESTIMATE
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER –XII
COST ESTIMATES
12.1
PRELIMINARY COST ESTIMATES FOR CIVIL, HYDROMECHANICAL, ELECTRO-MECHANICAL AND TRANSMISSION
WORKS
The estimate has been prepared to arrive at the capital cost of Lingza H.E. Project and
is of Pre-feasibility level of accuracy. The base date of the estimate is June 2003 Price
Level and the cost is expressed in Indian Rupees. The Cost Estimate is divided into
Civil, Electrical and Transmission Works. For Civil Works, the sub heads are as
under: -
I-WORKS
Under this head, provision has been made for various components of the Project as
detailed hereunder.
A-PRELIMINARY
Under this head, provision has been made for all surveys and investigations to be
conducted to arrive at the optimum of the project components.
B-LAND
This covers the provision for acquisition of land for construction of the project
colonies, offices and stores and compensation for trees and standing crops etc.
C-WORKS
This covers the cost of Diversion Tunnel and Coffer and Concrete Dam and Spillway
along with associated hydro- mechanical equipment.
J-POWER PLANT CIVIL WORKS
130
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
This covers the cost of project components viz. Intake Structure, Headrace Tunnel,
Power House and Transformer Cavern, Pressure Shaft, Surge Shaft, Tail Race Tunnel
and other appurtenant works.
The quantities indicated in the estimates for C - Works & J-Power Plant Civil Works
(Civil & HM) are calculated from the Preliminary Engineering Drawings and as per
experience of other on- going or commissioned projects. A provision has been made
for contingencies.
The unit rates for various items are taken as per the Guidelines issued by CEA for
preparation of PFRs. It has been assumed that the quarry is available at a distance of
10 Kms from the work site.
K-BUILDINGS
Under this head provision for both residential and non-residential have been provided.
Under the permanent category only those structures are included which will be
subsequently utilized during the operation and maintenance of the project utilities.
The costs are worked out on plinth area basis prevalent in the area for the type of
construction involved.
O-MISCELLANEOUS
Provision under this head has been made for C & J works for the Capital & running
cost of Electrification, Water Supply, Sewage disposal, Fire fighting equipments,
Medical assistance, Recreation, Post Office, Telephone and Telegraph Office, etc.
also the Provisions are made for the Security arrangements, inspection vehicles,
schools, transport of labour, Laboratory testing, R&M of Guest House and transit
camps, Community center, Retrenchment compensation, photographic instruments as
well as their R&M charges etc.
P-MAINTENANCE DURING CONSTRUCTION AND Y-LOSSES ON STOCK
131
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
A provision of 1% and 0.25% of C-Civil works, J-Power Plants, K-Buildings & RCommunications has been made for maintenance of works during construction period
and losses on stock respectively.
Q-SPECIAL TOOLS AND PLANT
It is assumed that the work will be carried out through contracts and not through
departmental construction. Accordingly, provision for general purpose equipment and
inspection vehicles only has been made as per CWC Guidelines.
R-COMMUNICATION
Provision under this head covers the cost of new roads, Widening/Improvement of
roads and strengthening of bridges. The cost of roads and bridges are based on the
prevalent rate structure prevalent in the area of the Project, for the type of
construction involved.
X-ENVIRONMENT AND ECOLOGY
Provision under this head has been taken as 2% of I Works towards Bio-diversity
Conservation, Creation of Green belt, Restoration of Construction Area, Catchment
Area Treatment, Compensatory Afforestation etc
12.2
II-ESTABLISHMENT
Provision for establishment has been made at 8% of I-works minus B-Land for civil
works.
12.3
III-TOOLS AND PLANTS
This provision is distinct from that under Q-Special T&P and is meant to cover cost of
survey instruments, camp equipment and other small tools and plants. The outlay is
provided at 1% of cost of I-works.
132
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
12.4
IV-SUSPENSE
No provision has been made under this head as all the outstanding suspense are
expected to be cleared by adjustment to appropriate heads at completion of the
project.
12.5
V-RECEIPTS AND RECOVERIES
Under this provision, estimated recoveries by way of resale or transfer of equipment
used in infrastructure works are provided for @ 75% of value booked under head QSpecial Tools and Plants. Also, the provision for recoveries on account of resale of
DG Set and temporary buildings have been considered.
12.6
ELECTRICAL & TRANSMISSION WORKS AND GENERATING
PLANT
The cost of generating plant and equipment is based on indigenous sources. The
prices of auxiliary equipment and services are based on prevailing market prices/costs
incurred at other ongoing or commissioned projects.
133
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
ABSTRACT OF COST OF WORKS
S.No
A
1.
2.
A
B
C
C
D
Description
CIVIL WORKS
DIRECT CHARGES
I - Works
A - Preliminary
B - Land
C - Works
J - Power Plant Civil Works
K - Buildings
O - Miscellaneous
P - Maintenance
Q-Special Tools & Plants
R - Communication
X - Environment & Ecology
Y - Losses on Stock
Total of I-Works
II - Establishment @ 8% of cost of I-Works less B-Land
III - Tools and Plants @ 1% of cost of I-Works
IV - Suspense
V - Receipt & Recoveries (-)
Total Direct Charges
INDIRECT CHARGES
a) Capitalised Value of Abatement of Land Revenue
b) Audit and Account Charges @1% of cost of I-Works
Total Indirect Charges
Total Of Direct & Indirect Charges
ABSTRACT :
Civil Works
Electrical Works
Transmission Works
TOTAL COST
IDC
Total Cost With IDC
134
Amount
(Rs. in Crores)
( June 2003
P.L.)
4.49
11.22
225.11
172.35
12.92
10.01
4.39
3.14
28.25
9.65
1.10
482.63
37.71
4.83
0.00
-2.44
522.73
0.12
4.83
4.95
527.68
527.68
97.36
5.02
630.05
69.75
699.80
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
A-PRELIMINARY
Rs. In lakhs
Sl
No.
1
Description of Work
Unit
Qty
Rate
Amount
Prefeasibility
1.1
Preparation of Prefeasibility Report
LS
14.00
2.0
Preparation of Detailed Project Report
2.1
Detail survey for final locationof project componenets
LS
20.00
2.2
Aerial survey, contour survey for reservoir basin
including establishment of permanent benchmarks.
LS
10.00
2.3
Geological and geophyical surveys and investigation
I)
Drifting
m
ii)
Geophysical
LS
iii)
2.4
Core drilling
m
Hydrological and Metrological surveys including
establishment of rain gauges/ river gauges and
discharge, sedimentation stations and their running
charge for 1 year
LS
8.00
2.5
Investigations for foundation and rock testing
LS
6.00
2.6
Investigation for availability of construction materials.
LS
3.50
2.7
Construction of access roads to facilitate investigations
LS
7.00
2.8
Model experiment.
LS
8.00
2.9
Computer and telecommunication facilities.
LS
3.00
2.10
Vehicles for inspecting officers for site investigations
LS
25.00
2.11
Camping equipment
LS
2.00
2.12
Preliminary
laboratory.
testing
LS
6.00
2.13
Consultant’s fees including charges for preliminary
design work or device
LS
15.00
2.14
Training of engineers during
preparation of project reports
LS
4.00
2.15
Ground water studies.
LS
6.00
2.16
Environment and ecological s tudies.
LS
10.00
2.17
Preparation and printing of DPR
LS
10.00
soil
test,
establishing
soil
investigation
135
and
400
0.10
40.00
20.00
300
0.10
30.00
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
247.50
Total( I+II)
3.0
Pre-Construction Stage Investigations
3.1
Topographical Surveys
LS
3.2
I)
Geological Investigation
Diamond Core Drilling
m
100
0.1
10.00
ii)
Exploratory Drift
m
100.00
0.1
10.00
iii)
iv)
Excavation in trenches & pits
Testing of Samples
LS
LS
3.3
Hydrological and Silt data collection - 2 sites for 4
years
3.4
Meteorological Data Collection 2 sites for 4 years
3.5
Construction material survey
I)
Topographical Survey
ii)
iii)
Collection and Transportation of samples
Laboratory Testing of Samples including charges for
all T&P and Machineries
3.6
3.7
Model studies
Seismological data collection for 4 years
3.8
Survey for layout of colonies and roads
I)
ii)
Residential-c u m-Office accomodation
Batching Mixing Plant and Workshop
iii) Project and quarry site road
3.9
Workcharged establishment for unforseen works
15.00
0.75
4.00
8.00
2.00
16.00
Year
8.00
0.40
3.20
LS
LS
4.00
0.05
0.20
3.00
6.00
LS
LS
Year
4.00
1
10.00
4
Sqm.
Sqm.
2.00
1.00
0.5
0.5
1.00
0.50
Sqm.
0.50
4.00
0.5
2
0.25
8.00
Year
4.0
Design & Consultancy
4.1
4.2
Cost of Design Establishement including procurement
of printing stationery and preparation of comp letion
report, History of Project etc.
Cost of Special Studies and Designs
4.3
Fees for Consultant and specialists
LS
LS
LS
4.4
5.0
Training of Engineers
Equipment
LS
LS
5.00
5.1
5.3
Drawing and Mathematical Instruments
Survey Instruments
10.00
30.00
5.4
Office instruments
LS
LS
LS
Grand Total :( I+II+III)
25.00
15.00
15.00
10.00
449.40
136
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
B-LAND
Sl.
No.
1.0
Description
3
4
5
Qty.
Rate
6.00
5.50
Ha
33.00
3.00
12.00
4.00
2.00
54.00
2.00
3.00
1.00
1.00
2.40
90.40
5.50
5.50
5.50
5.50
5.50
5.50
5.50
5.50
5.50
5.50
Ha
Ha
Ha
Ha
Ha
Ha
Ha
Ha
Ha
Ha
16.50
66.00
22.00
11.00
297.00
11.00
16.50
5.50
5.50
13.20
497.20
10.00
2.00
12.00
0.00
0.00
Ha
Ha
0.00
0.00
0.00
80
1.65
Ha
132.00
3.00
3.00
Private land Requirement
Permanent residential and non residential
buildings
Diversion tunnel
Submerged in the reservior area
Construction of dam/ wier
Construction material
Constrution of approach Roads
Power house
Construction of adits
Switch Yard
Surge Shaft
Land for Misc Purpose
Sub Total (1)
2.0
Rs. In lakhs
Unit Amount
Forest land
River bed
Underground
Sub total (2)
Other Compensation
Cost of crops standing on cultivated land
required @ 30% of cultivated land
Buildings with brick walls and GGI sheet
roofing
Compensation for trees
Misc. Compensation
Compensation for relocating electric and
telephone poles
Crop Compensation for submergence
Sub total (3+4)
Total (1+2+3+4)
Land on lease/ hire for 4 Years
Dumping area
137
9.00
Nos
LS
10.00
2.00
LS
0.50
200.00
353.00
850.20
2.40
Ha
1.20
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Dumping area for batching and mixing plant
Temporary Residential and Non- Residential
buildings
0.50
2.00
2.40
2.40
Ha
Ha
1.20
4.80
Contractors Colony
Contractors Construction facilities
Railway Siding Facilities
Electro - Mechanical Works
Hydro -Mechanical Works
Total (5)
Interest charges on account of award for the
period taking over possession of land and date
of award @ 12% per year of 25% cost of land
acquisition for two years
Solatium charges for compulsary acquisition
of land @ 30% of the cost of private land
2.00
2.00
1.00
1.00
1.00
2.40
2.40
2.40
2.40
2.40
Ha
Ha
Ha
Ha
Ha
4.80
4.80
2.40
2.40
2.40
24.00
29.83
149.16
Provision for legal charges @1% on total
compensation
Labour
and
material
required
for
measurement and demarcation of land and
properties @1%of land acquision
8.742
Establishment charges @6.25% of cost of
total compensation
Total
54.64
138
4.972
1121.54
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
ABSTRACT OF COST OF C - WORKS
S. N.
Description
Amount (Rs. In Lakhs)
Civil
HM
Total
1.
River Diversion Works
865.98
2.
Coffer Dam
848.62
3
Dam
14764.24
120.75
14884.99
4
Spillway
4993.30
359.42
5352.72
21472.13
597.77
22069.90
429.44
11.96
441.40
21901.58
609.72
22511.30
Total
Add Work Tax @
Total
139
117.60
983.58
848.62
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
DIVERSION TUNNELS
S.
N.
Description
Unit
1 Surface Excavation
1.1 Common excavation
1.2 Rock excavation
Quantity
Rate
Amount
in Rs.
Rs. in
Lakhs
Cum
Cum
25000
5000
125
300
31.25
15.00
Underground excavation
Cum
20000
1000
200.00
3
3.1
3.2
3.3
3.4
Rock Support System
Rock bolts
Steel Supports
Shotcreting
Concrete lagging
m
MT
Cum
Cum
10000
50
1000
150
400
42000
4000
7000
40.00
21.00
40.00
10.50
4
4.1
4.2
4.3
4.4
Concrete
Cement Concrete Lining M20
M15
M20
M25
Cum
Cum
Cum
Cum
3900
3500
100
2000
4000
2930
3390
3610
156.00
102.55
3.39
72.20
200
27000
Sub Total A
7.5%
54.00
745.89
55.94
Sub Total B
1%
2%
3%
2%
801.83
8.02
16.04
24.05
16.04
Total Civil
Cost
865.98
2
5.0 Reinforcing steel
6
7
8
9
10
MT
Miscellaneous and ancillary works @ 7.5% of
sub-total A
Instrumentation @ 1% of sub-total B
Dewatering @ 2% of sub total B
Contingency @ 3% of sub-total B
Work Charged establishment @ 2% of
Sub-total B
140
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
COFFER DAMS
S.
N.
Description
1 Surface excavation
1.1 Common excavation
Unit
Quantity
Rate
Amount
In Rs.
Rs. in
Lakhs
Cum
10000
125
12.50
Embankment Construction and
Backfill
2.1 Earth/Rock fill
2.2 Impervious Core
2.3 Filter
Cum
Cum
Cum
40000 518.00
15000 354.00
5000 901.00
207.20
53.10
45.05
3 Concrete including Formwork
3.1 M10
3.2 Concrete cut off wall
Cum
Sqm
2
4
5
6
7
Miscellaneous and ancillary works @
0.5% sub-total A
Dewatering @ 3% of sub total B
Contingency @ 3% of sub-total B
Work Charged establishment @ 2% of Subtotal B
141
2500
2000
Sub Total A
0.5%
2560
20000
64.00
400.00
781.85
3.91
Sub Total B
3%
3%
2%
785.76
23.57
23.57
15.72
Total Civil
Cost
848.62
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
DAM
S.
N.
Description
Unit
Quantity
Rate
in Rs.
Amount
Rs. in
Lakhs
1 Surface excavation
1.1 Common excavation
1.2 Rock excavation
Cum
Cum
250000
50000
125
300
312.50
150.00
2 Rock Stabilization and Supports
2.1 Rock bolts
2.2 Shotcrete
M
Cum
1500
500
400
4000
6.00
20.00
3
3.1
3.2
3.3
3.4
Concrete including Formwork
M10
M15
M20
M25
Cum
Cum
Cum
Cum
500
400000
20000
5000
2560
2930
3390
3610
12.80
11720.00
678.00
180.50
4
Reinforcing Steel
MT
500 27000
Sub Total A
135.00
13214.80
5
Miscellaneous and ancillary works
@2-3% sub-total A
6
7
8
9
Instrumentation @ 1% of sub-total B
Dewatering @ 3% of sub total B
Contingency @ 3% of sub-total B
Work Charged establishment @ 2% of Subtotal B
142
2.5%
Sub Total (1-6)
1%
3%
3%
330.37
13545.17
135.45
406.36
406.36
2%
270.90
Total Civil Cost
14764.24
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
SPILLWAY
S.
N.
Description
Unit
Quantity
Rate
Amount
In Rs.
Rs. in
Lakhs
1 Surface excavation
1.1 Common excavation
1.2 Rock excavatio n
Cum
Cum
40000
6000
125
300
50.00
18.00
2
2.1
2.2
2.3
Concrete including Formwork
M15
M20
M25
Cum
Cum
Cum
65000
2000
38000
2930
3390
3610
1904.50
67.80
1371.80
3
Reinforcing Steel
MT
4000
27000
1080.00
4
Structural Steel
MT
42000
5
Miscellaneous and ancillary works @12% sub-total A
150
Sub Total A
1.5%
63.00
4555.10
68.33
6
7
8
9
Instrumentation @ 1% of sub-total B
Dewatering @ 2% of sub total B
Contingency @ 3% of sub-total B
Work Charged establishment @ 2% of Sub-total
B
143
Sub Total B
1%
2%
3%
2%
4623.43
46.23
92.47
138.70
92.47
Total Civil Cost
4993.30
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
J-POWER PLANT APURTENANCE (CIVIL WORKS)
S.
NO.
Description
Amount (Rs. in Lakhs)
Civil
HM
Total
1
Power Intake
784.94
347.13
1132.07
2
Desilting Basins
793.25
151.83
945.08
3
Adits
1275.24
21.42
1296.66
4
Head Race Tunnel & Tail Race Tunnel
3054.82
14.28
3069.10
5
Surge Shaft
474.54
18.48
493.02
6
Pressure Shaft
684.70 1367.10
7
Power House Co mplex
8
Civil Works of Switchyard
2051.80
7505.75
7505.75
403.43
403.43
Total
14976.68
1920.24
16896.92
Add Work Tax @ 6.8%
299.53
38.40
337.94
Total
15276.21
1958.64
17234.86
144
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
INTAKE STRUCTURE
S.
N.
Description
Unit
Quantity
Rate
In Rs.
1 Surface excavation
1.1 Common excavation
1.2 Rock excavation
2
3
3.1
3.2
3.3
3.4
Rs. in
Lakhs
Cum
Cum
15000
5000
125
300
18.75
15.00
Underground excavation
Cum
4000
1000
40.00
Supports System
Rock bolts
Steel Rib Supports
Shotcreting
Concrete lagging
M
MT
Cum
Cum
1500
15
100
75
400
42000
4000
7000
6.00
6.30
4.00
5.25
Cum
Cum
500
8000
2930
3610
14.65
288.80
MT
1200
Sub Total A
1.5%
27000
324.00
722.75
10.84
4 Concrete
4.1 M15
4.2 M25
5
Reinforcement Steel
6
Miscellaneous and ancillary works @ 23% of sub-total A
7
8
9
10
Amount
Instrumentation @ 1% of sub-total B
Dewatering @ 1% of sub total B
Contingency @ 3% of sub-total B
Work Charged establishment @ 2% of Sub-total
B
145
Sub Total B
1%
1%
3%
2%
733.59
7.34
7.34
22.01
14.67
Total Civil Cost
784.94
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
DESILTING CHAMBER (INCLUDING SFT)
S.
N.
Description
1 Surface excavation
1.1 Common excavation
1.2 Rock excavation
Unit
Quantity
Rate
Amount
In Rs.
Rs. in Lakhs
Cum
Cum
5000
2000
125
300
6.25
6.00
2
Underground excavation
Cum
35000
1000
350.00
3
3.1
3.2
3.3
3.4
Rock Supports System
Rock bolts
Structural steel Rib
Shotcrete
Concre Lagging
M
MT
Cum
Cum
14000
50
1000
200
400
42000
4000
7000
56.00
21.00
40.00
14.00
4
4.1
4.2
4.3
Concrete
M15
M20
M25
Cum
Cum
Cum
2500
500
2000
2930
3390
3610
73.25
16.95
72.20
5
Reinforcing Steel
MT
27000
6
Miscellaneous and ancillary works
@3.5% sub-total
200
Sub Total A
3.5%
54.00
709.65
24.84
7
8
9
10
Sub Total B
1%
734.49
7.34
2%
3%
2%
14.69
22.03
14.69
Total Civil Cost
793.25
Instrumentation @ 1% of sub-total
B
Dewatering @ 2% of sub total B
Contingency @ 3% of sub-total B
Work Charged establishment @ 2% of
Sub-total B
146
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
ADITS
S.
N.
Description
Unit
Quantity
Rate
In Rs.
1 Surface Excavation
1.1 Common excavation
1.2 Rock excavatio n
Amount
Rs. in
Lakhs
Cum
Cum
25000
5000
125
300
31.25
15.00
Underground excavation
Cum
40000
1000
400.00
3
3.1
3.2
3.3
3.4
Rock Support System
Rockbolts
Steel Ribs Support
Shotcrete
Concrete lagging
M
MT
Cum
Cum
25000
200
2500
800
400
42000
4000
7000
100.00
84.00
100.00
56.00
4
4.1
4.2
4.3
4.4
Concrete
Cement Concrete Lining M20
M15
M20
M25
Cum
Cum
Cum
Cum
1200
5000
1000
2000
4000
2930
3390
3610
48.00
146.50
33.90
72.20
5
Reinforcment steel
MT
27000
6
Miscellaneous and ancillary works
@ 3-4% of sub-total A
200
Sub Total A
3.5%
54.00
1140.85
39.93
7
8
9
10
Instrumentation @ 1% of sub-total B
Dewatering @ 2% of sub total B
Contingency @ 3% of sub-total B
Work Charged establishment @ 2%
of Sub-total B
2
Sub Total B
1%
2%
3%
2%
1180.78
11.81
23.62
35.42
23.62
Total Civil Cost
1275.24
147
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
HEAD RACE AND TAIL RACE TUNNEL
S.
N.
Description
Unit
1 Surface excavation
1.1 Common excavation
1.2 Rock excavation
Quantity
Rate
Amount
In Rs.
Rs. in
Lakhs
Cum
Cum
4000
1000
125
300
5.00
3.00
Underground excavation
Cum
75000
1000
750.00
3
3.1
3.2
3.3
3.4
Rock Support System
Rockbolts
Steel Ribs Support
Shotcrete
Concrete lagging
M
MT
Cum
Cum
45000
450
4600
5500
400
42000
4000
7000
180.00
189.00
184.00
385.00
4
4.1
4.2
4.3
Concrete
Cement Concrete Lining M20
M15
M25
Cum
Cum
Cum
12000
12000
1000
4000
2930
3610
480.00
351.60
36.10
5
Reinforcement steel
MT
27000
6
Miscellaneous and ancillary works @ 78% of sub-total A
250
Sub Total A
7.5%
67.50
2631.20
197.34
2
7
8
9
10
Instrumentation @ 1% of sub-total B
Dewatering @ 2% of sub total B
Contingency @ 3% of sub-total B
Work Charged establishme nt @ 2% of
Sub-total B
148
Sub Total B
1%
2%
3%
2%
2828.54
28.29
56.57
84.86
56.57
Total Civil Cost
3054.82
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
SURGE SHAFT
S.
N.
Description
Unit
Quantity
Rate
Amount
In Rs.
Rs. in
Lakhs
1 Surface Excavation
1.1 Common excavation
1.2 Rock excavation
Cum
Cum
50000
10000
125
300
62.50
30.00
2
2.1
2.2
2.3
Underground excavation
Surge shaft
Surge shaft With Raise Borer
Concrete lagging
Cum
Cum
Cum
5500
125
150
1200
1500
7000
66.00
1.88
10.50
3
3.1
3.2
3.3
Rock Support System
Rockbolts
Steel Ribs Support
Shotcrete
m
MT
Cum
12000
25
450
400
42000
4000
48.00
10.50
18.00
Cum
Cum
3000
1200
3390
3610
101.70
43.32
MT
150
27000
Sub Total A
40.50
432.90
6.49
Sub Total (17)
439.39
4 Concrete
4.1 M20
4.2 M25
5
Reinforcement steel
6
Miscellaneous and ancillary works
@ 2-3% of sub-total A
7
8
9
10
1.5%
Instrumentation @ 1% of sub-total
B
Dewatering @ 2% of sub total B
Contingency @ 3% of sub-total B
Work Charged establishment @
2% of Sub-total B
1%
4.39
2%
3%
2%
8.79
13.18
8.79
Total Civil Cost
149
474.54
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
PRESSURE SHAFTS AND PENSTOCKS
S.
N.
Description
Unit Quantity
Rate
Amount
In Rs.
1
2
2.1
2.2
2.3
Underground excavation
Cum
14000
1200
168.00
Rock Support System
Rockbolts
Steel Ribs Support
Shotcrete
M
MT
Cum
11000
100
1200
400
42000
4000
44.00
42.00
48.00
Cum
11000
2930
Sub Total A
322.30
624.30
15.61
Sub Total B
1%
639.91
6.40
1%
3%
2%
6.40
19.20
12.80
3 Concrete
3.1 M15 Backfill concrete
4
5
6
7
8
Rs. in
Lakhs
Miscellaneous and ancillary works
@ 2-3% of sub-total A
2.5%
Instrumentation @ 1% of sub-total
B
Dewatering @ 1% of sub total B
Contingency @ 3% of sub-total B
Work Charged establishment @
2% of Sub-total B
Total Civil Cost
150
684.70
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
POWER HOUSE COMPLEX
S.
N.
Description
Unit
Quantity
Rate
Amount
Rs. in
Lakhs
1
Under Ground Excavation
Cum
2
2.1
2.2
2.3
Rock Stabilization and Supports
Rock bolts
Structural steel Rib
Shotcrete
3
3.1
3.2
3.3
1000
1600.00
M
MT
Cum
70000
400
100 42000
7000 4000
280.00
42.00
280.00
Concrete including Formwork
M15 backfill concrete
Concrete linning M20
M25
Cum
Cum
Cum
5000
2000
60000
4
Reinforcement Steel
5
Structural steel for roof trusses
6 Masonary
6.1 Stone
6.2 Brick
7
8
9
10
11
160000
2930
4000
3610
146.50
80.00
2166.00
MT
7000 27000
1890.00
MT
300 42000
126.00
Cum
Cum
Miscellaneous and ancillary works
@ 4-5% of sub-total A
Instrumentation @ 1% of sub-total
B
Dewatering @ 2% of sub total B
Contingency @ 3% of sub-total B
Work Charged establishme nt @ 2%
of Sub-total B
151
500
1500
Sub Total A
4.5%
2000
2000
10.00
30.00
6650.50
299.27
Sub Total (17)
1%
6949.77
2%
3%
2%
139.00
208.49
139.00
Total Civil Cost
7505.75
69.50
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
SWITCH YARD
S.
N.
Description
Unit Quantity
Rate
Amount
Rs. in
Lakhs
1
1.1
1.2
Surface Excavation
Common Excavation
Rock excavation
Cum
Cum
100000
4000
125
300
125.00
12.00
2
2.1
2.2
Rock Support System
Rock bolts
Shotcrete
M
Cum
1000
50
400
4000
4.00
2.00
Earthwork in filling
Cum
25000
342
85.50
Concrete
M15
M20
M25
Cum
Cum
Cum
1000
1000
1000
2930
3390
3610
29.30
33.90
36.10
5
Reinforcement Steel
MT
100
27000
27.00
6
Stone/ Brick Masonary
Cum
300
2000
Sub Total A
6
Miscellaneous and ancillary works
@ 4-5% of sub-total A
6.00
360.80
16.24
Sub Total B
377.04
7.54
11.31
7.54
Total Civil Cost
403.43
3
4
4.1
4.2
4.3
7
8
9
4.5%
Dewatering @ 2% of sub total B
Contingency @ 3% of sub -total B
Work Charged establishment @
2% of Sub-total B
2%
3%
2%
152
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
HYDRO MECHANICAL EQUIPMENT
S.
N.
1
2
a)
b)
3
a)
Detail of Items
Diversion tunnel gate & hoist
Gate(Fixed wheel type)including
ballast
Embedded Parts
Ropedrum hoist 80 T Capacity
Hoist platform and trestle
Spillway structure
Radial Gates
Embedded Parts (including
anchorages, hoist structure)
including breast wall liners
Hydraulic Cylinders 40T capacity
(with provision of 25% pushing
force)
Power packs
Nos. Wt./Set
(MT)
/ set
Total
Wt.
(MT)
Rate in
Rs.
Amount
in Lakh
2
30
60
60000
36.00
2
2
2
10
25
16
20
50
32
50000
100000
50000
10.00
50.00
16.00
3
3
40
25
120
75
100000
50000
120.00
37.50
6
LS
1200000
72.00
3
LS
500000
15.00
28
27
5
LS
60000
50000
50000
5500000
16.80
13.50
2.50
55.00
Bulkhead Gate( Slide type)
Embedded Parts
Lifting Beam
Gantry crane 55 T capacity
1
3
1
1
Portable oil filter unit along with
Contamination checking kit & Low
vacuum dehydration and
degassification unit
Portable trolley mounted gasoline
engine operated power pack
1
LS
500000
5.00
1
LS
500000
5.00
Intake structure
TrashRacks (including racking
guides)
Embedded Parts
28
9
5
1
200
200
50000
100.00
1
60
60
50000
30.00
153
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Trash rack cleaning machine
1
Intake gate(fixed wheel type)
including ballast
Embedded Parts
Rope drum hoist 45T Cap.
Hoist platform and trestle
2
25
50
60000
30.00
2
2
2
8
14
9
16
28
18
50000
100000
50000
8.00
28.00
9.00
C)
Bulkhead Gate (Slide Type)
Embedded Parts
Rope drum hoist 15T Cap.
Hoist platform and trestle
2
2
2
2
8
3
5
3
16
6
10
6
60000
50000
100000
50000
9.60
3.00
10.00
3.00
4
Desilting Chamber Gates
Desilting Chamber Gate (Slide
Type)
Embedded parts
EOT Crane 20T Cap.
1
11
11
60000
6.60
2
1
4
8
LS
50000
1800000
4.00
18.00
6
120
100000
50000
6.00
60.00
LS
4
1000000
20.00
b)
5
6
7
LS 10000000
Silt Flushing Gates (Slide Type)
Gates (Service & Emergency)
4
1.5
Embedded parts (including bonnet,
4
30
bonnet cover, gate body liner etc.)
Hydraulic Cylinders 105T Cap. (Double acting)
Power Pack
2
100.00
Surge shaft gate & hoist
Gate(Slide Type)
Embedded parts
Rope drum hoist 20T Cap.
Hoist platform and trestle
1
1
1
1
11
6
6
4
11
6
6
4
60000
50000
100000
50000
6.60
3.00
6.00
2.00
Tailrace channel gate & hoist
Gate (Slide type)
Embedded Parts
Monorail Hoist 10 T capacity
1
1
1
6
5
-
6
5
LS
60000
50000
750000
3.60
2.50
7.50
154
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
8
Pressure shaft steel Liner (ASTM
A 537 Class I )
Steel Liner
Bifurcation (ASTM A 517 Gr.F )
1
2
1750
50
Adit Gates
Adit gates
Embedded Parts
3
3
8
4
10
Instruments and Remote Control
11
D G Set 250 KVA
12
Spare parts & contingency @ 5%
for Spares Airvents, By Pass
Arrangements etc.
9
1750
100
70000
77000
1225.00
77.00
24
12
60000
50000
14.40
6.00
1
LS 10000000
100.00
1
LS
155
1500000
Sub Total
5%
15.00
2398.10
119.91
Total
2518.01
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
K-BUILDINGS
Sl
No
1.0
1.1
1.2
2.0
2.1
2.2
Description
Residential Buildings
Residential permanent
buildings
Service Charges @ 31%
Residential temporary
buildings
Service Charges @ 27%
Total (Residential)
Non-Residential Buildings
Non residential permanent
buildings
Service Charges @ 22.5%
Plinth
Area(Sqm).
3960
Rate
(Rs)
0.075
Unit
Rs. In lakhs
Amount
(Rs)
Sqm
297.00
92.07
3970
0.065
258.05
69.67
716.79
7930
3485
0.065
Sqm
226.53
50.97
Non residential and other
purposes temporary
buildings
Service Charges @ 20.5%
Total( Non-Residential)
4105
7590
46.28
549.55
Total(1+2)
23450
1266.35
Add for Works Tax @
0.055
Sqm
2%
Grand Total
156
225.78
25.33
1291.67
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
O-MISCELLANEOUS
Rs. In lakhs
Sl
No
1
1.1
1.2
1.2
Description
Quant.
Rate
Unit
Amount
CAPITAL COST
Purchase of Diesel Generator Sets (25 KVA)
including anciliary equipments etc.
3.00
2.50
Nos
7.50
20.00
10.00
km
200.00
LS
30.00
Cost of transmission line for construction
power
Water Supply, purification & distribution
arrangements including purchase of water
tankers,filters, cost of tanks & chlorination.
1.4
Providing sewage disposal and storm water
drains in office and residential complexes.
LS
25.00
1.5
Providing & fixing of fire fighting equipments.
LS
20.00
1.6
Providing telephone, Telegraph office, Post
office and Wireless equipments.
LS
20.00
1.7
Providing hospital equipments.
LS
15.00
1.8
Construction of children park and welfare
centres for officials and labourers.
LS
8.00
1.9
Furnishing and equipping of rest houses and
field hostels of officers and staff.
LS
5.00
1.10
Purchase of furniture and other articles for
labour welfare centres and clubs and schools.
LS
5.00
1.11
Purchase of equipment for quality control/field
Laboratories
LS
15.00
Sub Total Item 1
2.0
2.1
350.50
MAINTENANCE & SERVICE CHARGES
OF
R&M of Diesel Generator sets 3 Nos. for four
years.
R&M of Transmission line for four years.
12.00
4.00
Nos
48.00
15.00
4.00
km
60.00
2.2
R&M of water supply facilities to the staff and
labour colonies for four years
LS
10.00
2.3
R&M of sanitation and drainage facilities for
office and residential compllex and labour
colonies.
R&M of fire fighting equipments.
LS
8.00
LS
4.00
Maint. Of telecommunication system and post
offices.
LS
20.00
2.4
2.5
157
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
2,6
R&M of hospitals.
LS
16.00
2.7
LS
10.00
2.8
Maint. of parks and welfare centres, clubs and
school.
R&M of Rest houses and field hostels.
LS
8.00
2.9
R&M of research & quality control laboratories
LS
8.00
2.10
Labour welfare compensation and retrenchment
benefits.
LS
40.00
2.11
Providing Security & Policing
LS
8.00
2.12
R&M of Inspection vehicles and staff cars (25
nos) for four year
25*4
2.50
year
250.00
2.13
R&M of school buses, Ambulance Car etc. (4
nos) for for four year
4*4
1.80
year
28.80
Sub Total Item 2
518.80
3
MISCELLANEOUS
3.1
Foundation stone laying ceremony, inaguration
and visit of Dignitaries.
LS
20.00
3.2
Railway siding
LS
20.00
3.3
LS
16.00
3.4
Installation and maintenance of Petrol/Diesel
Pumps
Providing anti malarial measures
LS
2.00
3.5
Procurement of technical leterature.
LS
2.00
3.6
Model Exhibits
LS
4.00
3.7
Canteen facilities and co-operative stores.
LS
16.00
3.8
Photographic and Cinemagraphic equipment
and their maintenance
LS
8.00
3.9
Group insurance
LS
15.00
3.10
Publication and pamplets
LS
2.00
3.11
Creches
LS
2.00
3.12
Compensation for accident
LS
8.00
3.13
Training of personnels aboard includig study
course and visit
LS
15.00
3.14
Award to workers
LS
1.5
Sub Total Item 3
131.50
Grand Total Item (1+2+3)
1000.80
158
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Q-Spl T&P for Infrastructure Development
Sl.No.
Description of equipment
Quantity Rate
(Nos.)
(Rs in
Lacs)
1
2
Hydraulic Excavator, 1.0 cum.
Loader cum Excavator, 1.0/0.25 cum.
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
Crawler Dozer, 100 FHP
Wheel dozer 130 FHP
Motor Grader, 145 FHP
Diamond Core Drill (Mechanical)
Diamond Core Drill (Hyd)
Air Track/Wagon Drill
Jack Hammer/Pavement Breaker
Compressed Air (cfm)
Mobile Crane, 10 t Pick & Carry
Mobile Crane, 20 t (Rough terrain)
Road Roller, 8/10 t
Dewatering Pump
Tipper 4.5/6.0 cum.
Truck, 10 t
Low Bed Tractor Trailor, 30 t
Concrete Mixer, 14/10 cft
Explosive Van, 10 t
Water Tanker/Sprinkler, 10 KL
Petrol/Diesel Tanker, 10 KL
Bus/Mini Bus
Car/MUV
Jeep (Petrol/Diesel)
Ambulance
Workshop Equipment
Fire Tender
Recovery Van
Pick up Van/L.C.V
159
Amount
(Rs in
Lacs)
1
1
50.00
18.00
50.00
18.00
1
1
1
1
1
2
5
2000
1
1
1
L.S
2
2
1
2
1
1
1
4
2
20
2
L.S
1
1
2
50.00
95.00
60.00
15.00
60.00
15.00
0.35
0.0125
10.00
70.00
10.00
10.00
9.50
7.50
40.00
1.50
12.00
12.00
12.00
8.00
4.00
4.00
8.00
20.00
15.00
5.00
5.00
50.00
95.00
60.00
15.00
60.00
30.00
1.75
25.00
10.00
70.00
10.00
10.00
19.00
15.00
40.00
3.00
12.00
12.00
12.00
32.00
8.00
80.00
16.00
20.00
15.00
5.00
10.00
803.75
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
DISTRIBUTION OF COST UNDER HEAD Q - SPECIAL T & P AND V RECEIPT & RECOVERIES
Cost
(Rs. In lakhs
Q
R&R
Cost of equipments excluding inspection vehicles
652.75
163.19
122.39
Cost of inspection vehicles
151.00
151.00
30.20
Provision under head Q - Spl. T&P
803.75
314.19
Recoveries to be shown under V- Receipt and
Recoveries
160
152.59
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
R - COMMUNUCATION
Rs. In lakhs
SI
NO.
Description
1
Proposed new roads
3
Quantity Rate
(Rs.)
Unit Amount(Rs.)
Approach road to dam site.,DT,
Top of Dam
18.0
80.00
Km
1440.00
Approach road to power house site
3.0
80.00
Km
240.00
Switch yard
1.0
80.00
Km
75.00
Surgeshaft
8.0
80.00
Km
640.00
Colony Roads
2.0
75.00
Km
150.00
At Dam site
50.0
2.25
M
112.50
At Vawl across the river
50.0
2.25
M
112.50
Proposed new bailey bridges Cl
30
Total
2770.00
Add for Works Tax @
Grand Total
2%
161
55.4
2825.40
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
V - RECEIPT & RECOVERIES
S.
No.
Item
Amount
(Rs. In Lakhs)
1.
Recovery from the Sale of Equipments
152.59
2.
Recovery from the sale of DG Sets and
Transformers used for generating Construction
Power
3.
Recovery towards Temporary Buildings
(@ 15% of Amount for Temporary Buildings)
Total
162
1.50
89.97
244.06
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
ELECTRO MECHANICAL WORKS
Annex-I Page 1 of 2
Generator, Turbine and Accessories
S.No.
1
1
2
Item Particulars
2
(a) Generating units and Bus
Ducts 3X40 MW,
600 rpm, Head 736 meters
Step up transformer,3 phase
11/220 KV, 49 MVA,
DEC 2003 PRICE LEVEL
Excise Duty*
Amount
(Rs
%
Amount
Lakh)
Qty
Unit
Rate
3
3(a)
4
5
6
7
3
no.
3700.00
4440.00
16
710.40
323.40
16
51.74
222
16
35.52
222
16
35.52
16
115.200
16
39.78
Total
(Rs
Lakh)
5+7
5150.40
Rs/KW
3
no.
220.00
375.14
Rs/KVA
3
4
Auxiliary Electrical Equipment
for Power Stations
(Except Transformer) (5% of
item 1)
Auxiliary Equipment & Services
for Power stations
257.52
257.52
(5% of Item 1)
5
Bays
Switch yard(220 Kv)
6
120.00
720
835.20
Lacs/Bay
6
Spares (5% of 1 and 3% of 2 to
6) )
7
SUB TOTAL(1-6)
7164.19
8
Central Sales tax **4% of item 7
Transportation & Insurance 6%
of item 7
Erection & commissioning 8%
of item 7 Excluding
286.57
9
10
222
26.62
248.62
288.40
429.85
550.06
spares
11
12
13
Sub total item 7,8,9,10
Total of FC(XLPE Cable and
Termination kit) in INR(As per
Annexure-I)
Custom Duty @22% of item 12
8430.67
484.84
included
in above
item 12
163
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
14
Marine frieght and insurance
@6% Approx of 12
29.09
15
Inland Frieght and insurance 6%
of item 12
29.09
16
17
18
19
Erection & commissioning 8%
of item 12 Excluding spares
SUB TOTAL of FC ( item
12,13,14,15,16 in INR)
38.78
581.80
Subtotal of item no
17+12(Foreign plus indian
component)
Establishment,Contingency,other
charges
9012.47
723.08
11% of Item18 excluding duties
9735.54
GRAND TOTAL (In Lacs)
Annex-I Page 2 of 2
DEC 2003 price level
S.No.
Item Particulars
( USD)
4
5
6
7
5+7
280.00
1.68
22
0.37
2.05
7.00
22
1.54
8.54
Spares for above @ 3% of 2
0.05
22
0.01
0.06
Total
8.73
2
2
XLPE Cable (220 kV)
Rate
Custom
Duty*
Amount
( Lcs
USD)
1
Qty
3
600
m
Rate%
Amount'(
Lcs USD)
Total
(Lcs
USD)
USD/m
3
XLPE Cable termination Kit
20
no.
35000.00
each
4
*Custom duty in case of imported Items
**Not applicable for Imported Items
1 USD conversion rate as on
22/12/03=
45.52
164
10.65
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
POWER EVACUATION SYSTEM
Annex-II (page 1 of 1)
Dec 2003 Price level
S.No.
Item Particulars
1
2
1
220kV Double Circuit line
Qty
3
15
km
Excise
Duty*
Rate
Amount
(Rs Lcs)
(Rs
Lcs)
4
5
6
7
5+7
22.00
330.00
16
52.80
382.80
9.9
16
1.584
11.48
Rate
Total
Amount
(Rs
Lcs)
per km
3
Spares ( 3% of 1 )
4
Subtotal(1)
5
Central Sales tax **4% of item 4
Transportation & Insurance 6%
of item 4
Erection & commissioning 8%
of item 4 except spares
15.77
Subtotal(2)
Establishment,Contingency,other
charges
464.34
6
7
8
9
394.28
23.66
30.62
37.39
11% of Item 8
GRAND TOTAL (In Lacs)
501.73
*Custom duty in case of imported Items
**Not applicable for Imported Items
165
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – XIII
ECONOMIC EVALUATION
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CHAPTER – XIII
ECONOMIC EVALUATION
13.1
GENERAL
The Project has been contemplated as a run-off the river scheme on river Ringpi. The
project is estimated to cost Rs. 630.05 crores excluding IDC at June 2003 Price Level.
Sale price of energy generated at power house bus bars has been worked out as 3.24 Rs.
per unit with free power to home state (Table 13.2) & Rs. 2.85 per unit without free
power to home state (Table 13.2-A).
13.2
ECONOMIC JUSTIFICATION
The energy generation of the project with an installed capacity of 3X40 MW has been
estimated at 477.51 MU in a 90% dependable year.
13.3
COST ESTIMATES AND PHASING OF EXPENDITURES
The cost of construction of the project has been estimated at June 2003 price level with a
construction schedule of 5.5 years includ ing 1.5 years for Infrastructure works.
The estimated Present Day Cost of the project is Rs. 630.05 Crores without IDC at June
2003 Price level.
13.4
PHASING OF EXPENDITURE
The phasing of expenditure has been worked out on the basis of anticipated construction
programme.
166
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
The phasing of expenditure without IDC for present day cost is shown as below:
Year
Estimated Cost at June 2003 P.L.
(Rs. in Crores)
1st
63.00
2nd
88.21
3rd
126.01
4th
176.41
5th
94.51
5.5th
81.91
Net Cost
630.05
13.5 INTEREST DURING CONSTRUCTION (IDC)
Based upon above phasing of expenditure the interest during construction (IDC) have
been calculated with 70:30 debt equity ratio and 10.0% interest on loan for estimated
Present Day cost of the project.
The estimated IDC with estimated present cost
13.6
is Rs. 69.75Crores
COST OF ENERGY GENERATION
The cost of energy generation has been calculated for the annual energy generation in a
90% dependable year based upon following assumptions.
1.
Debt-equity ratio
70 : 30
2.
Annual interest rate on loan
10.0%
3.
Return on equity
16%
4.
Annual interest rate on working capital
10.0%
5.
O&M Charges
1.5% of Project Cost
6.
Free power to Home State
12% of the energy
167
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
available after losses
7.
1/12th of loan amount
Depreciation considered
during loan repayment
period.
The levellised tariff of the Project at present day cost works out to be Rs. 2.62 Per Unit
with free power to home state (Table 13.3) & Rs 2.31 per unit without free power to
home state. (Table 13.3-A).
168
Preliminary Feasibility Report
Lingza HE Project (3 x 40MW)
Table-13.1
STATEMENT SHOWING IDC CALCULATION AT PRESENT DAY COST (JUNE 2003 LEVEL)
PRESENT DAY COST
Civil Works
Electrical Works
INTEREST RATE PER ANNUM
EQUITY
LOAN
Present Day
Year
Cost
630.05 Crores
527.68 Crores
97.36 Crores
10%
30%
70%
Amount
Equity
Receivable
Loan
I.D.C
4
5
1
2
3
1
2
3
4
5
5.5
Total
63.00
88.21
126.01
176.41
94.51
81.91
630.05
63.00
88.21
58.73
209.94
IDC
Net cost of the project
Loan Outstanding
at the end of
half year
6
67.28
176.41
94.51
81.91
420.11
1.80
15.73
30.85
21.38
69.75
69.08
261.22
386.58
489.86
69.75
699.80
Crores
Crores
Equity
Loan
169
(Rs. in Crores)
Amount
Receivable
Equity
Loan
(for the half year)
7
8
63.00
88.21
58.73
209.94
209.94
489.86
69.08
192.14
125.35
103.28
489.86
Crores
Crores
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Table 13.2
UNIT COST OF ENERGY AT BUS BAR AT CURRENT PRICE LEVEL
(June 2003 P.L.)
(Based on 16% return on equity & 10% interest on loan, 10% interest on working capital)
1
2
3
4
5
6
7
8
9
10
11
12
A)
a)
b)
B)
a)
b)
Installed capacity
Cost of the Project (Net)
Interest During Construction
Total Cost of Project (Including IDC)
a) Equity
b) Loan
Annual Energy Generation
0.5% As Auxiliary Consumption of No. 5
Energy Available After Auxiliary Consumption
0.5% As Transformer Loss of No. 7
Energy Available After Transformer Loss
Free Power to Home State
Energy Available After Allowing Free
Power
Fixed and Running Charges
Capacity Charges
Interest on Loan
Depreciation Charges
(Limited to 1/12 th of Loan Amount)
SUB-TOTAL
Energy Charges
O&M Charges
Return on Equity
30%
70%
Rs.
Rs.
Rs.
Rs.
Rs.
0.70%
0.50%
12%
TOTAL
10.00%
46.94 Crore
40.82 Crore
87.76 Crore
1.50%
16.00%
10.00%
0.87
22.36
Rs.
13 Sale Price at Bus Bar/Unit
14 Cost of Generation at Bus Bar/Unit
(Without Allowing Free Power to Home State and Return on Equity)
10.50 Crore
33.59 Crore
44.09 Crore
2.32 Crore
Crore
134.18 Crore
3.24 Rs.
2.13 Rs.
Note : This unit rate is excluding water cess, income tax incentive, penalties etc.
170
MW
Crore
Crore
Crore
Crore
Crore
MU
MU
MU
MU
MU
MU
414.74 MU
SUB-TOTAL
c) Interest on Working Capital
I) O&M Charges for 1 month
II) 2 Months Average Billing
120
630.05
69.75
699.80
209.94
489.86
477.00
3.34
473.66
2.37
471.29
56.56
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Table-13.2 a
UNIT COST OF ENERGY AT BUS BAR AT CURRENT PRICE LEVEL
(June 2003 P.L.) WITHOUT FREE POWER TO HOME STATE
(Based on 16% return on equity & 10% interest on loan, 10% interest on working capital)
1
2
3
4
5
6
7
8
9
10
11
12
A)
a)
b)
B)
a)
b)
Installed capacity
Cost of the Project (Net)
Rs.
Interest During Construction
Rs.
Total Cost of Project (Including IDC)
Rs.
a) Equity
30%
Rs.
b) Loan
70%
Rs.
Annual Energy Generation
0.5% As Auxiliary Consumption of No. 5
0.70%
Energy Available After Auxiliary Consumption
0.5% As Transformer Loss of No. 7
0.50%
Energy Available After Transformer Loss
Free Power to Home State
0%
Energy Available After Allowing Free Power
Fixed and Running Charges
Capacity Charges
Interest on Loan
10.00%
Depreciation Charges
(Limited to 1/12 th of Loan Amount)
SUB-TOTAL
Energy Charges
O&M Charges
1.50%
Return on Equity
16.00%
SUB-TOTAL
c) Interest on Working Capital
I) O&M Charges for 1 month
II) 2 Months Average Billing
TOTAL
13 Sale Price at Bus Bar/Unit
120
630.05
69.75
699.80
209.94
489.86
477.00
3.34
473.66
2.37
471.29
0.00
471.29
MW
Crore
Crore
Crore
Crore
Crore
MU
MU
MU
MU
MU
MU
MU
46.94 Crore
40.82 Crore
87.76 Crore
10.50 Crore
33.59 Crore
44.09 Crore
10.00%
2.32 Crore
0.87
Crore
22.36
Crore
Rs.
134.18 Crore
2.85 Rs.
14 Cost of Generation at Bus Bar/Unit
2.13 Rs.
(Without Allowing Free Power to Home State and Return on Equity)
Note : This unit rate is excluding water cess, income tax incentive, penalties etc.
171
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
Table 13.3
CALCULATION OF ENERGY RATE WITH PRESENT DAY COST AS PER TARIFF NOTIFICATION
Annual Generation in a 90% dependable year
477 MU
O&M Charges
Annual Generation after allowing losses & free
Rate of increase of O&M Charges after 1st Year (Compounded)
power to home state in a 90% dependable year
414.74 MU
Interest rate on Loan
Total cost including IDC
Rs.
699.80 Crores
Interest rate on Working Capital
Equity
30%
Rs.
209.94 Crores
Return on Equity
Loan
70%
Rs.
489.86 Crores
Discounting rate
YEAR
OutCAPACITY CHARGES
CHARGES
Discounting
standing
(Rs.in Cr.)
(Rs.in Cr.)
(Rs. per
Factor
Loan
Interest Depre - Total Return
O&M
O&M
Interest on Working
Total
Capacity
Energy
Total
(Rs.in
on loan ciation
on
Charges
for
1
2 months
Capital Interest
charges
charges
Cr.)
equity
month
Average Billing
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
489.86
46.94
40.82
87.77
33.59
10.50
0.87
22.36
2.32
46.41
2.12
1.12
3.24
1.0000
2
449.04
42.86
40.82
83.68
33.59
11.13
0.93
21.78
2.27
46.99
2.02
1.13
3.15
0.8929
3
408.22
38.78
40.82
79.60
33.59
11.79
0.98
21.20
2.22
47.60
1.92
1.15
3.07
0.7972
4
367.39
34.70
40.82
75.52
33.59
12.50
1.04
20.63
2.17
48.26
1.82
1.16
2.98
0.7118
5
326.57
30.62
40.82
71.44
33.59
13.25
1.10
20.07
2.12
48.96
1.72
1.18
2.90
0.6355
6
285.75
26.53
40.82
67.36
33.59
14.05
1.17
19.51
2.07
49.71
1.62
1.20
2.82
0.5674
7
244.93
22.45
40.82
63.27
33.59
14.89
1.24
18.96
2.02
50.50
1.53
1.22
2.74
0.5066
8
204.11
18.37
40.82
59.19
33.59
15.78
1.32
18.42
1.97
51.35
1.43
1.24
2.67
0.4523
9
163.29
14.29
40.82
55.11
33.59
16.73
1.39
17.89
1.93
52.25
1.33
1.26
2.59
0.4039
10
122.46
10.21
40.82
51.03
33.59
17.73
1.48
17.37
1.89
53.21
1.23
1.28
2.51
0.3606
11
81.64
6.12
40.82
46.94
33.59
18.80
1.57
16.86
1.84
54.23
1.13
1.31
2.44
0.3220
12
40.82
2.04
40.82
42.86
33.59
19.93
1.66
16.36
1.80
55.32
1.03
1.33
2.37
0.2875
13
0.00
0.00
6.09
6.09
33.59
21.12
1.76
10.33
1.21
55.92
0.15
1.35
1.50
0.2567
14
0.00
0.00
6.09
6.09
33.59
22.39
1.87
10.55
1.24
57.22
0.15
1.38
1.53
0.2292
15
0.00
0.00
6.09
6.09
33.59
23.73
1.98
10.78
1.28
58.60
0.15
1.41
1.56
0.2046
16
0.00
0.00
6.09
6.09
33.59
25.16
2.10
11.02
1.31
60.06
0.15
1.45
1.59
0.1827
17
0.00
0.00
6.09
6.09
33.59
26.67
2.22
11.28
1.35
61.61
0.15
1.49
1.63
0.1631
18
0.00
0.00
6.09
6.09
33.59
28.27
2.36
11.56
1.39
63.25
0.15
1.52
1.67
0.1456
19
0.00
0.00
6.09
6.09
33.59
29.96
2.50
11.85
1.43
64.99
0.15
1.57
1.71
0.1300
20
0.00
0.00
6.09
6.09
33.59
31.76
2.65
12.15
1.48
66.83
0.15
1.61
1.76
0.1161
21
0.00
0.00
6.09
6.09
33.59
33.67
2.81
12.48
1.53
68.78
0.15
1.66
1.81
0.1037
22
0.00
0.00
6.09
6.09
33.59
35.69
2.97
12.82
1.58
70.86
0.15
1.71
1.86
0.0926
23
0.00
0.00
6.09
6.09
33.59
37.83
3.15
13.19
1.63
73.05
0.15
1.76
1.91
0.0826
24
0.00
0.00
6.09
6.09
33.59
40.10
3.34
13.58
1.69
75.38
0.15
1.82
1.96
0.0738
25
0.00
0.00
6.09
6.09
33.59
42.50
3.54
13.99
1.75
77.84
0.15
1.88
2.02
0.0659
26
0.00
0.00
6.09
6.09
33.59
45.05
3.75
14.42
1.82
80.46
0.15
1.94
2.09
0.0588
27
0.00
0.00
6.09
6.09
33.59
47.75
3.98
14.89
1.89
83.23
0.15
2.01
2.15
0.0525
28
0.00
0.00
6.09
6.09
33.59
50.62
4.22
15.38
1.96
86.17
0.15
2.08
2.22
0.0469
29
0.00
0.00
6.09
6.09
33.59
53.66
4.47
15.89
2.04
89.28
0.15
2.15
2.30
0.0419
30
0.00
0.00
6.09
6.09
33.59
56.88
4.74
16.45
2.12
92.59
0.15
2.23
2.38
0.0374
31
0.00
0.00
6.09
6.09
33.59
60.29
5.02
17.03
2.21
96.08
0.15
2.32
2.46
0.0334
32
0.00
0.00
6.09
6.09
33.59
63.91
5.33
17.65
2.30
99.79
0.15
2.41
2.55
0.0298
33
0.00
0.00
6.09
6.09
33.59
67.74
5.65
18.30
2.39
103.73
0.15
2.50
2.65
0.0266
34
0.00
0.00
6.09
6.09
33.59
71.81
5.98
19.00
2.50
107.89
0.15
2.60
2.75
0.0238
35
0.00
0.00
6.09
6.09
33.59
76.11
6.34
19.73
2.61
112.31
0.15
2.71
2.85
0.0212
TOTAL
9.1566
(A)
Note:
The charges per unit is exclusive of water cess, spares, incentive & Income Tax etc.
Levellised Tariff =(B)/(A)
172
1.50%
6%
10.0%
10.00%
16%
12%
Discounted
Tariff
(Paisa per
Unit)
16
3.24
2.81
2.45
2.12
1.84
1.60
1.39
1.21
1.05
0.91
0.79
0.68
0.38
0.35
0.32
0.29
0.27
0.24
0.22
0.20
0.19
0.17
0.16
0.14
0.13
0.12
0.11
0.10
0.10
0.09
0.08
0.08
0.07
0.07
0.06
24.03
(B)
2.62
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
CALCULATION OF ENERGY RATE WITH PRESENT DAY COST AS PER TARIFF NOTIFICATION
WITHOUT FREE POWER TO HOME STATE
Annual Generation in a 90% dependable year
477 MU
O&M Charges
Annual Generation after allowing losses & free
Rate of increase of O&M Charges after 1st Year (simple)
power to home state in a 90% dependable year
471.29 MU
Interest rate on Loan
Total cost including IDC
Rs.
699.80 Crores
Interest rate on Working Capital
Equity
30%
Rs.
209.94 Crores
Return on
Loan
70%
Rs.
489.86 Crores
Discounting rate
YEAR
CAPACITY
CHARGES
Discounting
Out(Rs.in Cr.)
(Rs.in Cr.)
(Rs. per
Factor
standing
Interest
Depre- Total Return
O&M
Interest on
Total Capacity
Energy
Total
Loan
on lo an
ciation
on
Charges O&M
2 months
Interest
charges
charges
(Rs.in
equity
1 month Average
Billing
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
489.86
46.94
40.82
87.77
33.59
10.50
0.87
22.36
2.32
46.41
1.86
0.98
2.85
1.0000
2
449.04
42.86
40.82
83.68
33.59
11.13
0.93
21.78
2.27
46.99
1.78
1.00
2.77
0.8929
3
408.22
38.78
40.82
79.60
33.59
11.79
0.98
21.20
2.22
47.60
1.69
1.01
2.70
0.7972
4
367.39
34.70
40.82
75.52
33.59
12.50
1.04
20.63
2.17
48.26
1.60
1.02
2.63
0.7118
5
326.57
30.62
40.82
71.44
33.59
13.25
1.10
20.07
2.12
48.96
1.52
1.04
2.55
0.6355
6
285.75
26.53
40.82
67.36
33.59
14.05
1.17
19.51
2.07
49.71
1.43
1.05
2.48
0.5674
7
244.93
22.45
40.82
63.27
33.59
14.89
1.24
18.96
2.02
50.50
1.34
1.07
2.41
0.5066
8
204.11
18.37
40.82
59.19
33.59
15.78
1.32
18.42
1.97
51.35
1.26
1.09
2.35
0.4523
9
163.29
14.29
40.82
55.11
33.59
16.73
1.39
17.89
1.93
52.25
1.17
1.11
2.28
0.4039
10
122.46
10.21
40.82
51.03
33.59
17.73
1.48
17.37
1.89
53.21
1.08
1.13
2.21
0.3606
11
81.64
6.12
40.82
46.94
33.59
18.80
1.57
16.86
1.84
54.23
1.00
1.15
2.15
0.3220
12
40.82
2.04
40.82
42.86
33.59
19.93
1.66
16.36
1.80
55.32
0.91
1.17
2.08
0.2875
13
0.00
0.00
6.09
6.09
33.59
21.12
1.76
10.33
1.21
55.92
0.13
1.19
1.32
0.2567
14
0.00
0.00
6.09
6.09
33.59
22.39
1.87
10.55
1.24
57.22
0.13
1.21
1.34
0.2292
15
0.00
0.00
6.09
6.09
33.59
23.73
1.98
10.78
1.28
58.60
0.13
1.24
1.37
0.2046
16
0.00
0.00
6.09
6.09
33.59
25.16
2.10
11.02
1.31
60.06
0.13
1.27
1.40
0.1827
17
0.00
0.00
6.09
6.09
33.59
26.67
2.22
11.28
1.35
61.61
0.13
1.31
1.44
0.1631
18
0.00
0.00
6.09
6.09
33.59
28.27
2.36
11.56
1.39
63.25
0.13
1.34
1.47
0.1456
19
0.00
0.00
6.09
6.09
33.59
29.96
2.50
11.85
1.43
64.99
0.13
1.38
1.51
0.1300
20
0.00
0.00
6.09
6.09
33.59
31.76
2.65
12.15
1.48
66.83
0.13
1.42
1.55
0.1161
21
0.00
0.00
6.09
6.09
33.59
33.67
2.81
12.48
1.53
68.78
0.13
1.46
1.59
0.1037
22
0.00
0.00
6.09
6.09
33.59
35.69
2.97
12.82
1.58
70.86
0.13
1.50
1.63
0.0926
23
0.00
0.00
6.09
6.09
33.59
37.83
3.15
13.19
1.63
73.05
0.13
1.55
1.68
0.0826
24
0.00
0.00
6.09
6.09
33.59
40.10
3.34
13.58
1.69
75.38
0.13
1.60
1.73
0.0738
25
0.00
0.00
6.09
6.09
33.59
42.50
3.54
13.99
1.75
77.84
0.13
1.65
1.78
0.0659
26
0.00
0.00
6.09
6.09
33.59
45.05
3.75
14.42
1.82
80.46
0.13
1.71
1.84
0.0588
27
0.00
0.00
6.09
6.09
33.59
47.75
3.98
14.89
1.89
83.23
0.13
1.77
1.90
0.0525
28
0.00
0.00
6.09
6.09
33.59
50.62
4.22
15.38
1.96
86.17
0.13
1.83
1.96
0.0469
29
0.00
0.00
6.09
6.09
33.59
53.66
4.47
15.89
2.04
89.28
0.13
1.89
2.02
0.0419
30
0.00
0.00
6.09
6.09
33.59
56.88
4.74
16.45
2.12
92.59
0.13
1.96
2.09
0.0374
31
0.00
0.00
6.09
6.09
33.59
60.29
5.02
17.03
2.21
96.08
0.13
2.04
2.17
0.0334
32
0.00
0.00
6.09
6.09
33.59
63.91
5.33
17.65
2.30
99.79
0.13
2.12
2.25
0.0298
33
0.00
0.00
6.09
6.09
33.59
67.74
5.65
18.30
2.39
103.73
0.13
2.20
2.33
0.0266
34
0.00
0.00
6.09
6.09
33.59
71.81
5.98
19.00
2.50
107.89
0.13
2.29
2.42
0.0238
35
0.00
0.00
6.09
6.09
33.59
76.11
6.34
19.73
2.61
112.31
0.13
2.38
2.51
0.0212
TOTAL
Note:
The charges per unit is exclusive of water cess, spares, incentive & Income Tax etc.
173
Table 13.3 a
1.50%
6%
10.0%
10.00%
16%
12%
Discounted
Tariff
(Paisa per
Unit)
16
2.85
2.48
2.15
1.87
1.62
1.41
1.22
1.06
0.92
0.80
0.69
0.60
0.34
0.31
0.28
0.26
0.23
0.21
0.20
0.18
0.16
0.15
0.14
0.13
0.12
0.11
0.10
0.09
0.08
0.08
0.07
0.07
0.06
0.06
0.05
9.1566
(A)
21.15
(B)
Levellised Tariff =(B)/(A)
2.31
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
PLATES
PLATE - 1
POWER HOUSE
POWER HOUSE
T.R.L.
AV.GROSS HEAD
FIRM POWER
INST. CAPACITY
T.R.L.
AV.GROSS HEAD
FIRM POWER
INST. CAPACITY
: 1060 m.
: 740 M
: 19.7 MW
: 160 MW
: 1800 m.
: 1150 M
: 19.7 MW
: 160 MW
RINGPI H.E. SCHEME
PANAN H.E. SCHEME
DIVERSION
BED LEVEL : 1055 m.
LINGZA
LAVEN
LINGZA H.E. SCHEME
DIVERSION
DIVERSION
BED LEVEL : 2950 m.
BED LEVEL : 1800 m.
POWER HOUSE
PANAN
T.R.L.
AV.GROSS HEAD
FIRM POWER
INST. CAPACITY
: 780 m.
: 310 M
: 28.4 MW
: 230 MW
SCALE- 1:50000
N
MAY, 1983
PANAN, LINGZA & RINGPI
H.E. SCHEMES
ON TOLUNG RIVER
(TISTA RIVER SYSTEM)
DRG.NO. HEPR-PS-BHM-784
PLATE-2
SCHEMATIC DIAGRAM SHOWING CASCADE DEVELOPMENT OF TEESTA RIVER BASIN (SIKKIM)
LACHEN PROJECT
SALENTFEATURES:-
UNDER CONST.BY NHPC
1. CATCHMENT AREA 1604sq.km.
2. DISCHARGE(Dependable)9.25 cumecs.
3500
TEESTA PROJECT
STAGE -V
SALENTFEATURES:1. CATCHMENT AREA
1772sqkms
2. DISCHARGE(Dependable)9.29cumecs.
3. F.R.L.
2287m.
4. TYPE OF DAM-Conc.GravityDam
SALENTFEATURES:1. CATCHMENT AREA
4336sqkm
2. DISCHARGE(Dependable) 60cumecs
3000
ELEVATION IN METERS
3500
8. FIRM POWER
38.44mw.
9. PROPOSED INSTALLED
CAPACITY
210mw.
3000
5. T.W.L.
1592m.
6. AVERAGE GROSS HEAD 683m.
3. F.R.L.
579m.
4. TYPE OF DAM-Conc.GravityDam
5. T.W.L.
359.5m.
6. AVERAGE GROSS HEAD 216.73m.
7. LENGTH OF TUNNEL 18km.
8. FIRM POWER
100mw.
9. PROPOSED INSTALLED
CAPACITY
510mw.
2500
3. F.R.L.
2650m.
4. TYPE OF DAM-Conc.GravityDam
5. T.W.L.
2290m.
6. AVERAGE GROSS HEAD 355m.
7. LENGTH OF TUNNEL 4.5km.
TEESTA PROJECT
STAGE -II
7. LENGTH OF TUNNEL 11.60km.
8. FIRM POWER
57.38mw.
9. PROPOSED INSTALLED
CAPACITY
330mw.
2500
TEESTA PROJECT
STAGE -III
TEESTA PROJECT
STAGE -I
SALENTFEATURES:-
2000 TEESTA PROJECT
STAGE -VI
SALENTFEATURES:-
1500
1000
1. CATCHMENT AREA
4874sqkm
2. DISCHARGE(Dependable) 93CUMECS
3. F.R.L.
341m.
4. TYPE OF DAM(Conc.GravityDam)
5. T.W.L.
253.5om.
6. AVERAGE GROSS HEAD 84.50m.
7. LENGTH OF TUNNEL 3.50km.
1. CATCHMENT AREA
2787sqkm.
2. DISCHARGE(Dependable)31cumecs
3. F.R.L.
1585m.
4. TYPE OF DAM(Conc.GravityDam)
5. HEIGHT OF DAM
103m.
6. T.W.L.
779m.
7. AVERAGE GROSS HEAD 800m.
SALENTFEATURES:-
8. LENGTH OF TUNNEL 12.93m.
9. FIRM POWER
180mw.
10. PROPOSED INSTALLED
CAPACITY
1200mw.
7. LENGTH OF TUNNEL 7.75km.
8. FIRM POWER
43.03mw.
9. PROPOSED INSTALLED
CAPACITY
320mw.
8. FIRM POWER
55.50MW.
9. PROPOSED INSTALLED
CAPACITY
360MW.
2000
1. CATCHMENT AREA 1461sq.km.
2. DISCHARGE(Dependable)10.8 cumecs.
3. F.R.L.
3258m.
4. TYPE OF DAM(Conc.GravityDam) 2Nos.
5. T.W.L.
2675m.
6. AVERAGE GROSS HEAD 730m.
1500
1000
TEESTA PROJECT
STAGE-IV
SALENTFEATURES:-
500
500
1. CATCHMENT AREA
3859sqkms
2. DISCHARGE(Dependable)56cumecs.
3. F.R.L.
722m.
4. TYPE OF DAM-Conc.GravityDam
5. T.W.L.
589m.
6. AVERAGE GROSS HEAD 183m.
000
11O
100
90
80
70
60
50
7. LENGTH OF TUNNEL 11km.
8. FIRM POWER
82.5mw.
9. PROPOSED INSTALLED
CAPACITY
495mw.
40
DISTANCE IN KILOMETER
30
000
10
20
0
PLATE-3
20'
6065
5070
5600
5000
U
CHH
ANG
ATH
W
DA
46
00
U
L CH
THU
JUM
4925
42
00
40'
5200
3190
460
0
4600
3000
U
HH
IC
DU
LU
DAM AXIS
440
0
8425
4115
0
480
4940
26
28 00
00
30
0
32 0
0
34 0
00
U
RAHI CH
100
0
14
00
22
00
260
0
12
00
1400
TO
LU
NG
1000
2200
1800
1800
1600
1400
1200
CH
U
ER
TA RIV
TEES
1000
1000
1200
1000
2400
RIN
GY
ON
GC
HU
1200
220
0
1600
1600
1800
AVG. GROSS HEAD 322
2725
1. NO DIMENSION SHALL BE MEASURED FROM
THIS DRAWING .
2. CONTOURS AND OTHER FEATURES HAVE
BEEN TRACED FROM THE S.O.I. TOPO-SHEET
NO. 78A/6 & 78A/10 (SCALE:- 1:50000).
1400
TEESTA H.E. PROJECT
(STAGE-IV)
1430
TW L 770
NOTES
DAM AXIS
2000
2000
1600
1800
1400
1200
800
1000
800
1400
1200
1800
30'
1600
1800
1600
1800
2200
2400
2600
3000
2800
2800
2600
2800
2600
2400
2600
27°
2600
2400
3000
3400
3800
4000
4200
3800
3200
3000
4000
4400
27°
4600
240
0
PO
KH
RA
MC
HU
4000
3580
42
00
2400
SUSPENSION BRIDGE
AVG GROSS HEAD 738.2
P.H. CAPACITY 3 X 47
5000
5000
100
0
2845
00
16 00
14
2008
120
0
1600
180
0
T W L 1098
5288
RA
NG
YO
NG
CH
HU
0
140
4600
360
0
3800
22
24 00
00
16
00
20
00
00
44
5485
00
18
3600
5259
2000
3000
3200
3400
4934
4600
PANAN H.E PROJECT
F R L 1095
R B L 1050
M D D L 1085
2800
2600
0
2202000
40
00
00
46
440
0
46
00
0
340
00
42
2600
3000
2800
2485
0
240
DAM AXIS
1200
3200
3800
42
00
4525
2200
3065
00
14
2400
3200
00
24
2503
T W L 1095
AVG. GROSS HEAD 746
P.H. CAPACITY 3 X 40
00
36 0
0
38
0
440
3400
2400
2200
T W L 1845
AVG. GROSS HEAD 541.1
P.H. CAPACITY 3 X 11
00
32
30'
00
18
DAM AXIS
3690
5000
20
00
00
24
0
280
2600
4000
00
48
2900
CANE BRIDGE
0
200
4565
3400
3200
3000
3000
4800
4600
4400
3800
3580
HHU
ONG C
RANGY
DAM AXIS
TW L 1853
AVG GROSS HEAD 1110
P.H. CAPACITY 2 X 35
3800
DAM AXIS
DAM AXIS
4000
4200
3355
3000
3400
35'
F R L 1845
R B L1795
M D D L1825
RANGYONG H.E PROJECT
F R L 1845
R B L1795
M D D L1825
3000
3200
00
34
26
0
2800 0
RUKEL H.E PROJECT
F R L 2395
R B L 2355
M D D L 2385
4850
HU
CH
NG
ZO
CH
U
0
320
4000
0
260 0
280
RU
KE
LC
HH
U
3400
3600
HU
CHA C
KONG
3400
3200
4060
2800
3000
32
00
260
0
4425
HU
CH
AR
PEG
0
3200
280
2800
4390
PAS
SAM
CHH
U
0
420
0
400
0
380 0
360 0
340
0
320
0
300
U
HH
MC
RA
UM
3400
LINGZA H.E PROJECT
F R L 1850
M D D L 1830
R B L 1795
RG
VIN
GR
UM
4400
4640
4600
00
28
2600
3000
3800
4200
3720
HHU
PI C
RING
5200
3775
4195
00
30
4180
5508
4460
4800
2810
4800
4965
3370
400
0
42
00
5718
5215
00
44
1000
50
00
4440
4200
48 4600
0
50 0
52 00
00
4600
00
44
0
460
4000
6671
0
400
00
48
4885
45'
5060
4800
6345
27°
5615
4600
5200
4600
0
400
6200
6400
4135
4660
4340
6200
00
50
RINGPI H.E PROJECT
F R L 2966
R B L 2940
M D D L2933
6888
4890
6539
4600
4235
4400
42
00
5643
00
48
45'
88° 30'
25'
KISH
ONG
CHU
88° 15'
00
50
27°
88° 15'
88° 30'
FEB.2004
F/DCE730/01/02
PLATE-4
SCHEMATIC DIAGRAM SHOWING CASCADE DEVELOPMENT
OF TOLUNG RIVER BASIN (SIKKIM)
ELEVATION IN METERS
3000
3000
LINGZA HE PROJECT
RINGPI HE PROJECT
2750
2750
2500
2500
2250
2250
PANAN HE PROJECT
RUKEL HE PROJECT
2000
2000
1750
1750
RANGYONG HE PROJECT
1500
1500
1250
1250
o
2
4
6
8
10
12
14
16
DISTANSE IN KILOMETER
18
20
22
PLATE 4.1
LINGZA H.E. SCHEME - SIKKIM
PLATE NO.- 6.1
TEESTA HYDRO ELECTRIC PROJECT(STAGE-I)
( 4 X 80 MW )
C H I N A
NACHUNGTHANGKHA
THANG CHHO
HYDRO ELECTRIC PROJECT
( 3 X 47 MW )
U
G CHH
THAN
GYAM
U
CHH
GEY
I
N
CH
HU
INTERNATIONAL BOUNDARY
MANGAN
E
RUN CHHU
A
B
RIN
GY
ON
G
HU
G CH
KUN
CHA
H
TIN
GC
HE
NK
HA
NG
C
TO
LUN
GC
HH
U
TI
T
M
YA
KA
HU
CH
HU
UNG CH
RONGD
RIMB
I CH
HU
LEGEND
CHH
U
CHA
BAK
HU
CH
DIK
HU
U CH
MONM
RAN
GPH
AP C
HHU
DIKCHU
DAM SITE
GANGTOK
MANGKHA
RA
NG
PO
CH
HU
GEZING
KHOLA
KALEJ
HU
CH
OM
H
KC
TA
U
HH
EC
GZ
HU
N
CH
LU
O
P
NG
RA
NOTES
1. NO DIMENSION SHALL BE MEASURED FROM THIS DRAWING.
IK
RAN
OR
U
H
CH
GNI
RON
PRE- FEASIBILITY REPORT DRAWING
SIRWANI
SINGTAM
N
ER
RIV
A
GREA
T RA
NGIT
RIVE
R
TA
ES
TE
T
NAYA BAZAR
U
NAMCHI
OLA
LI KH
RANG
H
HHU
PO C
RANG
RIS
RANGPO
HI
KH
OL
A
B
R
IVE
IT R
NG
RA
LA
KHO
NG
RIYO
R
AM O
RAM
RA
NG SOMBARE
BO
NG
KH
OL
A
TRIBUTARY
CHHU
BYU
CH
HU
REATHOK KHOLA
RIVER
RATE CHHU
HHU
AC
ROR
RISH
I KHO
LA
STATE BOUNDARY
ROAD
RE
FL
IC
HH
U
RA
TH
AN
G
IVER
TA R
TEES
HU
CH
RI
KHUNGME
CHHU
U
PREK
HH
GC
AN
UR
CH
OK
CH
HU
CH
LINGZA HYDRO ELECTRIC PROJECT
( 3 X 40 MW)
CHUNGTHANG
G CHHU
CHAUNRIKHIANG
LAMBI
TIKIPCHHU
RAH
I CH
HU
HU
CH
CH
HU
ON
RANGY
RONGNI STORAGE PROJECT
( 3 X 65 MW)
U
HH
MC
BO
RA
U
CHH
GPI
RIN
AM
MR
UM
TON
GSH
ION
GG
LAC
TA
IER
LU
NG
GL
RU
AC
KE
IER
L
SS
NG
YA
N E
P A
L
RUKEL HYDRO ELECTRIC PROJECT
( 3 X 11 MW )
DIKCHU HYDRO ELECTRIC PROJECT
( 3 X 35 MW )
HU
CH
ZE
MU
CH
HU
TA
RU
M
CHHU
POKE
HU
CH
UM
BUR
CH
HU
CHH
U
SE
BO
ZA
NG
THO
MPH
YAK
TEESTA HYDRO ELECTRIC PROJECT(STAGE-V)
( 3 X 170 MW )
HU
G CH
LUN
TOK
HHU
AC
GM
LUN
PANAN HYDRO ELECTRIC PROJECT
(4 X 50MW)
C
LEP HHU
KA
NG
HA
MR
YU
RANGYONG
LAN
GB
OC
HH
U
HU
CH
HA
LAS
U
HH
KC
NA
LHO
RINGPI HYDRO ELECTRIC PROJECT
( 2 X 35 MW )
HU
CH
NG
U
H
UT
PH
HU
CH
YA
K
NG
DO
CH
HU
GO
MA
CH
HU
ER
RIV
STA
TEE
U
HH
AC
OR
KH
NAK
UC
HH
U
TALAM HYDRO ELECTRIC PROJECT
( 2 X 35 MW )
LACHEN HYDRO ELECTRIC PROJECT
( 3 X 70 MW )
TE
ES
TA
RIV
ER
TIBET
VICINITY MAP
AL
WEST BENG
F/DCE730/01/02
0
140
0
160
0
180
0
200
0
220
0
240
2600
0
260
2400
2800
2200
2000
27°35'
PLATE :- 6.2
PI
NG
RI
U
CH
00
20
DESILTING CHAMBER
2 Nos. (95 X 5X 7.5 M)
INTAKE TUNNEL 3MØ
88°27'30''
00
18
DIVERSION TUNNEL 6MØ
H.S SHAPE
00
22
SILT FLUSHING
TUNNEL
ADIT-1
AX
IS
HEAD RACE TUNNEL 3.3 M Ø HORSE-SHOE
PROPOSED ROAD
00
24
2000
DA
M
180
0
1600
2200
1800
SURGE SHAFT 10 M Ø
ADIT-2
1600
NOTES
1600
RIN
GPI
CHU
PRESSURE SHAFT
2 M Ø INCLINED
1600
1400
SWITCHYARD
(200M. X 150M.)
M.I.V.
P.H.
M.A.T.
1. NO DIMENSION SHALL BE MEASURED FROM THIS DRAWING
TOL
UNG
CHU
20
00
1800
2. CONTOURS AND OTHER FEATURES HAVE BEEN TRACED
FROM THE S.O.I. TOPO- SHEET NO. 78A/6 (SCALE:- 1:50000) .
2600
T.R.T. 3.3 M. Ø H.S.SHAPE
TRANSFORMER
CAVERN
2800
24
00
22
00
20
00
18
00
16
00
14
00
1200
PRE- FEASIBILITY REPORT DRAWING
PROJECT LAY-OUT PLAN
F/DCE730/01/02
PLATE NO.- 6.3
2400
2000
INTAKE TUNNEL 3MØ
2400
PI
NG
RI
U
CH
DESILTING CHAMBER
2 Nos. (95 X 5X 7.5 M)
GATE OPERATION CHAMBER
HRT 3.3M. Ø H.S.
0
220
SPILLWAY BAY
3NOS. 4.0M. X 6.0M.
30
00
0
DA
M
12
50
00
TO
PE
L.
18
55
.0
M.
U/S COFFER DAM
NOTES
SILT FLUSHING TUNNEL
1.0X1.8M.D-SHAPED
0
200
1. NO DIMENSION SHALL BE MEASURED FROM
THIS DRAWING
2. CONTOURS AND OTHER FEATURES HAVE
DIVERSION TUNNEL 6MØ H.S.
16
50
00
BEEN TRACED FROM THE S.O.I. TOPOSHEET NO. 78A/6 (SCALE:1:50000) .
D/S COFFER DAM
PROPOSED ROAD
DA
M
AX
IS
PRE- FEASIBILITY REPORT DRAWING
1800
0
180
0
200
LAY-OUT PLAN
DAM AREA
F/DCE730/01/02
1400
1600
HRT 3.3 Ø H.S.SHAPE
1800
2000
PLATE NO.- 6.4
2000
PROPOSED ROAD
SURGE SHAFT 10 M Ø
1200
1800
PRESSURE SHAFT
2 M Ø INCLINED
1600
1400
PENSTOCKS 3NOS. 1.1M. Ø
NOTES
1. NO DIMENSION SHALL BE MEASURED FROM THIS DRAWING
2. CONTOURS AND OTHER FEATURES HAVE BEEN TRACED
CH
U
M.I.V.
1400
SWITCH YARD
(200M. X150M. )
FROM THE S.O.I. TOPO-SHEET NO. 78A/6 (SCALE:- 1:50000).
POWER HOUSE
(110M. X 17M. X 40M.)
M.A.T. 7M.Ø
D- SHAPE
TO
LU
NG
CH
U
RI
NG
PI
TRANSFORMER
CAVERN
T.R.T. 3.3 M Ø H.S.
H.S. SHAPE
PRE- FEASIBILITY REPORT DRAWING
1200
LAY-OUT PLAN
POWER HOUSE AREA
F/DCE730/01/02
PLATE NO.:- 6.5
?
TRESTLE
?
GATE OPERTATION
CHAMBER
SURGE SHAFT
10 M. Ø
?
EL 1860 M.
ASSUMED N.S.L.
?
FRL 1850.00
EL 1855.00
?
?
ADIT TO P.S.
3.3M. Ø D-SHAPE
DESILTING CHAMBER
(95M. X 5M.X7.5M.)
?
MDDL 1830.00
?
?
POWER HOUSE CAVERN
EL 1820.00
EL 1815.00
?
CABLE TUNNEL
EL.1133.00
BUS DUCT
HRT 3.3M. Ø H.S.
SILT FLUSHING TUNNEL
(1.0M.X1.80M. D-SHAPED)
STEEL LINED
PRESSURE SHAFT
2 M. Ø
TRANSFORMER CAVERN
EL.1110.00
T.R.T.
EL.1097.00
TWL1095.00
MIV CAVERN
17000
14000
C.C. BLOCKS
COFFERWALL
8000
NOTES:
1 ALL DIMENSIONS ARE IN MILLIMETERS AND LEVELS IN METERS.
UNLESS OTHERWISE SPECIFED.
2 NO DIMENSION SHALL BE MEASURED FROM THIS DRAWING.
PRE- FEASIBILITY REPORT DRAWING
WATER CONDUCTOR SYSTEM
L-SECTION
MAR.2004
F/DCE730/01/02
PLATE NO.:- 6.6
320000
125000
30000
165000
4000(TYP.)
STOPLOG GANTRY
CRANE
?
3000(TYP.)
L7
L6
L5
L4
L3
L2
L1
S1
S2
S3
R1
R2
R3
R4
R5
R7
R8
R9
?
?
R6
RADIAL GATE 4000 X 6000
NSL
?
?
?
ANTICIPATED ROCK PROFILE
NOTES:
1 ALL DIMENSIONS ARE IN MM AND LEVELS IN METRES.
UNLESS OTHERWISE SPECIFIED.
2. NO DIMENSION SHALL BE MEASURED FROM THIS
DRAWING.
UPSTREAM ELEVATION
PRE- FEASIBILITY REPORT DRAWING
DAM
UPSTREAM ELEVATION
MAR.2004
F/DCE730/01/02
PLATE NO.:- 6.7
DAM AXIS
STOPLOG GANTRY
CRANE
DAM AXIS
8000
8000
ROAD
DAM TOP EL 1855.00
DAM TOP EL 1855.00
BREAST WALL
FRL EL 1850.00
FRL EL 1850.00
3500
AIR VENT PIPE
MDDL EL 1830.00
STOPLOG GATE GROOVE
0.8
1
0.1
MDDL EL 1830.00
1
STEEL LINER
EL. VARIES
?
?
?
TRUNION BEAM
EL 1816.00
NON- OVERFLOW SECTION
00
R90
RADIAL GATE
R25000
CREST EL 1810.00
HIGH PERFORMANCE CONC.
FLIP BUCKET
15°
MAX. T W L
30°
NOTES:
NORMAL T W L
1
RBL ±EL 1795.00
1 ALL DIMENSIONS ARE IN MM AND LEVELS IN METRES.
UNLESS OTHERWISE SPECIFIED.
1
BUCKET INVERT EL 1798.25
2 NO DIMENSION SHALL BE MEASURED FROM THIS
DRAWING.
1
1
1
FOUNDATION
GALLERY
1
CONCRETE APRON
EL ±1780.00
?
?
?
?
?
COMPACTED BACKFILL
PRE- FEASIBILITY REPORT DRAWING
DRAINAGE HOLE
90000
12250
7000 LONG ROCK ANCHORS
@1500 c/c STAGGERED
GROUT CURTAIN HOLES
DAM
SPILLWAY- MAXIMUM SECTION
SPILLWAY & NON-OVER FLOW
CROSS-SECTION
MAR.2004
F/DCE730/01/02
PLATE NO.- 6.8
4000 LONG 25 Ø ROCK BOLTS/
ANCHORS 1500 c/c
4000 LONG 25Ø ROCK BOLTS/
ANCHORS 2000 c/c
32Ø 5000 LONG ROCK BOLTS /
ANCHORS @ 2000 c/c
CONC.LINING 225THK.
100 THK. SHOTCRETE
WITH WIREMESH
HRT3.3 M. Ø
100 THK. SHOTCRETE
WITH WIREMESH
R.C.C. LINING 300 THK.
50/75 THK. SHOTCRETE
Ø1
00
00
7500
Ø60
00
CONC.LINING 750 THK.
1.5
1
0
00
Ø3
Ø600
0
32Ø 5000 LNG ROCK BOLTS/
ANCHORS @ 1500 c/c
5000
PRESSURE SHAFT
SECTION - DESILTING CHAMBER
TYP. SECTION - DIVERSION TUNNEL
TYP. SECTION - SURGE SHAFT
NOTE :-
2000 LONG 25 Ø ROCK BOLTS/
ANCHORS 1000 c/c
CONC. LINING 225 THK.
50 THK.
SHOTCRETE
1 ALL DIMENSIONS AREIN MILIMETRES AND LEVELS
2000 LONG 25 Ø ROCK BOLTS/
ANCHORS 1000 c/c(IF REQUIRED)
IN METRE UNLESS OTHERWISE SPECIFIED.
2 NO DIMENSION SHALL BE MEASURED FROM THIS
BACK FILL 750 THK.
DRAWING.
16
50
Ø
Ø3
300
STEEL LINER
00
20
Ø
50THK.
SHOTCRETE
PRE-FEASIBILITY REPORT DRAWING
Ø330
0
TYPICAL CROSS SECTION
TYP. SECTION - HRT
OF CONSTITUENTS OF WATER
TYP. SECTION - PRESSURE SHAFT
CONDUCTOR SYSTEM & DIVERSION TUNNEL
MAR.2004
00
F/DCE/730/01/02
PLATE 8.1
TO 220KV
FEEDER-1
TO 220KV
FEEDER-2
CVT
FUTURE BAY
CVT
CVT
SA
220KV
BUS-1
BUS
COUPLER
BUS CVT-1
S.A.
220KV
BUS-II
S.A.
S.A.
S.A.
BUS CVT-2
XLPE CABLE
XLPE CABLE
XLPE CABLE
GSU Tr.3Ø,49 MVA
GSU Tr.
GSU Tr.
UAT
11/ 220/ 3 KV
UAT
EX. Tr.
UAT
11 / 0.415KV,500KVA
EX. Tr.
SC
SA
EX. Tr.
PTSP
SC
SA
PTSP
SC
SA
PT
PT
PT
PT
PT
PT
PTSP
FOR
METERING &
PROTECTION
FOR
G-III
NGT
UNIT -III
64G1
64G2
G-II
NGT
UNIT -II
64G1
64G2
DVR DUPLICATE
PROTECTION
G-I
40MW,11 KV
NGT
UNIT -I
SINGLE LINE DIAGRAM
64G1
64G2
MANJIT
MAR, 2004
BINOD
V.K.SINGH
NH/DEM/LIN/SLD/01
00
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
ANNEXURES
Annexure-4.1
GEOLOGY OF THE AREA AROUND THE PROPOSED LINGZA
HEDROELECTIRIC PROJECT, TEESTA, BASIN, SIKKIM
INTRODUCTION
The Central Electricity Authority (CEA), as a part of an exercise estimate balance
hydroelectric potential in the county have identified 399 schemes with installed capacity
of about 1,50,000 MW in various river basins. The schemes thus identified were
subjected to ranking studies by applying different parameters. With result of ranking
studies, 162 schemes with probable installed capacity of 50,600 MW have been selected
to be taken up for preparation of Pre-Feasibility Reports (PFR’s) in first phase. The
schemes thus found feasible are proposed to be taken up for further development during
X and XI Five Year Plans. Out of 162 schemes selected to be taken up for preparation of
PFR’s in first phase, 10 are located in Teesta Basin in Sikkim.
The proposed Lingza Hydroelectric Project is one of the ten schemes that are
being taken up in first phase.
This run of river scheme envisages construction of
diversion dam/weir across Ringpi Chhu just down stream of powerhouse of Ringpi
Hydroelectric Project (27O 37’ 20” N: 88O 27’ 09” E; 78 0/6), a water conductor system
comprising 4 km long HRT and an underground powerhouse with probable installed
capacity of 160 MW located on left bank of Rangyong Chhu downstream of its
confluence with Ringpi Chhu and just north of proposed powerhouse of the Rangyong
Hydroelectric Project (27O 33’ 30” N: 88O 26’ 30” E, 78 0/6) upstream of Lingza.
REGIONAL GEOLOGY
The area around the proposed project is located in North Sikkim in Central
Crystalline axial region and is characterised by sharp crested snow bound mountains.
The ridges trend both in E-W and N-S directions. Teesta River, main draining agency of
Sikkim flows almost N-S in the area. The important tributaries of Teesta are Lach Chhu,
Toloung Chhu Chakung Chu, Ringpi Chu and their numerous tributaries. The valleys of
rivers are U-shaped and small streams have formed deep gorges. Vegetation is observed
up to EI . 3.900 m and many lakes are present at high altitudes.
The area around the proposed project has been mapped by Raina (1966)
Chakraborti and Banerjee (1982), Kumar et al (1984), Neogi et al (1984) and Neogi et al
(1986). The stratigraphic sequence established by the officers of GSI on the basis of
geological mapping is given below:
GROUP
LITHOLOGY
Gondwana
Grits, pebble cum boulder beds and
carbonaceous shales with occasional
coal
seams,
pegmatite,
quartzite
(Tourmaline bearing)
Daling
Inter bedded quartzite and chlorite
sericite phyllite / schist.
Lingza Granite
Quartzite/Biotite schist
Chungthang
Interbedded
quartzite
and
garnetiferous quartz biotite schist .
Calc – silicate rock / marble.
Garnet – kyanite – sillimanite – biotite
– quartz – schist.
Central
Crystalline
Gneissic
Banded gneiss with augen gneiss and
Complex
quartz – biotite gneiss.
Augen gneiss
The area falls within axial belt of Central Crystalline Zone of the North Sikkim
Himalayas where the rock types are mainly high grade gneisses (CCGC) having
interbands of metasedimentaries represented by calc – silicate / quartzite, high grade
schists and their fine inter laminations. The metasedimentaries occur as enclaves in the
high-grade gneisses in the area around the proposed project. All these rock types are
often intruded by discordant tourmaline bearing quartz veins and pegmatite.
2
The higher grade gneisses belonging to the Central Crystalline Gneissic Complex
(CCGC) Group vary in composition from a gneiss in which feldspar is predominant with
respect to quartz to quartz biotite gneiss in which feldspar is almost absent (Chakraborti
& Banerjee, 1982 and Neogi et al, 1986) with frequent association of garnet, tourmaline
and sillimanite / kyanite depending up on bulk chemical composition. While the former
type is well foliated with streaks of biotite, the latter is compact and poorly foliated. The
different types of these gneisses occurring at different structural levels are banded gneiss,
augen gneiss and streaky gneiss. A gradual passage from one type to other type, both
vertically and laterally, is rather common. The banded type is characterized by alternate
bands of quartz feldspar and biotite. These bands are at places stretched giving rise to
augens which are composed predominantly of single grains of feldspar or occassionally
quartz or their aggregate. The latter may be the result of metamorphic differentiation.
The augens are both deformed or undeformed and are invariably warped around by
biotite flakes defining the gneissic – foliation. The augens are stretched in the direction of
regional schistosity. The high grade gneisses are often intruded by tourmaline granite at
places and are associated with interbands of calc silicate – quartzite and garnetiferous
biotite schist and various other schists belonging to Chungthang Group. These have
locally been mapped as Kanchendzonga Gneiss, Chungthang Gneiss and Darjeeling
Gneiss by various workers earlier. According to Neogi et al (1986), there exists a
complete gradation both laterally and in down dip direction amongst above mentioned
gneisses. Their repetition is due to normal morphological variation and unlinked with
folding and thrusting. Various structura/textural types of these gneisses stated above
have also been observed in all the so called gneissic groups of Central Crystalline axial
region and have been referred as “High Grade Gneisses” of Central Crystalline Belt
which are also comparable to Darjeeling Gneisses of Lesser Himalayas.
The metasedimentaries of the area belonging to the Chungthang Group are
represented by a sequence of lithounits varying from calcareous to arrnaceous and
argillaceous lithofacies. These comprise calc silicate rocks, quartzite, high grade
micaceous schists occasional amphibolites and their fine grained interlaminations.
3
Neogi et al (1986) have clubbed together calc silicate rocks and quartzites as these
invariably occur together. Prominent bands of these rocks have been observed near Be
and Myong, north of Talung gompa and near Phygn and south of Kishong. These have
NE-SW trend are locally folded. Calcareous bands are easily identified by their greenish
colour within banded calc silicate / quartzite assemblage.
Apart from carbonates and
quartz, stumpy diopside and needle shaped tremolite have also been observed in these.
Garnet is generally leached giving rise to ferruginous staining. The quartzite is sericite
quartzite. Thin laminations of biotite are observed in quartzite at places. The rocks are
occasionally boudinaged. Carbonaceous biotite schist is found associated with southern
west calc silicate / quartzite band. Tourmaline bearing silica veins and pegmatites have
been observed occasionally intruding these rock types.
Daling Series of Raina (1966) having two zones viz phyllite zone and schistose
zone has been mapped as low grade metamorphites of Daling Group by Kumar et al
(1984). Daling Group comprises quartz – chlorite – sericite schist phyllite, quartz –
sericite schist, quartz chlorite phyllite often associated with thin interbands of quartzite.
The low grade sedimentaries belonging to Daling Series from southern part of the area
structurally underlie the Lingtze Granite Gneiss. Near Gyathang and at some other
places, the frequency of presence of garnet is slightly higher and its grain size is
controlled by the original bulk composition of the rock. According to Kumar et al (1984)
these metasedimentaries typically resemble the Gorubathan Formation of Daling Group
and hence been named “low Grade Daling” .
The granite gneiss which crops out near north of Senkhalang with an E-W trend
and northerly dips is also observed NW of Kendong and north of Karsang to form the
western limb of major antiformal closure. It occupies a unique position between lowgrade and high-grade metasedimentaries and is conformable to both. This granite is a
well foliated, coarse grained, sheared streaky biotite gneiss and occasionally contains
garnets. At places, augens of quartz and felspar stretched parallel to the foliation plane
are recorded within this unit.
Tourmaline and biotite bearing granites are the younger granites having
discordant relationship with high-grade
gneisses and high-grade metasedimentaries.
4
Compositionally, these are mainly quartz-feldspar rich leucogranite varying from coarse
grained to fine grained aplitic variety and shows disseminated flakes of biotite.
Tourmaline grains are observed generally in structural highs.
Gondwanas, according to Raina (1966) include grits, pebble cum boulder beds
and carbonaceous shales with ocassional coal seams. Pebble cum boulder bed forms the
marker horizon for Gondwana. Arkosic sandstone (felspathic grit) forms the other main
rock type. It is light yellow to dark grey coloured and is infolded within pebble beds.
STRUCTURE AND TECTONICS
The area exposes a sequence of gneissic rocks and associated metasedimentary
rocks of Central Crystalline Belt of North Sikkim and the structural fabric elements
observed pertain to features in the area predominated by high grade litho-facies which
have undergone polyphase deformation and metamorphism.
The primary structures
include compositional banding. The gneisses show lithological banding which can be
attributed to metamorphic differentiation. Bedded characters are observed only in calc
silicate – quartzite multilayers. The high-grade schists also show compositional banding
of alternate quartz rich and calc silicate rich bands. There is no evidence however to
indicate that these bandings are relict of primary sedimentary banding. However, broad
parallelism of the bandings and later imposed pervasive planes, S2, indicates that these
could be transposed.
The secondary structures include planar surfaces like gneisses foliation,
schistosity which include bedding schistosity (S1), regional schistosity (S2) and fracture
cleavage (S3). Bed Gneissic foliation forms the most prominent fabric element of high
grade metamorphic tectonics. These ‘S’ surfaces are marked by parallel lithological
layering and preferred dimensional orientation of minerals. The gneissic foliation in the
area generally trends NE-SW with moderate NW dips.
The metasedimentaries associated with the gneisses show a pervasive schistosity
where lithological layering is absent. The fabric is defined by preferred orientation of
tabular mica crystals.
Bedding schistosity (S1) is incipient and is parallel to the
5
compositional banding in metasedimentaries. This ‘S’ surface could not be related to any
tectonic structure in the area and could be described as another inherited fabric element
along with bedding. The regional schistosity (S2) is most pervasive structural element in
metasedimentaries. The axial plane schistosity is symmetrically oriented with respect to
axial planes of folds (F1). The trend of regional schistosity is parallel to the gneissic
foliation. The fracture cleavage (S3) is defined by discrete parallel fractures and are also
axial plane cleavages related to F2 crenulation. Due to varying styles of the F2 folds the
orientation of the S3 surfaces varies with respect to regional schistosity ‘S2’. The linear
structurs include striping lineation, pucker axis lineation and mineral lineation.
The area comprises a sequence of high-grade metasedimentaries and gneisses that
show evidence of having undergone polyphase deformation with complex pattern of folds
due to repeated super-imposition of successive fold forms.
Grouping of different
generations of folds on the basis of styles and spatial attitudes has not been possible due
to their complex forms.
Broadly three generations of fold movement could be
deciphered. F1 folds, the earliest recognizable folds have compositional banding and
bedding schistosity as their form surface and are of tight isoclinal reclined to inclined
folds. Their style and spatial orientation as observed in the area is comparable to these
observed in Daling Group of rocks exposed south of present area. The F2 folds have
involved all the above mentioned surfaces. These show a variety of styles ranging from
appressed isoclinal folds to open warps, small-scale chevron folds or multi-hinged
disharmonic folds. The calc silicate / marble quartzite bands show regional warps along
NW-SE axis due to this phase of folding. The effects of F3 folds have been observed
mainly on regional scale. On macro scale they are of the nature of minor broad warps
that have folded the weakly developed S3 planes. No planar surface related to this phase
of folding are apparent. F3 warps are only locally developed in high-grade
metasedimentaries and have N-S oriented axis.
Zones of intense mylonitisation have been observed in the gneisses but there is no
basis to conclude that these could represent planes of thrusting on the basis of evidence
like distinct truncation of lithounits reorientation of major folds (F2), development of
small scale faults etc.. Chakraborty and Banerjee (1982) have marked NNW-SSE
trending thrust near Manual and NW-SE trending thrust near Naga. Neogi et al (1984)
6
observed minor slips and faults occurring commonly within gneisses and
metasedimentaries along S3 planes near hinge zone of F2 folds. The slips are more
common where folds are tight. A meso scale normal vertical fault trending N-S has been
found with in low grade metasedimentaries about 2 km north of Brang village.
Silicification, chloritization and mylonitization are found along this fault plane.
SEISMOTECTONICS AND SEISMICITY
Seismotectonically the area under reference is located in Axial Belt of Central
Crystalline Zones of North Sikkim. According to Narula at al (2000) the northern part of
the area is occupied by poorly metamorphosed sequence (Tethyan) folded during
Himalayan Orogeny. Similar tectonic pockets representing Gondwana sequence crop out
within Rangit Window as well as lenticular tectonic wedge along the Main Boundary
Thrust (MBT). The northern Tethyan Belt is followed successively to the south by highgrade complex of Central Crystallines and low-grade complex of Lesser Himalayan rock
worked during Himalayan Orogeny.
The latter packet is exposed within tectonic
windows as well as linear belt between Main Central Thrust (MCT) and MBT. South of
MBT the foot hill region is occupied by sequence of frontal belt affected by the terminal
phase of the Himalayan Orogeny. Adjacent Peninsular tract is covered by Quaternary
alluvial fill along the foredeep.
In the southwestern part, Peninsular element is
represented by small inliers of gneissic complex and Rajmahal Trap. The basement
gneissic complex, representing a part of Shillong massif along with marine transgressive
cover are present in south eastern part. Like other parts of Himalayas, this area is the high
grade Central Crystallines from comparatively lower grade Lesser Himalayan packages
which are separated from the Siwalik Belt by MBT. At places, particularly towards east,
several subsidiary thrust are presented between MCT and MBT. Besides these, several
approximately N-S trending gravity faults are present particularly within northern
Tethyan Belt and the southern foot hill belt. Within northern Tethyan Belt these N-S
faults define some well knows graben structures, viz. Pum Qu Graben and Yadong Gulu
Graben. In the former, the faults affecting the Quaternary glacial deposits are clearly
7
evident. The latter graben is considered to be longest one in Tibetan Plateau and is
segmented into several N-S smaller grabens. The foredeep tract east of Munger –
Saharsha Ridge is known as Purnia Basin where Gondwana sequence has developed over
the rifted basement. The structural configuration of this foredeep region is architectured
by a set of almost N-S trending faults resulting in development of alternate horst and
graben structures. The westernmost is the Munger – Saharsha Ridge which alternates
towards east by Purnia Basin. The western and eastern boundaries of Purnia Basin are
defined by the Munger - Saharsha Ridge Morginal Fault (MSRF) and Malda Kishanganj
Fault (MKF). The former fault known as Sainthia – Brahmani Fault further south, along
which cluster of earthquakes have been recorded by the Geological Survey of India, has
been found seismically active. Further east the prominent tectonic feature is the Rangpur
Ridge bound by MKF and Jangipur – Goribandha Fault, Teesta Fault and Katihar –
Nailphamari Fault. Several subsidiary faults, parallel to Teesta Fault forming grabens are
reported from ridge.
Gondwana sequence is found to have developed within these
grabens. Along with transverse faults, several lineaments cutting across the Himalayan
belt are also present.
These exhibit NE and NW trends. The NE trending Azun
Lineament considered to be trace of northern extension of East Patna Fault,
Kanchanjunga Lineament and NW-SE trending Teesta and Purnia lineaments are other
prominent transverse lineaments. The basement contours corroborate the presence of
Purnia Saddle and Rangpur Ridge.
Most of the earthquakes in this area are shallow focus (<40 km) earthquakes and
have magnitude range of 4.5 to 5 .5 in general. Considering the spatial distribution of
seismic activity the region can be broadly divided into three blocks. The Central Main
Himalayan block with considerable seismicity separates the northern Tethyan Block and
southern Foredeep Block with subdued seismicity. Of the 51 seismic events recorded in
the region over a period of 58 years between 1935 and 1993, five had magnitude more
than 5.5 i.e. ranging between 5.5 and 6.0 and rest 46 had magnitude between 4.5 and 5.5
and 8 events with depth of focus >40 km. The depth of focus for one event, that of
21.05.1935, has been interpreted to be 140 km. As such observed seismic events are
mostly concentrated in Main Himalayan Belt. Keeping in view the seismotectonic set up
and seismicity, the area has been kept in Zone – IV as per Map of India Showing Seismic
Zones (IS - 1893 (part –I) : 2002).
8
GEOTECHNICAL APPRAISAL
The proposed Lingza Hydroelectric Project is located downstream of Ringpi
Hydroelectric Project. As per geological map, the area around the proposed diversion
structure exposes Banded Gneisses with augen gneisses and quartzite and biotite gneisses
belonging of Central Crystalline Gneissic Complex. The rocks are well foliated and
jointed. Keeping in view the general topography of the area It is suggested that type of
structure and its final site be selected after assessing the thickness of overburden the
riverbed and on the abutment and availability of bed rock for locating intake structure for
the water conductor system. The water conductor system comprising 4 km long HRT is
aligned on the left bank of Rinpgi Chhu. The rocks expected to be encountered in the
proposed HRT include banded gneisses with augen gneiss belonging to CCGC in initial
and final reaches and calc silicate / marble and quartzite / biotite quartzite schist
belonging to Chungthan Group of metasediments along with augen gneisses of CCGC in
middle reaches. The rocks of CCGC and Chungthang Group are interbanded. These are
well foliated and jointed.
One suspected thrust fault between rocks of CCGC and
Chungthang Group may be encountered in downstream reaches.
The tunneling
conditions are likely to be good to fair in general excepted in the influence zone of the
thrust or where local faults and shear / mylonitised zones are encountered where poor
conditions can be expected. Similarly water ingress along with poor conditions can be
expected in calc silicate / marble rock is these are cavernous and water charged. The
powerhouse with probable installed capacity is proposed as an underground structure on
the left bank of Rangoyong Chhu upstream of Lingza. The rocks exposed around the site
of proposed structure are banded and augen gneisses and quartz – biotite gneisses of
CCGC. These are expected to provide fair tunneling media and supports be designed
accordingly. However, presence of local poor rock zones can not be ruled out. The
proposed project is located in Zone IV as per Map of India Showing Seismic Zones (IS –
1893 (part-I) : 2002).
Therefore, required seismic coefficient will have to be
incorporated in the designs of appurtenant structures of the project. This preliminary
geotechnical appraisal is without field visit to site.
9
REFERENCE
Chakraborti, B., and Banerjee, H., (1982). Geology and Structure of the Area around
Chungthang - Mangan – Tolung, North Sikkim. Unpubl. Prog. Rep. Geological Survey
of India, F.S. 1980-81.
Kumar, J.P., and Mitra, P.K. (1984). Geology and Structure of the Area Around
Sakkyong, Mangan, Dikchu, Lingi and Mangka Covering Parts of North South and East
Sikkim. Unpubl. Prog. Rep. Geological Survey of India, F.S. 1982-83.
Narula, P.L. Acharayya, S.K., and Banerjee, J., (Eds) (2000). Seismotectonic Atlas of
India and its Environs, GSI Publication.
Neogi S., Purkaint, B. and Samaddar, A.K. (1984). Geology of the Area Around
Tashiding – Lapdang – Maidang La-Karshang – Lampokhari – Khungre, West District,
Sikkim. Unpubl. Prog. Rep. Geological Survey of India, F.S. 1982-83.
Neogi, S., Kumar, J.P., Mitra, N.D., Samaddar, A.K. and Dawande, A.K. (1986).
Geology of the Area Around Tolung – Thijp, - Kishong, North Sikkim District, Sikkim.
Unpubl. Geological Survey of India Prog. Preg., F.S. 1983-84.
Raina, U.K. (1966).
Geological Mapping in the western part of Sikkim. Unpubl.
Geological Survey of India, Rep., F.S. 1965-66.
10
Annexure-4.2
TECHNICAL REPORT ON SEISMIC HISTORY AND SEISMICITY OF THE
TEESTA BASIN OF SIKXKIM COVERING PROPOSED SITES FOR
HYDROELECTRIC SCHEMES
Historical and instrumentally recorded data on earthquakes show that the whole area of
the proposed sites for hydroelectric schemes at Dikchu, Rongni Storage, Panan,
Namlum, Zedang, Teesta St-I, Ringpi, Lingza, Rukel and Rangyong in Sikkim lies in a
region liable to damage due to moderate to great earthquakes. Noteworthy earthquakes
which affected the region in the past are (i) the Cachar earthquake of 10.01.1869
(Magnitude= 7.5 on Richter scale), (ii) the Shillong plateau earthquake of 12.06.1897
(Magnitude= 8.7), (iii) the Dhubri earthquake of 02.07.1930 (Magnitude= 7.1), (iv) the
Bihar-Nepal Border earthquake of 15.01.1934 (Magnitude= 8.3), (v) the Assam
earthquake of 15.08.1950 (Magnitude= 8.5) and (vi) the Nepal-India Border earthquake
of 21.08.1988 (Magnitude= 6.4). The 1897 earthquake had its epicentral tract in and
around Shillong where there was considerable damage to lives and property, in addition
to other effects of very strong ground shaking. One of the significant observations made
on this earthquake was that boulders were thrown out vertically upwards from their
original places showing that the force of earthquake motion exceeded the force due to
gravity, at least momentarily. The earthquake was followed by a large number of
aftershocks.
In addition to the above significant earthquakes, the region has experienced
several earthquakes of lesser intensity originating within a radius of 450 km around
Shillong and neighbouring regions. A list of important earthquakes from I.M.D.
catalogue occurred in the region bounded by Lat. 25.00 to 30.00°N and Long. 86.00 to
91.00°E for the period 1505 to 2001 is enclosed.
The occurrence of earthquakes in Sikkim region is broadly associated with the
tectonic activity along the well-known faults in the Himalayas such as the Main
Boundary Thrust (MBT) and the Main Central Thrust (MCT). Besides, earthquakes
occurring along some other faults namely Malda-Kishanganj Fault, Tista Fault, PurniaEverest Lineament, Katihar-Nailphamani Fault, Dhubri Fault etc. have also affected the
region.
In the seismic zoning map of India prepared by a committee of experts under the
auspices of Bureau of Indian Standards (BIS: 1893: Part I 2002), the entire area of
Sikkim has been placed in the zone IV. The seismic zone IV is broadly associated with
a seismic intensity VIII on Modified Mercalli (MM) scale. It may be mentioned that the
seismic intensity VIII corresponds to a horizontal ground acceleration range of 51350cm/sec2 or an average acceleration of 172cm/sec2 in any direction. The ground
acceleration and hence the intensity of an earthquake at a place depends on magnitude
of earthquake, distance from the focus, duration of earthquake, type of underlying soil
and its damping characteristics and liquefaction potential. The damage to the buildings
1
founded on sandy soil is higher than that in the similar type of buildings having their
foundation on hard bedrock. Also, the damage will be higher for higher magnitude and
long duration earthquakes, less epicentral distance soft soil conditions and area with
high liquefaction potential.
Presently, there is no scientific technique available anywhere in the world to predict
occurrence of earthquakes with reasonable degree of accuracy with regard to space,
time and magnitude. It is, therefore suggested that appropriate steps may be taken to
ensure that the dwellings and other structures in the region are designed and constructed
as per guidelines laid down by Bureau of Indian Standards (BIS) to minimize the losses
caused by earthquakes. Suitable seismic design parameters may be adopted as per
recommendations of National Committee on Seismic Design Parameters (NCSDP)
for designing and engineering Hydroelectric Projects.
EXPLANATION OF COMPUTER OUTPUT (IMD CATALOGUE)
1.
2.
3.
4.
“O” – Time means time of Origin of Earthquake in UTC.
“Depth” means Focal Depth in Kilometers. If depth is reported as 33, it means
that the earthquake is located in the crust but its focal depth could not be
determined.
“MAG” means magnitude on Richter scale.
“Zero” under any column means that the parameters have not been determined.
2
MODIFIED MERCALLI INTENSITY SCALE (ABRIDGED)
CLASS OF REMARKS
EARTHQUAKE
I
Not felt except by a very few under specially favourable circumstances.
II
Felt only by a few persons at rest, specially on upper floors of buildings; and
delicately suspended objects may swing.
III
Felt quite noticeably indoors, specially on upper floors of buildings but many
people do not recognize it as an earthquake; standing motor cars may rock
slightly; and vibration may be felt like the passing of a truck.
IV
During the day felt indoors by many, outdoors by a few, at night some
awakened; dishes, windows, doors disturbed; walls make creaking sound,
sensation like heavy truck striking the building; and standing motor cars rocked
noticeably.
V
Felt by nearly everyone; many awakened; some dishes, windows, etc. broken; a
few instances of cracked plaster; unstable object overturned; disturbance of
trees; polls and other tall objects notices sometimes; and pendulum clocks may
stop.
VI
Felt by all, many frightened and run outdoors; some heavy furniture moved; a
few instances of fallen plaster or damaged chimneys and damaged slight.
VII
Everybody runs outdoors, damage negligible in buildings of good design and
construction; slight to moderate in well built ordinary structures; considerable
in poorly built or badly designed structures; and some chimneys broken, noticed
by person driving motor cars.
VIII
Damage slight in specially design structures; considerable in ordinary but
substantial buildings with partial collapse; very heavy in poorly build structures;
panel walls thrown out of framed structured; falling of chimney, factory stacks,
columns, monuments and walls; heavy furniture overturned, sand and mud
ejected in small amounts; changes in well water; and disturbs person driving
motor cars.
IX
Damage considerable in specially designed structures: well designed framed
structures thrown out of plumb; very heavy in substantial buildings with partial
collapse; buildings shifted off foundations; ground cracked conspicuously; and
underground pipes broken.
3
X
XI
XII
Some well built wooden structures destroyed; most masonry and framed
structures with foundations destroyed; ground badly cracks; rails bent;
landslides considerable from river banks and steep slopes; shifted sand and mud;
and water splashed over banks.
Few, if any, masonry structures remain standing; bridges destroyed; broad
fissures in ground, underground pipelines completely out of services; earth
slumps and landslips in soft ground; and rails bent greatly.
Total damage; waves seen on ground surfaces; lines of sight and levels distorted;
and objects thrown upward
4
LIST OF EARTHQUAKES FROM IMD CATALOGUE OCCURING BETWEEN LAT25 . 00 TO 30 . 00
DEG. AND LONG 86 . 00 TO 91 . 00DEG. E FOR THE PERIOD 1505 TO 2001
DATE
O-TIME
LAT
LONG
DEPTH
Y
M
D
Hr
Mn
Sec
Deg-N
Deg-E
Km
1833
1834
1834
1842
1842
1843
1849
1852
1897
1899
1909
1918
1923
1923
1926
1930
1930
1930
1930
1930
1930
1930
1932
1932
1933
1934
1934
1934
1935
1936
1936
1936
1936
1937
1938
1938
1938
1939
8
7
7
2
11
8
2
5
6
9
2
2
4
9
12
7
7
7
7
7
7
7
3
3
3
1
1
7
5
5
6
6
9
8
1
2
4
6
26
8
21
5
11
10
27
0
12
25
17
4
24
9
4
2
3
4
4
8
8
13
24
25
6
15
16
21
21
30
9
18
7
15
29
26
13
4
0
0
0
21
0
0
0
0
11
0
0
17
22
22
11
21
0
18
21
4
9
14
16
4
13
8
4
0
4
7
0
14
2
11
4
12
1
22
0
0
0
15
0
0
0
0
6
0
0
54
3
3
15
3
19
54
34
32
43
0
8
29
5
43
59
0
22
8
2
56
30
36
13
10
10
36
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
49 . 0
6.0
42 . 0
23 . 0
34 . 0
5.0
44 . 0
.0
24 . 0
.0
12 . 0
44 . 0
32 . 0
38 . 0
25 . 0
22 . 0
.0
31 . 0
38 . 0
42 . 0
27 . 0
49 . 0
48 . 0
8.0
43 . 0
17 . 0
.0
27 . 50
25 . 80
25 . 80
25 . 00
25 . 00
27 . 00
27 . 00
27 . 00
25 . 90
27 . 00
27 . 00
29 . 60
29 . 60
25 . 30
29 . 60
25 . 80
25 . 80
25 . 80
25 . 80
25 . 80
25 . 80
25 . 80
25 . 80
30 . 00
25 . 70
26 . 60
28 . 00
25 . 80
28 . 80
25 . 70
27 . 50
26 . 60
27 . 50
30 . 00
27 . 50
28 . 00
26 . 00
28 . 50
86 . 50
89 . 40
89 . 40
87 . 00
90 . 00
88 . 30
88 . 30
88 . 00
91 . 00
88 . 30
87 . 00
87 . 80
87 . 80
91 . 00
87 . 80
90 . 20
90. 20
90 . 20
90. 80
90 . 80
90. 80
90 . 80
90 . 20
89 . 20
90 . 50
86. 80
86 . 00
89 . 40
89 . 30
90 . 50
87 . 00
90 . 30
87 . 00
90 . 00
87 . 00
90 . 50
91 . 00
86 . 50
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
140 .
0.
0.
0.
0.
0.
0.
0.
0.
0.
5
MAG
7.5
6.3
6.0
5.5
6.5
5.5
6.0
6.5
8.7
6.0
5.0
6.0
5.5
7.1
6.0
7.1
5.5
5.5
5.5
5.5
5.5
5.5
5.5
5.5
5.8
8.3
5.6
5.5
6.3
5.3
5.5
5.8
5.7
5.8
5.8
5.7
5.2
5.7
1940
1945
1949
1950
1951
1951.
1952
1952
1955
1958
1959
1960
1960
1961
1961
1963
1964
1964
1964
1964
1964
1965
1965
1967
1968
1968
1969
1970
1971
1971
1971
1972
1972
1973
1973
1974
1974
1975
1975
1975
1975
1975
1975
1976
1977
1978
1978
1979
1979
1979
8
5
12
2
4
5
3
11
3
11
6
7
8
9
12
2
2
3
4
8
11
1
1
3
8
10
11
7
10
10
12
8
11
3
8
3
3
1
2
4
6
11
11
9
6
10
10
4
4
6
2
19
10
26
7
28
6
19
27
23
10
29
21
29
25
22
1
27
13
30
9
12
12
2
18
28
5
25
24
31
4
21
6
22
1
24
24
23
6
24
24
21
26
14
5
14
23
2
11
19
3
5
19
3
20
15
9
10
14
20
4
10
3
22
11
1
11
23
3
2
16
13
13
11
14
17
20
1
8
15
8
14
10
1
14
14
16
1
6
1
15
13
15
6
19
18
14
1
16
16
3
2
37
35
29
59
11
23
38
15
25
42
29
36
19
32
28
3
19
35
12
32
55
47
18
48
25
35
59
54
38
4
56
6
5
16
17
37
39
35
38
49
2
43
21
48
36
16
8
29
59 . 0
53 . 0
14 . 0
48 . 0
12 . 0
19 . 0
23 . 0
28 . 0
43 . 0
48 . 0
15 . 0
44 . 6
4.9
30 . 0
10 . 0
30 . 0
19 . 2
41 . 1
57 . 3
7.3
51 . 9
24 . 1
18 . 1
13 . 0
58 . 0
30 . 1
13 . 7
26 . 0
6.3
48 . 2
.2
34 . 2
13 . 5
57 . 4
15 . 5
1.1
35 . 3
42 . 6
48 . 7
51 . 2
28 . 1
27 . 9
31 . 1
51 . 6
37 . 4
48 . 9
50 . 4
46 . 5
12 . 6
8.4
6
28 . 00
25 . 10
26 . 00
28 . 00
25 . 90
29 . 00
29 . 60
29 . 80
29 . 90
28 . 79
30 . 00
26 . 90
27 . 00
28 . 00
27 . 00
27 . 20
27 . 30
27 . 13
27 . 52
27 . 36
29 . 53
27 . 40
27 . 31
28 . 70
26 . 42
27 . 57
27 . 66
25 . 72
28 . 30
26 . 18
27 . 92
27 . 33
26 . 88
28 . 12
29 . 59
27 . 66
27 . 63
27 . 44
27 . 95
27 . 44
27 . 74
26 . 96
28 . 15
29 . 81
26 . 07
27 . 66
28 . 56
26 . 46
25 . 98
26 . 74
90 . 50
90 . 90
89 . 00
90 . 50
90 . 50
87 . 00
90 . 80
86 . 60
90 . 20
86 . 94
91 . 00
90 . 30
88 . 50
87 . 00
90 . 00
87 . 10
87 . 78
89 . 36
90 . 17
88 . 21
86 . 04
87 . 84
87 . 68
86 . 38
90 . 62
86 . 03
90 . 24
88 . 58
87 . 19
90 . 65
87 . 95
88 . 01
88 . 43
87 . 15
89 . 17
86 . 00
86 . 01
88 . 37
87 . 67
87 . 04
87 . 50
86 . 54
87 . 80
89 . 57
88 . 43
87 . 33
86 . 78
90 . 68
88 . 84
87 . 48
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
11 .
29 .
0.
0.
0.
33 .
29 .
1.
21 .
33 .
23 .
18 .
20 .
22 .
37 .
13 .
32 .
57 .
33 .
29 .
33 .
59 .
33 .
63 .
0.
3.
33 .
63 .
26 .
33 .
0.
33 .
75 .
0.
0.
33 .
33 .
33 .
1.
5.2
6.1
6.0
6.0
6.8
6.0
5.5
6.0
6.3
5.5
5.7
6.5
5.5
5.5
5.5
5.2
4.8
5.0
5.2
5.1
5.0
5.8
5.2
4.8
5.1
4.9
5.0
5.1
4.8
4.7
5.2
4.5
4.4
5.0
4.9
5.4
4.7
4.5
4.7
4.9
4.8
4.9
5.0
5.4
4.7
4.8
4.4
4.4
4.7
5.2
1979
1979
1980
1980
1980
1980
1981
1981
1982
1982
1982
1982
1982
1982
1983
1983
1983
1984
1985
1985
1985
1985
1986
1986
1986
1986
1986
1986
1986
1987
1987
1987
1987
1987
1987
1987
1987
1987
1987
1987
1987
1987
1987
1988
1988
1988
1988
1988
1988
1988
10
11
6
11
12
12
2
11
1
2
4
6
7
8
10
12
12
1
5
6
6
10
1
1
2
2
4
10
12
4
4
5
6
9
9
9
9
10
10
11
12
12
12
1
1
1
3
4
4
4
17
16
11
19
22
26
9
21
28
26
5
20
6
18
16
16
23
25
25
7
17
2
7
10
2
10
12
25
1
23
25
10
22
25
26
29
29
6
22
25
6
11
12
10
10
19
27
9
20
25
1
19
5
19
4
5
15
4
7
0
2
15
6
18
22
15
19
23
0
18
21
16
20
3
0
12
12
21
19
9
22
5
23
23
1
17
21
22
21
19
23
6
5
6
6
11
5
12
6
16
44
17
25
0
36
19
49
25
18
5
19
29
13
1
3
15
35
49
28
23
52
33
20
46
13
56
44
25
14
5
13
10
6
16
3
30
12
18
23
20
29
39
49
18
31
23
56
57
40
4
22 . 2
27 . 4
15 . 4
44 . 5
8.0
44 . 9
21 . 6
5.6
7.6
47 . 5
41 . 1
19 . 8
32 . 0
7.6
14 . 5
40 . 1
44 . 2
44 . 6
18 . 7
59 . 0
49 . 0
50 . 3
.4
30 . 9
50 . 7
23 . 0
2.2
30 . 4
29 . 0
56 . 8
47 . 0
42 . 3
53 . 5
29 . 0
3.0
28 . 3
30 . 0
17 . 2
56 . 0
40 . 0
44 . 0
40 . 0
.0
35 . 0
42 . 7
51 . 0
30 . 0
55 . 7
25 . 8
3.7
7
27 . 97
27 . 95
25 . 79
27 . 40
26 . 67
29 . 08
27 . 20
29 . 52
25 . 47
25 . 79
27 . 38
26 . 24
25 . 88
27 . 04
29 . 51
28 . 37
25 . 87
27 . 49
27 . 60
26 . 87
25 . 65
27 . 19
27 . 40
28 . 65
27 . 92
28 . 15
28 . 63
26 . 12
28 . 30
27 . 93
25 . 30
28 . 99
28 . 40
29 . 84
29 . 82
29 . 91
29 . 70
29 . 90
27 . 07
27 . 70
27 . 00
26 . 04
29 . 80
29 . 75
29 . 89
27 . 80
27 . 10
29 . 84
27 . 02
26 . 90
87 . 62
88 . 69
90 . 31
88 . 80
89 . 59
88 . 88
89 . 76
89 . 12
90 . 89
90 . 62
88 . 84
89 . 97
90 . 31
89 . 26
90 . 31
86 . 65
87 . 91
86 . 10
88 . 48
90 . 21
90 . 20
89 . 73
88 . 43
86 . 56
86 . 45
87 . 86
86 . 57
88 . 26
87 . 80
87 . 01
88 . 46
87 . 26
87 . 17
90 . 37
90 . 45
90 . 41
90 . 41
90 . 42
89 . 06
86 . 17
88 . 52
90 . 92
90 . 40
90 . 29
90 . 44
88 . 80
88 . 42
86 . 87
86 . 72
86 . 54
33 .
39 .
68 .
1.
33 .
66 .
16 .
50 .
33 .
48 .
9.
33 .
8.
51 .
33 .
116 .
33 .
11 .
33 .
33 .
22 .
45 .
41 .
63 .
33 .
87 .
33 .
33 .
10 .
48 .
10 .
33 .
33 .
19 .
33 .
33 .
46 .
10 .
19 .
33 .
42 .
57 .
45 .
50 .
10 .
33 .
70 .
33 .
55 .
79 .
4.6
4.6
4.9
6. 0
4.4
4.5
4.9
4.8
4.4
4.6
5.0
4.5
5.0
4.6
4.5
4.2
4.3
4.6
4.6
4.8
4.6
4.4
4.7
5.5
4.5
4.7
4.8
.0
.0
4.7
.0
4.5
4.1
5.1
4.4
4.6
4.5
4.7
4.2
4.5
.0
4.6
4.8
4.7
4.7
4.3
4.1
4.4
5.4
4.7
1988
1988
1988
1988
1988
1988
1988
1988
1988
1988
1988
1988
1988
1988
1988
1989
1989
1989
1989
1989
1989
1989
1989
1989
1990
1990
1990
1990
1990
1990
1990
1990
1990
1990
1991
1991
1991
1991
1991
1991
1991
1991
1991
1991
1992
1992
1992
1992
1992
1992
5
5
5
8
8
8
8
8
9
9
9
12
12
12
12
2
4
4
5
5
6
7
10
11
1
1
2
2
2
3
5
5
7
10
1
3
3
6
8
8
9
9
10
12
3
4
4
4
7
7
10
26
28
20
20
22
24
29
1
2
27
10
13
24
27
12
9
16
10
22
11
30
10
19
9
10
18
22
23
1
6
19
13
29
5
4
15
8
7
19
25
27
30
21
7
1
4
20
24
30
7
16
23
23
23
11
9
12
22
6
19
15
6
13
2
23
2
0
23
19
13
21
4
22
2
23
18
13
14
18
10
2
11
12
14
0
4
18
11
22
19
11
13
19
22
13
17
19
6
8
16
30
13
9
38
34
55
12
4
35
10
24
29
32
56
44
31
2
20
24
42
4
10
11
29
1
12
33
25
47
30
18
50
6
50
55
28
59
36
28
26
56
13
52
41
41
43
22
24
24
16 . 1
5.5
12 . 0
10 . 1
56 . 0
34 . 7
34 . 3
17 . 0
11 . 3
34 . 3
10 . 0
31 . 4
17 . 3
22 . 0
1.8
57 . 0
36 . 3
33 . 0
34 . 0
31 . 0
45 . 7
44 . 0
56 . 0
34 . 0
21 . 8
21 . 7
48 . 3
16 . 6
19 . 3
28 . 0
9.0
57 . 0
11 . 0
28 . 0
8.0
38 . 0
18 . 2
57 . 8
29 . 1
41 . 0
49 . 3
40 . 8
57 . 0
45 . 1
50 . 8
3.9
20 . 7
59 . 7
17 . 6
46 . 6
8
25 . 32
27 . 45
28 . 00
26 . 72
26 . 90
26 . 61
26 . 77
26 . 39
26 . 80
26 . 56
27 . 19
26 . 38
27 . 14
26 . 90
27 . 98
30 . 00
29 . 11
29 . 20
27 . 70
27 . 38
26 . 39
30 . 00
28 . 36
29 . 00
28 . 15
26 . 52
29 . 39
29 . 14
29 . 38
28 . 70
29 . 99
25 . 40
28 . 20
27 . 60
28 . 90
28 . 10
28 . 34
26 . 30
25 . 27
26 . 80
26 . 70
29 . 90
26 . 00
27 . 79
29 . 40
27 . 40
28 . 10
25 . 80
29 . 30
29 .60
90 . 88
88 . 61
89 . 70
86 . 63
86 . 70
86 . 74
86 . 44
87 . 50
86 . 53
86 . 48
88 . 37
86 . 68
87 . 97
88 . 00
87 . 86
89 . 86
90 . 02
89 . 70
87 . 20
87 . 86
90 . 70
90 . 50
87 . 49
89 . 70
88 . 11
86 . 67
89 . 95
90 . 02
90 . 02
88 . 40
89 . 98
90 . 93
86 . 90
89 . 10
87 . 92
89 . 20
87 . 55
90 . 37
88 . 66
90 . 70
88 . 40
90 . 40
88 . 60
87 . 96
89 . 40
87 . 10
88 . 00
90 . 60
90 . 20
90 . 20
33 .
42 .
33 .
65 .
38 .
33 .
41 .
33 .
33 .
33 .
28 .
33 .
52 .
41 .
38 .
53 .
10 .
33 .
33 .
4.
50 .
33 .
38 .
33 .
35 .
66 .
10 .
54 .
10 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
64 .
33 .
10 .
10 .
33 .
33 .
33 .
65 .
113 .
33 .
33 .
55 .
33 .
14 .
4.4
4.7
.0
6.4
.0
4.3
4.7
4.5
4.5
4.3
5.0
.0
4.4
4.4
4.6
.0
5.1
.0
.0
5 .0
4.5
.0
4.7
4.4
5.7
4.4
4.5
4.9
4.3
4.2
4.2
.0
4.5
.0
.0
.0
4.7
4.0
4.7
.0
.0
.0
.0
4.7
4.3
4.3
4.9
4.2
4.8
5.9
1992
1992
1992
1992
1992
1992
1992
1993
1993
1993
1993
1993
1993
1993
1993
1993
1993
1994
1994
1994
1995
1995
1995
1995
1995
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1996
1997
7
7
7
7
8
8
8
2
3
3
3
3
7
7
9
12
12
1
4
5
1
1
8
12
12
1
1
3
4
5
5
5
5
7
7
7
7
7
7
7
7
8
8
9
9
10
10
12
12
1
30
30
30
30
4
8
9
15
3
20
20
31
3
9
5
14
14
16
15
25
1
12
8
6
11
25
25
23
26
10
11
11
14
3
3
3
3
4
6
13
22
3
18
13
25
3
14
30
30
22
9
13
17
19
22
19
22
14
5
14
21
13
2
16
6
2
2
14
14
7
19
23
16
0
9
7
7
16
16
9
3
7
5
7
10
10
10
18
8
8
15
7
2
3
17
1
14
11
15
11
7
36
28
6
50
50
34
29
17
51
26
44
0
23
5
27
27
22
28
38
36
39
52
50
49
15
15
7
31
7
58
27
41
0
10
19
49
11
12
29
54
12
48
41
41
29
49
8
16
12
39 . 1
42 . 0
53 . 9
13 . 3
3.0
42 . 6
46 . 4
40 . 8
31 . 0
59 . 7
39 . 4
10 . 1
22 . 2
17 . 3
54 . 6
44 . 4
44 . 4
38 . 3
48 . 7
53 . 7
13 . 6
51 . 0
48 . 8
33 . 0
36 . 0
19 . 3
13 . 0
34 . 2
3.0
1.8
50 . 2
11 . 2
8.9
28 . 9
33 . 8
42 . 9
50 . 5
4.6
39 . 4
4.0
7.0
6.0
.0
8.6
17 . 2
3.1
12 . 7
18 . 9
29 . 5
4.4
9
29 . 90
29 . 80
30 . 00
29 . 80
29 . 90
29 . 90
28 . 70
25 . 90
25 . 40
29 . 10
29 . 00
29 . 10
28 . 30
26 . 80
27 . 20
28 . 40
28 . 40
26 . 40
25 . 90
26 . 60
27 . 80
29 . 40
26 . 40
25 . 20
27 . 60
28 . 00
28 . 40
27 . 20
27 . 80
30 . 00
29 . 90
29 . 90
29 . 70
29 . 90
29 . 90
30 .00
29 . 90
30 . 00
29 . 90
29 . 90
30 . 00
30 . 00
25 . 80
27 . 00
27 . 40
28 . 20
29 . 90
27 . 43
27 . 23
25 . 60
90 . 30
90 . 30
90 . 40
90 . 20
90 . 40
90 . 30
86 . 50
87 . 50
90 . 20
87 . 30
87 . 40
87 . 30
86 . 60
86 . 00
87 . 30
86 . 80
86 . 80
89 . 10
90 . 50
87 . 80
87 . 60
88 . 20
90 . 40
91 . 00
87 . 50
87 . 00
86 . 90
88 . 30
87 . 60
88 . 10
88 . 10
88 . 10
87 . 90
88 . 10
88 . 20
88 . 20
87 . 80
88 . 10
87 . 90
88 . 10
88 . 00
88 . 20
90 . 10
88 . 20
88 . 50
87 . 50
88 . 20
86 . 63
86 . 50
90 . 30
33 .
33 .
33 .
33 .
10 .
33 .
37 .
30 .
33 .
12 .
21 .
20 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
48 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
33 .
33 .
33 .
33 .
37 .
33 .
33 .
4.2
4.4
4.5
4.3
4.2
4.3
4.3
5.0
4.5
5.8
5.0
5.1
4.7
4.6
4.5
4.8
4.8
3.9
4.2
4.6
4.9
4.9
4.4
4.5
4.0
5.2
4.4
4.0
5.2
4.8
4.8
4.3
4.1
4.1
5.0
4.3
4.1
4.9
3.8
4.3
4.5
4.1
4.4
4.5
5.0
4.5
4.4
5.0
3.6
.0
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1997
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1998
1
3
3
4
4
5
7
7
7
7
8
8
9
10
10
10
10
11
11
11
12
12
1
2
2
2
3
3
3
5
7
8
8
8
8
8
8
8
8
8
9
9
9
9
9
9
9
9
9
9
25
3
22
4
7
26
5
8
9
12
10
17
18
11
12
30
30
14
27
27
8
8
16
1
12
28
15
16
18
13
31
18
24
25
25
25
25
25
25
30
3
3
3
3
3
4
4
4
6
10
20
9
21
10
13
0
6
21
7
23
11
20
7
10
19
2
20
12
16
16
2
6
18
17
2
4
20
10
18
1
17
4
7
9
9
10
12
13
15
3
18
18
18
21
23
0
1
21
21
22
8
29
16
8
0
45
22
16
18
41
53
3
37
11
45
2
3
30
11
55
3
37
6
32
40
59
35
35
12
24
50
10
32
43
56
25
43
39
16
49
15
22
51
0
2
36
10
16
35
57
28 . 7
40 . 0
4.8
41 . 0
42 . 0
32 . 1
53 . 5
49 . 8
52 . 9
9.7
17 . 2
32 . 8
10 . 0
10 . 3
25 . 8
52 . 0
.0
23 . 9
57 . 0
52 . 1
55 . 8
57 . 8
42 . 5
48 . 2
29 . 1
30 . 7
29 . 3
2.0
18 . 9
55 . 6
18 . 3
20 . 6
21 . 5
6.0
44 . 0
6.0
4.3
49 . 5
2.7
48 . 1
56 . 5
19 . 2
38 . 6
53 . 5
28 . 3
17 . 9
18 . 4
13 . 7
49 . 4
16 . 9
10
30 . 00
27 . 24
29 . 89
25 . 50
27 . 40
27 . 70
28 . 80
29 . 83
29 . 90
29 . 90
29 . 16
28 . 13
28 . 87
27 . 70
30 . 00
29 . 50
29 . 20
25 . 30
27 . 60
27 . 70
27 . 48
27 . 48
30 . 00
28 . 10
26 . 50
27 . 00
28 . 55
26 . 90
27 . 36
28 . 18
28 . 01
27 . 55
30 . 00
29 . 99
29 . 83
29 . 98
29 . 96
29 . 92
29 . 97
29 . 90
27 . 85
27 . 97
27 . 65
27 . 72
27 . 60
27 . 45
27 . 77
27 . 65
27 . 86
27 . 20
88 . 00
86 . 00
88 . 15
90 . 80
86 . 50
86 . 90
86 . 86
88 . 31
88 . 40
88 . 40
89 . 49
87 . 56
86 . 15
86 . 40
88 . 00
89 . 70
89 . 40
87 . 70
87 . 34
87 . 76
87 . 17
87 . 16
86 . 00
87 . 10
88 . 10
87 . 50
86 . 88
89 . 68
88 . 33
89 . 80
87 . 73
90 . 98
87 . 92
88 . 09
87 . 91
88 . 10
88 . 09
88 . 12
88 . 10
87 . 98
86 . 94
87 . 04
86 . 80
86 . 88
86 . 73
86 . 46
86 . 79
86 . 72
86 . 89
88 . 34
33 .
45 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
0.
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
10 .
33 .
22 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
33 .
4.4
4.7
4.4
3.8
4.4
.0
4.8
3.7
4.1
.0
3.4
.0
4.6
4.3
.0
5.3
4.9
.0
5.1
4.2
5.0
.0
4.0
4.5
4.6
4.4
4.4
3.8
4.0
4.9
4.1
5.2
.0
4.1
4.4
4.4
4.4
3.8
4.4
4.0
5.6
.0
4.4
4.1
4.6
4.1
4.2
.0
4.6
4.7
1998
1998
1998
1998
1998
1998
1998
1998
1998
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
1999
2000
2000
2000
2000
2000
2000
2000
9
9
9
9
10
10
10
11
12
1
3
3
3
4
5
5
6
7
8
9
9
9
9
9
10
10
11
11
1
3
3
4
6
7
8
9
9
9
9
10
11
11
11
1
1
2
3
4
6
9
12
21
26
30
11
13
16
26
1
28
25
25
31
10
7
9
13
4
1
5
8
16
20
21
15
18
5
17
28
25
25
10
13
4
1
5
8
20
21
15
5
7
17
20
25
21
13
18
20
6
5
23
20
2
22
14
14
10
5
16
5
20
22
20
17
8
7
6
8
2
18
12
7
13
7
16
15
5
16
5
20
20
7
6
8
2
18
7
13
7
15
5
5
12
12
18
20
7
7
7
8
24
48
29
0
47
17
14
35
10
4
47
32
42
53
8
38
5
24
28
8
20
28
54
33
12
57
27
10
4
47
42
38
5
24
28
8
28
54
33
57
11
27
54
7
21
44
53
16
19
52 . 1
40 . 6
44 . 1
55 . 1
49 . 9
51 . 9
16 . 7
27 . 6
9.2
33 . 9
54 . 3
57 . 4
57 . 8
39 . 7
52 . 3
57 . 7
6.4
15 . 2
51 . 2
22 . 8
27 . 9
9.8
5.6
39 . 8
1.0
55 . 7
21 . 4
14 . 0
33 . 9
54 . 3
57 . 4
39 . 7
6.4
15 . 2
51 . 2
22 . 8
27 . 9
5.6
39 . 8
1.0
21 . 4
57 . 6
13 . 8
27 . 5
33 . 3
43 . 2
38 . 3
45 . 2
43 . 8
8.9
11
27 . 85
29 . 94
27 . 52
29 . 94
26 . 35
29 . 74
30 . 00
27 . 75
27 . 93
28 . 22
28 . 51
28 . 50
28 . 57
28 . 04
27 . 22
27 . 40
28 . 14
25 . 42
28 . 37
28 . 07
27 . 90
27 . 55
27 . 24
25 . 16
29 . 61
26 . 68
28 . 59
28 . 09
28 . 22
28 . 51
28 . 50
28 . 04
28 . 14
25 . 42
28 . 37
28 . 07
27 . 90
27 . 24
25 . 16
29 . 61
28 . 59
27 . 10
28 . 04
27 . 78
29 . 94
28 . 36
27 . 43
26 . 55
26 . 04
28 . 52
86 . 90
88 . 00
86 . 13
88 . 11
86 . 40
87 . 88
88 . 19
87 . 89
87 . 64
87 . 31
88 . 28
87 . 63
86 . 81
87 . 85
90 . 64
89 . 45
86 . 64
90 . 28
86 . 79
87 . 53
87 . 91
87 . 71
87 . 98
88 . 86
90 . 06
87 . 22
87 . 08
89 . 18
87 . 31
88 . 28
87 . 63
87 . 85
86 . 64
90 . 28
86 . 79
87 . 53
87 . 91
87 . 98
88 . 86
90 . 06
87 . 08
89 . 13
89 . 22
86 . 02
89 . 72
86 . 56
87 . 85
90 . 26
90 . 31
86 . 86
33 .
33 .
33 .
33 .
90 .
33 .
33 .
73 .
33 .
41 .
33 .
13 .
21 .
33 .
33 .
15 .
33 .
33 .
40 .
33 .
19 .
33 .
23 .
2.
33 .
33 .
23 .
33 .
41 .
33 .
12 .
33 .
33 .
33 .
40 .
33 .
19 .
22 .
2.
33 .
23 .
14 .
33 .
33 .
0.
33 .
108 .
33 .
33 .
33 .
4.2
4.1
3.9
5.1
4.4
.0
.0
5.1
4.8
4.0
3.8
4.2
.0
4.2
.0
.0
4.4
3.8
5. 0
4.5
3.7
.0
4.1
3.9
4.4
.0
3.7
3.6
4.0
3.8
4.2
4.2
4.4
3.8
5.0
4.5
3.7
4.2
3.9
4.4
3.7
3.8
3.3
5.0
5.0
4.7
4.1
3.3
4.3
4.2
2000
2001
2001
2001
2001
2001
2001
2001
2001
2001
2001
2001
2001
2001
2001
2001
2001
2001
2001
2001
10
1
2
2
2
4
4
4
4
4
4
5
5
6
7
7
8
9
9
12
3
16
9
27
27
3
3
8
20
28
29
3
21
12
3
6
6
4
27
2
17
8
10
1
16
23
23
18
18
10
10
16
21
10
19
23
6
22
22
22
8
6
20
46
21
8
26
35
35
37
39
2
55
47
16
4
23
8
40
41
22 . 4
57 . 4
55 . 7
7.0
25 . 6
38 . 0
4.4
49 . 3
2.7
59 . 1
9.1
59 . 6
7.8
46 . 6
18 . 4
3.4
32 . 7
3.7
11 . 1
14 . 8
NO. OF EARTHQUAKES = 358
12
26 . 88
26 . 42
27 . 24
26 . 48
28 . 38
27 . 74
27 . 82
28 . 16
26 . 13
28 . 55
28 . 70
27 . 63
28 . 54
28 . 46
26 . 15
27 . 65
27 . 47
25 . 37
26 . 99
27 . 18
89 . 8
90 . 24
89 . 67
90 . 55
86 . 97
86 . 13
86 . 18
88 . 57
90 . 67
87 . 14
87 . 14
90 . 47
86 . 72
86 . 57
89 . 20
88 . 64
87 . 47
90 . 96
87 . 76
88 . 33
33 .
33 .
13 .
20 .
33 .
33 .
18 .
20 .
33 .
33 .
33 .
33 .
33 .
20 .
6.
10 .
9.
15 .
2.
15 .
2.8
.0
3.9
4.7
4.9
4.6
3.5
3.9
4.6
5.0
4.5
3.8
3.8
3.9
3.6
2.7
4.3
3.7
4.1
4.8
Annexure 6.1
PRELIMINARY RANKING STUDY REPORT- BY CEA
Lingza Hydro Electric Scheme (Org. No. HEPR-PS-BHM-784):
The Ringpi appear to permit another run-of-the-river type hydro electric
scheme utilizing the river waters available downstream of Ringpi power
house for power generation. The scheme would involve construction of a
diversion structure immediately downstream of the power house under
Ringpi hydro electric scheme at a site where the river bed level is +1795 m.,
a tunnel about 4 Km. long for carrying the waters to a power house to be
located on the main Talung Chhu river at a site where the river bed level is
1055 m. The power house would operate under a gross head of 740 MW.
and have an optimum generating capacity of about 160 MW enabling firm
power generation of about 20 MW. The scheme would enable annual energy
of 715 GWH and 780 GWH respectively in 90% and 50% dependable years.
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
ANNEXURES 6.2
TITLE
No.
Reply on CWC’s Comments on Hydrology
1-3
Reply on CEA (HP&I) General Comments &
Comments on Power Potential Studies.
4-5
Reply on Comments of SP&PA Division CEA
6-7
Reply on comments on CMDD(E&NE), CWC
8-9
Annexure 6.2
REPLY ON CWC’s COMMENTS ON HYDROLOGY OF
LINGZA HE PROJECT
In reference to letter no. 7/9/(NHPC)/2003/HPI/1500 dt. 20-1-2004, point wise reply to the CWC
observations are placed as below:
CWC Observations
Reply of NHPC
Data
Rainfall - The report has quoted the paper of
As
explained
in
earlier
meetings
and
availability
Sh. Biswas and Bhadram in which data of 42
correspondences, the paper of Biswas and
raingauge stations, 24 of which is equipped
Bhadram has been quoted in the report to explain
with SRRG have been stated to be available.
the precipitation characteristics. At present,
However rainfall data has not been furnished
NHPC has rainfall data of only the 11 raingauge
in the report and only the period of data
stations whose data availability status is shown in
availability of 11 raingauge stations located
the report. As desired, the annual rainfall at these
u/s of the Teesta-V HEP is given in the
11 stations for the available period is enclosed as
report.
Annexure-I.
Consistenc
(i) Though the rainfall data of 11 raingauge
(i) None of the raingauge stations out of the
y of data
stations available with NHPC could not be
remaining 31 raingauges as mentioned in the
utilized in the study due to the reason that
report of C.V.V Bhadram are located in the sub-
none of the stations are within the project
basin under consideration.
catchment, the project authorities may put in
their effort to verify whether any of the
remaining stations as mentioned in the report
lies in the project catchment and to explore
the possibilities of utilization of the data in
the study.
(ii) A complete list of all rainfall and
discharge stations of Teesta Basin may be
(ii) The list of rainfall stations lying upto the
furnished.
catchment of Teesta-V has already been shown in
the data availability status given in report.
However, as referred by the paper 42 raingauge
stations exist in the entire Teesta Basin. Rainfall
and discharge stations lying in the entire Teesta
basin are of not relevant for the present projects.
Water
(i) Only graphical presentation comparing
The available average 10-daily series at Lachen
availability
the avg. 10-daily discharges of the four
has already been sent along with the replies of
1
studies
methodologies has been furnished in the
Rukel and Rangyong projects. Tolung Chu data
report. The data and the analysis of Lachen
has not been used as the series obtained using this
adopted for the project has not been
data was on a much higher side as compared to
furnished without which checking is not
other three series and no consistency checks
possible. In the absence of site-specific data,
could be applied to check the reliability of the
the use of Tolung Chu data would be more
data. Hence for the time being Lachen G&D data
reliable. The snowfed area covers a major
has been used.
portion of the project catchment and without
It has been verified that none of the raingauge
establishing hydro-meteorological similarity
stations out of the remaining 31 raingauges as
transfer of data from other sub-basin would
mentioned in the report of C.V.V Bhadram are
be unjustified. Before discarding Tolung Chu
located in the sub-basin under consideration.
data the project authorities are advised to
verify whether any of the remaining 31 rain
gauges are located in the sub-basin and to
utilize the same after applying consistency
checks and results incorporated. Rainfallrunoff factor based on Tolung Chu data may
be evaluated before discarding the data. The
results obtained may be compared with the
series
obtained
from
Lachen
before
recommending the yield series. Efforts may
be made to collect site specific data and
water availability studies may be reviewed
based on observed data.
(ii) The basis of deriving the catchment
reduction factor is not given.
(ii) The catchment reduction factor has been
obtained on the basis of rainfed area at both the
sites. Rainfed catchment of Lachen site is 574
(iii) A series of projects is bieng planned in
Sq.km and of Lingza is 124 Sq.km.
Teesta Basin and Integrated studies on water
(iii) Cascade development need to be done at a
availability need to be done incorporating the
later stage.
likely releases from the u/s power house and
independent catchment contributions.
Design
(i) The design flood studies done by NHPC
(i) As already explained in our earlier replies
Flood
are too empirical to be relied upon even for
also, for such detailed studies as suggested for
PFR. The project authorities may also
this stage i.e PFR, neither the database is at all
calculate
sufficient nor necessity felt by us. During
the
PMF
value
using
SUH
2
approach as suggested in North Brahmaputra
feasibility
stage,
deterministic/
probabilistic
Basin (Sub Zone-2(a) report published by
approach will be used, based on more observed
CWC by obtaining the PMP/SPS value and
data.
temporal distribution of rainfall from IMD
and following 2 bell per day approach and
incorporate this value also in the comparative
study to get a more realistic value.
(ii) Short interval data may be collected and
the design flood should be reviewed based on
(ii) It is not felt necessary to perform such
observed data.
detailed study during PFR stage.
Sedimentati
The sedimentation rate for the region is about
We are aware of the findings of CWC studies
on
0.1765 Ham/Sq.km/year as per CWC studies
published in the Compendium on silting of
published in the Compendium on Silting of
reservoirs in India. As per that report, the
Reservoirs In India which is higher than the
sediment rate varies from 0.05658 to 0.2785
rate proposed for the project. As stated in the
Ham/Sq.km/year
report more detail study is required. Data
Brahmaputra basin. But the silt rate adopted for
may also be collected from the completed
this particular project has been calculated on the
projects of the basin.
basis of observed sediment data at Dikchu and is
As per the terms of preparation of PFRs and
more
as emphasized in the meetings conducted by
“Compendium on silting of reservoirs in India”.
CEA sedimentation studies are required to be
The necessity of detailed sedimentation study
carried out and incorporated in the PFRs.
showing the new zero elevation, revised area
region
for
specific
Indus,
than
Ganga
that
and
given
in
capacity curve etc. is not felt during PFR stage.
General
The PFR must bring out the limitations of the
The PFR has pointed out the limitation of the
hydrological studies carried out for the PFR
studies after each study and establishment of
and
G&D site, rainfall stations etc. are also
suggest
improvements,
recommendations
hydrological
for
opening
new
Moreover, all the CWC comments along with
observations, data to be collected etc. may be
their replies are also being appended in the PFR’s
given which will help us as guidance to the
for future reference.
taking
up
method
highlighted in the PFR.
of
agency
stations,
specific
the
detail
investigations/DPR must review the network
in consultation with HSO, CWC.
The hydrological studies for the PFR may be
revised incorporating the above observations.
3
REPLY ON COMMENTS OF CEA (HP & I ) ON DRAFT PFR OF LINGZA H E
PROJECT, (120MW) SIKKIM.
(CEA Letter No.7/9/(NHPC)/HP&I/2003/1552 dated 12.12.2003 )
Sr.No. CEA (HP&I)’s Comments
NHPC’s reply
GENERAL COMMENTS :
1
It may be ensured that the Initial
Environmental studies incorporated
in the PFR are as per scope of work
for PFR.
This has been considered.
2
The Financial Parameters may be
taken as per guidelines sent vide our
Lr. No. 7/9/HPI-2003/1118-1123,
dated 21 st October, 2003.
The Financial Parameters may be
taken as per guidelines of CEA
3
It may be ensured that the Cost
Estimates is prepared as per the
Guidelines sent vide our Lr.
No.7/9/HP&I/2003/1163-1172, dated
24.10.2003.
Cost Estimates have been prepared
as per the Guidelines of CEA
4
NHPC
may
indicate
recommendations for further studies
required wherever necessary in the
relevant chapters of PFRs for
consideration
during
Feasibility
Report/DPR stage.
.
It may be ensured that the Installed
Capacities & assessment of power
benefits takes into account various
comments and advise given in this
regard.
Recommendation for further studies
required for preparation of FR/DPR
has been indicated wherever
necessary
6
It may be ensured that the hydrology
adopted is approved by CWC.
Hydrology adopted is as discussed
and decided in the meetings with
CEA
7
The power evacuation arrangements
considered in the PFR should take
into account views and suggestions of
SP&PA Division of CEA.
The power evacuation arrangements
considered in the PFR has taken into
account views and suggestions of
SP&PA Division of CEA.
5
4
The
installed
capacities
and
assessment of power benefits require
no change.
8
Cost of Projects etc has been
mentioned in lakhs where as it should
be in crores in cost of energy
statements.
POWER POTENTIAL STUDIES:
Gross storage and live storage in
1
terms of Mcum and MWhr may
please be indicated in the power
potential studies chapter.
Necessary correction has been
incorporated.
Gross storage and live storage in
terms of Mcum and MWhr has been
indicated in the power potential
studies chapter.
2
Justification for FRL, MDDL, TWL,
Proposed installed capacity of
120MW has not been brought out
properly in text portion of Chapter
VII studies carried out and presented
in tables need also to be explained in
the chapter.
Justification for FRL, MDDL,
TWL, Proposed installed capacity of
120MW has been modified as per
Civil Design recommendations and
brought out in text portion of
Chapter VII studies carried out, and
also explained in the chapter.
Annual energy generation in 90%
dependable year and design energy
(with 95% availability has been
indicated separately in the text and
in table 7.5A. In table 7.5A energy
with 95% machine availability has
been modified and presented in text
and table form.
3
A table giving the summary of
studies indicating yearly inflows,
annual energy generation, load factor
of operation during monsoon and
lean flow period may be presented in
studies.
A table giving the summary of
studies indicating yearly inflows,
annual energy generation, load
factor of operation during monsoon
and lean flow period has been
presented in studies as per annex-B
Table 7.5.
.
4
NHPC
may
indicate Recommendation for further studies
recommendations for further studies required for preparation of FR/DPR
required for preparation of FR/DPR.
has been indicated wherever
necessary
5
REPLY ON COMMENTS OF SP&PA DIVISION ON DRAFT PFR OF
LINGZA HE PROJECT
(CEA Letter No.7/9/(NHPC)/HP&I/2003/9 dated 02.01.2004 )
Comment
Reply
4.1
General
The project is located in the river As this is only general description of the
Ringpi Chu in Dzongu area of North project. No reply is required.
District of Sikkim. The project
involves construction of a 75m high
concrete dam, a 4.0km long Head
Race Tunnel and an underground
power house with an installed capacity
of 120MW. This power house will be
runoff river type and well connected
from Mangan by 17km long state
PWD road.
4.2
Construction Power
The necessary construction power This has been already been considered in
shall be availed from Phodong 2x2.5 the draft PFR.
MVA, 66/11 kV substation or from
Mangan S/s which will be decided at
the time of DPR.
4.3
Switchyard
A cable tunnel of size 2.0m x 3.0m The required information will be taken
will take off from transformer area care of during preparation of FR/DPR
and shall carry cable to a surface stage.
switch
yard.
The
switchyard
measuring approximate 200m x 150m
shall be formed in cutting and filling.
No details of switchyard are available
in PFR.
4.4
Power evacuation
NHPC proposed power will be This has been incorporated in the final
generated at 11 kv and stepped up to PFR.
220 kv through 49 MVA 11/220 kv
unit transformer. Power will be
evacuated through 11km 220KV S/C
to Teesta III.
6
In the consultation with NHPC
officers the schemetic transmission
system to evacuate power generated in
the various hydro projects proposed
inTeesta basin has been evolved and is
enclosed. Accordingly it is also
advised that power generated at 11 kv
and be stepped up to 220 kv and
evacuated through 220 kv D/C line to
pooling point of Teesta Stg-III. In
view of this, following no. of bays
may be provided in the switchyard.
Generator bays – 3
220kv line bays –2
Bus coupler bay – 1
4.5
Cost
In the PFR, cost of 5 no of bays and This has been incorporated in the final
220KV D/C line has been taken. PFR.
Accordingly in the PFR cost of 6 no of
bays and transmission network may be
revised.
7
REPLY ON COMMENTS OF CMDD DIRECTORATE, CWC ON PFR OF
LINGZA HE PROJECT
(Letter No CWC P.U. No. 20/2/03-CMDD(E&NE)/136 dated 26.2.2004)
1.
Comments of CEA/CWC
Replies of Design Division
The report should indicate the The study on alternative layouts and
alternative layouts and alternative alternative locations has been included in
locations
of
project
components further studies during FR/DPR stage
examined during the preparation of when more information on topography,
PFR to bring out their merits and geology, construction material etc. shall
demerits of each including the finally be available.
adopted in PFR. The reasons for
rejecting the particular alternative
should be elucidated justifying the
rejection.
2. Preliminary survey should be made Availability of Construction material has
to ensure the quality and quantity been addressed in revised Chapter–IV
regarding availability of construction (Topo-graphical & Geo-technical aspect
material.
of PFR). The construction material
testing shall be done during FR/DPR
stage for ensuring quality of construction
material.
3. The PFR should include some The right bank of the dam site was not
geophysical information about the approachable.
Therefore
geo-physical
project location, which should be survey was not feasible. Sufficient rock
ensured by field study.
exposure was available in the power
house area, hence geo-physical survey
was not required at this stage.
8
4. For river diversion purpose non- Reasons have been detailed in revised
Monsoon flood of 300 cumecs has chapter-VI
(conceptual
layout
and
been considered. But reason for planning of PFR).
considering this value has not been
furnished.
5. It should be mentioned in the report This is as per decision taken in the
that the PMF value has been vetted by progress review meeting on PFR with
hydrology (NE)Dte. CWC.
CEA.
6. The GSI report has not been GSI report is included as annexure 4.1.
incorporated in the PFR.
7. The reason for providing concrete This has been discussed in ‘conceptual,
dam over rock fill dam please may layout and planning’ chapter of PFR.
incorporated in PFR.
8. Schematic plan of all schemes in The same has been incorporated in the
one basin should be furnished.
PFR.
9