GOVERNMENT OF INDIA GOVERNMENT OF NEPAL Ministry of Water Resources, Ministry of Energy River Development and Ganga Rejuvenation

PANCHESHWAR DEVELOPMENT AUTHORITY (PDA) (Bi-national Entity of India and Nepal)

PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

VOLUME I SECTION 1: EXECUTIVE SUMMARY

Consultant:

[email protected], Website: http://www.wapcos.gov.in PANCHESHWAR DEVELOPMENT AUTHORITY (Bi-national Entity of India and Nepal)

PANCHESHWAR MULTIPURPOSE PROJECT

DETAILED PROJECT REPORT

VOLUME - I SECTION 1: EXECUTIVE SUMMARY

PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Section 1: Executive Summary

Section 1: Executive Summary Page i PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Section 1: Executive Summary Page i PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

PANCHESHWAR MULTIPURPOSE PROJECT

SECTION 1: EXECUTIVE SUMMARY

Table of Contents

Sub-Section Sub-Headings Page Nos. 1.1 Introduction 1 1.1.1 Background 1 1.1.2 Project Location 2 1.1.3 Mahakali River Basin 3 1.1.4 Climate 4 1.1.5 Water Resources 4 1.1.6 Access 4 1.1.7 Project Features 4 1.1.8 Hydropower Potential in the Mahakali Basin 5 1.1.9 Population and Economy of the Project Area 5 1.1.10 Resettlement and Relocation Plans 5 1.1.11 Physical Environment 5 1.2 Previous Studies 6 1.2.1 WAPCOS Initial Studies -1971 6 1.2.2 Nepal DPR -1995 6 1.2.3 Joint Investigations by JPO-PI (2000-02) 6 1.2.4 Indian draft DPR -2003 6 1.3 Field Investigations and Studies of Pancheshwar 7 Multipurpose Project 1.3.1 Topography 7 1.3.2 Hydrology & Meteorology 8 1.3.3 Geology/ Geotechnics 11 1.3.3.1 Regional Geology 11 1.3.3.2 Geotechnical Investigations 12 1.3.3.3 Geology of Pancheshwar Reservoir 13 1.3.3.4 Geology of Pancheshwar Dam site 14 1.3.3.5 Geology of Pancheshwar Spillway and Plunge pool 15 1.3.3.6 Geology of UGPH on Left Bank (Nepal Side) 16 1.3.3.7 Geology of UGPH on Right Bank (India Side) 17 1.3.3.8 Geology of Diversion Works –Tunnels and Coffer dams 18 1.3.3.9 Geology of Rupaligad Dam Site and Spillway 18 1.3.3.10 Geology of UGPH on the Left Bank (Nepal Side) 20 1.3.3.11 Geology of UGPH on the Right Bank (India side) 20 1.3.3.12 Geology of Diversion works- Tunnels and Coffer Dam 21

Section 1: Executive Summary Page i PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.4 Sedimentation Studies 22 1.4.1 Pancheshwar Reservoir 22 1.4.2 Rupaligad Re-regulation Reservoir 23 1.5 Construction Materials 23 1.5.1 Materials Survey 23 1.5.2 Material Requirements - Pancheshwar 24 1.5.3 Laboratory Tests - Pancheshwar 24 1.5.4 Material Requirements - Rupaligad 25 1.6 Seismicity 26 1.7 Infrastructure and Communication Survey 26 1.8 Benefit Assessment & Project Optimization of 27 Pancheshwar Multipurpose Project 1.8.1 Power Market Review 27 1.8.2 Power and Energy Benefits 27 1.8.3 Irrigation Benefits 28 1.8.4 Flood Control Benefits 31 1.9 Design of Civil Structures & Preliminary Layout of 31 Pancheshwar Multipurpose Project 1.9.1 Pancheshwar Rockfill Dam 31 1.9.1.1 Concrete Dam Axis 31 1.9.1.2 Rockfill Dam Axis 32 1.9.2 Reasons for Selection of Rockfill Dam 33 1.9.2.1 Geological Consideration 33 1.9.2.2 Seismic Consideration 34 1.9.2.3 Materials Consideration 34 1.9.3 Pancheshwar - General Layout and Project Components 34 1.9.3.1 General Layout 34 1.9.3.2 Diversion and Outlet Facilities 34 1.9.3.3 Diversion Tunnels 35 1.9.3.4 Cofferdams 35 1.9.3.5 Depletion Arrangements 35 1.9.3.6 Design of Rockfill Dam 36 1.9.3.7 Foundation Treatment of Pancheshwar Dam 36 1.9.3.8 Design of Pancheshwar Spillway 36 1.9.3.9 Intake and Pressure Tunnels 37 1.9.3.10 Vertical Drop Shafts/ Penstocks 37 1.9.3.11 Pancheshwar Dam - Power Houses 37 1.9.3.12 Pancheshwar Dam - Downstream Surge Galleries 37 1.9.3.13 Draft Tube Tunnels/ Tail Race Tunnels at Pancheshwar 38 1.9.4 Rupaligad Re-Regulating Dam 38 1.9.4.1 General Layout 38 1.9.4.2 Rupaligad Concrete Gravity Dam 38 1.9.4.3 Rupaligad Dam - Spillway and Energy Dissipation 39 Arrangement

1.9.4.4 Rupaligad Dam - Diversion Arrangements 40 1.9.4.5 Rupaligad Dam – Power Intakes and Headrace Tunnels 40 1.9.4.6 Rupaligad Dam - Power Powerhouse caverns 41

Section 1: Executive Summary Page ii PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.9.4.7 Rupaligad Dam – Tailrace Tunnels 41 1.10 Design of Electrical and Mechanical Works 41 1.10.1 Pancheshwar Power Stations 41 1.10.2 Rupaligad Power Stations 42 1.11 Transmission System for Pancheshwar Multipurpose 42 Project 1.11.1 Evacuation System for Pancheswar Power Plants 42 1.11.2 Evacuation System for Rupaligad Power Plants 43 1.12 Environmental and Socio-Economic Impact 44 Assessment 1.12.1 Flora & Fauna 44 1.12.2 Rehabilitation & Resettlement 44 1.12.3 Environmental Management Plan including R & R Plan 45 1.13 Construction Schedule and Equipment Planning 45 1.13.1 Basic Considerations 45 1.13.2 Access Roads and Infrastructure Facilities 45 1.13.3 Equipment Planning 46 1.13.4 Construction Programme 46 1.14 Cost Estimates & Phasing of Expenditure 46 1.14.1 Abstract of Cost Estimates 46 1.14.2 Phasing of Expenditure 49 1.15 Economic and Financial Evaluation 49 1.15.1 Cost chargeable to Irrigation and Flood Control 50 Component 1.15.2 Cost chargeable to Power Component 50 1.15.3 Capitalized Cost of Hydropower Project 52 1.15.4 Levelized Tariff and Internal Rate of Return (IRR) 52 1.16 International and Interstate Aspects 52 1.16.1 Irrigation Benefits 53 1.16.2 Power Benefits 54 1.16.3 Inter-state Agreements 54 1.16.4 Interstate Aspects of the Project 55 1.16.5 International Aspects of the Project 55 1.16.6 Dispute Resolution Mechanism 56 1.16.7 Power Purchase Agreements 56 1.17 Project Management and Design Engineering 56 Consultancy 1.18 Conclusions and Recommendations 57

List of Annexure Annex-I Salient Features of Pancheshwar Dam 59 Annex-II Salient Features of Rupaligad Re-regulating Dam 65

Section 1: Executive Summary Page iii PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

List of Tables

Table No. Description Page No. Table 1.3-1 Average Monthly Temperature at Pancheshwar dam 8 site Table 1.3-2 Average Monthly Rainfall at Pancheshwar dam site 9 Table 1.3-3 Average Monthly Lake Evaporation at Pancheshwar 9 dam site Table 1.3-4 Average Monthly Inflows at Pancheshwar dam site 9 Table 1.3-5 Floods for different Return period (m3/s) 10 Table 1.3-6 Rock Sequence from South (Tanakpur) to North 10 (Tawaghat) Table 1.3-7 Changes in Reservoir Capacity with sedimentation 11 Table 1.5-1 Construction Materials Balance – Pancheshwar 24 Table 1.8-1 Annual Energy Generation 28 Table 1.8-2 Total Water Requirement of India and Nepal 68 including River Eco-System (in m3/s) Table 1.14-1 Abstract of cost of Pancheshwar Dam 47 Table-1.14-2 Abstract of Cost of Rupaligad Dam 48 Table 1.14-3 Yearly requirement of funds to both countries (in 49 INR Million) Table 1.15-1 Assessment of Project Benefits 50 Table 1.15-2 Apportionment of project cost in power and irrigation 51 sector Table 1.15-3 Phasing of Expenditure on power component of 52 PMP (in INR million) Table 1.15-4 Levelized Tariff and IRR for different loan repayment 52 periods Table 1.16-1 Various parameters of Project 54

Section 1: Executive Summary Page iv PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

List of Drawings

Sr. No. Drawing No. Title of Drawings A. General

1. DRG.NO.WAP/PANCH/ES-01 Index Map of Pancheshwar Multipurpose Project 2. DRG.NO.WAP/PANCH/ES-02 Regional Geological Map of Project Area

B. Pancheshwar Dam

3. DRG.NO.WAP/PANCH/ES-03 Geological Map of Pancheshwar Dam Site 4. DRG.NO.WAP/PANCH/ES-04 Layout Plan Showing Drill Holes & Drifts 5. DRG.NO.WAP/PANCH/ES-05 Geological Section along Rockfill Dam 6. DRG.NO.WAP/PANCH/ES-06 General Layout Plan of Pancheshwar Dam 7. DRG.NO.WAP/PANCH/ES-07 L-Section along Pressure Tunnel 8. DRG.NO.WAP/PANCH/ES-08 Maximum Section of Rockfill Dam 9. DRG.NO.WAP/PANCH/ES-09 Pancheshwar Spillway – Maximum Over Flow Section 10. DRG.NO.WAP/PANCH/ES-10 Pancheshwar Spillway- Maximum Non-Over Flow Section 11. DRG.NO.WAP/PANCH/ES-11 Power House Cross-Section 12. DRG.NO.WAP/PANCH/ES-12 Layout Of Machine Hall, Bus Duct Galleries & Transformer Hall 13. DRG.NO.WAP/PANCH/ES-13 Schematic Diagram of 11kv & 415v Ac Switchgears 14. DRG.NO.WAP/PANCH/ES-14 Location Plan of Quarry, Borrow Area and Muck Disposal Areas C. Rupaligad Re-regulating Dam

15. DRG.NO.WAP/PANCH/ES-15 Geological Map with Location of Drill Holes and Drifts at Rupaligad 16. DRG.NO.WAP/PANCH/ES-16 Geological Section along the Rupaligad dam 17. DRG.NO.WAP/PANCH/ES-17 Rupaligad Dam – General Layout Plan 18. DRG.NO.WAP/PANCH/ES-18 L-Section Through Water Conductor System 19. DRG.NO.WAP/PANCH/ES-19 Rupaligad Dam - Upstream Elevation 20. DRG.NO.WAP/PANCH/ES-20 Maximum Non-Over Flow Section of Dam 21. DRG.NO.WAP/PANCH/ES-21 Rupaligad Power House Cross-Section 22. DRG.NO.WAP/PANCH/ES-22 Layout Plan of M/C Hall, Bus Duct Galleries & Transformer Hall 23. DRG.NO.WAP/PANCH/ES-23 Schematic Diagram of 11kv & 415 V L.T.A.C. Switchgears 24. DRG.NO.WAP/PANCH/ES-24 Location Map of Quarry area, Roads and Infrastructure Facilities at Rupaligad dam

Section 1: Executive Summary Page v PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Section 1: Executive Summary Page vi PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

SECTION 1: EXECUTIVE SUMMARY

1.1 Introduction

1.1.1 Background

A Treaty between His Majesty's Government of Nepal and Government of India concerning the Integrated Development of the Mahakali River including Sarada Barrage, Tanakpur Barrage and Pancheshwar Project was signed on February 12, 1996 by the Prime Ministers of India and Nepal. As per Article-3 of the Treaty, both the governments agreed to implement the Pancheshwar Project on the Mahakali River where it forms the international boundary between the Far Western Development Region of Nepal and the Uttrakhand State in India. In accordance with the principles enunciated therein, the Project shall be designed to produce the maximum total net benefits, accruing to both the parties, in the form of power generation, irrigation, flood control, etc.

The Pancheshwar dam project is a bi-national project, primarily aimed at energy production. In addition, it would enhance the food grains production in both the countries by providing additional irrigation resulting from the augmentation of dry season flows. Due to moderation of flood peaks at reservoir(s), incidental flood control benefits are also envisaged from the project.

Actual photograph of Pancheshwar dam site

Section 1: Executive Summary Page 1 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Pursuant to the Article-10 of the Treaty, the Government of India (GOI) and the Government of Nepal (GON) agreed to set up the Pancheshwar Development Authority, an independent autonomous body, to finalize the Detailed Project Report and expedite the implementation of the Pancheshwar Project. The Authority is headed by the Water Resources/ Energy Secretaries from the GOI and GON. It was agreed that the Pancheshwar Development Authority (PDA) shall take immediate measures to finalize the Detailed Project Report (DPR) of Pancheshwar Multipurpose Project.

In order to expedite the finalization of the Pancheshwar DPR, the water resources/ energy secretaries of India and Nepal decided to award the work of updation of DPR including the additional field investigations, if necessary, to M/s WAPCOS Limited, in the second meeting of the Governing Body of PDA held in November 2014 at New Delhi.

The updated DPR is aimed to summarize the results of all previous studies and field investigations carried out by both sides independently and/or jointly including the additional field investigations and studies carried out by WAPCOS Limited; to develop a mutually acceptable technical solution, estimate with sufficient accuracy the project costs and benefits, and carry out the analyses required to confirm economic and financial feasibility of the Project in accordance with the principles enshrined in the Mahakali Treaty -1996.

1.1.2 Project Location

The Pancheshwar dam site is located near the Pancheshwar temple which is about 2.5 km downstream of the confluence of River Mahakali with the Sarju River. A re- regulating dam is also proposed downstream of the main dam to even out peaking flows released from Pancheshwar power houses for meeting downstream irrigation water requirement. For this purpose, two alternative locations were identified; one at Rupaligad, 27 km downstream of the main dam and another at Purnagiri, 61 km downstream of main dam. Finally, the Rupaligad site was agreed by the two sides for locating the re-regulating dam in the 3rd meeting of Joint Committee of Water Resources (JCWR) held in November 2009 at Pokhara (Nepal). An Index Map showing location of main dam, re-regulating dam and the exiting irrigation structures is at Figure 1.1-1.

The project structures, including the reservoir area, lie in the Champawat, Pithoragarh, Bageshwar and Almora districts of Uttarakhand state in India and in the Baitadi and Dharchula districts of Nepal.

Section 1: Executive Summary Page 2 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Figure 1.1-1: Index Map of the Project

1.1.3 The Mahakali River Basin

The Mahakali (Sarada) basin up to the Pancheshwar dam site has a total catchment area of 12,276 km2; out of which an area of 9,861 km2 lies in India, and remaining 2415 km2 in Nepal.

During its course, the Mahakali river carries the flows from a number of major tributaries, viz. the Dhauli Ganga (catchment 1357 km2), the Gauri Ganga (catchment 2300 km2) and the Sarju (catchment 4019 km2) from the Indian side and the river Chamaliya (catchment 1572 km2) from t he Nepal side. The other minor tributaries joining the Mahakali River, below the Pancheshwar site are the Lohawati and the Ladhiya rivers from Indian side and the Surnayagad, the Rupaligad, the Sirsegad and the Ragunkhola from the Nepal side before the Mahakali River emerges onto the Gangetic plains near the Purnagiri temple before the Tanakpur town.

Section 1: Executive Summary Page 3 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.1.4 Climate

The south - west Monsoon sets in the project area in the last week of May or in early June and continues up to the mid October. The total annual rainfall in the basin ranges from 1000 mm to 2000 mm, out of which 70-75% of the total precipitation occurs during the monsoon months of June to September. The maximum precipitation generally occurs in the months of July and August.

1.1.5 Water Resources

The long term average discharge at the Pancheshwar dam site is estimated to be 582m3/s. A n additional runoff from the intervening catchment between the Pancheshwar to Rupaligad site is estimated to be 39 m3/s.

1.1.6 Access

At present, the only access to the project area by road is through Tanakpur - Lohaghat -Pancheshwar (about 130 km), from the Indian side. Access to the dam site from the Nepal side is possible only by helicopter or by 40km road from the Patan village and then 20 km trekking.

The existing roads on both sides will need major improvement and relocating for the construction of the project as the last portion of the Indian road, approaching the actual dam site would be submerged in the reservoir. A new road along the left bank of the Mahakali River on the Nepal side has been proposed from the Brahmadeo village to the Pancheshwar dam site for transport of heavy equipment and generating units. This road would be connected to the Tanakpur town in India by constructing a new bridge over the Mahakali River.

1.1.7 Project Features

The Pancheshwar project comprises of a 311m high rock fill dam at Pancheshwar with two underground power houses, one on each bank, having a total installed capacity of 4800 MW (six units of 400MW each on either side). In addition, a 95m high concrete gravity dam has been envisaged at Rupaligad with two underground power stations, one on each bank of the river having a total installed capacity of 240 MW (two units of 60 MW each on each side). Besides the dams, the project shall have all the appurtenant works, like, spillway, intake structures, water conductor system, surge shafts, pothead yards, etc.

The project will generate 7678 GWh energy annually at the main dam power stations and 1438 GWh at the Rupaligad re-regulating dam power stations during 90% dependable year.

In addition, the storage project will enhance the natural river flows during the non- monsoon months, and provide the year round irrigation to agricultural land in the Kanchanpur District in Nepal. There would be intensification of irrigation system on

Section 1: Executive Summary Page 4 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT the Indian side during the Rabi season. Besides the above, the project will also have incidental flood benefits on both sides.

1.1.8 Hydropower Development in the Mahakali Basin

No other storage scheme has been envisaged on the main stem of the Mahakali River upstream of the proposed Pancheshwar dam. On the Indian side, a storage project near Chamgad was envisaged on the River Sarju, as an alternative to the Pancheshwar Project which has been shelved as it would be submerged in the Pancheshwar reservoir.

The National Hydroelectric Power Corporation (NHPC), India has commissioned a 280 MW Dhauliganga HE Project in the upstream of Pancheshwar reservoir on the Dhauliganga River. Some more schemes are also planned on the river Gauriganga in the upstream of Pancheshwar reservoir.

Similarly, the Nepal side has planned a 30 MW HE Project, a medium size project on the Chameliya river. In addition, Nepal has also carried out a master plan study of the Mahakali River in their territory.

1.1.9 Population and Economy

The population density in the project area on both sides, India (259 persons/ km2) and Nepal (69 persons/ km2 as per EIA Report of Nepal side) is low as compared to average densities in both the countries. Subsistence agriculture is at present the primary economic activity in the project area, both in India and in Nepal.

1.1.10 Resettlement and Relocation

The Pancheshwar reservoir will displace a total of 29436 project affected families (PAF) due to Pancheshwar dam on the Indian side and 2786 households (as per 2006 data) in the Baitadi District on Nepal side of the river. In Nepal, it is proposed to use part of the agricultural area to be irrigated by the project to relocate these persons in Kanchanpur. The persons affected on the Indian side would be resettled at appropriate locations in consultation with the local population by the state administration as per the resettlement policies in India.

The Rupaligad dam would also submerge a total area of 396 ha of which 182 ha lies in India and rest in Nepal. About 1587 families in eleven villages of the district Champawat would be affected in India. The PAFs in Nepal side are being collected from Nepal.

1.1.11 Physical Environment

The main reservoir of Pancheshwar would submerge 116 km2 area of which 76 km2 would be in India and balance in Nepal. About 21.95 km2 of agriculture land in India and 13.78 km2 in Nepal would be coming under submergence of Pancheshwar reservoir.

Section 1: Executive Summary Page 5 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

The project area is mostly covered with Sal forests, which could be classified as moderately thick. One endangered tree species, Alstonia Scholaris, is located in the project area.

The intervening catchment area up to the Rupaligad dam consists of Shiwalik Sal forest and Himalyan Chir forests, with young to full grown trees. The area has variety of trees having commercial value such as Sal, Sheesam, Chir, Sain, Bakli, Haldu, Bahedi, Jhingan, Toon, Khair, Gutel, Rohini, Kaula etc.

1.2 Previous Studies

1.2.1 WAPCOS Initial Studies -1971

Investigations and basic studies for the Pancheshwar Project were initially carried out by the State of Uttar Pradesh during the 1960s. These investigations mainly covered the Topographical Surveys, Geological Investigations, Construction Material Investigations and Hydro-meteorological Observations. Based on the above field investigations, a feasibility report on the Pancheshwar project was prepared by WAPCOS India Limited in November 1971. It suggested a 247m high concrete gravity dam at Pancheshwar with a dam toe powerhouse having four units of 250 MW each.

1.2.2 Nepal DPR -1995

Based on the independent studies carried out by the Indian side from 1981 to 1991 and some joint studies carried out during the years 1991 to 1994, the Nepal side prepared a draft DPR of Pancheshwar Multipurpose Project in 1995 and forwarded it to the Indian side for consideration. On examination the DPR, it was realized that additional field investigations and studies were required to finalize a mutually acceptable report.

1.2.3 Joint Investigation by JPO-PI

Realizing the need for additional investigations and studies to be carried out jointly, for the main dam as well as for the re-regulating dam at an optimal location, it was decided to set up a Joint Project Office (JPO-PI) at Kathmandu with field offices at the project sites in 1999. The required investigations and studies were carried out by JPO-PI between 2000-2002 for locating the downstream re- regulating dam either at Rupaligad or at Purnagiri site.

1.2.4 Indian Draft DPR -2003

After completion of additional surveys and investigations at Pancheshwar dam, Rupaligad and Purnagiri dam sites, JPO –PI tried to finalize a mutually agreeable DPR in 2002. However, it could not be completed due to difference in opinion on certain issues, mainly, units’ size and installed capacity of Pancheshwar power plants, non-finalization of location of downstream re-regulating dam, assessment of

Section 1: Executive Summary Page 6 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT irrigation benefits to India, apportionment of the project cost to each side, etc. The JPO-PI was closed in July 2002 and the relevant data/ records were shifted to Central Water Commission, New Delhi.

In order to ensure that the newly collected data, during the joint field investigations carried out by the JPO-PI, does not remain unutilized, a draft report was prepared by the Indian side which could form a basis for finalization of the joint detailed project report, later on. The Indian draft DPR -2003 envisaged a 184 m high rock fill dam at Purnagiri site, as a re-regulating dam, to intercept the intervening basin area of around 3000 sq km and make optimal use of hydro power potential of the Mahakali River. The Indian draft report of 2003 had retained many project parameters related to main dam at Pancheshwar as suggested in the Nepal DPR- 1995.

1.3 Field Investigations and Studies

1.3.1 Topography

Based on the understanding reached at a meeting of representatives of the Nepalese and Indian Survey Departments held in Kathmandu on September 4-6, 1991, topographic maps of the dam site were prepared jointly covering both banks of the river up to EI 940 m, with 2m contour interval. In addition, maps were also prepared jointly by the Survey of India (Government of India) and Department of Surveys (Government of Nepal) for reservoir area and re-regulating dam sites.

Section 1: Executive Summary Page 7 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

In addition to the above, detailed topographic surveys have been carried out recently by WAPCOS Limited for the areas to locate Owners' and Contractors' camps, temporary construction facilities, borrow areas and other infrastructures facilities, including the proposed new road along the Nepal bank.

1.3.2 Hydrology & Meteorology

1.3.2.1 Field data

A meteorological station was set up at Pancheshwar dam site in 1982 in the Indian side. A similar station was established at the Pancheshwar Field Camp on the Nepal side in 1989. The JPO-PI also set up weather stations at Pancheshwar, Rupaligad and Purnagiri sites in 1999 recording daily/ hourly rainfall, dry /wet bulb temperatures, maximum and minimum temperatures, wind speed & direction and sunshine.

In addition, gauge discharge and silt observations were also started at Pancheshwar dam site by India from 1983 and later on, joint observations were carried out from Nepal bank of the river during 1991-93.

The aforesaid data was obtained by WAPCOS Limited from the concerned agencies and utilized in the assessment of long term average annual discharge at the project sites, flood and sediment load estimation.

Additional rainfall data available with India Meteorological Department and the Government of Nepal was also collected and utilized in the updated hydrological studies.

1.3.2.2 Mean Monthly Temperature

The climate and precipitation pattern over the project area is governed by the monsoon. The mean monthly temperature at the Pancheshwar dam site varies between 140 C to 300 C, as shown in the Table-1.3-1.

Table 1.3-1: Average Monthly Temperature at Pancheshwar dam site

Month T0C Month T0C Month T0C January 14.2 May 28.8 September 28.7 February 16.4 June 30.4 October 24.5 March 21.1 July 29.1 November 19.5 April 26.4 August 29.2 December 14.9

1.3.2.3 Monthly Rainfall

Total annual rainfall in the basin ranges from 1000 mm to 2000 mm, with about 75% of the total precipitation occurring during the monsoon months of June to September. Maximum precipitation generally occurs in July and August. The

Section 1: Executive Summary Page 8 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT average monthly rainfall at Pancheshwar Dam site is given in The Table 1.3-2.

Table 1.3-2: Average Monthly Rainfall at Pancheshwar dam site

Month mm Month mm Month Mm January 29.3 May 98.2 September 146.7 February 45.0 June 103.7 October 35.6 March 33.2 July 220.6 November 5.4 April 41.4 August 201.0 December 18.9

1.3.2.4 Mean Lake Evaporation

The lake evaporation data recorded at the measurement stations set up by both sides was adopted and given in Table- 1.3-3.

Table 1.3-3: Average Monthly Lake Evaporation at Pancheshwar dam site

Month Mm Month mm Month Mm January 22.8 May 149.7 September 98.5 February 38.8 June 133.8 October 85.5 March 77.0 July 123.3 November 43.6 April 135.4 August 108.3 December 26.2

1.3.2.5 Mean Monthly Inflows at Pancheshwar

The 50 years mean monthly flows starting from January 1962 to December 2012 are developed for the Mahakali River at the Pancheshwar Dam site on the basis of earlier gauge heights recorded by India, Nepalese gauge heights along with flow measurements. A correlation was established with the measured flows of the Karnali River as well. According to these studies, the average annual flows of the Mahakali River at Pancheshwar dam site, Rupaligad and Purnagiri GDS sites are estimated to be 582 m3Is, 621 m3Is and 667 m3/s respectively, with the monthly distribution as shown in the Table 1.3-4, Table 1.3-5 and Table 1.3-6.

Table 1.3-4: Average Monthly Inflows at Pancheshwar dam site

Month m3/s Month m3/s Month m3/s January 164 May 334 September 1193 February 150 June 602 October 507 March 157 July 1383 November 268 April 206 August 1805 December 194

Section 1: Executive Summary Page 9 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Table 1.3-5: Average Monthly Inflows at Rupaligad dam site

Month m3/s Month m3/s Month m3/s January 176 May 345 September 1287 February 162 June 621 October 536 March 167 July 1481 November 291 April 215 August 1935 December 207

Table 1.3-6: Average Monthly Inflows at Purnagiri GDS site

Month m3/s Month m3/s Month m3/s January 190 May 355 September 1409 February 175 June 647 October 575 March 177 July 1606 November 315 April 224 August 2106 December 221

1.3.2.6 Runoff from Intermediate catchment

Based on the above flow data, the intermediate catchments’ contribution between the Pancheshwar - Rupaligad was assessed to utilize it for the corresponding energy production at Rupaligad. Further, the intermediate catchments’ contribution between the Rupaligad - Purnagiri sites was assessed to meet the water requirements for irrigation in the downstream at the Tanakpur barrage.

The annual average runoff from the intermediate catchments between Pancheshwar and Rupaligad and between Pancheshwar and Purnagiri sites are estimated as 1230 Million m3 and 2695 Million m3 respectively.

Section 1: Executive Summary Page 10 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

The 75% dependable year runoff from the intermediate catchments between Pancheshwar and Purnagiri/ Tanakpur barrage site has been assessed around 2175 Million m3 only.

1.3.2.7 Flood Estimation at Pancheshwar dam site

The Probable Maximum Precipitation (PMP) in earlier studies was estimated on the basis of the storm of September 28-30, 1924, which had occurred to the west of the Mahakali Basin in India. It was reviewed and found valid as on date. Based on the above PMP, the PMF at the Pancheshwar and Rupaligad dam sites remains unchanged and assessed to be 23,500m3/s and 27,700m3/s respectively. Floods of smaller return periods were also determined through statistical analysis.

The Table 1.3-7 gives a summary of the basic characteristics of different floods considered in the design of civil works for Pancheshwar as well as Rupaligad dams.

Table 1.3-7: Floods for different Return period (m3/s)

Return Period (yrs) Pancheshwar Peak Flow Rupaligad Peak Flow 10 8272 8878 25 9867 10590 50 11078 11890 100 12310 13212 500 15296 16417 1000 16651 17871

1.3.2.8 Flood Estimation at Re-regulating Dam

The corresponding flood peaks at Rupaligad were estimated on catchment area proportionate basis (proportionate to 3/4th power of Area). The above floods would be reviewed with the available site-specific data before taking up the construction of diversion works.

1.3.3 Geology/ Geotechnics

1.3.3.1 Regional Geology

 The physiographic setting of Nepal and Uttrakhand State of India is dominated by the Great Himalayan Mountain Range which are the result of the collision between the Eurasian and Indian Tectonic plates. As the Indian plate is sub- ducted under the Eurasian plate, the upper crust is sheared off into a series of thrust sheets. With the continued movement of the plates these sheets are crumpled and folded. The collision of the plates started 40 to 50 million years ago and uplift has continued since that time in conjunction with igneous intrusion, and erosion, to produce the present day landform.

Section 1: Executive Summary Page 11 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

 The collision between the plates has produced five distinct physiographic provinces that extended the length of Nepal parallel to the Himalayas. All five of the physiographic provinces are represented in a 150 km wide region of Pancheshwar Multipurpose Project covering adjacent areas of India & Nepal.

 The area around the project site from south to north is occupied by a gamut of rock types comprising of sedimentary, meta-sedimentary and crystalline, which are separated from each other by tectono-structural discontinuities. A generalised sequence of the rocks in the area is shown in Table-1.3-8 from south (Tanakpur) to North (Tawaghat).

 The Pancheshwar dam is to rest over the rocks belonging to Almora Crystallines (Kalikot formation in Nepal). This Proterozoic Group of rocks, along with Central and Askot Crystallines and Ramgarh Group, are characterized by regionally metamorphosed katazonal meta-sediments of green schist and amphibolites facies.

 Pancheshwar Multipurpose Project is located within two important tectonic surfaces, the Main Central Thrust (MCT) towards north at a distance of about 80 km and the Main Boundary Thrust (MBT) towards south at about 25 km.

1.3.3.2 Geotechnical Investigations:

To carry out the geological studies for the project area, extensive geological and geotechnical investigations had been carried out at Pancheshwar and Rupaligad re- regulating dam site(s) starting from early eighties. It included surface geological mapping, diamond core drilling, test adits, seismic refraction surveys, in-situ rock mechanics testing, micro-seismic instrumentation and laboratory testing.

The work of geotechnical investigations at Pancheshwar and Rupaligad dam sites were resumed again in the year 2015-16 by WAPCOS. Additional samples were collected at site and tested in the laboratory by CSMRS, New Delhi.

Section 1: Executive Summary Page 12 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

For updating the Pancheshwar DPR, following additional geotechnical explorations were conducted by WAPCOS Limited:

 Twelve new boreholes at rock fill dam axis at Pancheshwar, two holes at Chamtada landslide area in the upstream of the Pancheshwar dam, two deep holes; one on each underground cavern area totalling of 1800m.  In-situ rock mechanics tests in the existing drifts to ascertain the rock mass characteristics at Pancheshwar dam site.  Geological and geotechnical investigations at the alternate Rupaligad dam site (lower dam axis) by drilling around 20 boreholes at dam axis and appurtenant structures, totalling 2000 m in length.  All the boreholes were logged by the resident geologists at site and rock samples were tested in the laboratories at CSMRS, New Delhi. The results of in-situ and laboratory tests are given in the relevant sections.

1.3.3.3 Geology of Pancheshwar Reservoir

The Pancheshwar Reservoir is oriented in a north northeast-south southwest direction which is roughly perpendicular to the north-westerly regional structural trend of the geologic units. The principal structural features that can be identified within the reservoir are a series of Klippe or windows, which represent remnants of a Nappe or recumbent fold, where older igneous and metamorphic rocks from the MCT zone have been juxtaposed over groups of younger meta-sedimentary rocks. The dam site is located on the Dadeldhura Klippe.

Section 1: Executive Summary Page 13 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

The rocks within the reservoir are relatively weak with the exception of the dolomite and quartzite units. In addition, the dip of the rock is generally steep, especially near the dam, which is favourable to reservoir impermeability. There are no signs of Karst conditions that could contribute to reservoir leakage.

1.3.3.4 Geology of Pancheshwar Dam Site:

Considering abutment attributes and completeness of geological investigation, experts of CWC and WAPCOS recommended for investigation of the dam axis D-D’. The axis D-D’ has been considered for Rockfill dam and further explored during present investigation. In the dam site area, the river flows southerly through a deeply entrenched, 70m - 150m wide water channel with 4-10m deep water with steeply sloping abutments (1:1), local sub-vertical micro scarps, and nick points and abrupt changes in the slope gradient. The rocks are exposed at the toe of the abutments and at higher slope segments thickness of overburden varies up to a maximum of 38.40m. In the core zone of the dam, Quartz -biotite gneiss (Qbg) & Quartz- feldspathic Mica schist (Qfms) are exposed at places; Quartz- feldspathic Mica schist (Qfms) & Quartz biotite gneiss (Qbg) outcrops in the U/S part of shell -zone whereas Quartz biotite gneiss (Qbg), Micaceous quartzite (Mqtz) & Augen Gneisses (Augn) in the D/S part of the shell zone. These rocks strike N51°W-S51°E and generally dip steeply (70° to 75°) in SW quadrant. However, because of intricate folding, local

Section 1: Executive Summary Page 14 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT variations in the attitude of the formations are noted. The axial core zone along dam axis D-D’ including either of abutments has been explored with the help of 10 drill holes. Considering the exploratory holes taken in the central river section and either of the abutments a geological section along dam axis D-D’ has been evolved to illustrate the sub-surface geological framework.

1.3.3.5 Geology of Pancheshwar Spillway and Plunge pool

It is proposed to construct a 122.5 long gated spillway with crest level at 658m. The spillway (dam) axis is oriented in N42° W- S42°E. The ground elevation in the spillway dam domain varies from 710m to 800m. It is obligatory to keep the foundation at El.650m. This would involve 175m (max.) deep excavation to house the proposed spillway head works. It is anticipated that at the foundation level, hard and compact micaceous quartzite and quartz biotite gneiss would be met with. It is proposed to excavate slopes at 1(H): 4(V) and 1(H): 6 (V) in moderately fresh rock however for safe excavation.

The longitudinal geological section illustrates the sub-surface geology of spill channel domain from straight reach of the approach channel to plunge pool. The spill channel is aligned N45Eº-S45ºW. As stated earlier, the rock excavation of the order of 175m depth is required to house the spillway dam at El. +625m. A 122.50m wide and 410.00m long chute emanating from the head works would run down at the gradient of 2.5(H):1 (V), upto flip bucket. This involves the rock excavation varying from 175m to 145m deep. The lateral training walls are proposed with 4m base width and 7m height. The plunge pool is located about 315 downstream of the concrete apron on the left bank of the Mahakali River. The Rollegad nallah crosses the approach to the plunge pool about 205m D/S of the concrete apron, hence it shall have diverted suitably to Mahakali River, before the crossing. As discussed earlier, the spillway slope in the domain could be classified into two parts viz. rocky slope segment above the Rollegad north of Rollegad nallah crossing and fan terraced slope between Rollegad and Mahakali River in the south.

The spill channel –plunge pool area has been explored with the help of 5 drill holes In the sections of Rollegad nallah the rock are sporadically exposed. However due to erratic weathering, locally the overburden has large thickness ranges upto 24.50m (SDH-5). The rocks are moderately weathered to a depth of 39m (max); at further depth, fresh and compact rock mass is encountered. In the section south of Rollegad nallah trending across the fan terrace 35m thick overburden consisting of fanglomerate deposits, has been encountered. The explorations reveal that the foundation domain of the spill channel consists of litho-units Quartz feldspathic mica schist, (Qfms, GSI 40-50), quartz- biotite gneiss, (Qbg, GSI 55-65), Micaceous quartzite (Mqtz, GSI 55-65) and augen gneiss (Augn, GSI 60-75); further beyond the plunge pool domain quartz feldspathic mica schist (Qfms) are anticipated. The foundation of the training wall would rest on litho-units Mqtz, and Augn. The major

Section 1: Executive Summary Page 15 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT part of the spill channel consists of augen gneiss (Augn), whereas the plunge pool domain consists of quartz mica schist (Qfms).

1.3.3.6 Geology of UGPH on left Bank (Nepal Side)

The UGPH (H x W x L) 57.3m x 23m x 286.5m is located with the core of the ridge left bank (max. EL 780m) forming water divide between Rollegad Nallah in the south and another unnamed nala in the north. The crown and invert are kept at EL. 454.80m and 397.50m respectively. The ground elevation in the ridge line varies from El 670m to 780m and accordingly the vertical burden above cavity crown varies from 167m to 325m. The lateral cover towards Mahakali River varies from 210 to 260m. The UGPH area consists of three litho- units viz. Micaceous quartzite with bands of granitized schist (Mqtz), Quartz- biotite gneiss (Qbg) and Augn gneiss (Augn); the Mqtz occurs in the central part of the cavity. Whereas the Qbg and Augn are exposed in the NW and SE parts respectively. These strike in N70°W-S70°E and dip 80° in S20°W. Thus the long axis of the cavity is oblique to the foliation with internal angle of 50°. Two new holes NDH 9 and NPH 02 were recently a drilled by WAPCOS in the vicinity of UGPH. The drill core results revealed that with depth the rockmass improves and rock quality Q value also increases. The core results reveal the UGPH will be drive in fair to good rockmass condition. The Q value varies 1.5 to 7.5 in NDH-9 and 1.8 to 10 in the NPH-2.

Based on review of the sub- surface explorations, the dam site regime has been classified into two units viz. (a) the core zone of the abutments below El 550m (i.e. vertical cover of 200m) and lateral cover of 100-150m and (b) surficial cover above EL550 (vertical cover <200m) and lateral cover <100m. Thus, in view of large vertical (>300m) and lateral cover (>200), the powerhouse cavity in Nepal side lies in the core zone. Accordingly, the litho-units in UGPH domain have been geo-mechanically classified assigning RMR base for Augn, Mqtz and Qbg litho-units.

The intake of the Power tunnel (3Nos -Ø8.7m) is proposed 650m U/S of the Rockfill dam axis. Geological section has been drawn to illustrate ground conditions based on geological map and subsurface data projected from nearest drill holes located on adjoining appurtenants viz drill hole NDH-12, SDH-1 and NPH-2 and D-15. The initial part of the power tunnel trend sub- parallel to the strike of the formation of the area and further swerves towards south and then SW to enter the UGPH cavity. The tail race tunnel ensuing from surge chamber, trends in south-west direction to carry discharges back to south-easterly flowing Mahakali River. The proposed PT system negotiates across litho- unit’s viz. Qfms, Mqtz and Augn. At the distal end of the TRT the second band of the litho-unit Qfms is exposed. These are traversed by multiple of discontinuities.

The vertical cover, excepting for initial and terminal reaches, is > 200m ranging to a maximum of 390m. Geological section has illustrated ground conditions along PT-

Section 1: Executive Summary Page 16 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

TRT system based on geological map. As seen from the section, the dominant tunnelling ground for PT is the disturbed blocky rock mass of Qfms. Minor bands of Qbg, Mqtz and Augn would also be intercepted. Considering vertical and lateral cover, litho-units likely to be encountered, angle between trend of the proposed orientation of the tunnels and foliation, vertical cover above the tunnel grade and lateral cover over the PT-TRT system, it has been classified into seven segments.

1.3.3.7 Geology of UGPH on Right Bank (India Side)

The UGPH (H x W x L) 57.3m x 23m x 286.5m on India side is located in the core zone of the abutments with vertical burden 159-353m and lateral cover of >245m. The modified orientation of long axis of the cavity (N54°E-S54°W), is nearly 50° oblique to the main direction of stresses and oblique to foliation (56°). The cavity domain has been explored by 360m long drift also; however, 3D logs are available for 270m. The drift has intercepted Mqtz with four numbers of foliation parallel minor shear seams. It would be worthwhile to excavate cross cuts and conduct in-situ tests for further rock mechanic characterization. For preliminary evaluations, a schematic geological section of the UGPH cavity domain has been developed based on geological comprehension based surface based geological map. It is seen that UGPH and associated cavity are located within 450m wide bands of micaceous quartzite associated with granitized mica schist. The quartzite rock mass is attributed with GSI values of 55-65. The Rock mass classification in core zone of the mountain can be taken from attributing these with RMR 41 to 60. Considering these, the excavation response in the cavity has been evaluated following simplified procedure of Russo (2007).

The excavation response in case of PT/ TRT tunnels has been dealt with, in general describing the broadly expected rock mass condition and tunnelling issues for want of precise subsurface data. The right bank has been taken up for detailed assessment with the help of drill hole NPH-1 which has been drilled recently in power house location falling close to middle reaches of the tunnel. Important subsurface data from a few older drill holes have also been imported for the sake of the incorporation of potential weak zones of significant thickness and long distance continuity with possibility of intersecting the tunnel e.g. the shear/ fracture zones of 12m and 14m thickness encountered in drill holes A1/2 and A2/6 respectively in river section. The different lithological zones have been ascertained with their several geotechnical attributes albeit with limitation for want of rock conditions at tunnel grade. Of these, initial, middle and end reaches are of significance. Initially along a stretch of 570m, the tunnel alignment runs oblique to foliation cleavage/ foliation joint planes. Middle 800m long reach strikes these master discontinuities at an acute angle of around 300 and remaining end reach of 600m length is transected by foliation at right angle.

Section 1: Executive Summary Page 17 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.3.3.8 Geology of Diversion Works- Tunnels and Coffer dams

A geological section has been developed for DT No. 2 having 2733.00m long, 14m dia. circular shape on the left bank. The inlet and outlet portals are proposed at an El. of 410.0 m and El. of 397.0 m respectively. The diversion tunnel is located between an area 2073.15 m upstream and 732.72 m downstream of Rockfill dam axis on the left bank. The upstream coffer dam would be located about 910.0m (along centerline of River) upstream of rockfill dam axis with a dam top El. of 461 m. Similarly, the downstream coffer dam will be 550.0 m (along C/L of River) downstream of the rockfill dam axis with dam top El. at 436 m. The diversion tunnel alignment is traversed by two nallah at RD 111.74m and 1766.3m. The nallah at RD 1766.3m is deeply incised which can possibly be structurally controlled and could be the source of water seepage in the diversion tunnel. The rock cover above the diversion tunnel is estimated around 96-227 m at between RD 200 to 2690m. The diversion tunnel corridor on the left bank with lateral cover ranging from 73.96m – 744m. The initial 887.9m would have Augn gneiss (Augn) as tunnelling ground. The units Quartz feldspathic mica schist (Qfms) and Quartz biotite gneiss (Qbg) would be intercepted between 887.9- 2067m and 2067-2225m. The unit’s micaceous quartzite (Mqtz) & Augn gneiss (Augn) would be intercepted between 2225-2338m and 2338- 2788m sections, respectively. The remainder of the tunnel would have Quartz feldspathic mica schist (Qfms) as tunnelling ground.

On the right bank, a geological section has been developed for DT No. 4 having 2504.00m long, 14m dia. circular shape. The inlet and outlet portals will be located at an El. of 410.0 m and El. of 397.0 m. The diversion tunnel is located between an area 1582m upstream and 922m downstream of Rockfill dam axis on the right bank. The upstream coffer dam is about 910.0 m upstream of rockfill dam axis with a dam top El. of 461 m. Similarly, the downstream coffer dam is about 550.0 m downstream of the rockfill dam axis with dam top El. at 436.0 m. The diversion tunnel alignment is traversed by five nallah at RD 536m, 686m, 1299m, 1684m and 2378m. The nallah at RD 2378m is deeply incised which has possibility of water seepage in the diversion tunnel. The rock cover above the diversion tunnel is around 38-275 m at between RD 200 to 2495m.The DT system would have lateral cover ranging from 85-512m. Approximate rock mass quality estimates and assessment of overall tunnelling condition has been attempted zone wise based on the surface and subsurface geological projections.

1.3.3.9 Geology of Rupaligad Dam Site and Spillway

A 95m high concrete gravity dam is to be located on an intercalatory sequence of Quartzite and Mica schist, dominated by the former. The quartzite is whitish grey, medium grained and strong (GSI 60 to 70). The Mica schist is greenish grey to light grey, fine to medium grained, well foliated and weak to moderately strong (GSI 35 to

Section 1: Executive Summary Page 18 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

45). Foliation runs almost parallel to slightly askew to dam axis with moderate dips predominantly towards upstream. Major joint sets mostly exhibit a favourable orientation. From subsurface exploratory data, it is evident that the thickness of overburden is maximum 5m on abutments and slightly weathered to fresh rock occurs either just below the overburden or a couple of metres beneath. However most of the drill hole sections are conspicuous of frequent nil to low RQD zones. The dam foundation is not homogeneous as the competent quartzite is often associated with Mica schist bands of up to 10m thickness. This intercalatory association of alternating foundation media of differing strength parameters renders the foundation heterogeneous. It will be reasonable, therefore, to design the foundation on the strength of weaker foundation rock to avoid possibility of differential settlement and avail the competence of stronger foundation rock as an additional advantage. Over all permeability values vary between Lu<1 and 43. But more commonly the higher values are restricted around 20-30Lu only. The permeability tends to decrease gradually with depth but reversal and deviation from this trend are also recorded. As observed in drill hole core, both the Quartzite and Mica schist are fairly well fractured with variations in core recovery and considerable fluctuation in RQD within the envelope of low to moderate RQD. In general, with spot specific modifications, rock cut slopes of 600 and 650 are likely to be stable on abutments with the corrective measures.

A centrally located bucket type, gated spillway with crest level at 386.00m is proposed to pass a maximum flood discharge of 27,700 m3/s at the Rupaligad dam site. It is 192.00m long along the dam axis with downstream extension of around 200m up to the end of plunge pool as a part of energy dissipation arrangement. It is to be founded on a heterogeneous foundation consisting of relatively competent Quartzite (RMR 56-67 and GSI 60-70) with weaker intercalations of Mica schist (RMR 35-51and GSI 35-45) as depicted by all the drill holes drilled in Dam/ spillway domain. Deepest foundation in the river bed as depicted in case of the main dam is anticipated at a depth of around 35m (EL 335m).The maximum depth in the river bed for the foundation of all concrete structures including the appurtenant for energy dissipation has to be lowered down to bedrock underlying a maximum pile of 33m thickness of RBM. On left bank, a stripping of 12 t0 16m deep (EL 378m to EL 382m) from the surface will be enough to rest the foundation. The same 3m thick shear/ fracture zone intersected in drill hole DH-3 may encroach upon the dam foundation on the left bank in spillway section required dental treatment attendant with contact grouting and provision of drainage holes. This is a foliation shear and is likely to strike the dam length at a low angle (150 to 200) crossing the dam body for a considerable length. On right bank maximum excavation to a depth of 10m to16m (EL380m to EL 365m) is foreseen. As projected in drill hole DH-2, a one m thick shear zone is anticipated to encroach upon the downstream toe part of dam necessitating dental treatment as mentioned in respect of left bank shear zone. This is also a bedding shear and may intersect dam length at a low angle.

Section 1: Executive Summary Page 19 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.3.3.10 Geology of Rupaligad UGPH on the Left Bank (Nepal Side)

A power house cavern with dimension of 24.00m X 49.50m X 112.00m (W/H/L) is proposed on the left bank of the river at Rupaligad site between the elevation of 338m and 388.50m with a vertical cover of 146m and lateral cover of around 136m. The transformer cavern has been located at about 48m away to obviate mutual interference of lateral stresses. This extent of rock participation between the two caverns of respective width of 24.00m and 19.00m should be duly analysed from tunnel stability point of view to avoid instability emanating from mutual interference of the lateral stresses. The cavern will be excavated in moderately strong to strong quartzite with intercalatory weaker bands of garnetiferrous mica schist. These schist bands may form significant horizons of relatively weaker strength for a thickness of up to 10m. They are repeatedly found as intercalations in Quartzite in drill hole core of dam axis area. The longer axis of power house cavern was fixed in N150W- S150E (N3450) direction at an angle of 600 from foliation strike. The vertical cover of 140m does not rise any possibility of encountering squeezing condition in softer Mica schist bands during excavation. The rock mass characterization carried out in surficial outcrops of Quartzite and drill hole core in adjoining part is indicative of RMR value of 45 to 57 and GSI 60 to 70 (Fair to Good rock). In respect of garnetiferrous Mica schist/Mica schist, it varies between RMR 35 to 50 and GSI 35 to 45 (Poor to Fair rock). Based on the extrapolation of these data, the rock mass quality in proposed power house cavern is indicative largely of “Poor” to “Fair” and “Good” tunnelling media. Stereographic projection and wedge analyses indicates that Joint plane J1^J3, J1^J4 and J1^J5 form wedges with moderate to steep plunge in vulnerable direction. Similarly, joint planes J2^J4, J2^J5 and J3^J4, J3^J5 also produce intersecting wedges on the wall of cavern with moderate plunge on the wall.

Twin Tailrace tunnels of 7m dia and 56 m length are to be excavated with 18m wide intervening column of rock mass. The tunnels extend in S75OW direction striking foliation at an angle of 300. They are to be driven through moderately strong Quartzite ( RMR 50-60 ) with intercalated bands of soft and weak Mica schist (RMR 35-43) designating the rock mass largely as Fair-Good Rock with poor reaches in Mica schist. TRT out fall is to be founded on competent quartzite exposed on the surface. Foundation grade is likely to be available here at a very shallow depth. Steep rock cut slopes are foreseen to be stable at outlet portal of TRT with Shotcreting and selective rock bolting.

1.3.3.11 Geology of Rupaligad UGPH on the Right Bank (India side)

The power house cavern on right bank with dimension of 24.00m X 49.50m X 112.00m (W/H/L) is proposed between the elevation of 338 and 388.50m. The NSL above the cavern is EL 538m. The power house cavern is thus confined under a vertical and lateral rock cover of 150m having optimum rock participation from either

Section 1: Executive Summary Page 20 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT direction. It is to be located in moderately strong to strong quartzite with relatively weaker intercalatory bands of garnetiferrous mica schist. The presence of these schistose bands of up to 10m thickness as observed in proximity to dam seat may denigrate the overall quality of rock mass in power house cavity. Actual presence of any significant weak zone traversing the power house and transformer hall caverns can be further ascertained after the completion of subsurface exploration by drifts. So far, the available data do not reveal any possibility of extrapolated weak zone crossing these underground structures. Thus the power house cavern axis strikes the general foliation trend at an angle of 750. The vertical cover of 150m rules out any possibility of encountering squeezing condition in softer Mica schist bands during excavation. The rock mass characterization based on surficial outcrops and drill hole data from adjoining area is indicative of RMR of 50 to 63 and GSI 60 to 70 (Fair to Good rock) in Quartzite. In respect of garnetiferrous Mica schist/Mica schist, it varies between RMR 35 to 50 and GSI 35 to 45 (Poor to Fair rock). Based on the extrapolation of these data, the rock mass quality in proposed power house cavern is indicative largely of “Fair” and “Good” tunnelling media with localised bands of Poor to Very poor rock mass.

Further, 92m long twins Tail Race Tunnels of 7m dia. are contemplated in N600W- S600E direction, almost sub parallel to parallel of foliation cleavage/joint. The tunnel will be driven predominantly through moderately strong Quartzite (RMR 45-55) with intercalated bands of weaker Mica schist mostly with orientation specific poor rock mass characteristics (RMR 30-38). Outlet portal back slopes are gentle and likely to be stable with minimum remedial measures. TRT outfall is located on overburden comprising slope wash material of sandy-silty soil and talus boulders. A drill hole is proposed (DH-28) to probe the overburden thickness and evaluate foundation for outfall.

1.3.3.12 Geology of Diversion Works- Tunnels and Coffer dams at Rupaligad site

The bearing of 1023m long 12m dia proposed diversion tunnel on the left bank shows two kinks along the alignment. The tunnel is to be driven through moderately strong to strong Quartzite with intercalated subordinate bands of Mica schist traversed by several sets of discontinuity. The tunnel is to be driven through moderately strong to strong Quartzite with intercalated bands of Mica schist traversed by several sets of joints. The Quartzites are characterized by RMR 45 to 63 (Fair to Good Rock). However, the intercalated Mica schist bands, which are up to 10m thick, denigrate the overall rock mass quality. These bands in addition to remaining 40% rock mass along the tunnel alignment constitute weak tunneling media characterized by RMR 30 to 45 (Poor to Fair Rock mass). The average foliation trend of rocks is N750 W-S750E with a dip of around 500 towards N150E i.e. towards upstream of the tunnel. If tunnel is driven from outlet portal side, no significant adversely oriented wedges are anticipated at crown along all variations in

Section 1: Executive Summary Page 21 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT tunnel alignment. Joint planes J2^J5 only form wedge near crown with a shallow plunge. Mainly top heading and benching with short advances will be applicable as tunnelling method.

Another 958m long and 12m dia diversion tunnel is proposed on the right bank. Its alignment is also punctuated by three kinks. As per the projection from surface geological map more than 70% of the tunnel excavation is to be accomplished in moderately strong to strong quartzite with intercalated bands of Mica schist, predominated by the former. Remaining 30% rock mass is likely to consist mainly of weak to moderately strong Garnetiferrous Mica schist with thinly interbanded quartzite. A 50cm thick foliation parallel shear zone has been inferred at around RD 260m in Mica schist below Kharagnala. Very poor rock conditions are expected in this zone for a short stretch of a few meters. The foliation strikes the veering tunnel alignment at an angle of 320 to 750. According to rock mass quality estimates, the Quartzite is characterized by RMR 45 to 65 (Fair to Good Rock), intercalated Mica schist horizon by RMR 35 to 45 (Poor to Fair Rock) and Shear/ fracture zone by RMR 15 to 20 and GSI 20 to 30 (Very Poor Rock). The maximum vertical rock cover over the tunnel is 234m abstaining squeezing possibility in Mica schist horizon due to convergence.

A 24m high and 163.0m long rock fill coffer dam with an impervious clay core and upstream concrete face is proposed at 148m upstream of main dam axis. The upstream cofferdam area is occupied mainly by garnetiferrous Mica schist with thin interbands of Quartzite. The maximum depth of bed rock in river section to found the core is likely to be of the order of 32 to 35m. Construction of coffer dam on riverine overburden after consolidation by high pressure jet grouting may be considered to avoid deeper excavation for founding the impervious core.

A 17m high and 110m long rock fill dam is proposed at about 200m downstream of the main dam. Competent Quartzite with intercalatory Mica schist is available on each bank almost at surface or at a very shallow depth. However, in the riverbed, which will accommodate the maximum length of the dam, the bed rock is anticipated to be available at a depth of a couple of meters on the river edge to as much as about 33m in the deepest channel bed beneath a thick pile of riverine sediments..

1.4 Sedimentation

1.4.1 Pancheshwar Reservoir

The average sediment rate of last 26 years data (1983 to 2013 with gaps) has been considered along with the depth integrated sample sediment rates obtained for the period 1990 to 1992. The average sediment rate of these values excluding the year 2007 is 3.42 mm/year including 20% as bed load. The annual sediment load at Pancheshwar dam site has been estimated 41.98 Million m3.

Section 1: Executive Summary Page 22 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

The Full Reservoir Level of 680 m has been finalized and sedimentation studies have been carried out with this level only. Trap efficiency of the reservoir has been calculated by Brune's method and sedimentation distribution in the reservoir has been done using the Borland and Millar Empirical Area Reduction Method. The result of the study such as the percentage loss of gross storage, live storage and dead storage after 25, 50, 70 and 100 years of sedimentation have been described in detail in relevant sections.

During the first 100 years of operation of the reservoir, the trap efficiency will be of the order of 96% and the material that is not decanted in the reservoir may go through the turbines. The un-trapped annual sediment load amounts to about 1.16 million cubic metre, which corresponds to a sediment concentration of about 63 ppm, indicating turbidity nearly acceptable as drinking water.

1.4.2 Rupaligad Re-regulation Reservoir

The annual trapped volume of sediment in Rupaligad reservoir has been estimated to be more than 0.5% of the gross capacity of reservoir. As per IS Code No. 12182 - 1987 "Guidelines for determination of effects of sedimentation in planning and performance" the problem of sedimentation was treated as serious. To deal with the sediment load from the Rupaligad catchment, sluice spillway has been provided at Rupaligad dam. During monsoon, major sediment load would be flushed in the downstream through sluice gates.

1.5 Construction Materials

1.5.1 Materials Survey

Field investigations to assess the availability of different types of construction materials in the vicinity of the project area had been carried out by India and Nepal separately and also jointly by them. The first field investigations were carried out by India to locate a source of impervious core material for the earth-rockfill dam. Three borrow areas for impervious material, three borrow areas for fine sand and four borrow areas for boulders cum sand were located in the Indian Territory during 1983- 84. Between 1989 and 1991, field investigations were carried out by the Nepalese side to obtain a preliminary assessment of the availability of construction materials in Nepalese territory. In 1993, India and Nepal conducted joint field investigations primarily in India, although some samples were collected from Nepal areas also.

As a part of additional field investigation and studies, JPO-PI entrusted the work of construction materials investigation and rock mechanics tests to Central Soil and Material Research Station, New Delhi (CSMRS) to ascertain the quantity & quality of impervious core material and rockfill material for the main dam. CSMRS had carried out field investigations for core material in 2001-02 and thirty two representative bulk soil samples were collected for laboratory testing on Indian side. Tiger quarry on left bank and big Elephant Quarry on right bank were explored for shell material.

Section 1: Executive Summary Page 23 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.5.2 Materials Requirement - Pancheshwar

The Table 1.5-1 below summarizes the volumetric requirements for rockfill dam at Pancheshwar and source of the materials in the vicinity of the project site.

Table- 1.5-1: Construction Materials Balance – Pancheshwar

Material Type of Requirement Source of Availability Distance from Structure of Material Material of Material dam (km) (Mm3) (Mm3) Impervious Dam Patan (Nepal) 14.36 64 km Soil Impervious 13.18 Rato-Mato 26.60 30 km Core (Nepal) Pulhindola 38.04 15 km (by road) (India) Harkhera 17.29 10 km (by road) (India) Sand and Required 1.54 - coarse Filter 4.69 Excavation aggregate Binayak 8.47 9 km (Nepal) Kharyani 1.65 30 km (Nepal) River Bed 1.10 - Shell Rock fill + 120.00 Required 57.45 - material River bed + Excavation Rip rap Tiger Quarry Unlimited 2 km Coarse (Nepal) aggregate / Concrete 2.88 Leopard Unlimited 15 km Crushed Quarry (Nepal) sand River Bed 14.90 4 to 5 km Elephant Unlimited 2 km Quarry (Nepal)

1.5.3 Laboratory Tests - Pancheshwar

CSMRS, New Delhi carried out laboratory testing of samples collected during the field investigations taken up by JPO-PI. Suitable impervious material with most of the above characteristics is available from the Harkheda borrow area. The sand and gravel materials from which the filters will be processed will come from required excavations in the river bed as well as from terrace deposits along the river, in particular the Binayak Borrow Area, about 6 km upstream of the dam. The material from Tiger quarry and Spillway excavation will be utilised for shell material.

With a few exceptions, there exist in the vicinity of the dam site construction materials of sufficient quality and quantity to construct the proposed rock fill embankment and appurtenant structures.

Section 1: Executive Summary Page 24 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

The rock available from Tiger quarry, Binayak quarry, River boulder quarries, Diversion tunnel (Nepal side), Spillway (Nepal side), Swillghad village and Ghoria Nallah are found suitable for use as coarse aggregate in concrete for non-wearing surface only.

Therefore, WAPCOS Ltd investigated further area and finally located a rock quarry for use of coarse aggregate in concrete, two km below the dam axis (Tiger Quarry) on the Nepal bank suitable for the wearing surface.

The water samples were also collected near Pancheshwar dam site from the river Sarju and river Mahakali by CSMRS team for testing to use the river water for concrete structures.

1.5.4 Materials requirement for Rupaligad dam

Approximately 1.25 million m3 of coarse aggregates will be required for construction of Rupaligad dam and its appurtenant structures. For this purpose, WAPCOS has carried out survey and located a rock quarry near the Rayal village which is suitable in all respects for use as coarse aggregates in concrete for wearing as well as non- wearing surfaces. The aggregates from the rock quarry near the dam axis will be used for non-wearing surfaces only, if required.

Section 1: Executive Summary Page 25 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.6 Seismicity

The site for Pancheshwar Project lies within the most complex tectonic belt, the Main Himalayan Belt. It is bounded by the MCT in the north (65 km) and MBT in the south (25 km), both of which are believed to be presently active. Pancheshwar dam is to rest over rocks belonging to Almora Crystallines/ Dadeldhura (Proterozoic), interpreted as a nappe structure confined between the North and South Almora Thrusts.

A seismo-tectonic review of the project area reveals that the site lies in a hyperactive seismic environment. The project area forms part of the Main Himalayan Seismic Zone. The seismic activity has been related to the under-thrusting Indian Plate below the Lesser Himalaya and is found concentrated along the detachment surface, MCT, and the basement thrust. A seismically active belt striking north-northwest over a length of about 1.10 km and located about 80 km northeast of the dam site was uncovered by the micro-seismic investigations carried out.

The Rangun Khola Fault, located approximately 30 km south of the dam site, is considered to be the most critical source of seismic activity for the project. For such maximum credible earthquake, different attenuation models applied led to estimates of the maximum peak acceleration at the site ranging from 122 to 256 gals. On the other hand, a statistical analysis of the available historical records gave peak accelerations of 90 gals for a return period of 100 year and of 104 gals for 200 years with the most conservative attenuation model considered.

Reservoir induced seismicity is not considered a problem for the project.

The magnitude of Maximum Credible Earthquake (MCE) is estimated to be 8.1. On the basis of the tectonic features in the vicinity of the project site and the distribution of the hypocenters of past-earthquake, the closest distance of the fault rupture plane for MCE is estimated as 39 km. In order to review the seismic design parameters of the project, CWPRS, Pune was assigned the study and they have recommended horizontal coefficient 0.24 and vertical coefficient 0.16, for the dynamic analysis of the Pancheshwar project.

1.7 Infrastructure and Communication Survey

 In order to transport the generating units to Pancheshwar, a new road capable of transportation of over sized consignments of electro-mechanical equipment was envisaged on left bank on Nepal side from Brahmdev – Kancheshwar - Rangun Khola – Simatta – Sirsha – Rupaligad – Dhamkudi – Pancheswar. The oversized consignments will be transported on 16 axle Trailers, for which 15 m wide road has been planned with a turning radius of 25 m at critical bends.

 The total length of new road has been assessed 90 Km from Brahmdev to Pancheshwar via Rupaligad dam site, involving about twenty minor and major

Section 1: Executive Summary Page 26 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

bridges of spans from 50 m to 600 m. A major bridge across Rangun Khola (600 m span) and a tunnel of 2.0 km in length at Simalta village are also proposed to reduce the length of road by 8 km.

1.8 Benefit Assessment & Project Optimization

1.8.1 Power Market Review

In order to evaluate the potential for the Project to sell all the energy produced from the time of its commissioning, a review of the latest available power market forecasts and power system expansion plans for northern India and Nepal has been carried out. Data on the power market and power system of Northern India has been taken from Central Electricity Authority, India; for the power system of Nepal from the latest official documents made available by Nepal Electricity Authority, Nepal.

1.8.2 Power and Energy Benefits

Reservoir simulation studies have been carried out to compute the firm power (MW) and annual energy production (GWh) from the Pancheshwar Multipurpose Project with re-regulating dam at Rupaligad site. The Pancheshwar powerhouse would operate in the interest of power generation while protecting downstream irrigation requirement and would provide peaking benefits.

The Rupaligad pond would store the peaking outflows from Pancheshwar Power Stations and re-regulate them to provide continuous river flows to meet the irrigation water requirement downstream.

FRL for Rupaligad re-regulating dam has been adopted as + 420 m considering tail water level of Pancheshwar Power Houses. The MDDL for Rupaligad was considered as 400 m, with a view to provide the diurnal storage of 56 Million m3.

For carrying out the simulation studies, water requirement of local communities @ 5% of the annual average flow at Pancheshwar dam site was reserved and not considered for the power generation. The downstream irrigation water requirements have been protected from Pancheshwar reservoir after taking into account the additional water available from the intervening catchment between Pancheshwar and the Tanakpur barrage.

The results of the simulation studies indicate the firm power at Pancheshwar as 767 MW as shown in the Table 1.8-1 below. The annual energy benefits are assessed as 7678 GWh on 90% dependable basis with a total installed capacity of 4800 MW in two power stations, one on each bank of the river (six units of 400 MW in each power house). The proposed installation would enable operation of the station to provide four hours daily block of peaking capacity and the stations would operate at a load factor of 15-16%.

Section 1: Executive Summary Page 27 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

In addition, the annual energy generation benefits from Rupaligad dam would be in the order of 1438 GWh on 90% dependable basis. An installed capacity of 240 MW, comprising two units of 60 MW each are proposed in each of the two power houses; one on left bank and the other on right bank of the river.

Table 1.8-1: Annual Energy Generation

Pancheshwar Annual Energy Generation (GWh) Installed 90% Dependable year Study Period Average Capacity Pancheshwar Rupaligad Total Pancheshwar Rupaligad Total (MW) 3200 7678 1438 9116 10063 1559 11622 3600 7678 1438 9116 10180 1559 11738 4000 7678 1438 9116 10248 1559 11806 4400 7678 1438 9116 10299 1559 11858 4800 7678 1438 9116 10327 1559 11885 5200 7678 1438 9116 10349 1559 11908 5600 7678 1438 9116 10366 1559 11925 6000 7678 1438 9116 10375 1559 11934 6400 7678 1438 9116 10375 1559 11934

Based upon the cavern width of 23 m and transport considerations, the units size at Pancheshwar have been selected as 400 MW.

1.8.3 Irrigation Benefits

1.8.3.1 Existing consumptive uses of Nepal and India

 Banbasa Barrage

The waters of Mahakali River are being utilized for irrigation in India since the commissioning of Banbasa Barrage in 1928. Some Terai area in Nepal has also been benefited by the Mahakali waters drawn from the Banbasa Barrage.

In accordance with the earlier agreement of 1928, Nepal is entitled to draw 28.35 m3/s (1000 ft3/s) of water in monsoon season (from 15th May to 15th October) and 4.25 m3/s (150 ft3/s) in the dry season from the Banbasa Barrage. This water drawn from Banbasa Barrage provides irrigation to a command area of 11,600 ha; 4800 ha under MIP stage-I and 6800 ha under MIP stage-II in Kanchanpur district of Nepal.

For providing the irrigation facilities to India, a canal on right bank with 326 m3/s (11,500 ft3/s) discharge capacity for India and another canal on left bank with 28.35 m3/s (1000 ft3/s) capacity for Nepal were constructed by signing an agreement between British India and the King of Nepal in 1920.

Section 1: Executive Summary Page 28 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

 Tanakpur Barrage

Another barrage at Tanakpur, about 10 km upstream of the Banbasa barrage was constructed in 1985 by M/S National Hydro-electric Power Corporation of India, across river Sarada, in India to generate power. For commissioning of the Tanakpur HEP, an agreement was reached between India and Nepal in 1991 which was subsumed in the Article-2 of the Mahakali Treaty.

Under the Article-2 of the Treaty, Nepal is entitled to receive 28.35 m3/s (1000 ft3/s) water in the wet season and 8.50 m3/s (300 ft3/s) of water in the dry season from the Tanakpur Barrage. A new canal of 28.35 m3/s (1000 ft3/s) discharge capacity has been constructed from the Tanakpur Barrage, under the grants-in-aid assistance by the Ministry of External Affairs, GOI to supply additional water to Nepal.

 Lower Sarada Barrage

In the early seventies, the State Government of Uttar Pradesh (Irrigation Department) commissioned another project known as Sarada Sahayak Pariyojna (System) in district Lakhimpur Kheri of Uttar Pradesh. The original command of Sarada canal system, lying East of Sarada Sahayak Feeder was deleted from the Sarada canal system and transferred to the Sarada Sahayak system in 1975.

The Sarada Sahayak system with design discharge of head works as 650 m3/s draws irrigation supplies from the Lower Sarada Barrage, 160 km downstream of Banbasa Barrage, during monsoon season and dependent on the Mahakali waters for meeting the irrigation requirements in the lower command area (20 lakh ha).

The inflows in the Mahakali River during the monsoon season are sufficient to meet the existing water requirements of India and Nepal at Banbasa, Tanakpur and Lower Sarada barrages.

1.8.3.2 Existing Use of Nepal for Irrigation

The existing consumptive uses of Nepal are thus, agreed under the Article 1 & 2 of the Treaty in a year as 451 MCM from Banbasa barrage and 529 MCM from the Tanakpur Barrage respectively. Total existing use of Nepal is of the order of 980 MCM per annum

1.8.3.3 Existing Water Use of India for Irrigation

Total existing water requirement of India comprise of (i) Existing Water Requirement of Sarada canal system throughout the year and (ii) Existing Water Requirement of Sarada Sahayak system for monsoon period. The existing water use of India through Upper Sarada Canal system and Sarada Sahayak system are of the order of 7,071 MCM & 4,790 MCM respectively totalling to 11,861 MCM per annum.

Section 1: Executive Summary Page 29 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.8.3.4 Irrigation Benefits from the project

Irrigation benefits in Nepal have been assessed on the basis of the previous studies on the proposed irrigation area in Nepal from the project, illustrated in the report of Pancheshwar Consortium (PACO)-1991 on Field Investigations within Nepal Territory.

Irrigation benefits in India have been assessed on the basis of evaluation of surplus augmented flows available during dry season after meeting requirement for existing irrigation in India and Nepal as well as additional irrigation in Nepal. For this purpose maximum additional irrigation that is techno economically feasible in Nepal from Mahakali river has been considered.

A 75% dependable year criteria has been used for defining the available water resources. Depending on the availability of sufficient regulated water in the Mahakali River, a total command of about 93,000 ha could be developed in Nepal between Mahakali and Karnali.

1.8.3.5 Future Water Requirement of Nepal

Under the Article-4 of the Treaty, India shall supply 10 m3/s (350 ft3/s) water for irrigation of Dodhara – Chandani area of Nepalese Territory. Further, as per the Article-5 of the Treaty, water requirements of Nepal are given prime consideration in the utilization of the waters of the Mahakali River. With the availability of augmented flows in the post-Pancheshwar scenario, it has been assessed that a maximum crop area of 170,720 ha can be brought under irrigation (including 6,040 ha of Dodhara- Chandani area) in Nepal with the available additional water on implementation of Pancheshwar Multipurpose Project. For development of this command, additional water requirement will be of the order of 3,073 MCM. Thus, total water use by Nepal will be 4,053 MCM comprising of 980 MCM as existing use and 3,073 MCM as future use.

1.8.3.6 Future Water Requirement of India

Additional Irrigation in India from Pancheshwar Multi-purpose Project has been considered during dry season only as enough water is available in Sarada River for irrigation in existing commands during monsoon even for without Project scenario. Considering the power releases from Pancheshwar and water available in the intervening catchment from Pancheshwar to the Tanakpur Barrage, after meeting the existing requirement of Nepal and India and future requirement of Nepal, additional 1,905 MCM of water would be available to India in the post-Pancheshwar scenario. With the additional water to India, annual irrigation may be enhanced by 2.59 lakh Ha. Thus, total water use of India will be of the order of 13,766 MCM on implementation of Pancheshwar Multipurpose Project. A detailed statement indicating the total water requirement of India and Nepal is given in the Table 1.8 -2.

Section 1: Executive Summary Page 30 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.8.4 Flood Control Benefits

Since no dedicated storage is proposed for flood control, benefits on account of reduced floods are incidental. The average annual value of the potential flood control benefits in Nepal was computed through a statistical analysis of the annual flood damages with and without the project along the 50 years economic life of the plant. Without the project, the average annual flood damages in Nepal were computed to reach 0.81 million US$, that would be reduced to 0.15 Million US$ per year after the project implementation as stated in the draft Indian DPR of 2003. WAPCOS has reviewed the potential annual flood control benefits in India and Nepal; and estimated INR 740 million and INR 160 million respectively, at 2015 price level.

Thus, total annual flood benefits in the post Pancheshwar scenario would be of the order of INR 900 million at 2015 price level.

1.9 Design of Civil Structures of Pancheshwar Multipurpose Project

The course of the River Mahakali in its upstream reaches is characterized by very steep drops both on the main river and its tributaries. In its middle and lower reaches it flows through relatively gentle gradients providing a good scope for a storage project. Accordingly, in the preliminary studies, various sites were considered for location of a storage dam project just downstream of the confluence of river Mahakali with Sarju. The dam site was selected in view of the narrow gorge flanked by high rising hills and gentle gradient. In the present study, the same site was studied further for the Pancheshwar Multipurpose Project which consists of main dam and a re-regulating dam at Rupaligad, around 27 km downstream of Pancheshwar dam.

1.9.1 Pancheshwar Dam

A considerable area around the proposed dam site had been investigated in the past by India and Nepal in detail, to explore the surface as well as subsurface geology of the dam site and to locate a suitable dam axis. The investigations were carried out by drilling a number of bore holes and drifts in different phases of project investigation; the details of which are included in the relevant sections of the report.

1.9.1.1 Concrete Dam Axis

In the initial studies, a dam axis (shown as “CC” on the map below) was explored during the period from the year 1964 to 1971 by excavating 12 drifts and eight inclined drill holes for locating a 247 m high concrete gravity dam. Geological investigations were continued further on this axis by conducting drill holes beyond the period 1983 by the Indian side to ascertain the depth of stripping in the abutments. It was transpired that sound rocks are available in the abutments at a varying depth of 30 to 60 m. In general, the depth increases in the upper reaches in the left abutment. Besides blocky and jointed nature of the strata in the different

Section 1: Executive Summary Page 31 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT zones, the shear zones form an integral part of the rock.

With subsequent change in favour of a higher dam with top elevation around + 688 m, the axis CC got dropped in the project layouts, not only because of the geological problem indicated above but also due to the limited elevations of the left abutment crest which itself being at about dam top elevation. An alternative axis “BB” was selected for concrete dam, 115 m upstream of axis CC. The new axis had the topographical advantage of allowing construction of a higher dam. The bore holes drilled at the crest of the left abutment indicated availability of good foundation rock at elevation + 706 m, 18 m above the dam top, thus getting over the geological problem for accommodating a higher dam.

1.9.1.2 Rockfill Dam Axis

A dam axis for rockfill dam was also investigated around 360 m upstream of axis CC and mentioned as axis AA in the map, so that the d/s toe of the rockfill dam is accommodated within the gorge section, upstream of major cross drainage joining River Mahakali from left and right flanks and the dam body did not extend to comparatively weak Quartz Mica Schist, but limited to the Augen Gneiss. On physiographic consideration, the rockfill dam axis was marginally adjusted and shifted 30 m downstream later on referred to as the axis DD on the map.

After 5th meeting of the Joint Group of Experts held in March 1991, it was decided to carry out geotechnical investigations jointly covering the river bed, abutments and the underground power house locations on both banks of Mahakali River. It included deep drill holes and extension of drifts up to the power house locations. Geophysical surveys at diversion tunnel intakes and head race tunnel intakes were also undertaken to finalize the project layout of Pancheshwar rockfill dam and its appurtenant works. In-situ rock tests and laboratory tests on rock samples were conducted to determine the rock mass characteristics in the foundation of the dam and underground power house caverns.

Thus, four alternative dam axes at Pancheshwar were investigated in the past; which are designated as axis AA, BB, CC and DD and shown in the Figure 1.9-1:

Section 1: Executive Summary Page 32 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Figure-1.9-1: Map showing the location of dam axis AA, BB, CC and DD

In accordance with approved Terms of Reference (ToR) for review of the Rockfill dam, results of all previous investigations were reviewed by WAPCOS and a need was felt to drill few more boreholes along the dam axis DD. WAPCOS drilled seven more bore holes along the dam axis in the latest exploration program, with total length of drilling 581m at the dam axis D-D.

1.9.2 Reasons for selection of rockfill dam

The reasons in favour of the rockfill dam at Pancheshwar have been dealt in the earlier project reports of 1995 and 2003 in detail; which are summarized as under:

1.9.2.1 Geological Consideration

In view of the geological conditions, the rockfill dam was a preferred choice considering the very high stresses which are likely to be developed for a high concrete dam on broken and heterogeneous granitised quartzite rock mass with shears and weathered schist band. Further, extensive treatment of the foundation will be required in case of concrete dam to strengthen the rock mass involving extra cost. In case of rockfill dam, advantage has been taken by providing partial cutoff trench in the de-stressed portion of the right flank which reduces the excavations involved. However, construction of Chute spillway on the left bank will require extensive slope stabilization measures. Extra provision of cost may also be kept for treatment of slide zone near the upstream toe on left flank of rockfill dam.

Section 1: Executive Summary Page 33 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.9.2.2 Seismic Consideration

The project area falls in zone-V of Seismic Zoning Map of India (IS: 1893, 2002). The region has been rocked by several damaging earthquakes. The rocks of high grade complex Central Crystalline is bound by Martoli Thrust in north and MCT in south. Similarly another high grade complex, Almora crystalline, is delineated on either side by North Almora Thrust and South Almora Thrust. The high grade complex is separated from Tertiary Group of rocks by MBT. The tertiary group is delineated in southern portion by the MFT or Himalayan Frontal Fault which has surface manifestations at places. Neotectonic activities have been reported along Karakoram Fault, ISZ, MBT and MFT. Recently fresh exercises on seismic analysis and evaluation of site specific seismic parameters were taken by CWPRS, Pune with updated robust data base covering period up to 2015; and the recommendations are given as below.

The horizontal seismic coefficient of a 0.24 g and the vertical seismic coefficient 0.16g are recommended for pseudo-dynamic design analysis for Pancheshwar Multi- Purpose Project for rockfill type of dam. In view of high seismicity of the project site, the rockfill dam is preferred over concrete dam from safety considerations. The rockfill dam has the inherent quality of earthquake shock absorption because of its damping characteristics and comparatively large time period.

1.9.2.3 Materials Consideration

Detailed investigations were carried out by CSMRS, New Delhi earlier to assess the suitability and availability of various construction materials viz. Core, filter, rock fill, coarse and fine aggregates both on Indian and Nepalese sides. Based on the field and laboratory investigations, the total quantity of suitable construction materials for each category was assessed. The quantity requirement for each of the construction material had been estimated on the basis of the drawings prepared during detailed design studies for the rockfill dam and found adequate. In the present study, the availability of material for rockfill dam is reviewed and reassessed. The adequacy has been established and the details are given in relevant sections.

1.9.3 Pancheshwar - General Layout and Project Components

1.9.3.1 General Layout

The present layout of Pancheshwar dam and power stations has been developed with available topographic maps, updated topography and engineering geological investigations. The layout is given in the Drawing No. WAP/ PANCH/ ES - 06.

1.9.3.2 Diversion and Outlet Facilities

Overtopping of any partially constructed dam is very serious and may be disastrous. Therefore, embankment dams are mostly designed for a 100 year return period flood. In the instant case, since the dam height is more than 300 m and the risk due

Section 1: Executive Summary Page 34 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT to overtopping will be much more, it was decided to adopt a higher than 100 year return period flood. Based on the precedence of the Tehri Rockfill dam in India with a height of 260.50 m, a diversion flood of 16,652 m3/s corresponding return period of 1 in 1000 year, has been adopted for Pancheshwar Rockfill dam. Accordingly, the diversion facilities comprising of six diversion tunnels with a total length of 16753 m, have been provided in left and right abutments along with upstream and downstream cofferdams.

1.9.3.3 Diversion Tunnels

Six diversion tunnels, each 14m dia, circular shaped are provided to pass the diversion flood. The length of each tunnel varies from 2504m to 3685m. The invert levels at the inlet portals of tunnels are proposed at EI 410 m(+/-) to suit the river level. The downstream portions of four tunnels are proposed to be utilized as tailrace tunnels and the diameter proposed for such reaches to suit the tailrace discharge hydraulics.

1.9.3.4 Cofferdams

Based on the studies, the crest of the upstream coffer dam is proposed at EL461.0m which provides a freeboard of 1.5m for passing 1000 year flood. During most of the construction period, with all the tunnels in operation, this crest level would provide significantly larger freeboard for floods of lower return period. The crest of the downstream cofferdam was selected at El 436.0 based on the available tail water rating curve. This crest level would provide a freeboard of about 3.5 m above the level of the computed 1000 year maximum outflow.

1.9.3.5 Depletion Arrangements

The depletion arrangements provided in the earlier studies at EL 544m are designed for a discharge of 580 cumec. With this depletion arrangement to deplete the reservoir upto EL 544.00m it takes 225 days. In the emergency situation the depletion of even the top 20 m of the reservoir would take about 40 days. If a gated structure is provided with about 20 m high gates they can store 2 BCM of water, which is nearly one third of the live storage. By opening the gates the top 20 m can be depleted in 2 to 3 days only. Accordingly two depletion arrangements by utilising two diversion tunnels to function as depletion tunnels have been made one on each bank has been provided at EL 540 m having a capacity of about 900 cumec each. The depletion tunnels will be connected to one of the diversion tunnels with a goose neck arrangement. Since the head over the crest of depletion tunnels upto crest of main spillway is very high, during the detailed design stage one additional inlet at EL + 600 m can be provided to deplete the reservoir from EL. +659m to 600 m and then through the depletion sluice at EL +540 m.

Section 1: Executive Summary Page 35 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.9.3.6 Design of Rockfill Dam

The proposed arrangement includes a rockfill dam with crest at EI 691 m, a separate gated side channel spillway on the left abutment, two identical underground powerhouses located one in each abutment and two intermediate outlets located in tunnels under the respective power intakes. The maximum height of the dam is 311 m above the foundation. The crest of the dam is 20 m wide and approximately 814m long. The dam axis has been located as far downstream as possible, into the narrower portion of the valley, to minimize embankment volume. The downstream toe has been kept upstream of a deep gully dissecting the left abutment which will be part of the spillway discharge area.

A rockfill dam with central earth core and thick filter transitions upstream and downstream is a fundamentally safe structure at seismically active sites and is considered the most appropriate dam type for the Pancheshwar. A symmetrical, central impervious core is proposed with upstream and downstream slopes of 0.3:1. The central core has been preferred over the inclined core as it would rest almost entirely on competent quartz biotite gneiss. Due to the potentially high site seismicity and moderately weak rock available for Rockfill material, a 3.5:1 upstream slope and a 2.0: 1 downstream slope have been adopted for the layout. The dam height has been provided with a total freeboard of 11 m above FRL.

1.9.3.7 Foundation Treatment of Pancheshwar dam

The dam foundation will be stripped of colluvium, talus and other loose deposits. The foundation for the core, two upstream filters and three downstream filters will be excavated through the uppermost weathered rock to fresh, sound, groutable rock. At dam crest level, the depth of rock excavation for the core foundation is anticipated to be of the order of 30 to 50 m, decreasing to a few metres under the 20 m thick alluvial deposits in the river channel. Dental concrete will be used to fill all depressions in the core foundation and to provide an even, non-erodible surface against which to place and compact the core material. Consolidation grouting has been proposed 6 m c/c below full area of C.O.T. The depth of consolidation grouting has been kept as 0.15 H (where H is the hydraulic head) subject to a minimum of 10 m. Curtain grouting beneath the core foundation is proposed below C.O.T after completing the consolidation grouting. The grout curtain shall consist of three rows at 3m c/c. The spacing between Primary Holes shall be 6m and between secondary holes 3m. The depth of Grout Curtain shall be 2/3 H where H is the water head subject to a minimum of 10m.

1.9.3.8 Design of Pancheshwar Spillway

The side-channel spillway is located on the left abutment. In order to avoid the necessity for large free-standing retaining walls adjacent to the dam core, the spillway has been placed completely in rock cut and independent of the dam. The spillway facility comprises approach channel and side-channel spillway, Spillway

Section 1: Executive Summary Page 36 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Chute and Flip bucket and Plunge pool. The concrete dam spillway structure having height of 63.0 m with a total length of 185.50m comprises of 122.5 m long Over flow and 63.0m long Non-Over flow sections on both the sides, with 650.0m long approach channel on upstream has been provided on the left bank (Nepal side) of river Mahakali.

1.9.3.9 Intake and Pressure Tunnels

Due to rock fill character of the dam material, the intake is not located in the dam body and, hence the intake structure is proposed to be located inside the reservoir away from the dam body. Six circular steel lined pressure tunnels having lengths varies from 1000m to 1230m are proposed on either bank for diverting the water for power generation. The centre line of tunnel has been kept at EL 600.00 at its start at intake.

1.9.3.10 Vertical Drop Shafts / Penstocks

Water from intake level at El. 600 m (centre line) has to be led to the centre line of the units at El. 411m. The diameter of the vertical drop / pressure shaft has been calculated as 8.70 m. At the bottom of the shaft, the water conductor turns horizontal and each one is bifurcated to feed two machines. The entire shaft and the horizontal unit tunnels are to be steel lined. 24 to 40 mm thick ASTM 517 GR.-F steel lining is proposed. The excavated diameter of tunnel will be about 9.7 m.

1.9.3.11 Pancheshwar dam- Power Houses

The proposed underground power house will accommodate the Six units of 400 MW capacity each. The power house opening will be located in quartzites / grainsized schist. After giving due consideration to the size of openings required for housing the generating units, transformers etc. and the geology of the area, it is decided to adopt, a two cavern layout for the power house. The first cavern, designated as the machine hall cavern, accommodates the generating units and other ancillary equipment etc. excluding the MIV, whereas the second cavern, designated as the transformer hall cavern, on the downstream will house the unit transformers and the GI switches. The caverns are aimed to be so located as to be excavated in single rock type and are oriented to produce minimum over breaks / rock falls. The size of machine hall cavity to house the vertical shaft Francis turbine has been proposed as 23m x 57.3m x 286.5m. The MIV will be accommodated in other cavity. The transformer hall cavern will be 18.50 wide, 32m high and will also have a length of 224m. Draft tube gates will be accommodated in this cavern.

1.9.3.12 Pancheshwar dam - Downstream Surge Galleries

Transient studies have been carried out and based on the study it is proposed to provide a d/s surge gallery. The size of downstream surge gallery has been proposed as 90m (L) X 20 m (W) X 60m (H) on both India and Nepal side.

Section 1: Executive Summary Page 37 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.9.3.13 Draft Tube Tunnels/Tail Race Tunnels at Pancheshwar

Independent circular elbow type draft tube tunnels have been provided for each unit. The invert level of the draft tube has been kept at El. 399.20m. The draft tube tunnels from 3 units combine into one tail race tunnel of 12.25m in dia. These two tail race tunnels will then join the diversion tunnels proposed for the rockfill dam construction. The diversion tunnel will be plugged at its junction point with tail race tunnel u/s of junction point.

1.9.4 Rupaligad Re-Regulating Dam

1.9.4.1 General Layout

As per the provisions in Mahakali treaty, the proposed power stations at the Pancheshwar would be operated as peaking station to maximize power benefits to the power system of India and Nepal. To even out the fluctuations in the releases due to peaking operation of the Pancheshwar power Stations, a downstream re- regulating dam with adequate storage capacity needs to be constructed to provide continuous river flows downstream. A re-regulating structure at Rupaligad with adequate pondage has been agreed to for further investigations and included in the scope of the WAPCOS.

Based on the updated survey & investigations, a new dam site was selected d/s of the earlier site. The FRL for Rupaligad re-regulating dam has been adopted as 420m considering tail water level of Pancheshwar dam. In addition to topographical and geological considerations, the dam axis is selected at the nearest possible location from the Pancheshwar dam where it can provide a live storage of about 56.43 M m3 for at least 4 hr peaking corresponding to 4800 MW plants. Accordingly, the dam axis at 'B-B' has been finalized on the downstream of Rupaligad Nala considering geological and topographical aspects.

1.9.4.2 Rupaligad Concrete Gravity Dam

The Rupaligad dam intercepts a total catchment area of 13,490 km2 and envisages construction of a concrete gravity type dam of 95 m high above the deepest foundation level and 265 m long at the top of dam. The overall length of the non- overflow section of the dam is 73.50 m extending on both the flanks of the spillway. The overflow section of the dam is 192m long. The dam top has been kept at EL.428.00m.

The dam would provide a gross pondage of 81.25 Mm3 and live pondage of 56.43 Mm3 between MDDL +400.00m and FRL +420.00m to enable the re-regulation envisaged under the project.

Section 1: Executive Summary Page 38 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

The non-overflow section of the dam has the following features:

 Deepest foundation level = EL 376.00 m  Top width of the dam = 8.00 m  Upstream Slope = 0.3 (H) : 1 (V)  Downstream Slope = 0.8 (H) : 1 (V)

Given the height of the dam section, requisite numbers of drainage and inspection galleries have been provided. An elevator shaft has been provided in the left side non-overflow section in order to access the galleries. Stair Shafts have also been provided in the left and right side non-overflow sections.

The PMF at Rupaligad dam site has been estimated 27,700 m3/s and River Mahakali, like other Himalayan rivers, carries a lot of sediment load during the monsoon period. At this stage of project planning, determining reservoir operating levels and spillway and intake sill levels becomes important as they have a direct bearing on the sediment management in the reservoir, as well as on the possible encroachment of live storage. Moreover, design of spillway itself has to be such that both flood control and sediment control are effectively assured.

It is desirable that the spillway is accommodated within the river valley in order to minimize excavation on the banks. At the project site, a provision of low level sluice spillways is adequately effective for flood and sediment management.

1.9.4.3 Rupaligad dam – Spillway and Energy Dissipation arrangement

To optimize the spillway crest level, several studies were conducted to pass the PMF of 27,700 m3/s; with varying crest level and number of spillway bays. The alternative, with crest level at EL 386.00m and 12 spillway bays each of 9.5 m (W) X 14.5m(H), and adjacent bays are separated by twin piers, each 6.5 m thick, has been finalized as it fits suitably in the available valley width.. Discharging capacity of the spillway has been verified using the criterion given in IS-11223-1984, which stipulates an emergency condition such that 10% of the number of gates or at least one gate should be considered inoperative while deciding the dimensions of spillway waterway. It is confirmed that the proposed spillway has a discharging capacity to pass PMF of 27,700 m3/s through 11 gates with MWL at EL 424.0m.

Various alternatives for energy dissipation arrangements were also considered. Due to high intensity of discharge, provision of a stilling basin was ruled out and a flip/ trajectory bucket has been adopted. Hydraulic design of the flip bucket has been done as the procedure given in IS 7365:1985. As per the IS code, bucket flip angle is normally kept between 30˚ to 40˚. From Geological explorations at the dam site, bed rock is available at about 20 m below the river bed level; i.e. at EL 340.0m. Hence, a pre-formed plunge pool, with bottom at EL 340.0m has been proposed.

Section 1: Executive Summary Page 39 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.9.4.4 Diversion Arrangements

The diversion tunnels at Rupaligad dam site have been designed to pass a design flood of 2000 m3/s only and aligned behind the powerhouses due to physical constraints. The tunnels are aligned such that sufficient covers to other structures are available. A single tunnel having capacity to pass the entire diversion flood will either have a large diameter or will require a higher driving head. The driving head will increase height of the upstream coffer dam, increasing its quantities and prolonging its construction period. Therefore, it has been decided to have two diversion tunnels each of 12 m diameter with circular shape, one each on either bank, each capable of passing a discharge of 1000 m3/s.

In order to provide comfortable working space for construction of main dam, the upstream coffer dam (Colcrete) is proposed to be located at a minimum clear distance of 75 m from the anticipated edge of excavation for foundation of the main dam. The Colcrete dam has been selected as its downstream face shall be stepped to make it serve as energy dissipater during overtopping. The toe will be provided with a launching apron for saving river bed from erosion during overtopping. The heel will be provided with a concrete apron or pad for making grouting activity independent of the construction of dam. Elevation of the deepest bed at the dam axis is anticipated at EL.361.00 m; and it has been adopted at the location of upstream coffer dam. Considering the elevation of the water pool at the cofferdam is 383.50 m and providing a free board of 1.5 m; top of the coffer dam has been kept at 385 m. The length of upstream coffer dam worked out as 163.00 m and height of the dam at the deepest section is 24.00 m.

The downstream coffer dam is proposed to be located at a minimum clear distance of 200m from the anticipated edge of excavation for foundation of the plunge pool. A rockfill dam section has been selected on the same lines as the upstream coffer dam. Elevation of the deepest bed at downstream is assumed at EL 360.00 m and the same was adopted as the foundation level for d/s coffer dam. The top level of downstream coffer dam has been kept at EL. 377.00 m with a free board of 1.5 m. The length of Downstream Coffer Dam is 110.00m and Overall height of the dam at the deepest section is 17.00 m.

1.9.4.5 Rupaligad dam - Power Intakes and Headrace Tunnels

Straight type intake structures having asymmetrical approach has been envisaged on the u/s of the Rupaligad Reregulating dam to divert the design discharge of 300m3/s through water conductor system on each bank of the river Mahakali for generation of power. The power intake structure comprises of two independent intakes on either side of the river at a distance of around 90 m from the dam axis one for each of the Head Race Tunnel (Steel Lined) connecting the power intake to the power house. Each intake has been provided with a trash-rack structure at the u/s edge and gates and hoisting arrangements for closing or opening of the flow into the Head Race Tunnel (Steel Lined).

Section 1: Executive Summary Page 40 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Two numbers 6.5m dia. steel lined HRT have been provided on each side of the river bank to convey the design discharge from the power intake to the generating units. The HRT are steel lined up to the proposed underground powerhouse located d/s of the dam axis. The length of the four HRT (two on each side) varies from 284m to 354m upto D-line of Power house.

1.9.4.6 Rupaligad dam - Power House Caverns

The general arrangement the powerhouse has been developed for the installation of two units of 60 MW each and two vertical axis Kaplan Turbines. The powerhouse Cavern is 112m (L) X 24.0 m (W) X 49.5m (H) in size units are placed at 28 m c/c. About, 26 m long erection bay is located at the Left end, while the 24 m long control block is located at the right end of the machine hall cavern. The centerline of runner is set at El 353.55 m.

1.9.4.7 Rupaligad dam - Tail Race Tunnels

Two numbers tail race tunnels each of 7.00 m dia. for the left and the right bank power houses have been envisaged to convey 150cumec each of design discharge from the generating units back to the River Mahakali. The length of tailrace tunnels is approx. 89m for the right bank power house(Indian side) and 55m for the left bank power house (Nepal side) respectively. The invert level of the tailrace tunnel at the start EL 344.00 and at the outfall is 362.0m where the Min. tail water level is EL 363.0m.

1.10 Design of Electrical and Mechanical Works

1.10.1 Pancheshwar Power Stations

The Pancheshwar Power Houses are proposed to have a total installation of 4800 MW with six units of 400 MW each on either side. The alternative units of 350 MW, 400 MW and 540 MW were also considered. However, the unit size of 400 MW was preferred considering the maximum permissible cavern width and transport limitation of the Over Sized Cargo/ heaviest components. The salient parameters of the underground power stations are as under:

1. Size of MIV Caverns 192m x 10m x 24m (LxBxH) 2. Power House Caverns size 286.5m x 23m x 57.30m (LxBxH) 3. Transformer Hall Caverns size 254 x 18.5 x 31.50m (LxBxH) 4. Size of the service Bay 60m x 23m 5. Turbine Centre line Elevation 411.8 m 6. Machine Hall/Transformer Hall EL 428.8m 7. Type of Turbine Vertical Francis 3 8. Rated Discharge 184 m /s 9. Rated Net head 235m

Section 1: Executive Summary Page 41 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Provision for appropriate governing equipment, generator and excitation equipment, generator transformer, switching scheme, electrical auxiliaries, cooling system, ventilation system, fire protection system, internal communication system has also been made. The heaviest assembly required to be lifted by EOT cranes is assembled rotor which is expected to weigh 800T. Two cranes each of 425/ 80/ 10T operating in tandem using a lifting beam will be provided.

1.10.2 Rupaligad Power Stations

The salient features of the Rupaligad power stations having two units of 60 MW each on either bank are given as under:

 Power House Caverns size 112 m x 24m x 49.5 m (LxBxH)  Transformer Hall Caverns size 75 x 19 x 31m (L x B x H)  Machine Hall/ Transformer Hall EL EL. 366 m  Centre-Line of runner EL. 353.55 m  Type of Turbine Vertical Kaplan type  Rated Net head 44 m  Rated Discharge 150 m3/s  Speed 150 rpm

1.11 Transmission System of Pancheshwar Multipurpose Project

1.11.1 Evacuation System for Pancheswar Power Plants

The step-up generation voltage of the Pancheshwar power plants at the India and Nepal side is envisaged to be made from 21 kV to 400 kV through GTs for power evacuation. The bus configuration of the switchyard would be double main-bus scheme with GIS technology.

A surface mounted pothead yard each close to underground power plants at Indian and Nepalese territories is proposed to be established and transmission lines for power evacuation would take-off from thereon.

Presently, no 400kV AC transmission system and 400 kV EHV sub-stations are existing in Nepal grid. By the time of commissioning of Pancheshwar MPP, it is expected that Nepal would harness many other hydroelectric generation projects in the western and eastern parts of their country. Accordingly, Attaria, Lamki, Butwal, etc. deem to be the prospective locations for creating major EHV AC pooling points for various upcoming hydro projects, which would enable to supply power to various load centres in Nepal and transfer surplus outside Nepal after meeting its load demand. Considering this, generation from Pancheswar in Nepal is proposed to be pooled at Attaria in western Nepal, about 120km from Pancheswar and thereon to a pooling point at Bareilly in India through cross border interconnection across

Section 1: Executive Summary Page 42 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Mahakali River. On the Indian side, generation from Pancheswar MPP will be pooled at the Moradabad sub-station in the northern region (NR) for supply to load centres.

In view of the above, following 400 kV transmission system for evacuation of power from Pancheshwar has been proposed:

 Pancheshwar MPP (Indian side) – Moradabad (tentative location in India) 400kV 2 x double circuit ACSR Quad Moose conductor lines.  Pancheshwar MPP (Nepal side) – Attaria (tentative location in Nepal) 400kV 2 x double circuit ACSR Quad Moose conductor lines.  Pancheshwar MPP (Indian side) – Pancheshwar MPP (Nepal side) 400kV double circuit with ACSR Quad Moose conductor line.  Attaria - Bareilly 400kV 2 x double circuit ACSR Quad Moose conductor lines.  4x125 MVAr Bus reactors at Pancheshwar (Nepal side) Switchyard.  4x125 MVAr Bus reactors at Pancheshwar (Indian side) Switchyard.  2x125 MVAr Bus reactors at Attaria 400kV.  Provision of space for additional four 420 kV line reactors on Indian side at Pancheswar switchyard/ pothead yard, one reactor at Pancheswar end of each circuit, depending on the actual length of the transmission line on the Indian side. Due to high fault current at Pancheswar and limitation of 400 kV GIS equipment capacity, the 400kV Pancheswar (Indian side) - Pancheswar (Nepal side) double circuit inter-connection would be kept normally open and used in case of emergency situation only.

1.11.2 Evacuation System for Rupaligad Power Plants

The generated power at Rupaligad is proposed to be stepped up from 11kV to 220 kV using three phase GTs for evacuation through 220kV transmission system. The pooling point for Rupaligad power plant in the Indian side is considered to be the existing 220 kV Sitarganj (PG) sub- station in the Northern Region. In the Nepal side, the generated power is proposed to be pooled at Attaria; along with power generated at Pancheswar on the Nepal side. The transmission systems for Rupaligad power stations are envisaged as under:

 220 kV double circuit line with ACSR Zebra conductor from Rupaligad power plant (India side) to Sitraganj (PG) in the Northern Region of India.  220 kV double circuit line with ACSR Zebra conductor line from Rupaligad power plant (Nepal side) to 400/220kV pooling station at Attaria in Nepal.  A 220 kV single circuit inter-connection, with ACSR zebra conductor, between the power plants at Rupaligad.

Section 1: Executive Summary Page 43 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.12 Environmental and Socio-Economic Impact

The objective of Environmental and Socio Economic Impact Assessment study is to identify the possible environmental effects due to the proposed Pancheshwar Multipurpose Project and to suggest measures to mitigate the anticipated adverse impact in the environment. This study in Indian portion has been carried out by WAPCOS whereas Water Resources Consultant Pvt. Ltd., Kathmandu has carried out studies in the Nepal portion.

1.12.1 Flora & Fauna

The proposed project area supports good vegetation in the submergence area. The vegetation may be divided into the following categories in India: tropical forest, subtropical forest, temperate forest, sub-alpine forest and alpine forest. The classification of vegetation in Nepal is subtropical hill sal forest, subtropical mixed deciduous forest and subtropical chirpine forest. Chir forest is predominant in the catchment mainly in the upper reaches of hills (1500 to 1800m). The second predominant species, Oak can be found in the upper reaches of hills (1800 -2700 m). Cedrus deodar is the most common species in the area and can be found in the hills (1350-2050 m). Sal, Sisso, Khair and Tansen are other species in the area.

This area is the home of a wide variety of mammals, reptiles and birds. This region is rich in mammalian fauna i.e. Sambhar, Barking deer, Wild bear, Jackal etc. Fauna of this region include many species of goats and hare and they are distributed all over higher altitude ranges. Among the carnivores, the most beautiful is the snow leopard. The others include jackal, cats, brown and black bear. Himalayan monal pheasant, the western tragopan, the satyr tragopan, chir pheasants and kottars are the birds found here. In the Nepalese portion, weasel, jungle cat, wolf, rhesus monkey, langur, porcupine etc. are found. The Mahakali, Sarju, Panar and Ramganga harbour richest diversity for any cold water river. The major groups found are trouts, mahseers, minor carps and leaches. They contribute significantly in meeting the food requirement of local inhabitants.

1.12.2 Rehabilitation & Resettlement

Of the 116 km2 submergence area of Pancheshwar dam, 76 km2 lies in India and the rest in Nepal. It covers 123 revenue villages in Pithoragarh, Champawat and Almora districts and 25 Village Development Committees (VDCs) and one Municipality in the districts of Darchula and Baitadi in Nepal. A total of 29436 PAF on the Indian side and 2786 PAF on the Nepalese side are likely to be affected by the Pancheshwar dam reservoir. In addition, 1587 families in eleven villages of the district Champawat in Uttarakhand State are likely to be affected due to the Rupaligad dam.

On both sides, there are a number of temples and other religious places would get submerged in the reservoir area besides many installations for drinking water supply schemes. These temples are important cultural heritage of the local people.

Section 1: Executive Summary Page 44 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.12.3 Environmental Management Plan including R & R Plans

An amount of INR 29,860 million has been provided in the estimate for Environmental Management Plan including rehabilitation and resettlement (R&R) plan of the project affected families (PAF) on both sides. In addition, INR 16,555 million has been kept towards the compensation of private land on the Indian side and INR 4000 Million on the Nepal side under Environmental Management Plan.

1.13 Construction and Equipment Planning

1.13.1 Basic Considerations

It is essential to optimize the construction cost vis-a-vis construction period taking into consideration price escalation and interest during construction as well as lost benefits due to delay in completion. Therefore, even sizeable increases in the construction cost of components dictating the critical path for the project commissioning would be justified should they allow a significant shortening of the construction period.

1.13.2 Access Road and Infrastructure

Due to its bi-national character, the project shall be accessible both from Nepal and India. Indian access being the most important from construction point of view, as most of the material and equipment is likely to be delivered to the site from India.

Various roads proposed to be constructed in the project area would be in the form of metalled access roads, metalled service roads and gravelled haul roads. It is proposed to have main access to the project from Tanakpur; It has been proposed to improve the existing road from Bareilly to Pancheshwar for transporting heavy equipments. The improved road would be used for transportation of construction materials and for general access road to the project site. It has therefore been proposed to have separate access road for project area. Champawat-Kot-Ratapani- Dam site access road is found to be more suitable. The route proposed is the shorter and links most of the infrastructure facilities. It has better road geometry profile and passes through less forest area.

Various infrastructure facilities, like office buildings, residences, stores, workshops, laboratories, hospital, schools, etc. would be provided near project site to ensure smooth implementation, operation and maintenance of the project. Two major residential colonies at Chaunda and Nidil on India side and Palaki and Sontala on Nepal side are proposed for the project personnel at Pancheshwar. At Rupaligad site, it has been proposed to have residential complex for project officers and staff. Provision of land development has also been made for skilled and unskilled construction labour. The total land requirement is 150 ha for this purpose at Pancheshwar and Rupaligad site.

Section 1: Executive Summary Page 45 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.13.3 Equipment Planning

Keeping in view that the volume of placement for the project is substantial, mechanised construction has been planned for all types of construction jobs so as to achieve consistent quality at a faster rate and also to minimise the requirement of skilled manpower. Mechanisation requires a great degree of planning as regards to cost, production, work methods etc. Equipment planning has been done based on the topography, geology, climate, sources of materials, access to project and infrastructure facilities required. To avoid a large number of loading units and their matching hauling fleet required for the completion of the project, conveyor belt systems are being contemplated to transport clay and shell material for rockfill dam. The selection of appropriate equipment, loading and hauling fleet and/ or conveyors system has been based on the hourly peak requirement and maximum size of the equipment available in India.

As most of the construction work is likely to be executed on contract basis, the tentative requirement of machines/ equipment has been worked out for analysis of rates of work and for cost estimates. Though the contractors in all probability may suggest their own construction techniques and equipment for the execution of the job based on the equipment actually available with him, the present exercise will help in evaluating the reasonableness of the bids and the construction methods within the overall construction schedule and cost estimates.

1.13.4 Construction Programme

The construction programme has been drawn up to complete the Pancheshwar project in 10 years and Rupaligad in five years.

1.14 Cost Estimates & Phasing of Expenditure

1.14.1 Abstract of Cost Estimates

The project cost for both Pancheshwar and Rupaligad dams and associated works has been estimated at 2015 price level as under:

Sl. Name of project component Estimated cost Remarks No. 1. Pancheshwar ₹294830 Million Annex-I 2. Rupaligad ₹ 36,250 Million Annex-II 3. Total cost ₹331080 Million The cost of transmission system associated with Pancheshwar as well as Rupaligad has not been included in the project cost. The power of Pancheshwar Multipurpose Project is going to be mainly fed into Northern grid of India after meeting the local requirement of Nepal. The cost of entire power evacuation system for Pancheshwar Multipurpose Project including Rupaligad will be considered under separate project proposals.

Section 1: Executive Summary Page 46 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Similarly, cost of infrastructure for developing additional irrigation in India and Nepal has also not been included in the project cost. A substantial expenditure on infrastructure for irrigation particularly in Nepal may have to be incurred to realize full irrigation potential of the project.

The General Abstract of costs for Pancheshwar Multipurpose Project including Rupaligad Re-regulating dam are given in detail, in the Table-1.14.1 & 1.14.2 respectively.

Table 1.14-1: Abstract of cost of Pancheshwar Dam (INR Million)

Minor Head Electro- Total Civil Mechani Detailed Head of Work Works cal Works DIRECT CHARGES I-WORKS A-Preliminary 5100 3171 8271 B-Land 28530 28530 C-Works including HM works 105657 105657 J-Power Plant Civil Works 35133 35133 K-Building 1880 1880 M-Plantation 100 100 O-Miscellaneous 7800 7800 P-Maintenance during construction 1450 1450 @1% of C,J,K,R Q-Special T&P 520 520 R-Communication 21100 21100 S-Power Plant & Electrical System 48059 48059 X-Environment & Ecology 29860 29860 Y-Losses on Stock @0.25% of C,J,K & 340 340 R Total of I-Works 237470 51230 288700 ESTABLISHMENT 10447 1762 12209 III-TOOLS & 215 260 45 PLANTS IV-SUSPENSE 0 0 V-RECEIPT & -7860 -7860 RECOVERIES (-) Total of Direct Charges 240102 53207 293309 Indirect Charges (a) Capitalized value of abatement of land revenue @ 5% of cost of 203 275 Culturable land (b) Audit & Account Charges 1187 131 1318 Total of Indirect Charges 1390 131 1521 Total Cost (Direct charges + Indirect 241492 53338 294830 Charges)

Section 1: Executive Summary Page 47 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Table-1.14-2: Abstract of Cost of Rupaligad Dam

Amount ₹ Million

Minor Head Electro- Total Civil Mechani Detailed Head of Work Works cal Works DIRECT CHARGES I-WORKS A-Preliminary 780 430 1210 B-Land 2690 2690 C-Works 11920 11920 J-Power Plant Civil Works 8060 8060 K-Building 505 505 M-Plantation 50 50 O-Miscellaneous 1560 1560 P-Maintenance during construction 235 235 @1% of C,J,K,R Q-Special T&P 320 320 R-Communication 2690 2690 S-Power Plant & Electrical System 4262 4262 X-Environment & Ecology 1980 1980 Y-Losses on Stock @0.25% of C,J,K & 60 60 R Total of I-Works 30850 4692 35542 ESTABLISHMENT 1410 276 1686 III-TOOLS & 19 34 15 PLANTS IV-SUSPENSE 0 0 V-RECEIPT & -1208 -1208 RECOVERIES (-) Total of Direct Charges 31067 4987 36054 Indirect Charges (a) Capitalised value of abatement of land revenue @ 5% of 15 15 cost of Culturable land (b) Audit & Account Charges 154 12 166 Total of Indirect Charges 169 12 181 Total Cost (Direct charges + Indirect Charges) 31235 4999 36234 Cost at April,2015 Price Level Say 36250

Section 1: Executive Summary Page 48 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.14.2 Phasing of Expenditure

The Pancheshwar Complex is programmed to be completed in 10 years time period while Rupaligad Complex would be completed in 5 years time period. The disbursement schedules of project expenditure in respect of Pancheshwar and Rupaligad Complexes have been prepared spreading the cost of individual project components along the implementation period according to construction programme.

The total capitalized cost of power component of the Pancheshwar Multipurpose Project amounting to INR 305748.81 Million (including IDC and FC) has been distributed in ten years. In addition, cost of Irrigation component has been assessed as INR 66,255 Million at April 2015 price level. The annual funds to be arranged by India and Nepal have been indicated below, indicating the cost charged to power and irrigation and the share of cost to be borne by India and Nepal.

Table 1.14-3: Yearly requirement of funds to both countries (in INR Million)

Year Cost of Irrigation Cost of Power component Total Yearly (INR 66255.00 Million) Equity (20%) Amount of Debt (80%) Expenditure (million) India Nepal India Nepal India Nepal India Nepal (67%) (33%) (50%) (50%) (50%) (50%) 1 887.82 437.28 2648.25 2648.25 3536.07 3085.53 2 1775.64 874.55 5296.50 5296.50 7072.14 6171.05 3 2663.46 1311.84 7944.75 7944.75 10608.21 9256.59 4 3551.28 1749.11 10593.00 10593.00 14144.28 12342.11 5 4439.10 2186.40 12638.11 12638.11 17077.27 14824.51 6 6658.65 3279.60 20219.05 20219.05 26877.70 23498.65 7 6658.65 3279.60 22213.84 22213.84 28872.49 25493.44 8 6658.65 3279.60 24369.81 24369.81 31028.46 27649.41 9 6658.65 3279.60 26699.98 26699.98 33358.63 29979.58 10 4439.10 2186.40 22899.39 22899.39 27338.49 25085.79 Total 44390.85 21864.15 26482.50 26482.50 129040.16 129040.16 199913.51 177386.81

This information has been used for economic evaluation of the project components.

1.15 Economic and Financial Evaluation

The cost of the Pancheshwar project has been apportioned between Power and Irrigation sector in proportion to the assessment of (i) power benefits and (ii) irrigation benefits along with flood control benefits in accordance with provisions of the Mahakali Treaty. The benefits are summarized in the Table 1.15-1 below:

Section 1: Executive Summary Page 49 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Table 1.15-1: Assessment of Project Benefits

Sl. Project Benefits India Nepal Total (INR) No. 1. Power Benefits 18325 Million 18325 Million 36650 Million 2. Irrigation benefits 5505 Million 2870 Million 8375 Million 3. Flood Control Benefits 740 Million 160 Million 900 Million Total 24570 Million 21355Million 45925 Million

The irrigation benefits have been assessed based upon the existing and future water requirements of India and Nepal as already indicated in the Table 1.8 – 2.

From the above, the ratio of (i) power benefits to (ii) Irrigation + Flood Control Benefits from the Project has been calculated = 36650 : 9275 = 80 : 20. Hence the cost of joint works related to Pancheshwar dam and reservoir has been divided in the ratio of 80:20 to calculate the cost of power project.

Further, it may be mentioned that the re-regulating dam/ structure at Rupaligad has been envisaged mainly for irrigation consideration where the releases from Pancheshwar power plants during peaking operation would be collected and re- regulated to provide continuous flows downstream to meet irrigation water requirement of existing command areas in India and Nepal. As such, the cost of re- regulating dam and its appurtenant works at Rupaligad has been charged 100% to the irrigation component. As the power generation at Rupaligad dam is only incidental in nature, the cost of power facilities and power plants of Rupaligad has only been charged to the power project.

1.15.1 Cost chargeable to Irrigation and Flood Control Component

Based on the above, 20% of the cost of common works (joint works) related to Pancheshwar dam and 100% of the cost of Rupaligad re-regulating dam and its appurtenant works have been apportioned to the irrigation sector; which would be, in turn, shared by India and Nepal, in the ratio of irrigation and flood control benefits accrued to them (67% : 33%). The irrigation and flood control benefits are indicated in the Table 1.15-1 above.

1.15.2 Cost chargeable to Power Component

The project cost of Pancheshwar dam complex chargeable to power component includes the cost of J-Power Plant Civil works, cost of S- Power Plant & Electrical System and 80% of the cost of common works of Pancheshwar dam and appurtenant works. In case of Rupaligad dam complex, the project cost chargeable to power component includes only the cost of J-Power Plant Civil Works and S- Power Plant & Electrical System as shown in the Table 1.15-2 below:

Section 1: Executive Summary Page 50 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Table 1.15-2: Apportionment of project cost in power and irrigation Project component Pancheshwar Rupaligad Total Cost (INR Million) (INR Million) (INR Million) 1. Cost of J-Power Plant Civil 35,133 8,060 43,193 works 2. Cost of S- Power Plant & 48,072 4,260 52,332 Electrical System 3. Cost of Joint works 211,625 23,930 235,555 4. Cost of Joint works chargeable 169,300 Nil 169,300 to power @ 80% for Pancheshwar (and Nil for Rupaligad) A. Project Cost chargeable to 252505 12,320 264,825 power component = {(1)+(2)+ (4)} B. Cost of Joint works chargeable 42,325 23,930 66,255 to Irrigation component @ 20% for Pancheshwar + full cost of Rupaligad re-regulating dam Total Estimated Cost 294830 36,250 331080

i. Cost of irrigation component of PMP = INR 66,255 Million (20.01 %). ii. Total cost of power project (Hard Cost) = INR 264,825 Million

The construction period of Pancheshwar project has been indicated 8 years in the Mahakali Treaty. In addition, a period of 2 years will be required for pre- construction activities. As such, a total 10 years period has been considered in the analysis. The year succeeding the year of commissioning has been taken as reference year (11th year after commencement of construction) for working out the present value of cost. The hard cost of power project (INR 264,825 Million) has been spread over 10 years, as given in the Table 1.15-3 below.

Table 1.15-3: Phasing of Expenditure on power component of PMP

1st yr 2nd yr 3rd yr 4th yr 5th yr 6th yr 7th yr 8th yr 9th yr 10th yr 2% 4% 6% 8% 10% 15% 15% 15% 15% 10% 20% Equity 80% Debt (from India & Nepal) (raised from Financial Institutions) 5296.5 10593 15889.5 21186 26482.5 39723.75 39723.75 39723.75 39723.75 26482.5

Here, it may be mentioned that Interest during construction (IDC) on hard cost of the power project and financing charges( FC) on the debt would be minimized if both governments provide amount of equity upfront, say in the initial stage of construction, as mentioned in the aforesaid Table. In addition to IDC, 1% of loan amount has been considered as financing charges on the loan amount.

Section 1: Executive Summary Page 51 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.15.3 Capitalized Cost of Hydropower Project

The capitalized cost of power component of Pancheshwar Multipurpose Project (after adding the Interest during construction (IDC) and Financing charges for loan component) has been estimated as INR 305,748.81 Million for proposed relaxed norms viz. rate of interest @ 10%, R o E @ 14 % and repayment period of loan as 20 years. The cost of Irrigation component which has been estimated INR 66,255 Million, has not been included in the aforesaid capitalized cost of the Project. This cost is based upon April 2015 price index without any escalation amount.

1.15.4 Levelized Tariff and Internal Rate of Return (IRR)

In order to recommend the best option for financing of the project, the Levelized Tariff of the project and IRR have been calculated for different loan repayment periods as shown below:

Table 1.15-4: Levelized Tariff and IRR for different loan repayment periods

Option Equity: Norms Repayment Internal Levelized Tariff (in INR) Debt period of Rate 90% Average loan Return Dependable energy (%age) Energy year year I 30;70 CERC 12 years* 14.65 7.96 6.11

II 20:80 CERC 12 years* 13.02 8.00 6.14

III 20:80 Modified 20 years 10.23 5.65 4.33

IV 20:80 Modified 25 years 10.24 5.66 4.34

V 20:80 Modified 30 years 10.25 5.66 4.35

VI 20:80 Modified 35 years 10.25 5.67 4.35

* Assuming 90% loan would be returned in 12 years.

1.16 International and Interstate Aspects

During the prolonged negotiations held on the Pancheshwar project, Nepal has asked India to recognize that both parties have equal entitlement in the utilization of the waters of the Mahakali River. The Indian side agreed to their entitlement under the Mahakali Treaty-1996, without prejudice to their respective consumptive uses of the waters of the Mahakali River.

An understanding was reached between the two sides finally in the year 1996 when the Mahakali Treaty was signed on February 12, 1996 between the Government of India and the Government of Nepal concerning the integrated development of the Mahakali River.

The main features of the Mahakali Treaty-1996 in respect of the Pancheshwar Project are covered in the Article-3 and summarized as under:

Section 1: Executive Summary Page 52 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

. Both Parties have equal entitlement in the utilization of the waters of the Mahakali River without prejudice to their respective existing consumptive uses of the waters of the Mahakali River. . Water requirements of Nepal shall be given prime consideration in utilization of the waters of the Mahakali River. Both the parties shall be entitled to draw their share of waters of the Mahakali River from the Tanakpur Barrage and/or other mutually agreed points. . The Project shall be designed to produce the maximum total net benefit. All benefits accruing to both the Parties with the development of the Project in the forms of power, irrigation, flood control etc., shall be assessed. . The P roject shall be implemented as an integrated project including power stations of equal capacity on each side of the Mahakali River and the total energy generated shall be shared equally between the Parties. . The cost of the project shall be borne by the parties in proportion to the benefits accruing to them. . Both the Parties shall jointly endeavour to mobilize the finance required for the implementation of the Project. . A portion of Nepal’s share of energy shall be sold to India. The quantum of such energy and its price shall be mutually agreed upon between the Parties. . The principles for assessment of project benefits are explained further in the letters dated 12 February, 1996 exchanged by the two Governments along with the Mahakali Treaty, as under:

 Net power benefit shall be assessed on the basis of, inter alia, saving in costs to the beneficiaries as compared with the relevant alternatives available,  Irrigation benefit shall be assessed on the basis of incremental and additional benefits due to augmentation of river flow, and  Flood control benefit shall be assessed on the basis of the value of works saved and damaged avoided (to both sides of the river).

1.16.1 Irrigation Benefits

The waters of Mahakali River are being utilized for irrigation in India since the commissioning of Banbasa Barrage in 1928. Some Terai area in Nepal has also been benefited by the Mahakali waters drawn from the Banbasa Barrage.

With the availability of augmented flows in the post-Pancheshwar scenario, it has been assessed that a maximum crop area of 170,720 ha (including 6,040 ha of Dodhara-Chandani area) in Nepal can be brought under irrigation with the availability of additional water on implementation of Pancheshwar Multipurpose Project. For development of this command, additional water requirement will be of the order of

Section 1: Executive Summary Page 53 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

3,073 M m3. Total water use by Nepal will be 4,053 M m3 comprising of 980 M m3 as existing use and 3,073 M m3 as future use.

Irrigation benefits in India have been assessed on the basis of evaluation of surplus augmented flows available during dry season after meeting requirement for existing irrigation in India and Nepal as well as additional irrigation in Nepal. Having considered the power releases from Pancheshwar and water available in the intervening catchment from Pancheshwar to the Tanakpur Barrage, India will be able to make use of 1,905 M m3 of additional water in the post-Pancheshwar scenario and annual irrigation potential in India works out as 2.59 lakh Ha. Thus, total water use of India will be of the order of 13,766 M m3.

The detailed statement of total water requirement of India and Nepal including River Eco-system below Banbasa barrage is already indicated in the Table 1.8 – 2.

1.16.2 Power Benefits

As mentioned in the preceding paragraphs, the power plants at Pancheshwar dam are designed as the peaking stations having a total installed capacity of 4800 MW which would generate 7678 GWh of power during peaking hours, say around 4 hours a day in non-monsoon period in the 90% dependable year. In addition, the power stations at Rupaligad would generate another 1438 GWh power as base load stations in 90% dependable year. The total power produced at Pancheshwar + Rupaligad dam power plants shall be shared equally between India and Nepal as per the Mahakali Treaty. The total energy generation in the 90% dependable year as well as in average year from Pancheshwar Project are shown in the Table 1.16-1 below:

Table 1.16-1: Various parameters of Project

Sl. No. Particulars Pancheshwar Rupaligad Total dam dam 1. Installed Capacity (MW) 4800 240 5040 2. 90% dependable annual 7678 1438 9116 generation (GWh) 3. Annual Load Factor (%) 18.26% 68.42% 20.65% 4. Hours of peaking during Lean 03.84 Base Load Season 5. Average Annual Generation (GWh) 10327 1559 11885

1.16.3 Inter-state Agreements

As explained in the preceding paragraphs, at present, no agreement exists on sharing of the Mahakali Waters between party States or with neighbouring countries, except the Treaty referred above. If required, a formal agreement on sharing of the

Section 1: Executive Summary Page 54 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Mahakali waters may be put up before the Party States for consideration by the PDA, while implementing the Project.

1.16.4 Interstate Aspects of the Project

It may be mentioned that, when the Pancheshwar dam site was surveyed and formulated initially by the State Irrigation Department, the project area on the Indian side was administered by the undivided State of Uttar Pradesh. Later on, in the year 2000, the province of Uttar Pradesh was divided in two States and the main dam project area has been transferred to the newly formed State of Uttrakhand in India. The issue of sharing of irrigation assets / water resource between Uttrakhand and Uttar Pradesh is yet to be settled.

1.16.5 International Aspects of the Project

Besides the Mahakali Treaty with Nepal, the Government of India had also entered into another Treaty (known as the Ganga Treaty) in 1996 with the Government of Bangladesh on sharing of the Ganges waters during dry season (1 January- 31 May) at Farakka barrage. As such, any water resource development project proposed in the Ganga basin is required to seek a no objection from the Union Ministry of Water Resources, River Development and Ganga Rejuvenation, to ensure that the proposed scheme has no adverse effect on the lean season inflows at Farakka Barrage.

It may be mentioned here that the river Ganga drains an area of 8,61,452 sq. km along its length (2525 km) up to its outfall in Bay of Bengal. Its water resources potential has been estimated as 525.02 Billion Cubic Meter out of which 250 BCM is considered utilizable by creating suitable storage schemes in the upper reaches of the river. At present, the live storage capacity created by India is around 60 BCM including the projects under construction.

The Pancheshwar dam project shall intercept an area of 12,276 sq km and average annual flow at Pancheshwar dam site has been estimated 18.35 BCM. A total of 11.90 BCM of the Mahakali waters are already utilized annually by the State Governments in India in the existing irrigation projects whereas 0.98 BCM of water is utilized by Nepal. Rest of the Mahakali waters pass as floods which is aimed to be stored in the Pancheshwar reservoir.

After implementation of the Pancheshwar Project, the Nepal side may utilize around 3.07 BCM as additional water in the irrigation in their territory and 1.90 BCM of water would be available to the Indian side to increase the irrigation.

The Pancheshwar dam project has been primarily envisaged to store flood waters during monsoon that would be utilized for energy production and to enhance food grains production through assured irrigation. Thus, the dam project would not have any adverse impact on the lean season flows at Farakka. The catchment area

Section 1: Executive Summary Page 55 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

(12,276 sq km) at dam site is less than 1.5% of the total basin area at Farakka barrage.

1.16.6 Dispute Resolution Mechanism

Under Article-7 of the Mahakali Treaty, both sides have agreed not to use or obstruct or divert the waters of the Mahakali River adversely affecting its natural flow and level except by an agreement between the concerned parties. In order to meet the water requirement of local communities living along both sides of the Mahakali River, they are provided right to use the Mahakali waters limiting to the five percent of the average annual flow at Pancheshwar.

Further, under Article-9 of the Treaty, there shall be a Mahakali River Commission to deal with the disputes arising out of interpretation of the provisions made in the Mahakali Treaty. The Commission shall be guided by the principles of equality, mutual benefit and no harm to either party. The Commission shall be composed of equal number of representatives from both the parties.

The functions of the Commission shall, inter-alia include the following:

a. To seek information on and, if necessary, inspect all structures included in the Treaty and make recommendation to both the Governments to take steps which shall be necessary to implement the provisions of this Treaty. b. To make recommendations to both the Governments for the conservation and utilization of the Mahakali River as envisaged and provide for in the Treaty. c. To provide expert evaluation of projects and recommendations thereto. d. To co-ordinate and monitor plans of actions arising out of the implementation of the Treaty; and e. To examine any differences arising between the Parties concerning the interpretation and application of the Treaty.

1.16.7 Power Purchase Agreements

Pancheshwar Project shall be implemented as an integrated project including power stations of equal capacity on each side of the Mahakali River and the total energy generated therein shall be shared equally between the two parties. However, any surplus power from the Nepal share shall be purchased by India on mutually agreed rates. This would require the long term power purchase agreements with power distribution companies/ entities in India and Nepal.

The Pancheshwar Development Authority (PDA) shall act as power producing company/ entity and may be allowed to enter into such agreements with purchasers on behalf of both Parties.

Section 1: Executive Summary Page 56 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

1.17 Project Management and Design Engineering Consultancy

The Pancheshwar Development Authority (PDA) may consider the engagement of a reputed agency/ consultancy firm as “Consultant” to undertake the project management during construction through competitive bidding. The consultancy firm may assist and advise the Authority in preparation of bid documents and evaluation of bids. During the construction, the agency would be responsible and provide requisite expert manpower at site for general supervision of works in accordance with technical specifications, inspection of materials at manufacture’s workplaces before despatch, monitoring of progress of works at site, preparation of completion drawings, etc.

The Consultant shall specify in his technical proposal to the Authority, approach and methodology to carry out his duties and for providing services towards planning, engineering, design, supervision and monitoring of progress of works at site on behalf of the Authority.

After award of the contracts, the Consultant would prepare a detailed program based on the reviewed and accepted programs of different Contractors and also the likely interfaces and activities with regard to the project execution at different levels. State- of-the art software will be used to prepare such schedules which will primarily include early starts and finishes, late starts and finishes, free and total floats, bar charts and important information like shut down, vacation etc. These schedules will form the base line programme for monitoring the execution of the project. During the course of the construction, this program will be reviewed periodically and updated taking into account the site conditions and requirements. Similarly, in consideration of the present practices, requirement of equipment, plant and machinery will be assessed to reduce the construction cost and the time too.

The Consultant, in consultation with Authority, will monitor and supervise model tests of the turbines and other equipment carried out by the Manufacturer/ Contractor at his workplace to ensure that the prototypes shall meet the requirements and specifications under the contract.

1.18 Conclusions and Recommendations

The Detailed Project Report can be summarized as follows:

 The field investigations carried out and basic data available so far are sufficient to support the present design level and to confirm the technical feasibility of Pancheshwar Multipurpose Project. Some additional field investigations and studies may be required in pre-construction stage to develop the final design of the project.

 The optimum layout for the main Pancheshwar dam with power plants of 4800 MW is based on a maximum normal reservoir level of 680 m a.s.l. and on a

Section 1: Executive Summary Page 57 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

rockfill type of dam. The project included a downstream re-regulating dam with 240 MW power stations, to assure a continuous flow to the irrigation in the downstream.

 As presently conceived, the project can be implemented and fully commissioned in a 10 year period, starting from the moment a firm decision at the political level is taken.

 The cost of the entire bi-national infrastructure at 2015 price level is estimated to be in the order of INR 33,108 Crore, excluding import duties and taxes.

 The environmental impact of the project is manageable. Sufficient provision has been made for EMP as well as detailed resettlement plans for PAF.

 The project will generate 9116 GWh dependable energy per year. It will meet the water demand for existing and committed irrigation systems in India. It will also provide water to irrigate 93,000 ha command area in Nepal.

 The economic and financial indicators are sufficient to attract private capital for the development of the scheme, provided a firm economic and legal framework is established.

 The Detailed Project Report is considered a suitable basis to start negotiations for financial closure of the project.

 In the mean time, on-going field activities, particularly the recording and measurement of hydrological, meteorological and micro-seismic data, should continue.

Section 1: Executive Summary Page 58 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Annex-I Salient Features of Pancheshwar Multipurpose Project Pancheshwar Dam (12 x 400 MW = 4800 MW)

A. LOCATION 1. Country India and Nepal Champawat / Uttrakhand Baitadi / Nepal 2. River Mahakali 3. Main Pancheshwar dam Near Pancheshwar Temple Longitude L/B, Nepal 80o 15’ 5” R/B, India 80o 14’41” Latitude L/B, Nepal 29o 25’ 40” R/B, India 29o25’53” 4. Re-Regulating dam at Rupaligad 27 km downstream of Pancheshwar dam Longitude L/B, Nepal 80o 12’ 6.15” R/B, India 80o 12’ 14.63” Latitude L/B, Nepal 29o 07’ 38.81” R/B, India 29o 07’ 55.78” B. HYDROLOGY 1. Drainage area of the river at 12,276 km2 Pancheshwar dam Site 9861 km2 (India) 2415 km2 (Nepal) 2. Average Annual Rain fall 1996.5 mm ( 1962-2012) 3. Average Annual Yield 582 m3/s (Pancheshwar)

4. 75% Dependable Annual Discharge 16128 Mm3 (Pancheshwar) 5. Probable Maximum Flood (PMF) 23,500 m3/s (Pancheshwar)

6. Design Flood for diversion 16,652 m3/s (Pancheshwar) (1000-year return period) 7. Annual sediment Load 58.18 Mm3/year C. PANCHESHWAR DAM 1. Main Dam Rock fill with clay core a. River bed level E.L. 410.00 m b. Deepest Foundation Level E.L. 380.00 m c. Top of dam E.L. 691.00 m d. Height of dam 311.00 m e. Length of dam at top 814.00 m

Section 1: Executive Summary Page 59 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

f. Upstream slope 3.5 (H):1 (V) g. Downstream slope 2 (H) : 1 (V) h. Top Width 20.00 m i. Full Reservoir Level E.L. 680.00 m 2. Coffer Dams a. Type Rockfill b. Crest level of upstream Coffer dam 461.00 m c. Crest of downstream Coffer dam 436.00 m d. Height of U/S Coffer dam 81 m from Bed Rock e. Height of D/S Coffer dam 56 m from Bed Rock 3. Spillway a. Type Gated Chute b. Crest length 185.5 m c. Crest level E.L. 658 m d. Invert level of Plunge Pool E.L.347.00 m e. Energy Dissipater Trajectory Bucket Type 4. Diversion Tunnels a. Numbers Six (3 on each side) b. Diameter & Shape 14 m, Circular c. Inlet level 410.00 m d. Outlet level 397.00 m 5. Main Reservoir a. Full Reservoir Level 680.00 m b. Minimum Draw Down Level 615.00 m c. Dead Storage 5317 Mm3 d. Submergence area of Pancheshwar 116 Km2 (Total) reservoir 76 Km2 (India) 40 Km2 (Nepal) e. Gross capacity 11355 Mm3 f. Live Storage 6038 Mm3 g. New Zero Elevation after 100 year El. 511 m h. Submergence due to Pancheshwar dam Villages 123 villages (In Pithoragarh, Almora &Champawat Districts of India) 25 VDCs and one Municipality in Darchula & Baitadi Districts in Nepal 6. Power Intake

Section 1: Executive Summary Page 60 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

a. Numbers Six ( 3 on each bank) b. No. of gates 12 (Service gate) + 12 (Emergency Gate) c. Size 7.2 m (W) x 8.7 m (H) d. Invert level EL. 587.40 m e. Center line of intake EL. 600.0 m 7. Down Stream Surge Galleries a. Numbers Four (2 nos. on each side) b. Size 90 m (L) X 20 m( W) X 60 m (H) 8. Pressure Tunnels (Vertical + Horizontal) a. Number Six (3 nos. on each side) b. Type Steel Lined c. Finished Diameter 8.70 m d. Invert level at inlet EL 596.00.m e. Design Discharge 368 m3/s of each tunnel 9. Power Houses a. Number & Type Two (one on each side), Underground b. Size 290 m (L) x 23 m (W) x 59 m (H) on each bank c. Installed capacity 12 x 400 MW d. Transformer cavern 224 m (L) x18.5 m (W) x32 m (H) on each bank e. No. of Vertical drop shafts Six (3 on each side) Diameter 8.70 m Height 188.2 m each f. Maximum Tail Water Level (at PMF) El. 435.00 m g. Normal Tail Water Level El.420.70 m h. Minimum Tail Water Level El.419.30 m 10. Tail Race Tunnels a. Numbers, Diameter & Type Four – two on each side; of dia10m, Circular b. Invert level at outlet EL 397.00 m 11. Draft Tube Tunnels a. Numbers, Diameter & Type 12 (six on each side) of dia 7.00 m, Circular Elbow b. Invert Level EL 402.00 m 12. Main Generating Plant

Section 1: Executive Summary Page 61 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

12.1 Turbines a. Type of turbines Francis b. Rated Output 406 MW c. Net rated / design head 235 m d. Synchronous speed 166.67 rpm e. Efficiency at Rated head & output 94.5 % f. Specific speed 134.5 m-kW g. Design discharge 184 m3/s h. Normal / Min. TWL EL. 420.7 m / 419.3 m i. Type of Draft tube Cylindrical 12.2 Main Inlet Valves a. No.& Type of valve Six- Bi-plane Butterfly on each side b. Diameter 5.00 m c. Design head 375 m d. Max. operating flow 184 m3/s 13. Generator a. No. & Type Six - Semi-umbrella on each side b. Rated Output 400 MW c. Max. output 440 MW d. Short circuit ratio 1.1 e. Terminal Voltage 21 KV f. Power Factor 0.85 g. Efficiency at Rated full load 98.5 % h. Stator Diameter 9.68 m i. Stator Height 8.60 m j. Rotor Diameter 7.80 m k. Rotor weight 763 T l. Generator F.P. System Water 13.1. Isolated Phase Bus Duct a. Rating 24/16000 kV/Amp. b. Generator Circuit breaker rating Not provided 14. H.V. Equipment 14.1 Generator Transformers a. No. & Type 40, 1-Phase b. Rated capacity 519 (3x173) MVA c. Cooling ODWF/OFWF

Section 1: Executive Summary Page 62 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

14.2 H.V. Switchgears a. Type SF6 GIS Double bus bar b. Voltage Rating 400 KV c. No. of GIS bays 11 on each bank 14.3 H.V. Cables /GITL a. Means of power evacuation GITL b. No. of Circuits, voltage rating 3, 400 KV 14.4 Reactor a. No. & Type 2 nos., 3-phase b. Capacity & Voltage rating 80 MVAr, 400 KV 15 Mechanical Aux. Systems 15.1 EOT Cranes a. Nos. & capacity of cranes for PH 2 no. of 400 / 80/10 T on each bank b. Span 21 m c. Nos. & capacity of cranes for MIV 1 no.,150 T on each bank cavern 15.2 Lifts a. No. & capacity of lifts in P.H. & Tr. 5 nos. of 10 persons capacity each Hall caverns 16. Power Benefits a. Pancheshwar Power Plant i. Firm Power 767.27 MW ii. Load Factor 18.26% iii. Annual Generation (90% 7678 GWh dependable year) b. Rupaligad Power Plant i. Firm Power 133.80 MW ii. Load Factor 68.42 % iii. Annual Generation (90% 1438 GWh dependable) 17. Estimated Cost of the Project (2015 price Level) a. Pancheshwar dam i. Civil Works INR 241,492 Million ii. E-M Works INR 53,338 Million iii. Total Cost INR 294830 Million b. Rupaligad i. Civil Works INR 31,250 Million

Section 1: Executive Summary Page 63 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

ii. E-M Works INR 5,000 Million iii. Total Cost INR 36,250 Million c. Combined i. Total Cost INR 331,080 Million ii. Cost Chargeable to Power INR 264,825 Million iii. Cost Chargeable to Irrigation INR 66,225 Million

Section 1: Executive Summary Page 64 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Annex-II

Rupaligad Re-regulating Dam (4 x 60 MW = 240MW) A. LOCATION a. Countries India and Nepal b. Districts Champawat, Uttrakhand, India, Baitadi, Nepal c. River Mahakali d. Dam Axis 1070 m downstream of Rupaligad Nalla confluence e. Power House Two nos. powerhouse – one on each bank f. Rupaligad Dam Longitude, L/B 800 18' 25.07'' (Nepal) R/B 800 18' 15.75'' (India) Latitude, L/B 290 16' 55.761'' (Nepal) R/B 290 16' 55.711'' (India) B. HYDROLOGY a. Catchment area up to Dam site 13,490 km2 b. Average annual rainfall 1938 mm c. Average Annual Discharge 618.60 m3/s d. Probable Maximum Flood(PMF) 27700 m3/s e. Annual Sediment Load 5.83 Mm3 (95% Trap Efficiency at Pancheshwar) C. RUPALIGAD RESERVOIR a. Full Reservoir Level (FRL) EL 420.00 m b. Minimum Draw Down Level (MDDL) EL 400.00 m c. Submergence Area 396.00 Ha. d. Gross Capacity 81.25 Mm3 e. Live Storage 56.45 Mm3 f. Dead Storage 24.80 Mm3 g. Maximum Water Level (MWL) EL 424.00 m D. RE-REGULATING DAM a. Type Concrete Gravity dam b. Average river bed level EL 361.00 m c. Deepest foundation level EL 333.00 m d. Crest Level (Top of the Dam) EL 428.00 m e. Height of Dam 95 m f. Length of Dam at top 265 m g. Width of Dam at top 8.00 m E. SPILLWAY a. Type Sluice Spillway with Bucket Trajectory b. Length of spillway portion (Overflow) 192.00 m c. Crest Gates 12 Nos Radial of 9.50 m (W) x 14.50 m (H) each d. Design Discharge 27700 m3/sec e. Crest level EL 386.00m f. Full Reservoir Level EL 420.00 m

Section 1: Executive Summary Page 65 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

F. INTAKE STRUCTURES a. Type Bell Mouth b. No. Of Intake 4 No. (2 on each bank) c. No. Of Openings 8 No. (4 on each bank) (2 openings converge into one HRT) d. No. of Gates 8 No. (4 on each bank) e. Size of Opening 3.0 m (H) X 5.53 m (W) f. Centre Line of Intake EL 392.00 m g. Invert Level of Intake EL390.50 m G. DIVERSION TUNNELS a. Number Two no.(1 on each bank) b. Design flood for Diversion 2000 m3/s (1000 m3/s on each side) c. Shape and size Circular, 12.00m d. Invert Level at Inlet EL.366.00m e. Invert Level at outlet EL.361.00m H. COFFER DAMS Upstream Coffer Dam a. Type Colcrete b. Top Width 6 m c. Top Level EL.385.00m d. Foundation Level EL.361.00 m e. Height 24 m f. Length at top 163 m Downstream Coffer dam a. Type Rockfill b. Top Width 7 m c. Top Level EL.377.00m d. Foundation Level EL.360.00m e. Height 17 m f. Length at top 110 m I. HRT (Steel Lined) a. No. of HRT 4 No. (2 on each side) b. Design Discharge 150.00m3/s each c. Shape and size Circular, 6.5 m dia. d. Centre Line of HRT at Intake EL392.00m e. Invert Level at Inlet EL 390.50m J. POWER HOUSE CAVERNS a. No. and Type Two nos.(1 on each bank), Underground b. Size 24.00 m (W) x 49.50 m (H) x 112.00 m (L) c. Service Bay Level EL 366.00 m d. Type of Draft Tube gate Bonneted type e. Size of Draft Tube Gate 7 m (H) X 6 (W) K. TRANSFORMER CUM GIS HALL CAVERN a. Type Underground b. Size 19.00 m (W) X 31.00 m (H) X 75.00 m(L)

Section 1: Executive Summary Page 66 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

L. GENERATING EQUIPMENT a. Type of turbine Kaplan b. No. of Turbines Four ( Two on Each Side) c. Unit Spacing 28.00 m d. Net rated / design head 44.00 m e. Rated Output 60 MW f. Synchronous speed 150 rpm g. Max. / Min net head 50.70m / 30.70 m h. Runner throat diameter 4.80 m i. Efficiency at Rated head & output 95 % j. Normal Operating / Min. TWL 367.00m/ 363.00m k. Design discharge 150 m3/sec. MAIN INLET VALVE a. No.& Type of valve Two nos., Bi-plane butterfly b. Diameter 5.5 m GENERATORS a. No. & Type Four (Two nos. on each bank), Semi-umbrella type b. Rated Output 60 MW/ 71 MVA c. Max. output 66 MW/ 78 MVA d. Terminal Voltage 11 kV e. Power Factor 0.85 f. Efficiency at Rated full load 98.5 % TRANSFORMER CUM GIS a. No. & Type of Transformer 2 nos., 3 F b. Rated capacity 78 MVA c. Voltage Ratio 11/220 kV M. TAIL RACE TUNNEL a. Design Discharge 150.00m3/s each b. Numbers Four nos. (2 on each bank) c. Size and Shape 7.0m dia, Circular d. Invert Level at outlet Portal EL 362.0m N. POTHEAD YARD a. Area 85m X 32.5m b. Elevation EL 420.00m O. CABLE TUNNEL a. Type Underground b. Size and Shape 6.5 m X 6.5 m, D-shaped P. ENERGY GENERATION a. Installed Capacity & Type 240 MW, Base Load b. Annual Generation 1438 GWh c. Annual Load Factor 68.42 % Q. ESTIMATED COST Civil Works INR 31,250 Million E & M Works INR 5,000 Million Total INR 36,250 Million (Say)

Section 1: Executive Summary Page 67 PANCHESHWAR MULTIPURPOSE PROJECT DETAILED PROJECT REPORT

Table 1.8 - 2: Total Water Requirement of India and Nepal including River Eco-System (in m3/s)

Month Water Existing Irrigation uses of India Water Requirement of Nepal Total Water demand to be protected Utilization by the Local Existing irrigation Existing Irrigation at Total Existing Irrigation Future Irrigation Total Compulsory Gross Water Additional water Community uses of Sarada Lower Sarada Barrage Existing requirement of requirement of Irrigation Downstream Requirement for available to permitted canal system at (Sarada Sahayak Irrigation Nepal at Banbasa Nepal for 93000 ha Requirement releases for India and Nepal India during from Banbasa system) during uses of India Barrage and including of Nepal maintaining River (5)+(8)+(9) Rabi season for Mahakali Barrage( for Monsoon Season Tanakpur Barrage requirement of eco-system below Irrigation River round the year) for round the year Dodhara Chandani Banbasa Barrage benefits 3 (16th June - 15th Oct.) area @ 10 m /s

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) June 29.15 283.90 135.30 419.20 56.70 39.20 95.90 0.00 515.10 - July 29.15 296.70 650.00 946.70 56.70 160.60 217.30 0.00 1164.00 - Aug. 29.15 294.00 174.00 468.00 56.70 84.10 140.80 0.00 608.80 - Sept. 29.15 295.90 650.00 945.90 56.70 137.50 194.20 0.00 1140.10 - Oct. 29.15 280.80 213.30 494.10 34.90 175.20 210.10 0.00 704.20 - Nov. 29.15 217.20 0.00 217.20 12.75 20.55 33.30 10.00 260.50 134.46 Dec. 29.15 179.30 0.00 179.30 12.75 35.45 48.20 10.00 237.50 145.16 Jan. 29.15 156.40 0.00 156.40 12.75 42.45 55.20 10.00 221.60 145.27 Feb. 29.15 142.00 0.00 142.00 12.75 54.05 66.80 10.00 218.80 165.73 March 29.15 143.10 0.00 143.10 12.75 84.65 97.40 10.00 250.50 136.91 Apr. 29.15 165.50 0.00 165.50 12.75 191.95 204.70 10.00 380.20 3.37 May 29.15 236.00 0.00 236.00 34.90 143.80 178.70 10.00 424.70 - Mean (m3/s) 29.15 224.23 151.88 376.12 31.09 97.46 128.55 5.83 510.50 121.82 Volume 920.00 7,071.00 4,790.00 11,861.00 980.00 3,073.00 4,053.00 184.00 16,100.00 1,905.00 (in Million m3)

Note:

1. Use of water permitted from Mahakali River by the Local Community, @ 5% of the annual average inflow at Pancheshwar, has been subtracted from the gross water availability at Pancheshwar under the provision of Article-7 of Mahakali Treaty. 2. As per Article 1 (2) of the treaty, a flow of minimum 10 m3/s is to be maintained for River eco system below Banbasa Barrage. However, as the releases below Banbasa Barrage to meet requirement of Sarada Sahayak system for the monsoon months from June to October are higher than the requirement of eco-system, no compulsory releases from Pancheshwar are considered for these months. 3. It is presumed that the augmented flows that may be available from Pancheshwar, after meeting the existing demands of India and existing and future demands of Nepal shall be utilized fully by India for additional irrigation.

Section 1: Executive Summary Page 68 Consultant:

76-C, Institutional Area, Sector – 18, Gurgaon – 122015, Haryana (INDIA) Telephone: 0124-2342576, Fax: 0124-2349187 [email protected], Website: http://www.wapcos.gov.in