ENVIRONMENTAL MANAGEMENT PLAN OF DIBANG MULTIPURPOSE PROJECT , ARUNACHAL PRADESH
Prepared for NHPC Limited
WAPCOS LIMITED
CONTENTS
SERIAL PAGE CONTENTS NO. NO. CHAPTER 1 PROJECT DESCRIPTION 1.1 Introduction 1-1 1.2 Dibang Multipurpose Project: Historical Milieu 1-2 1.3 Environmental Management Plan (EMP) 1-3 1.4 Outline of Environmental Management Plans 1-4 CHAPTER 2 BIODIVERSITY CONSERVATION AND MANAGEMENT PLAN 2.1 Introduction 2-1 2.2 Compensatory Afforestation 2-1 2.3 Conservation Plan for Endangered species of plants 2-1 2.4 Establishment of Gardens for Voucher Specimen 2-4 2.5 Wildlife Conservation 2-5 2.6 Biodiversity Conservation 2-7 2.7 Preparation of peoples Biodiversity Registers (PBR) 2-11 2.8 Forest Protection Plan 2-11 2.9 Safeguards during construction phase 2-13 2.10 Biodiversity Management Committee (BMC) 2-14 2.11 Cost Estimate for Biodiversity Conservation Plan 2-15 CHAPTER 3 CATCHMENT AREA TREATMENT PLAN 3.1 Introduction 3-1 3.2 Catchment Area Treatment 3-2 3.3 Estimation of Soil Erosion 3-2 3.3.1 Drainage 3-3 3.3.2 Delineation of Watersheds and Sub-watersheds 3-3 3.3.3 Slope 3-4 3.3.4 Land Use/ Land Cover Mapping 3-6 3.3.5 Soils 3-11 3.3.6 Sediment Yield Index Model 3-12 3.3.7 Sediment Yield Weightage Value 3-13 3.3.8 Delivery Ratio 3-14 3.3.9 Sediment Yield Index 3-14 3.3.10 Prioritization of Subwatersheds 3-14 3.4 Methodology for Prioritization 3-14 3.5 Assignment of Erosivity Weightage Value 3-15 3.6 Assignment of Delivery Ratios (DRs) 3-16 3.7 Computation of Silt Yield Index 3-16 3.8 Prioritization of Subwatersheds 3-20 3.9 Area Identified for CAT 3-21 3.10 Period and Schedule of Implementation 3-22 3.11 Details of Treatment Measures with Unit Cost Estimate 3-26 3.11.1 Silt Retention Dams 3-26 3.11.2 Contour bunding 3-27 3.11.3 Brush Wood Check Dams 3-27 3.11.4 Loose Bolder Check Dam 3-28
i 3.11.5 Gabion Structures 3-30 3.11.6 Biological Measures 3-30 3.12 Administrative Charges 3-31 3.13 Administrative Setup 3-31 3.14 Contingency Charges 3-31 3.15 Monitoring, Evaluation and Maintenance 3-32 3.16 Cost Estimate 3-32 3.17 Cost Estimate for CAT Plan 3-34 CHAPTER 4 FISH MANAGEMENT PLAN 4.1 Introduction 4-1 4.2 Fish In Dibang River 4-1 4.3 Conservation And Management Considerations Of Dibang 4-2 River 4.4 Management Measures 4-3 4.5 Recommendations 4-5 4.5.1 Fish Hatchery 4-5 4.5.1.1 Seed Collection 4-5 4.5.1.2 Analysis of Water Quality 4-6 4.5.1.3 Seed Stocking 4-6 4.5.1.4 Organization of Fishermen 4-6 4.5.1.5 Other Requirements 4-6 4.5.1.6 Conservation of Downstream River Bed 4-6 4.5.2 Management of Reservoir Fisheries 4-7 4.5.2.1 Institutional Mechanism 4-7 4.5.2.2 Staffing Pattern 4-7 4.5.2.3 Planning and Monitoring 4-8 4.6 Cost Estimates for Fish Management Plan 4-8 CHAPTER 5 GREENBELT DEVELOPMENT PLAN 5.1 Introduction 5-1 5.2 Plantation 5-1 5.3 Cost Estimate for Greenbelt Development 5-2 CHAPTER 6 GEO - ENVIRONMENTAL MANAGEMENT PLAN 6.1 Introduction 6-1 6.2 Landslide Control 6-1 6.2.1 Landslide Control Measures 6-1 6.2.2 Treatment of slope conformation 6-2 6.3 Drainage of Landslide Areas 6-3 6.4 Mitigation Measures 6-6 6.5 Cost Estimate for Geo-Environmental Management Plan 6-12 CHAPTER 7 MUCK DISPOSAL PLAN 7.1 General 7-1 7.2 Muck Disposal Areas 7-1 7.3 Restoration of Muck Disposal Sites 7-2 7.3.1 Engineering Measures 7-2
ii 7.3.2 Phyto-remediation of Muck Disposal Areas 7-2 7.3.2.1 Re-vegetation of Spoil Tips 7-7 7.3.2.2 Soil Working and Plantation Technique 7-7 7.3.2.3 Species for Plantation 7-9 7.3.2.4 Irrigation Facility 7-9 7.3.2.5 Fencing 7-9 7.3.2.6 Watch and Ward 7-9 7.4 Recommendations 7-9 7.5 Cost Estimate for Muck Disposal Plan 7-10 CHAPTER 8 RESTORATION PLAN FOR QUARRY AREAS 8.1 Quarry Sites 8-1 8.2 Stabilization of Quarry Sites 8-5 8.2.1 Stabilization through phytoremediation 8-5 8.3 Cost Estimates for Restoration Plan for Quarry Areas 8-8 CHAPTER 9 LANDSCAPING AND RESTORATION OF CONSTRUCTION AREAS AND ENVIRONMENTAL MANAGEMENT IN ROAD CONSTRUCTION 9.1 Restoration of Construction Sites 9-1 9.2 Post Project Construction Landscaping 9-1 9.3 Cost estimate for Restoration of Construction Areas 9-2 9.4 Environmental Management in Road Construction 9-2 9.4.1 Design 9-3 9.4.2 Construction 9-3 9.4.3 Drainage 9-4 9.4.4 Grassing and Planting 9-4 9.4.5 Control of Landslides along the roads 9-5 9.4.6 Species recommended for plantation 9-5 Cost estimate for Environmental Management in Road 9.4.7 9-6 Construction 9.5 Restoration of Colony and Office Complex 9-6 Cost estimate for Landscaping & Restoration of 9.6 Construction areas and Environmental Management in 9-7 Road Construction CHAPTER-10 PUBLIC HEALTH DELIVERY SYSTEM 10.1 General 10-1 10.2 Mosquito Control Measures 10-1 10.2.1 Reservoir Operation 10-1 10.2.2 Residential Colonies For The Workers 10-1 10.2.3 Other Measures 10-2 10.3 Traditional Medicinal Practices 10-2 10.4 Development of Medical Facilities 10-2 10.4.1 Manpower 10-2 10.4.2 Proposed Health Facilities at Construction Sites and Labour 10-3 Camp 10.5 Surveillance 10-4 10.5.1 Malaria Control Activities 10-4 10.5.2 Vaccination and Health Check-Up Camps 10-5
iii 11.5.3 Health Extension Activities 10-5 10.6 Cost Estimates for Public health Delivery System 10-5 10.6.1 Fixed Cost (Non-Recurring) 10-6 10.6.2 Variable Cost (Recurring) 10-6 10.6.3 Overall Expenditure 10-7 CHAPTER 11 PLAN FOR SOLID WASTE MANAGEMENT AND SANITATION FACILITIES IN LABOUR CAMPS 11.1 Introduction 11-1 11.2 Quantity of Solid Waste Generation 11-1 11.3 Composition of Municipal Solid Wastes 11-2 11.4 Administrative Set Up 11-3 11.5 Solid Waste Management Plan 11-4 11.5.1 Segregation at source 11-4 11.5.2 Primary Storage of Wastes 11-5 11.5.3 Collection of Solid Wastes 11-7 11.5.4 Waste Handling 11-8 11.5.5 Transportation of Solid Wastes 11-8 11.6 Disposal of Solid Waste (Non-degradable Portion) 11-9 11.7 Treatment of Solid Waste (Degradable Portion) 11-10 11.8 Sanitation Facilities in Labour Camps 11-11 11.8.1 Increase in Labour Population 11-11 11.8.2 Facilities in Labour Camps 11-11 11.9 General Sanitary Measures 11-13 11.10 Cost estimate for Solid Waste Management Plan 11-13 CHAPTER 12 SAFETY PRACTICES DURING CONSTRUCTION PHASE 12.1 Introduction 12-1 12.2 Traffic Management During construction phase 12-1 12.3 Measures to be taken during Excavation of Earth 12-1 12.4 Safety practices during construction phase 12-2 12.5 Fire protection in labour camp and staff colonies 12-2 12.6 Cost estimate for safety practices during construction phase 12-5 CHAPTER 13 ENERGY CONSERVATION MEASURES 13.1 Introduction 13-1 13.2 Energy Conservation during construction phase 13-1 13.2.1 Construction of LPG depot & LPG Connection 13-1 Other Energy Conservation measures during construction 13.2.2 13-2 phase 13.3 Energy conservation during operation phase 13-2 13.4 Energy saving measures for population in study area 13-2 13.4.1 Distribution of Kerosene oil stoves 13-2 13.4.2 Distribution of Pressure Cookers 13-3 13.4.3 Solar Cookers 13-3 13.4.3 Installation of Improved Chulhas 13-4 13-4 13.5 Cost Estimate for Energy Conservation measures
iv CHAPTER 14 RESETTLEMENT AND REHABILITATION PLAN 14.1 Existing Guidelines for Resettlement Programme in 14-1 Arunachal Pradesh 14.2 Objectives of R&R Plan 14-2 14.3 Definitions 14-3 14.4 Resettlement and Rehabilitation Grants 14-6 14.4.1 Compensation for Land along with Rights and Privileges 14-6 14.4.2 Housing Benefit and Compensation 14-7 14.4.3 Land Allotment and Compensation 14-7 14.4.4 Ex Gratia for the Landless 14-8 14.4.5 Ex Gratia for those Affected Families who are left with less 14-8 than 1 ha of land 14.4.6 Land Development Assistance 14-8 14.4.7 Livelihood Grant for Landless 14-8 14.4.8 Livelihood Grant for those who have been left with less than 14-8 1 ha of land 14.4.9 Financial Assistance for Self Employed 14-9 14.4.10 Transportation Grant 14-9 14.4.11 Assistance for Construction of Cattle shed 14-9 14.4.12 Subsistence Allowance 14-9 14.4.13 Pension for Life for Vulnerable Affected Persons 14-9 14.4.14 Schedule Tribe Family Grant 14-9 14.4.15 Training for Livelihood 14-10 14.4.16 Free Electricity 14-10 14.4.17 Special Provision 14-10 14.5 Financial Outlay for R&R Benefits 14-10 14.6 Application for Grant and Grant Distribution 14-12 14.7 Infrastructure Facility at Resettlement Site / Colony 14-12 14.7.1 Financial Outlay for Infrastructure Facilities 14-13 14.8 Lump sum Cash Assistance 14-15 14.9 Monitoring and Evaluation 14-15 14.10 Cost estimate for R&R Plan 14-16 CHAPTER 15 COMMUNITY AND SOCIAL DEVELOPMENT PLAN 15.1 Community and Social Development Plan (CSDP) 15-1 15.1.1 Aim of CSDP 15-1 15.1.2 Objectives of CSDP 15-1 15.2 Concerns raised during Public Hearing 15-2 CHAPTER 16 PLAN FOR PROTECTION OF CULTURAL IDENTITY OF LOCALS 16.1 Introduction 16-1 16.2 Strategies / Guidelines 16-1 16.3 Protection of Cultural Identity of Local Tribal 16-1 16.4 Protection of the Natural Habitat of Local Tribals 16-2 16.5 Regulation of Traffic on Roads 16-2 16.6 Institutional Arrangements 16-3 16.7 Action Plan 16-3
v 16.8 Surveillance Measures 16-4 16.9 Support to cultural Heritage/Programmes 16-4 16.9 Cost estimate of Plan for Protection of Cultural identity of 16-5 locals CHAPTER 17 CONTROL OF WATER, AIR AND NOISE POLLUTION 17.1 Water Pollution Control 17-1 17.1.1 Control of water pollution during construction phase 17-1 17.1.2 Control of Water Pollution during operation phase 17-1 17.2 Air Pollution Control 17-2 17.2.1 Control of Emissions 17-2 17.2.2 Control of Air Pollution due to DG Sets 17-2 17.2.3 Dust Control 17-3 17.3 Noise control Measures 17-4 17.3.1 Control of Noise from construction equipment 17-4 17.3.2 Control of Noise from DG sets 17-4 17.3.3 Control Noise from crushers 17-5 17.4 Implementing Agency 17-6 CHAPTER 18 DISASTER MANAGEMENT PLAN 18.1 Dam Break Analysis 18-1 18.1.1 Governing Equations 18-3 18.2 Salient Features 18-8 18.3 Requirement of Field Data 18-9 18.3.1 Field Survey 18-9 18.3.2 Topographic Characteristics 18-9 18.3.3 Channel Roughness 18-10 18.3.4 Numerical Applications 18-11 18.3.5 Need of Considering Extended Width 18-16 18.4 Emergency Action Plan 18-24 18.5 Disaster Management Plan 18-24 18.5.1 Dimension of Disaster and Area/Population likely to be 18-25 Affected 18.6 Financial Outlay for Disaster Preparedness and Mitigation 18-27 18.6.1 Financial Outlay for Installation of VSAT Communication 18-27 System 18.6.2 Evacuation Plans 18-28 18.6.3 Notification 18-28 18.7 Cost Estimate for Disaster Management Plan 18-29 18.8 Conclusions 18-30 CHAPTER 19 ENVIRONMENTAL MONITORING PROGRAMME 19.1 The Need 19-1 19.2 Environmental Monitoring Cell 19-1 19.2.1 Monitoring Mechanism 19-1 19.3 Areas of Concern 19-2 19.4 Water Quality 19-2 19.5 Air quality and Meteorology 19-3
vi 19.6 Noise 19-4 19.7 Ecology 19-4 19.8 Incidence of Water Related Diseases 19-5 19.9 Landuse Pattern 19-5 19.10 Summary of Environmental Monitoring Programme 19-6 19.11 Cost estimate for Environmental Monitoring Programme 19-7 CHAPTER 20 ASSESSMENT OF ENVIRONMENTAL FLOW Environmental Flow in the Diverted stretch of about 1.2 km 20.1 20-1 between Dam and TRTs of Power House 20.2 Release of Minimum flows after TRT 20-5 CHAPTER 21 SUMMARY OF COST ESTIMATE 21.1 Cost for Implementing Environmental Management Plan 21-1
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CHAPTER1 PROJECT DESCRIPTION
EMP Report of Dibang Multipurpose Project
CHAPTER 1 PROJECT DESCRIPTION
1.1 INTRODUCTION The State of Arunachal Pradesh is situated in the north-eastern region of the country and lies between latitude 26°28' to 29°30' North and longitude 91°31' to 97°30' East. The State shares international boundaries with Tibet along the snow line in the north, with Bhutan in the west and Myanmar in the south-east. The State shares most of its southern boundary with Assam. The State also shares its boundaries with Nagaland for a small stretch on the southern side. The total geographical area of Arunachal Pradesh is 83743 sq km. Subansiri, Siang (or, Dihang), Dibang (or, Sikang), Siyom, Kameng, Lohit and Tirap are the major rivers of the State. Arunachal Pradesh has a huge hydro-potential, which is required to be tapped to meet the power demand of the country. As per the studies for the re-assessment of the potential carried out by CEA, Arunachal Pradesh has a probable installed capacity of 66065 MW and hydroelectric potential of Arunachal Pradesh is estimated at 34920 MW at 60% load factor. Dibang river system has a probable hydropower potential of about 10152 MW from 12 identified schemes. These schemes are run of river and storage types. Thus, it is extremely important to harness the hydropower potential of Arunachal Pradesh.
Dibang Multipurpose Project is being conceived on river Dibang which originates from snow covered southern flank of the Himalayas close to Tibet border at an altitude of more than 5000 m. The river emerges from the hills and enters sloping plain area near Nizamghat in Arunachal Pradesh, from where the river flows for a distance of 50 km to meet the river Lohit. The total catchment area of Dibang up to the dam site is 11276 sq km which lies entirely in India.
The proposed Dibang Multipurpose project is located in Lower Dibang Valley district of Arunachal Pradesh. The reservoir created due to the project will provide flood moderation benefits in the downstream. The back water in the reservoir will travel up to a length of 43 km in Dibangriver and its various tributaries – Airi Pani, Ilu Pani, Imu Pani, Ahi river, Ithun river, Emra river etc. which will facilitate promotion of navigation
1-1 EMP Report of Dibang Multipurpose Project by connecting inaccessible upstream villages/areas. The project after construction will be one of the biggest projects in terms of generation of hydropower in India.
The project headquarters is proposed to be at Pathar Camp on the right bank of river Dibang approximately 6 km downstream of dam site. The project has a poor connectivity from the railhead and the nearby towns (viz. Tinsukia, Dibrugarh, Pasighat, Itanagar, Tezpur etc.). The project is located about 43 km from Roing which is situated at a distance of 110 km from Tinsukia the nearest railhead. Airport at Mohanbari (Dibrugarh) is further 45 km from Tinsukia. Up-gradation of electricity generating capacity is an urgent national need, to meet the ever increasing power demand. The north-eastern region has huge hydel potential for electricity generation. Layout plan of the project is shown in Fig. 1.
1.2 DIBANG MULTIPURPOSE PROJECT: HISTORICAL MILIEU Brahmaputra Board geared up investigation works of Dibang Multipurpose Project in 2001-02 and the Pre-Feasibility Report (PFR) was prepared by them in March, 2002. As per the PFR, the project comprised of a 263 m high rock fill dam at Munli with upstream concrete face. The project was planned to generate about 3000 MW hydropower from a surface powerhouse and also for flood moderation at downstream.
Brahmaputra Board continued the survey and investigation works for preparation of Detailed Project Report. During a review meeting held in office of Chairman, Central Water Commission (CWC) on 21.11.02, where representatives from Brahmaputra Board, Ministry of Water Resources and NHPC were present, it was decided that NHPC would take up the work of drilling and drifting required for preparation of Detailed Project Report.
Subsequently Dibang Multipurpose Project was transferred to NHPC by Ministry of Water Resources vide F No. 24/2(D)/2001-ER/4972-77 dt. 20.12.2002 and order was formally issued to NHPC under section 18A of the Electricity (Supply) Act vide Ministry of Power (MoP) letter no. 22/7/2001-DO (NHPC) dated December 24th, 2002 to establish, operate and maintain the project. In the letter by Ministry of Water Resources it was also decided that Brahmaputra Board will continue to prepare
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Detailed Project Report with active involvement of CWC and NHPC. Accordingly, based on the Pre-Feasibility Report, NHPC had undertaken detailed survey & investigation works. Later, after the joint meeting of senior officials/experts of CWC, Brahmaputra Board and NHPC, project data was reviewed by the above team and the present dam axis was fixed at 460 m downstream of the earlier investigated dam axis and also it was proposed to make the power house underground inside a hill on right bank of River Dibang near the dam, thereby reducing the tunnel length considerably. Subsequently, further investigation activities were taken up on the new dam axis and in power house area. In the meantime the work of preparation of Detailed Project Report was also entrusted by Ministry of Water Resources to NHPC including the design of the project independently vide F No-24/4/D/2004-ER/93-97 dated 7th Jan 2005.
1.3 ENVIRONMENTAL MANAGEMENT PLAN (EMP) Environmental Management Plan (EMP) is suggested on the basis of the identified impact in the Environmental Impact Assessment. EIA is a planning tool that is now generally accepted as an integral component of sound decision-making. The objective of EIA is to foresee and address potential environmental problems/concerns at an early stage of project planning and design. EIA/EMP should assist planners and government authorities in the decision making process by identifying the key impacts/issues and formulating mitigation measures. Ministry had issued sectoral guidelines some time ago.
EMP comprehensively covers all aspects of the natural and human environment so that adverse impact, if any is taken care of and the project does not create any hazard or affect the quality of life for generations. In case of a hydro power project, the natural river system is altered after the reservoir is created. The EMP should cover necessary treatment measures to maintain the life of the reservoir and sustain the services or power production from the project.
The major mitigation measures planned and proposed in the EMP of Dibang Multipurpose Project relate to both abiotic and the biotic components of the environment and are derived from the impacts predicted on the project specific
1-3 EMP Report of Dibang Multipurpose Project activities that would have adverse environmental impacts and require to be mitigated. 1.5 OUTLINE OF THE ENVIRONMENTAL MANAGEMENT PLANS The present document outlines the Environmental Management Plan for the Dibang Multipurpose Project. The contents of the Report are arranged as follows: Chapter-1: outlines the project description. Chapter-2: outlines the Biodiversity Conservation and Management plan. Chapter-3: outlines the Catchment Area Treatment. Chapter-4: presents the plan to minimize the impacts on fish population due to the proposed Dibang Multipurpose Project. Chapter-5: presents the Greenbelt Development Plan. Chapter-6: outlines the landslides control measures (geo-environmental management plan). Chapter-7: covers the muck disposal plan. Chapter-8: outlines the restoration plans for the quarry areas. Chapter-9: outlines measures suggested for landscaping and restoration of construction areas and environmental management in road construction. Chapter-10: covers Public Health Delivery system. Chapter-11: covers the plan for solid waste management and sanitation facilities in labour camps. Chapter-12: outlines the Safety Practices during construction phase. Chapter-13: outlines various energy conservation measures to be implemented during project construction as well as operation phases. Chapter-14: outlines the resettlement and rehabilitation plan for the project affected families. Chapter-15: outlines the Community and Social Development Plan. Chapter-16: delineates the plan to protect the cultural identity of the locals during project construction phase. Chapter-17: outlines the measures proposed to control water, air and noise pollution during construction phase. Chapter-18: delineates the details of Dam Break Analysis Study and Disaster Management Plan. Chapter-19: covers the Environmental Monitoring Programme for implementation during project construction and operation phases.
1-4 EMP Report of Dibang Multipurpose Project
Chapter 20: outlines the assessment of environmental flow. Chapter-21: outlines the cost required for implementation of various measures outlined as a part of Environmental Management Plan.
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Fig. 1: Layout Plan of Dibang Multipurpose Project
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CHAPTER 2 BIODIVERSITY CONSERVATION AND MANAGEMENT PLAN
EMP Report of Dibang Multipurpose Project
CHAPTER 2 BIODIVERSITY CONSERVATION AND MANAGEMENT PLAN
2.1 INTRODUCTION A detailed floral and faunal survey was carried out in the project area to assess the presence of various floral and faunal species. The rare and endangered species likely to be affected by the project were also assessed.
Conservation is the sustainable use of natural resources, so that it is preserved for future generation as well. Natural conservation involves proper management of natural wealth, places that sustain these resources besides the human pressure that affect the resources. The present chapter outlines the Bio-diversity Conservation Plan including plan for conservation of rare and endangered species as well.
2.2 COMPENSATORY AFFORESTATION The Forest Department of Arunachal Pradesh is responsible for conservation and Management of forests in the state. The total land required for the project is 5349.14 ha of which 4577.84 ha is forest land. A budget of ₹ 14774.18 lakh has been earmarked for Compensatory afforestation. The cost is likely to change at the time of Forest Clearance. The total degraded area to be afforested is (4577.84 x 2) = 9155.68 ha, say 9156 ha.
The valuation of timber and other non-timber forest produces (NTFPs) and NPV of the forest affected by the project shall be estimated by the Forest Department at the time of Forest Clearance.
2.3 CONSERVATION PLAN FOR ENDANGERED SPECIES OF PLANTS Some of the rare and endemic species like Cymbidium eburnum, Livistona jenkinsiana, Paphiopedilum fairrienum, Psychotriya aborensis, Albizia arunachalensis etc. have been reported from low hills of Arunachal Pradesh in the altitudinal range of 300-1500 m elevation (Nayar and Sastry, 1987-1990). During the survey, these species were not reported from the project and influence area of this project. In addition, some plant species which are cited as endemic to North East and also
2-1 EMP Report of Dibang Multipurpose Project occurring in hills of Arunachal Pradesh viz., Persea robusta, Phoebe hainesiana, Terminalia myriocarpa, Plectocomia himalayana, etc. have been recorded during the survey in the project catchment area (Kaul & Haridasan, 1987; Nayar, 1996; Chowdhery, 1999; Parthasarthy & Bahera, 2005; Choudhery 2008). Some species viz., Angiopteris evecta, Cyathia spinulosa, Entada pursaetha, Gynocardia odorata, Podophyllum hexandrum, Rhododendron edgeworthii, Taxus wallichiana are also considered to be threatened due to habitat loss and over-exploitation. In addition Coptis teeta (Mishmi teeta – Vulnerable as per BSI Red Data Book) may also be considered for conservation as this species is endemic and overexploited due to its medicinal value.
The peculiar topography, the area and the location of the dam on a comparatively narrow gorge, perhaps makes the creation of a comparatively long reservoir submerging more than usual, large forest area obligatory in this case. However, the redeeming feature is that the type of forest affected is, by no means unique to this area alone but occurs in other areas of the vast catchment. Moreover the percentage of forest-covered land in this catchment is quite high and the provision of compensatory afforestation should adequately take care of the possibility of upsetting the ecological balance. However, it is suggested that while clearing the forest area to be submerged, the Forest Department should take adequate care to translocate the rare species of plants particularly orchids, tree ferns and medicinal herbs and shrubs to other adjoining forest areas as far as feasible and the Project Authority should fully co-operate in this job. These should also ensure that their men and machineries create the least disturbance in the neighbouring forest areas.
Some of the techniques for ex-situ conservation are listed in Table 2.1. Table 2.1: Techniques of ex-situ conservation
Techniques Definition Seed storage Collection of seed samples at one location and their transfer to a gene bank for storage. The samples are usually dried to suitable low moisture content and then kept at sub-zero temperatures. Field gene bank The collecting of seed or living material from one location and its transfer and planting at a second site. Large numbers of accessions of a few species are usually conserved. Botanic garden / The collecting of seed or living material from one location and its arboretum transfer and maintenance at a second location as living plant
2-2 EMP Report of Dibang Multipurpose Project
collections of species in a garden or for tree species in an arboretum. Small numbers of accessions of a large number of species are usually conserved. In vitro storage The collection and maintenance of explants (tissue samples) in a sterile, pathogen-free environment. DNA / pollen The collecting of DNA or pollen and storage in appropriate, usually storage refrigerated conditions.
From the techniques mentioned in Table 2.1, creation of Botanic garden is proposed for conservation of endangered plants found in Dibang catchment area. It is proposed to afforest rare and endangered species over an area of 50 ha (as a part of compensatory afforestation) as a measure for ex-situ conservation and propagation. The rehabilitation plots are to be at least the size of 35 ha for trees and 10 ha for shrubs and 5 ha for herbaceous plants.
Many of the threatened plants and the superior germplasm that are going to be affected can be transplanted to safer locations. There are useful technologies that are available for this purpose. Appropriate technologies suiting to the species concerned could be adopted. Some of the vegetative propagation methods like airlayering, grafting, stump planting, cuttings, suckers, stolons, bulbil propagation etc may find application here.
There are many important trees and superior germplasm in the area particularly of timber species and bamboos. We need to create germplasm banks with the materials obtained from it. Though the same species could be found elsewhere, the germplasm may not be available. The propagation and cultivation of these species may be done in co-ordination with the State Forest Research Institute (SFRI), Itanagar or Regional Forest Research Institute, Jorhat. Similarly NERIST and RRL could take up some aspects of the study and action. The Forest School at Roing Range offices located at Roing and Santipur can be utilized in resume and rehabilitation.
In addition, an orchidarium and a fern house are proposed to be developed in the project area, in which important species of orchids and ferns collected from the catchment area will be conserved.
2-3 EMP Report of Dibang Multipurpose Project
An amount of ₹ 500 lakh may be earmarked for propagation of rare & endangered species including R&D activities. An amount of ₹ 50 lakh has been earmarked for development of orchidarium and fern house. Thus, total expenditure on this amount works out to (₹ 500 + ₹ 50) = ₹ 550 lakh.
2.4 ESTABLISHMENT OF GARDENS FOR VOUCHER SPECIMEN The proposed repositories would be of special interest to biodiversity conservation, scientific research, education and environmental awareness. Depending on the habitat of a species, two gardens are proposed to be established in an area of 9-10 ha of degraded land. An amount of ₹ 389.47 lakh has been earmarked for establishment of voucher garden. The details are given in Table 2.2.
Table 2.2: Cost estimate for establishment of gardens for voucher specimen
Particulars Amount (₹ lakh) Salaries / wages Research Scientist (1 No.) @ ₹ 1.0 lakh/month 12.00 Curator (2 Nos.) @ ₹ 40,000/month 9.60 Gardener (2 Nos.) @ ₹ 15,000/month 3.60 Peon (2 Nos.) @ ₹ 15,000/month 3.60 Total Salary for 1 year 28.80 Total Salary for 8 years @ 10% escalation per year …(A) 329.47 Establishment of Gardens Collection of seeds and plant species 5.00 Development of gardens (2 Nos.) 20.00 Development of nurseries (2 Nos.) 5.00 Plantation 5.00 Water supply system 5.00 Total …(B) 40.00 Laboratory Building 10.00 Equipment 5.00 Contingency 5.00 Total … (C) 20.00 Grand Total (A + B + C) 389.47 lakh
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2.5 WILDLIFE CONSERVATION As already described in EIA report, wildlife (birds and animals, including reptiles) resources of Dibang river catchment is very rich and varied. These species have been described in chapter 4 of EIA report along with their conservation status. A large number of animals like Goral, Takin, Snow-leopard, Hoolock gibbon. Assam Macaque, Mithun, Himalayan Black Bear, Wild Dog, Leopard, Clouded leopard, Leopard cat, Jungle cat, Pangolin etc. are reported to be present in the catchment. Even tigers may be sighted within the lower reaches. There are a large number of other species of deer, monkeys, antelopes, wild boar and smaller animals like mongoose, civets and squirrels that live in these forests.
No part of Mehao and Dibang Wild Life Sanctuaries will be affected either due to construction activities or due to submergence. It is expected that as the clearing of forest progresses, the wild animal population, including birds, will by natural instinct migrate to neighbouring safer places. However it is important that the adverse impact of the proposed Dibang Multipurpose Project on the faunal resources is kept at the minimum level. There are two ecologically sensitive area viz. Mehao Wildlife sanctuary and Dibang Wildlife sanctuary. These are located about 14 km and 35 km from reservoir periphery respectively. The Project Authority must take certain precaution that the labour force engaged in the construction work or the floating populations of outsiders, do not come in conflict with the wildlife population in the working area as well as its neighborhood forests. If possible, carrying firearms in the project area and its vicinity should be banned. Use of explosives and blasting material should be rigidly controlled and kept to the minimum.
During construction and operation phases and to prevent poaching in forest area around the project area, it is recommended that check posts be installed near major construction sites and labour camps. The range officer will supervise the guards of various check posts. It is also recommended that the staff manning these check posts have adequate communication equipment.
During construction phase in and around the main construction areas, i.e. the dam site, powerhouse site, etc. where construction workers congregate, some disturbance to the wildlife population may occur. Therefore, marginal impacts may be
2-5 EMP Report of Dibang Multipurpose Project on wildlife due to various construction activities. In view of this it is recommended that 4 check posts be developed in the major construction area i.e. one near intake and one near power house along the boundary of labour camps to implement anti- poaching measures during project construction phase. Each check post shall have 3 guards to ensure that poaching does not take place in the area. The guards will be supervised by a range officer. It is also recommended that the staff manning these check posts have adequate communication equipment and other facilities. Apart from inter-linking of check posts, communication link needs to be extended to Divisional Forest Office and the local police station also.
Purchase of anti-poaching kits: To capture and translocate wild animals out of human habitations or agricultural lands, various trapping equipments pertaining to anti-poaching activities are needed. In the absence of these the staff faces difficulties and all efforts made on this behalf are futile. For this an amount of ₹ 15 lakh has been earmarked. The anti-poaching kits will include equipment for self defense of the staff as well.
Infrastructure Development & Construction of Check Posts: This includes anti- poaching huts and rock shelters development. For effective monitoring, one watch tower is also proposed to be established at an identified place having high pressure of biotic interference. These basic amenities will be for the field staff to enable them to do effective patrolling in the areas. To improve vigilance for anti-poaching, better protection, enforcement for control grazing practices the construction of control- grazing-cum-anti poaching check posts has been suggested. An amount of ₹ 40 lakh can be earmarked for infrastructure development and construction of check posts.
Purchase of Survey equipment & Vehicle: In order to improve network and vigilance it is required to procure equipment like V-SAT and to document and develop a database IT infrastructure like laptops, L.C.D. projectors, altimeters, G.P.S., spotoscope, binoculars, video as well as digital still cameras are essential. Purchase of field vehicle will help in increased vigilance.
For better communication and purchase of survey equipment an amount of ₹ 20 lakh has been earmarked.
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Revival of Zoo and Development of Butterfly Park: For awareness of local people about the importance of wildlife conservation, a provision for revival of zoo at Roing and development of a butterfly park in the project area is proposed. A lump sum amount of ₹ 100.00 lakh is proposed to be kept.
A total of ₹ 334.20 lakh has been earmarked wild life conservation. The details are given in Table 2.3.
Table 2.3: Cost estimate for Wildlife Conservation Particulars Amount (₹ lakh) Salary / Wages Guards (12 nos.) @ ₹ 8000 per month 11.52 Range officer @ ₹ 20,000 per month 2.40 Total Salary for 1 year 13.90 Total Salary for 8 years @ 10% escalation per year 159.20 Purchase of anti-poaching kits 15.00 Infrastructure development & Construction of check posts 40.00 Purchase of Survey equipment & Vehicles 20.00 Revival of zoo and Development of Butterfly park 100.00 Total 334.20
2.6 BIODIVERSITY CONSERVATION a) Habitat Improvement Programme Habitat improvement programme is an integral part of biodiversity management. This programme consists of bringing into useful association of those condition needed by a species to reproduce and survive. The following activities have been proposed for habitat improvement programme:
Habitat Improvement for Avi-fauna: Forests are vital for the survival, foraging, breeding and nesting of avifauna. Natural forests provide a variety of food materials to the birds not only in the form of nectar of flowers, fruits, seeds etc. in the trees, shrubs, herbs and grasses but they also contain a large number of insects eaten by birds. In the forests, food is always available for the faunal component. Although most floral species flower during spring through summer but fruit maturation and
2-7 EMP Report of Dibang Multipurpose Project seed ripening takes place in them throughout the year. Therefore, first strategy of improvement of habitat for birds is avoiding nest predation or brood parasitism through maintenance of large contiguous forest tract. These areas have the ability to support the largest number of forest interior birds and will also be more likely to provide habitat for area sensitive species. It is more practicable to protect the existing forest area rather than creating new forest area. Another measure for habitat improvement for avifauna is to be installation of artificial nest boxes in the influence zone and catchment area of the project after consultation with the forest department as well as local NGOs. These nest boxes has been found to be quite beneficial for attracting hole nester birds. The size and capacity of boxes vary from one species to another. Feature of a Nest Box: The characteristic features of nest box are listed below and shown in Fig. 2.1.
Untreated wood (Jamun, mango, pine, cedar or fir) Thick walls (at least ¾ inches) Extended, sloped roof Rough or grooved interior walls Recessed floor, coated with primer and paint Drainage holes Ventilation holes Easy access for monitoring and cleaning Sturdy construction No outside perches
The entrance hole should have a 2-inch diameter and 6 inch depth from entrance hole. Nest boxes are placed on trees at height from 10-12 ft. Such nest boxes designs have been used with success.
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Fig. 2.1: Nest Box
It is proposed that one qualified person be hired for a period of eight years. An amount of ₹ 59.31 lakh can be earmarked for habitat improvement of avi-fauna in the study area. The details are given in Table 2.4.
Table 2.4: Cost of habitat improvement for avi-fauna in the study area
S. Amount Particulars No. (₹ lakh) A Non-recurring Cost 1 Cost of nests of different sizes (10” x 10” to 20” x 20”; 15.00 average cost ₹ 500 per wooden box) and installation in the area along with the green belt (3000 Nos.) 2 Repair and maintenance of the nests 5.00 B Recurring Cost (for 8 years) 1 Salary for one skilled person @ ₹ 25,000 per month for 34.31 implementation and data collection including 10% escalation 2 Contingencies (including avifaunal biodiversity 5.00 awareness programme for the local inhabitants) Total Cost (A+B) 59.31 b) Conservation and cultivation of Medicinal Plants It is proposed to develop a herbal nursery at appropriate location preferably in the Gram Panchayat. Self-help groups formed by women should be involved for the promotion of herbal drugs from the kitchen stock and rare medicinal plants. Species of medicinal plants proposed for plantation in the project area is given as below:
Acorus calamus Alpinia molucana Alstonia scholaris
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Arundo donax Betula alnoides Cinnamomum tamala Cissampelos pareira Costus speciosus Cotoneaster sp. Curcuma longa Dillenia indica Maesa indica Piper betel Podophyllum hexandrum Rubus moluccanus Sida acuta Swertia chirayta Terminalia arjuna T. bellerica Urena lobata .
For this programme to be undertaken on 20 ha land and creation of at least one herbal garden an amount of ₹ 50 lakh can be earmarked for this purpose. c) Eco-Development Works The Eco-development Committees and Village Conservation Committees (VCCs) can be constituted for this purpose which will help State Forest Department in capacity building and micro-planning of the various eco-developmental activities formulated for community development. The activities under this programme are aimed at improvement of livelihood of people living in the project area. This will include the wide publicity and awareness programme in the area.
Under this programme, the following activities are proposed: Training should be imparted to the school teachers in the project area for introduction of environmental education among the school children and exchange to knowledge on environment and ecology between the monastic and village schools. Publishing of research documents, pamphlets, brochures, hoardings Opening of biodiversity register in every village Advertisement of hazardous effect of fire through press, sign boards and public meetings will form the important activities under this component.
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An amount of ₹ 20 lakh is earmarked for this purpose. Thus a total of ₹ 129.31 lakh is earmarked for biodiversity conservation.
2.7 PREPARATION OF PEOPLES BIODIVERSITY REGISTERS (PBR) There is increasing realization that a vast amount of traditional knowledge on the plant species and their importance exists in the remote areas, villages and tribal areas of India. This knowledge remains both unexploited and underestimated. The local population of the region have a unique way of life and have developed their own system of medicine and food. Tribes use many plant species for medicinal use etc. to cure some of the prevalent diseases. Recording and exchange of this unique system of knowledge of economic and medicinal importance of the plant species would open doors for a new strategy of conservation. In addition to the documentation of the traditional knowledge on medicinal plants, cultivars, folk varieties, the proposed PBR would also prepare a list of para taxonomists, and local ‘vaids’ and record their knowledge. For this purpose, it is proposed that a team comprising of a scientist and Research Associate be engaged on contractual basis through tie-up with nearby university/research institution of repute having requisite expertise in the subject area. The activities spread over 8 years. A budget of ₹ 192.12 lakh has been earmarked for this purpose. The details are given in Table 2.5.
Table 2.5: Cost estimate for establishment of PBR
S. Particular Amount (₹ lakh) No. 1. Scientist (1 No.) @ ₹ 1.0 lakh/month 12.00 2. Research Associate (1 No.) @ ₹ 40,000/month 4.80 Total Salary for 1 year 16.8 Total Salary for 8 years @ 10% escalation per year 192.12
2.8 FOREST PROTECTION PLAN Various activities have been suggested for the biodiversity conservation and management of conservation sites are described in the following paragraphs: i) For the improvement of vigilance and measures to check poaching, check posts and watch towers will be needed. In order to strengthen the working capacity the officers of the State Forest/Wildlife Department they must be
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provided with necessary equipment that would increase their capability and efficiency. Equipment such as a camera, wireless, binoculars and other minor equipment (altimeter, spotoscope, search lights, sleeping bags, health kits, etc.). ii) Under the reward for informers programme it is proposed to engage the workers who are well acquainted with the area and are resourceful in gathering information for anti-poaching and better vigilance. These youth could be hired on a contractual basis. iii) The construction of bridges, inspection paths for more effective and meaningful patrolling of the staff should be undertaken. iv) The construction of an office complex for the purpose would be essential to monitor all these activities. v) Improvement of vigilance by procurement of field vehicles and motorbikes. vi) Creation of veterinary facilities and rescue camps for healthcare of wild animals and for controlling diseases. For this purpose it is essential to maintain a stock of medicines in addition to setting up of a mobile-rescue- cum-publicity-van. vii) Organizing occasional public awareness programmes, conducting training camps, preparation of research documents, pamphlets, brochures, hoardings, etc. viii) Provision of fire lines within critical areas to protect the forest from accidental fires An amount of ₹ 140 lakh has been earmarked for this purpose. The details are given in Table 2.6. Table 2.6: Cost estimate for Forest Protection Plan
Particulars Amount (₹ lakh) Reward programmes 20.00 Fire lines 50.00 Construction of bridges and patrolling paths 30.00 Mobile rescue van 20.00 Veterinary facilities 20.00 Total 140.00
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2.9 SAFEGUARDS DURING CONSTRUCTION PHASE During the construction phase, various adverse impacts on the wildlife are anticipated in the surrounding areas of the proposed project in terms of increased noise levels, land vibrations during tunnelling and blasting, release of air and water pollutants, etc. Mammals are the most vulnerable group affected by these negative impacts, which affect their movement, behaviour and breeding habit. To avoid and minimize the negative impacts from these activities project authorities are advised to prepare strict guidelines as follows. i) Strict restrictions shall be imposed on the workers at project sites to ensure that they do not harvest any species/produce from the natural forests and cause any danger or harm to the animals and birds in the wild. ii) Minimum levels of noise during construction activities will be maintained and no activity shall be carried out at night where the project site is in the close vicinity of animal/bird or human habitats especially located in the vicinity of dense forest area. iii) The fuel-wood to the labourers shall be provided from plantations meant for the purpose and/or the provision made for the supply of the free/subsidized kerosene/LPG from the depots being set up for this purpose to avoid forest degradation and destruction of animal habitats. iv) To avoid the deterioration of water quality and release of pollutants into the river, project authorities would provide proper sanitation facilities and garbage disposal bins to the workers/colony areas. v) The interference of human population would be kept to a minimum in the adjacent forested areas and it would be ensured that the contractors do not set up labour colonies in the vicinity of forests and wilderness areas. vi) The project authorities will be bound by the rules and regulations of the Wildlife Protection Acts (1972), Biological Diversity Act (2002), Forest Act (1980), Environment Protection Act (1986) and guidelines of State Biodiversity Conservation Strategy Action Plans (SBCSAP) for the preservation of habitats and protection of wild animals. vii) It will be ensured that the noise levels in no case go above 100-120 dB in the project area, particularly where human and wildlife habitats are located. One of the measures proposed to be adopted is that the blasting is to be restricted and avoided during nights, early mornings and late afternoons,
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which are the feeding times of most of the fauna. Blasting will be resorted to only if extremely necessary. For this strict blasting regime, i.e. controlled blasting under constant and strict surveillance should be followed. Some of the suggested methodologies for reduction and mitigation of noise so as to cause as little disturbance to the animals as possible are given below: a) Only well maintained/new equipment that produces lesser noise would be installed at the work sites. b) The best way to control the noise is at source. Certain equipment that needs to be placed permanently at one place like generators, etc. would be housed in enclosed structures to cut off the noise. c) The heavy equipment like rotating or impacting machines will be mounted on anti-vibration mountings. d) Wherever combustion engines are required they will be fitted with silencers. e) The traffic (trucks, etc.) used by the project works will be managed to produce a smooth flow instead of a noise producing stop and start flow. Necessary training/orientation will be provided to the traffic operators/drivers. Sounding of loud horns, etc. in the forested areas should be banned. Project authorities will use water sprinklers on the road to avoid the dust from construction activities. f) While clearing the land of vegetation for any project work, the project authorities will ensure that the work area has sufficient layer of tree cover around it. It will act as an effective noise absorber and dust barrier. The tree layer will act as buffer zone and these are known to cut off noise by about 3-12 dB at a site depending upon the density of vegetation. These measures will be planned in advance and well before starting operation at any site. g) The project authorities will monitor the noise at critical sites from time to time.
2.10 BIODIVERSITY MANAGEMENT COMMITTEE (BMC) The proposed Biodiversity Management Committee (BMC) will follow the guidelines of National Biodiversity Authority and State Biodiversity Conservation Strategy Action Plans (SBCSAP) to implement, monitor and evaluate the Biodiversity Management
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Plan of the proposed Dibang Multipurpose project. The activities of BMC shall be under the direct administrative control of the Chief Wildlife Warden/Principal Chief Conservator of Forests, Arunachal Pradesh. The BMC will comprise of following members. i. Chief Wildlife Warden/Principal Chief Conservator of Forests, Chairman Arunachal Pradesh ii. Chief (Environment), Dibang Multipurpose Project Member Secretary iii. DFO (s) (wildlife) of the concerned Division Member(s) iv. Two experts form University or renowned R & D Institutions Member v. Panchayat Representatives from at least 3 villages Member on a rotational basis vi. Representative of a well-known local NGO Member
The Chairman of the committee will have the right to assign various activities to various members for proper functioning and result-oriented tasks. Total budget for the committee’s routine functioning would be ₹ 50.0 lakh.
2.11 COST ESTIMATE FOR BIODIVERSITY CONSERVATION PLAN The total cost earmarked for Biodiversity conservation Plan is ₹ 1785.10 lakh. The details are given in Table 2.7.
Table 2.7: Cost earmarked for Biodiversity Conservation Plan
S. No. Activity Cost (₹ Lakh) 1. Conservation Plan for Endangered species 550.00 2. Establishment of gardens for voucher specimen 389.47 3. Wildlife Conservation 334.20 4. Biodiversity Conservation a) Habitat Improvement Programme 59.31 b) Conservation and cultivation of Medicinal plants 50.00 c) Eco-Development works 20.00 7. Preparation of People’s Biodiversity Register 192.12 8. Forest Protection Plan 140.00 9. Budget for Biodiversity Management Committee 50.00 Total 1785.10
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CHAPTER 3 CATCHMENT AREA TREATMENT PLAN
EMP Report of Dibang Multipurpose Project
CHAPTER 3 CATCHMENT AREA TREATMENT PLAN
3.1 INTRODUCTION The developmental activities, including hydroelectric projects, often have some impacts on natural resources. The environmental impacts of such projects together with faulty management practices, etc., ultimately lead to environmental degradation and consequently to rapid sedimentation of reservoirs. Accelerated soil erosion in the catchment areas of reservoirs and transport of detached material through the drainage network gives rise to a series of problems, notably siltation, depletion of flow capacity, steady loss of storage capacity, consistent drop in hydro-electric power generation and frequent floods. Therefore for sustainable hydropower development with least negative impact on the environment watershed management plays a pivotal role. In order to minimise the damage to the project as well as the immediate environment, the watershed management programmes involving extensive soil conservation measures in the catchment have assumed tremendous importance.
Watershed management primarily involves collection of information on a wide range of parameters of static and dynamic nature related to geology, hydrology, soil, geomorphology, topography, drainage conditions, land use / land cover, climate, etc. required for formulation of detailed and comprehensive Catchment Area Treatment (CAT) Plan. A comprehensively detailed Catchment Area Treatment Plan (CAT) should focus on: Mitigation measures for the erosion and landslide hazards resulting from the hydropower project activities i.e., activities in the direct impact zone (DIZ). The problem of silt and debris load to river from the susceptible areas of the catchment. Checking the sediment load from the tributaries directly discharging into the reservoir. Protecting the directly draining catchment from scouring / sloughing and slips.
Although the proposed Dibang Multipurpose Project is not expected to have any significant negative impacts on the environment, in the following pages measures to
3-1 EMP Report of Dibang Multipurpose Project minimize the entry of silt in to its reservoir and enhance its life as well as for conservation of the ecosystem, are described.
3.2 CATCHMENT AREA TREATMENT The proposed Dibang Multipurpose Project will be located on the river Dibang about 1.5 km upstream of confluence of river Dibang with river Ashu Pani in Lower Dibang Valley district of Arunachal Pradesh. The project is a storage scheme and involves construction of a 278 m high concrete gravity dam. Six Head Race Tunnels are proposed from the dam block to divert the water to power house. After generation of electricity in the underground powerhouse on the right bank of the river, the discharge will be directly led to the river through six Tail Race Tunnels.
The Dibang catchment receives a major portion of precipitation in the form of rainfall in addition to snow at the higher reaches. Generally the factors responsible for siltation are slope, together with the surface run-off, underlying rock/soil characteristics, vegetation aspects, etc. There is dense vegetation in the immediate catchment area of the present project. The natural soil erosion activity may take place in and around the areas. A catchment area treatment plan has been formulated with the main objective of arresting soil erosion in the catchment.
The Catchment Area Treatment is extremely crucial in the context of hydropower development as the life of the reservoir depends on the nature of the catchment, underlying rock/soil type, vegetation type, drainage pattern etc. Keeping in mind the topography, soil type, climate, land use and vegetation cover in the catchment area various measures, both engineering/bio-engineering and biological, are proposed to check the soil erosion, prevent/check siltation of reservoir and to maintain its storage capacity. The engineering measures comprise construction of check dams, wire crates, DRSM works, contour bunding, etc., while biological measures include mainly plantation of economically and environmentally important local and exotic taxa of trees.
3.3 ESTIMATION OF SOIL EROSION In order to formulate the treatment plan it is essential to identify areas prone/vulnerable to erosion and estimate the extent of soil erosion that is taking
3-2 EMP Report of Dibang Multipurpose Project place in the catchment area. Various factors that are responsible for soil erosion are the drainage pattern in the area, slope, soil type and the land use/land cover, etc. which have been studied for the formulation of the catchment area treatment plan.
3.3.1 Drainage The drainage system is the prime transport channel for the sediments as well as an important natural factor for causing land degradation. In order to prepare CAT Plan, one must understand the drainage pattern of that catchment. The river originates from the snow covered southern flank of the Himalayas close to the Tibet border at an elevation of more than 5000 m. The river Dibang cuts through deep gorges and difficult terrains in its upper reach through the mountains of the Dibang Valley and Lower Dibang Valley districts of Arunachal Pradesh. The total length of Dibang from its source to its confluence with Lohit river at Sadia in Assam is 195 km. The major tributaries of Dibang river are Mathun, Tangon, Dri, Ithun & Emra. A number of small tributaries i.e. Ahi, Airi Pani, Ilu Pani, Ashu Pani, Iphi Pani, Deo Pani etc also join the river. The important feature is that all the tributaries barring Ephi Pani & Deo Pani join Dibang in its hilly catchment. The three major tributaries viz Tangon, Dri and Mathun are almost equal in size because of which the shape of the Dibang catchment is comparatively wide in its upper reach. Drainage map of directly draining catchment is placed as Map 3.1.
3.3.2 Delineation of Watersheds and Sub-watersheds The total catchment area of the Dibang River up to the proposed Dam site is 11276 sq km. The directly draining catchment is 59811.88 ha, which constitutes the study area for CAT. The directly draining catchment comprises of nine sub-watersheds around the proposed reservoir area from the confluence of river Tangon with river Dibang up to the Dam site. The hierarchical delineation system developed by AISLUS (AISLUS Technical Bulletin - 9) was followed for the demarcation of sub- watersheds within the study area. The codification system as given in Watershed Atlas of India (AISLUS) was followed for Dibang catchment on 1:50,000 Survey of India topographical sheets. Directly draining catchment of river Dibang divides into nine sub watersheds viz., 3A2C4, 3A2C7, 3A2D1, 3A2D2, 3A2F5, 3A2G3, 3A2G4, 3A2H2 and 3A2H3. Out of these, five viz., 3A2C4, 3A2C7, 3A2D1, 3A2D2 and 3A2F5 are on the right bank and four viz., 3A2G3, 3A2G4, 3A2H2 and 3A2H3 are on
3-3 EMP Report of Dibang Multipurpose Project left bank. An index map of nine subwatersheds of directly draining catchment is given in Map 3.2. From the thematic maps of slope, drainage, soil, and land use, a Composite Erosion Intensity Unit (CEIU) map was prepared for each sub watershed for delineating different erosion intensity units of the sub watersheds. Areas of nine subwatersheds of directly draining catchment is given below in Table 3.1.
Table 3.1: Areas of nine subwatersheds of Directly Draining Catchment of Dibang River S. No. Subwatershed code Area (ha) Percentage 1 3A2C4 1318.41 2.20 2 3A2C7 786.89 1.32 3 3A2D1 15327.66 25.63 4 3A2D2 6778.89 11.33 5 3A2F5 5.15 0.01 6 3A2G3 545.40 0.91 7 3A2G4 2093.76 3.50 8 3A2H2 14844.65 24.82 9 3A2H3 18111.08 30.28 59811.88 100.00
3.3.3 Slope The slope plays a great role for the loss of soil and water from an area and thereby influences its land use capability. Together with the nature and texture of soil, it also determines the erodibility of the soils. In the directly draining catchment five slope categories were identified - Gentle (0 to 15 degrees), Moderate (16 to 30 degrees), Moderately steep (31 to 45 degrees), Steep (46 to 60 degrees), and Very steep (> 60 degrees). The slope details of directly draining catchment are shown in Table 3.2 and slope details of nine subwatersheds are presented in Table 3.3. The slope map of directly draining catchment is placed as Map 3.3. Slope maps of nine subwatersheds of directly draining catchment are presented in Map 3.6 to 3.14.
Table 3.2: Slope Details of Directly Draining Catchment
S. No Degrees Slope type Area (ha) Percentage 1 0 to 15 Gentle 12285.88 20.54 2 16 to 30 Moderate 22626.56 37.83
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EMP Report of Dibang Multipurpose Project
3 31 to 45 Moderately steep 19289.88 32.25 4 46 to 60 Steep 4134.64 6.91 5 > 60 Very steep 1474.92 2.47 59811.88 100.00
Table 3.3: Slope Details of nine subwatersheds of Directly Draining Catchment S. Area Subwatershed Degrees Slope Type Percentage No. (ha) 1 3A2C4 0 to 15 Gentle 111.48 8.46 16 to 30 Moderate 519.08 39.37 Moderately 31 to 45 steep 522.36 39.62 46 to 60 Steep 141.12 10.70 > 60 Very steep 24.37 1.85 Total 1318.41 100.00 2 3A2C7 0 to 15 Gentle 85.2 10.83 16 to 30 Moderate 278.45 35.39 Moderately 31 to 45 steep 325.64 41.38 46 to 60 Steep 87.36 11.10 > 60 Very steep 10.24 1.30 Total 786.89 100.00 3 3A2D1 0 to 15 Gentle 2442.44 15.93 16 to 30 Moderate 6074.28 39.63 Moderately 31 to 45 steep 5389.72 35.16 46 to 60 Steep 1243.92 8.12 > 60 Very steep 177.3 1.16 Total 15327.66 100.00 4 3A2D2 0 to 15 Gentle 1656.2 24.43 16 to 30 Moderate 2593.72 38.26 Moderately 31 to 45 steep 2271.12 33.50 46 to 60 Steep 212.48 3.13 > 60 Very steep 45.37 0.67 Total 6778.89 100.00 5 3A2F5 0 to 15 Gentle 0.04 0.78 16 to 30 Moderate 0.2 3.88 Moderately 31 to 45 steep 4.75 92.23 46 to 60 Steep 0.16 3.11 > 60 Very steep 0 0.00 Total 5.15 100.00 6 3A2G3 0 to 15 Gentle 187.36 34.35 16 to 30 Moderate 89.52 16.41 31 to 45 Moderately 222.36 40.77
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S. Area Subwatershed Degrees Slope Type Percentage No. (ha) steep 46 to 60 Steep 38.92 7.14 > 60 Very steep 7.24 1.33 Total 545.4 100.00 7 3A2G4 0 to 15 Gentle 167.6 8.00 16 to 30 Moderate 721.36 34.45 Moderately 31 to 45 steep 814.6 38.91 46 to 60 Steep 270.68 12.93 > 60 Very steep 119.52 5.71 Total 2093.76 100.00 8 3A2H2 0 to 15 Gentle 2168.04 14.60 16 to 30 Moderate 4663.68 31.42 Moderately 31 to 45 steep 5335.05 35.94 46 to 60 Steep 1678.16 11.30 > 60 Very steep 999.72 6.73 Total 14844.65 100.00
9 3A2H3 0 to 15 Gentle 5467.52 30.19 16 to 30 Moderate 7686.27 42.44 Moderately 31 to 45 steep 4404.28 24.32 46 to 60 Steep 461.84 2.55 > 60 Very steep 91.16 0.50 Total 18111.07 100.00 Grand Total 59811.88
3.3.4 Land Use/ Land Cover Mapping Land use and land cover mapping of the study area was carried out by standard methods of analysis of data through remote sensing technique coupled with GIS, followed by ground truthing. Geo-coded LISS-III data on CD ROMs and hard copies on the scale 1: 50,000 (available for the year 2003) were procured for digital image processing and preparation of thematic maps. Survey of India topographic sheets 82P/5, 82P/6, 82P/9, 82P/10, 82P/11, 82P/13, 82P/14, 82P/15, 82P/16, 82O/16, 91D/1, 91D/2, 91D/3, 91D/4, 91D/6, 91D/7, 91D/8 on 1:50,000 scale were used for the preparation of the base maps. These topo sheets were also used for the delineation of sub-watersheds of the immediate catchment of the project area. The sub-watersheds were then overlaid on the drainage map and land use map for determining drainage and land use details. All the thematic maps of catchment, viz.,
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EMP Report of Dibang Multipurpose Project base map, drainage map and land use / land cover map, etc., were then transferred to Geographic Information System (GIS) for further overlay analysis. The landuse landcover map is prepared using GIS mapping where inputs of toposheets of the catchments area and satellite imageries are used to come out with the land use / land cover pattern. The map is shown as Map 3.4.
Forest
Dibang catchment is covered by trees and other vegetation types, which are capable of producing timber and other forest produce. The vegetation are mostly of Northern Tropical Semi Evergreen and North Indian Moist Deciduous Forests. Varying degree of biotic disturbances, mainly due to traditional practice of jhuming has been experienced by few patches of forests. About 48.76 % (29163.44 ha) is dense forest whereas 12.41 % (7419.88 ha) is open forest of total directly draining catchment. In the proposed submergence area the dense mixed forest is limited along the bank of the river.
Settlement and Agriculture The catchment is lived by rural based settlement only, except few urban areas. Mostly in these areas shifting cultivation is practiced, baring a few patches like Hunli, reach between Ambolin to Anini etc., where terracing is done. Areas under agriculture / current jhum / habitation works out to be 6.44 % (3851.64 ha) while degraded forest / abandoned jhum works out to be 17.19 % (10281.64 ha) of total area of directly draining catchment.
Snow Covered Area Snow covered areas constitute about 0.23 % (139.52 ha) of directly draining catchment.
Barren / Rocky Area Rock exposures of varying lithology, often barren and devoid of soil cover and vegetation or covered with sparse vegetation, are noticed in the directly draining catchment. They occur generally as isolated exposure. The area under this category works out to be 13.13 % (7852.32 ha).
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Water Body Water bodies, mainly comprising of river Dibang and its tributaries, constitute about 1.84 % (1103.44 ha) of total directly draining catchment.
Landuse / landcover details of directly draining catchment are shown in Table 3.4 while subwatershed-wise landuse / landcover details are given in Table 3.5. Land use / land cover maps of different subwatersheds of directly draining catchment are presented in Map 3.6 to 3.14.
Table 3.4: Landuse Details of Directly Draining Catchment S. No. Class Area (ha) Percentage 1 Dense Forest 29163.44 48.76 2 Open Forest 7419.88 12.41 3 Degraded forest / Abondoned 10281.64 17.19 Jhum 4 Agriculture / Current Jhum / 3851.64 6.44 Habitation 5 Barren / Rocky 7852.32 13.13 6 Water Body 1103.44 1.84 7 Snow 139.52 0.23 Total 59811.88 100.00
Table 3.5: Subwatershed wise Land use / Land cover Details
S. Subwatershed EIMU Area No. code 1 3A2C4 Dense Forest 509.12 Open Forest 372.38
Degraded forest / 185.16 Abondoned Jhum Agriculture/Current 49.6 Jhum/Habitation Barren / Rocky 174.16 Water Body 27.99 Snow 0 Total 1318.41 2 3A2C7 Dense Forest 199.16 Open Forest 325.49
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EMP Report of Dibang Multipurpose Project
S. Subwatershed EIMU Area No. code Degraded forest / 78.28 Abondoned Jhum Agriculture / Current Jhum / 35.36 Habitation Barren / Rocky 82.36 Water Body 65.32 Snow 0.92 Total 786.89 3 3A2D1 Dense Forest 6748.4 Open Forest 1992.92
Degraded forest / 2916.51 Abondoned Jhum Agriculture / Current Jhum / 1143.64 Habitation Barren / Rocky 2199.48 Water Body 311.07 Snow 15.64 Total 15327.66 4 3A2D2 Dense Forest 3194.62 Open Forest 1012.92
Degraded forest / 1134.64 Abondoned Jhum Agriculture / Current Jhum / 394.92 Habitation Barren / Rocky 917.68 Water Body 102.91 Snow 21.2 Total 6778.89 5 3A2F5 Dense Forest 0.68 Open Forest 0
Degraded forest / 0.68 Abondoned Jhum Agriculture / Current Jhum / 1.16 Habitation Barren / Rocky 1.6 Water Body 1.03 Snow 0 Total 5.15 6 3A2G3 Dense Forest 130.08 Open Forest 173.37
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S. Subwatershed EIMU Area No. code Degraded forest / 88.84 Abondoned Jhum Agriculture / Current Jhum / 27.4 Habitation Barren / Rocky 78.2 Water Body 47.51 Snow 0 Total 545.4 7 3A2G4 Dense Forest 1390.04 Open Forest 107.76
Degraded forest / 280.6 Abondoned Jhum Agriculture / Current Jhum / 109.13 Habitation Barren / Rocky 187.72 Water Body 18.51 Snow 0 Total 2093.76 8 3A2H2 Dense Forest 6860.2 Open Forest 1932.84
Degraded forest / 2746.24 Abondoned Jhum Agriculture / Current Jhum / 954.32 Habitation Barren / Rocky 2147.7 Water Body 199.87 Snow 3.48 Total 14844.65 9 3A2H3 Dense Forest 10131.14 Open Forest 1502.2
Degraded forest / 2850.69 Abondoned Jhum Agriculture / Current Jhum / 1136.11 Habitation Barren / Rocky 2063.42 Water Body 329.23 Snow 98.28 Total 18111.07 Grand Total 59811.88
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Landuse details of submergence area are presented under Table 3.6 and Map 3.4A.
Table 3.6: Landuse of Submergence Area
Area Landuse class Percentage (ha) Abondoned Jhum / Degraded forest 755.26 18.84 Current Jhum / Habitation / Settled 286.98 7.16 cultivation Dense Mixed Forest 1551.76 38.71 Open Forest 619.52 15.45 Rocky 560.42 13.98 Water Bodies 235.06 5.86 Total 4009.00 100.00
3.3.5 Soils Soil details of directly draining area are shown in Table 3.7 whereas soil map of directly draining catchment is placed as Map 3.5.
Table 3.7: Soil Details of Directly Draining Catchment Mapping Unit (As S. Soil per Association with Erosivity Area (ha) No. Description NBSS & LUP) 1 1 Shallow, Moderately deep, Very 11151.52 excessively excessively drained severe drained, on moderately steep loamy- slope skeletal 2 2 Deep, loamy- Deep, somewhat Severe 1211.68 skeletal excessively drained loamy skeletal on moderately steep slope 3 3 Shallow, Moderately deep, Severe 11254.12 loamy- somewhat excessively skeletal drained on moderately steep slope 4 4 Shallow, Moderately deep, Severe 21553.76 loamy- somewhat excessively skeletal drained on very steep slope 5 7 Very deep, Moderately shallow, Severe 184.64
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EMP Report of Dibang Multipurpose Project
Mapping Unit (As S. Soil per Association with Erosivity Area (ha) No. Description NBSS & LUP) fine soils excessively drained clayey soils on steep slope 6 9 Deep, well Very deep, well- Moderate 7371.44 drained fine drained, fine loamy soils soils on moderate slope 7 11 Very deep, On moderate slope, Moderate 3389.12 well drained, very deep well fine loamy drained fine soils soils 8 46 Rocky - - 3695.6 mountains covered with perpetual snow and glaciers Total 59811.88
3.3.6 Sediment Yield Index Model The Silt Yield Index Model developed by All India Soil & Land Use Survey (Dept of Agriculture, Govt. of India) was followed for calculating sediment yield index. The SYI model considering sedimentation as product of erosivity, erodibility and areal extent was conceptualized in the All India Soil & Land Use Survey as early as 1969 and has been in operational use since then to meet the requirements of prioritization of smaller hydrologic units within River Valley Projects catchment areas.
The model conceptualizes sediment delivery from a hydrologic unit into a reservoir as a multiplicative function of the potential soil detachment representing the erosivity factor; the transportability of the detached material (delivery ratio) and the area of the hydrologic entity. This can be expressed as:
Sediment yield = f (Erosivity of soil x delivery ratio x area of hydrologic unit)
The erosivity is simulated with the sediment yield weightage value which is based on assessment of the composite effect of assemblage of erosivity determinants
3-12 EMP Report of Dibang Multipurpose Project whereas, the delivery ratio is adjudged by the likely delivery of the eroded material into the reservoir.
3.3.7 Sediment Yield Weightage Value The erosivity determinants are the soil and land attributes that have direct or reciprocal bearing on the unit of the detached soil material. The relationship can be expressed as: Soil erosivity = f (slope, soil parameters, land use / land cover) The functional behaviour of each of the attributes is discussed in the following paras:
(a) Slope: As the slope becomes steeper, the runoff coefficient increases, the kinetic energy and carrying capacity of the surface flow becomes greater, soil stability and as well the slope stability decreases and splash erosion increases. (b) Land use / land cover: Covers including plant canopy, plant residues, mulches or dense growing plants greatly modify the effect of rainfall and thus affect soil erosion. The plant canopy intercepts raindrops and the water dripping of the leaves is less erosive than unhindered raindrops. Moreover, the detachment of sediments does not occur on the portion of the covered soil surface because the drops are intercepted and there is no fall distance for drops to regain energy. The surface cover also slows down the run-off thus increasing flow depth which further decreases detachment by cushioning the impact of raindrops and reducing their hydrodynamic impact forces (Mutchler and Young, 1975). (c) Soil parameters: The soil properties influencing erodibility include particle size distribution, organic matter content, its association with different morphological features and effective soil depth. Infiltration rate and soil permeability which is function of soil texture, coarse fragments, effective soil depth, etc. determines the quantity of surface flow. Soil erodibility is also governed by the active surface area of the soil particles. Soil structure or aggregate stability is another important factor offering resistance to soil detachment. Soil details considered for calculating / identifying erosion intensity units in the directly draining catchment have already been given under Table 3.7 and Map 3.5.
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3.3.8 Delivery Ratio Delivery ratio refers to the percent of the soil material detached from the source area reaching the reservoir through surface flow or travelling through drainage courses. Since the transport phenomenon involves suspension of the soil material and its movement over the land surface of the hydrologic unit, the delivery ratio is governed both by the soil factors affecting the dispersion value of the soils and the watershed attributes determining the flow mechanism. The transport of the suspended material is governed by number of parameters namely shape and size of the watershed, physiography and relief, drainage pattern, drainage density, stream gradient, proximity of the eroded area to the active stream or reservoir and the presence or absence of silt traps within the watershed.
3.3.9 Sediment Yield Index The sediment Yield Index (SYI) is defined as the Yield per unit area and SYI Value for hydrologic unit is obtained by taking the weightage arithmetic mean of the products of the weightage value and delivery ratio over the entire area of the hydrologic unit by using suitable empirical equation.
3.3.10 Prioritization of Subwatersheds The prioritization of the hydrologic units within the vast catchments is based on the Sediment Yield Indices (SYI) of the smaller units. The subwatersheds are subsequently rated into various categories corresponding to their respective values.
3.4 METHODOLOGY FOR PRIORITIZATION The various steps involved in the application of model are: - Preparation of a framework of subwatersheds through systematic delineation and codification. - Rapid reconnaissance surveys leading to the generation of a map indicating erosion-intensity mapping units (EIMUs). - Assignment of weightage values to various mapping units based on relative silt-yield. - Assignment of maximum delivery ratios to various erosion intensity mapping units and assessment of adjusted delivery ratios for different subwatersheds. - Computing Silt-Yield Index for individual subwatersheds.
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- Grading of subwatersheds into very severe, severe, moderate, slight and very slight priority categories.
3.5 ASSIGNMENT OF EROSIVITY WEIGHTAGE VALUE The composite erosion-intensity mapping units were assigned relative erosivity values adjudged to be indicative of the combined effect of dynamic inter-relationship of the factors in terms of active erosivity of the units. The erosivity values were assessed as resultant of combined and reciprocal influence of a set of the factors viz., slope, land use and cover conditions, and soil characteristics.
For comparing different erosivity determinant attributed of various mapping units a statement on differentiating characteristics of the units was prepared and the relative values assigned to different units in a rational manner. A factor k, rated as an inertia factor signifying equilibrium between erosion and sedimentation was assigned erosivity value of 10 and was taken as a standard reference for comparison and proportional additions or subtractions from this basic value in discrete numbers were made assessing the collective effect of different attributes corresponding to potential sediment yield. Any addition to this factor is indicative of erosion roughly in proportion to the added factor whereas the subtraction is suggestive of the deposition possibilities. The erosivity values ranging from 8 (k-2) to 30 (k+20) have so far been assigned to various subwatersheds.
The details of areas falling in different Erosion Intensity Mapping Units (EIMUs) in the directly draining catchment is given in Table 3.8. The erosion intensity map of directly draining catchment is placed as Map 3.15. Erosion intensity maps of different subwatersheds of directly draining catchment are presented in Map 3.6 to 3.14. Table 3.8: EIMU Details Sl. No. EIMU Category Area (ha) Percentage 1 Very severe 419.6 0.70 2 Severe 10119.96 16.92 3 Moderate 12598.84 21.06 4 Slight 22627.94 37.83 5 Very slight 12802.58 21.40 6 Water body 1103.44 1.84
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7 Snow 139.52 0.23 Total 59811.88 100.00
3.6 ASSIGNMENT OF DELIVERY RATIOS (DRS) The delivery ratios were adjusted suitably for individual subwatersheds to account for the deposition of the detached material enroute the reservoir site. The distance of subwatershed from the reservoir site was considered as the major factor for adjusting the DR values. The criteria adopted for assigning the delivery ratio are mentioned in Table 3.9. Table 3.9: Delivery Ratio (DR) Distance from Nearest DR values stream (km) 0.00 - 0.50 0.95 0.51 - 1.00 0.90 1.01 - 1.50 0.85 1.51 - 2.00 0.75 2.00 - 2.50 0.65 2.51 - 3.00 0.55 3.01 - 3.50 0.40
3.7 COMPUTATION OF SILT YIELD INDEX The area of each of the mapping units is computed on GIS platform and silt yield indices of individual subwatersheds were calculated using the following equation:
SYI = ∑ (Ai x Wi x Di) x 100; i= 1 to n Aw where SYI = Sediment Yield Index Ai = Area of ith mapping unit Wi = Weightage value of ith mapping unit Di = Adjusted delivery ratio assigned to ith mapping unit N = No. of mapping units Aw = Total area of subwatershed
Calculation of sediment yield index for nine subwatersheds of directly draining catchment is shown in Table 3.10.
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EMP Report of Dibang Multipurpose Project
Table 3.10: Calculation of Sediment Yield Index Area Sl. Subwatershed Delivery Gross Sediment EIMU Area Weightage x No. code Ratio sediment yield yield index Weightage 1 3A2C4 Very severe 2.00 25 50.00 0.95 47.50 - Severe 153.84 21 3230.64 0.90 2907.58 - Moderate 259.44 18 4669.92 0.80 3735.94 - Slight 641.60 15 9624.00 0.70 6736.80 - Very slight 233.54 12 2802.48 0.60 1681.49 - Water body 27.99 0 0.00 0.00 0.00 - Snow 0.00 0 0.00 0.00 0.00 - 1318.41 15109.30 1146.02
2 3A2C7 Very severe 2.16 25 54.00 0.95 51.30 - Severe 78.96 21 1658.16 0.90 1492.34 - Moderate 119.88 18 2157.84 0.80 1726.27 - Slight 464.09 15 6961.35 0.70 4872.95 - Very slight 55.56 12 666.72 0.60 400.03 - Water body 65.32 0 0.00 0.00 0.00 - Snow 0.92 0 0.00 0.00 0.00 - 786.89 8542.89 1085.65 - 3 3A2D1 Very severe 94.12 25 2353.00 0.95 2235.35 - Severe 3235.72 21 67950.12 0.90 61155.11 - Moderate 3255.64 18 58601.52 0.80 46881.22 - Slight 5988.55 15 89828.25 0.70 62879.78 - Very slight 2426.92 12 29123.04 0.60 17473.82 - Water body 311.07 0 0.00 0.00 0.00 - Snow 15.64 0 0.00 0.00 0.00 - 15327.66 190625.27 1243.67
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Area Sl. Subwatershed Delivery Gross Sediment EIMU Area Weightage x No. code Ratio sediment yield yield index Weightage - 4 3A2D2 Very severe 1.24 25 31.00 0.95 29.45 - Severe 987.56 21 20738.76 0.90 18664.88 - Moderate 1458.88 18 26259.84 0.80 21007.87 - Slight 1693.68 15 25405.20 0.70 17783.64 - Very slight 2513.42 12 30161.04 0.60 18096.62 - Water body 102.91 0 0.00 0.00 0.00 - Snow 21.20 0 0.00 0.00 0.00 - 6778.89 75582.47 1114.97 - 5 3A2F5 Very severe 0.00 25 0.00 0.95 0.00 - Severe 1.08 21 22.68 0.90 20.41 - Moderate 2.36 18 42.48 0.80 33.98 - Slight 0.68 15 10.20 0.70 7.14 - Very slight 0.00 12 0.00 0.60 0.00 - Water body 1.03 0 0.00 0.00 0.00 - Snow 0.00 0 0.00 0.00 0.00 - 5.15 61.54 1194.87 - 6 3A2G3 Very severe 1.24 25 31.00 0.95 29.45 - Severe 72.80 21 1528.80 0.90 1375.92 - Moderate 125.08 18 2251.44 0.80 1801.15 - Slight 173.21 15 2598.15 0.70 1818.71 - Very slight 125.56 12 1506.72 0.60 904.03 - Water body 47.51 0 0.00 0.00 0.00 - Snow 0.00 0 0.00 0.00 0.00 - 545.40 5929.26 1087.14 -
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Area Sl. Subwatershed Delivery Gross Sediment EIMU Area Weightage x No. code Ratio sediment yield yield index Weightage 7 3A2G4 Very severe 42.24 25 1056.00 0.95 1003.20 - Severe 329.40 21 6917.40 0.90 6225.66 - Moderate 321.84 18 5793.12 0.80 4634.50 - Slight 1188.29 15 17824.35 0.70 12477.05 - Very slight 193.48 12 2321.76 0.60 1393.06 - Water body 18.51 0 0.00 0.00 0.00 - Snow 0.00 0 0.00 0.00 0.00 - 2093.76 25733.46 1229.05 - 8 3A2H2 Very severe 270.88 25 6772.00 0.95 6433.40 - Severe 2921.32 21 61347.72 0.90 55212.95 - Moderate 3477.84 18 62601.12 0.80 50080.90 - Slight 6388.20 15 95823.00 0.70 67076.10 - Very slight 1583.06 12 18996.72 0.60 11398.03 - Water body 199.87 0 0.00 0.00 0.00 - Snow 3.48 0 0.00 0.00 0.00 - 14844.65 190201.38 1281.28 - 9 3A2H3 Very severe 5.72 25 143.00 0.95 135.85 - Severe 2339.28 21 49124.88 0.90 44212.39 - Moderate 3577.88 18 64401.84 0.80 51521.47 - Slight 6089.64 15 91344.60 0.70 63941.22 - Very slight 5671.04 12 68052.48 0.60 40831.49 - Water body 329.23 0 0.00 0.00 0.00 - Snow 98.28 0 0.00 0.00 0.00 - 18111.07 200642.42 1107.84
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3.8 PRIORITIZATION OF SUBWATERSHEDS The gradation and assignment of priority ratings to the subwatersheds are based on the descending values of SYI values. As per the methodology of priority delineation of AISLUS the priority categories that have been classified based on the SYI values, are given in Table 3.11.
Table 3.11: Relation of Priority Categories and SYI Values
S. No. Priority Category SYI values 1 Very high > 1300 2 High 1200 - 1299 3 Medium 1100 - 1199 4 Low 1000 - 1099 5 Very low < 1000
SYI values assigned to nine subwatersheds of directly draining catchment is given below in Table 3.12.
Table 3.12: SYI Values assigned to different subwatersheds S. No. Subwatershed SYI value 1 3A2C4 1146 2 3A2C7 1086 3 3A2D1 1244 4 3A2D2 1115 5 3A2F5 1195 6 3A2G3 1087 7 3A2G4 1229 8 3A2H2 1281 9 3A2H3 1108
Based on the above criterion of AISLUS following priority categories in Table 3.13 have been assigned to the nine subwatersheds of directly draining catchment:
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Table 3.13: Priority ranking assigned to different subwatersheds S. No. Priority ranking SYI value Priority 1 3A2H2 1281 High 2 3A2D1 1244 High 3 3A2G4 1229 High 4 3A2F5 1195 Medium 5 3A2C4 1146 Medium 6 3A2D2 1115 Medium 7 3A2H3 1108 Medium 8 3A2G3 1087 Low 9 3A2C7 1086 Low
3.9 AREA IDENTIFIED FOR CAT For the catchment area treatment areas falling under very severe and severe erosion intensity categories i.e., 10539.56 ha will be required for treatment. The subwatersheds to be taken first and thereafter should be as per the above priority ranking. Various engineering and bioengineering measures like brushwood check dams, contour bunding, gabion structures, loose boulder check dams and silt retention dams are suggested for the very severe and severe erosion intensity areas. In addition, biological measures like plantation of shrubs and trees are also suggested for these areas.
In the upper catchment of the subwatersheds brushwood check dams are proposed to control the erosion in the first order basin. The whole length of the streams are segmented into 50 m interval and depending upon the gradient a total of 1276 brushwood check dams are proposed. In first order basin in the lower reaches, where discharge is higher and valley length is less, at 30 m intervals loose boulder check dams are proposed. Therefore, a total of 768 loose boulder check dams are proposed. In those areas where discharge is much higher, 259 gabion structures are proposed. In those areas where erosion intensity is severe and very severe countour bunding is proposed. Therefore, a total of 82 contour bunding will be constructed. In third order and more than third order basin 124 silt retention dams are proposed. It is seen that about 12 % and 18 % of the area are composed of open forest and degraded forest / abandoned jhum, respectively. Therefore, about 12 % of the total area of subwatershed shall be treated by means of plantation.
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3.10 PERIOD AND SCHEDULE OF IMPLEMENTATION The plan needs to be implemented in a phased manner so as to attain the goals set successfully. Keeping in view the local topography and climate, it is proposed to complete the CAT programme in five years (Table 3.14). The year wise break-up of the CAT work in different subwatersheds is given in Table 3.15 to 3.23 and Maps 3.16 to 3.24.
Table 3.14: Details of the Engineering and biological works to be undertaken under CAT Plan for the Dibang Multipurpose project Brush Loose Silt wood Contour Gabion Bolder S. Subwa- Retention Plantation check bunding Structure Check No tershed Dam (ha) Dam (Nos.) (Nos.) Dam (Nos.) (Nos.) (Nos.) 1 3A2C4 24 0 0 18 0 10 2 3A2C7 12 0 0 0 0 6 3 3A2D1 402 24 80 242 40 244 4 3A2D2 118 10 28 70 14 72 5 3A2F5 2 2 1 0 2 1 6 3A2G3 8 0 0 0 0 6 7 3A2G4 48 2 16 36 2 26 8 3A2H2 384 26 76 230 38 232 9 3A2H3 278 18 58 172 28 173 Total 1276 82 259 768 124 770
Table 3.15: Year-wise Treatment of subwatershed 3A2C4 of Dibang Multipurpose Project Loose Silt Brushwood Contour Gabion Bolder Retention Plantation Year check Dam bunding Structure Check Dam Dam (ha) (Nos.) (Nos.) (Nos.) (Nos.) (Nos.) 1st 4 0 0 2 0 2 2nd 6 0 0 6 0 2 3rd 6 0 0 4 0 3 4th 4 0 0 6 0 2 5th 4 0 0 0 0 1 Total 24 0 0 18 0 10
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Table 3.16: Year-wise Treatment of subwatershed 3A2C7 of Dibang Multipurpose Project
Loose Silt Brushwood Contour Gabion Bolder Retention Plantation Year check Dam bunding Structure Check Dam Dam (ha) (Nos.) (Nos.) (Nos.) (Nos.) (Nos.) 1st 2 0 0 0 0 1 2nd 2 0 0 0 0 1 3rd 4 0 0 0 0 2 4th 4 0 0 0 0 1 5th 0 0 0 0 0 1 Total 12 0 0 0 0 6
Table 3.17: Year-wise Treatment of subwatershed 3A2D1 of Dibang Multipurpose Project Loose Silt Brushwood Contour Gabion Bolder Retention Plantation Year check Dam bunding Structure Check Dam Dam (ha) (Nos.) (Nos.) (Nos.) (Nos.) (Nos.) 1st 80 2 12 40 6 38 2nd 110 6 20 54 16 48 3rd 120 8 20 60 10 75 4th 62 4 16 52 6 53 5th 30 4 12 36 2 30 Total 402 24 80 242 40 244
Table 3.18: Year-wise Treatment of subwatershed 3A2D2 of Dibang Multipurpose Project Loose Silt Brushwood Contour Gabion Bolder Retention Plantation Year check Dam bunding Structure Check Dam Dam (ha) (Nos.) (Nos.) (Nos.) (Nos.) (Nos.) 1st 24 0 4 12 2 11 2nd 32 4 8 16 4 14 3rd 36 4 6 18 4 22 4th 18 2 4 14 4 16 5th 8 0 6 10 0 9 Total 118 10 28 70 14 72
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Table 3.19: Year-wise Treatment of subwatershed 3A2F5 of Dibang Multipurpose Project Loose Silt Brushwood Contour Gabion Bolder Retention Plantation Year check Dam bunding Structure Check Dam Dam (ha) (Nos.) (Nos.) (Nos.) (Nos.) (Nos.) 1st 0 0 0 0 0 1 2nd 2 0 1 0 2 0 3rd 0 2 0 0 0 0 4th 0 0 0 0 0 0 5th 0 0 0 0 0 0 Total 2 2 1 0 2 1
Table 3.20: Year-wise Treatment of subwatershed 3A2G3 of Dibang Multipurpose Project Loose Silt Brushwood Contour Gabion Bolder Retention Plantation Year check Dam bunding Structure Check Dam Dam (ha) (Nos.) (Nos.) (Nos.) (Nos.) (Nos.) 1st 2 0 0 0 0 1 2nd 2 0 0 0 0 1 3rd 4 0 0 0 0 2 4th 0 0 0 0 0 1 5th 0 0 0 0 0 1 Total 8 0 0 0 0 6
Table 3.21: Year-wise Treatment of subwatershed 3A2G4 of Dibang Multipurpose Project Loose Silt Brushwood Contour Gabion Bolder Retention Plantation Year check Dam bunding Structure Check Dam Dam (ha) (Nos.) (Nos.) (Nos.) (Nos.) (Nos.) 1st 8 0 4 6 0 4 2nd 12 0 4 8 0 5 3rd 14 2 4 8 2 8 4th 8 0 4 8 0 6 5th 6 0 0 6 0 3 Total 48 2 16 36 2 26
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Table 3.22: Year-wise Treatment of subwatershed 3A2H2 of Dibang Multipurpose Project Loose Silt Brushwood Contour Gabion Bolder Retention Plantation Year check Dam bunding Structure Check Dam Dam (ha) (Nos.) (Nos.) (Nos.) (Nos.) (Nos.) 1st 76 4 12 38 4 36 2nd 106 6 20 52 14 46 3rd 114 8 18 56 10 71 4th 60 4 14 50 6 51 5th 28 4 12 34 4 28 Total 384 26 76 230 38 232
Table 3.23: Year-wise Treatment of subwatershed 3A2H3 of Dibang Multipurpose Project Loose Silt Brushwood Contour Gabion Bolder Retention Plantation Year check Dam bunding Structure Check Dam Dam (ha) (Nos.) (Nos.) (Nos.) (Nos.) (Nos.) 1st 54 2 8 28 4 27 2nd 78 4 14 38 10 34 3rd 82 6 14 44 8 53 4th 44 4 12 36 4 38 5th 20 2 10 26 2 21 Total 278 18 58 172 28 173
The prioritization of sub-watersheds for treatment measures has been done with particular reference to the silt yield index and proximity with the reservoir rim. The areas showing severe erosion intensity in all subwatersheds, especially those located in the vicinity of the reservoir must be taken on priority basis for the treatment programme. Shrubs and trees to be planted under biological interventions have to be reared in the nursery to be created for this purpose. No separate nursery is proposed for the CAT Plan as the one proposed for Compensatory Afforestation Plan will serve the requirements of the plans. The cost estimates for the creation and maintenance of the plant nursery are given in the budget estimate for the Biodiversity Conservation Plan. The year wise break-up of the specific work to be undertaken in different sub-watersheds is given in Table 3.24. .
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EMP Report of Dibang Multipurpose Project
Table 3.24: Year wise break-up of the work to be done under CAT Plan Loose Silt Brushwood Contour Gabion Bolder Retention Plantation Year check Dam bunding Structure Check Dam Dam (ha) (Nos.) (Nos.) (Nos.) (Nos.) (Nos.) 1st 250 8 40 126 16 121.00 2nd 350 20 67 174 46 151.00 3rd 380 30 62 190 34 236.00 4th 200 14 50 166 20 168.00 5th 96 10 40 112 8 94.00 Total 1276 82 259 768 124 770.00
3.11 DETAILS OF TREATMENT MEASURES WITH UNIT COST ESTIMATE The unit cost of the engineering measures is as per the CPWD gazette (reference number S/O/R 1:1 2004-2005). For the biological measures the unit cost for plantation is based on the Forest Department, Govt. of Arunachal Pradesh’s notification no. FOR-01-42/Cons/2002/16, 128-188 T dated 30.06.2003.
3.11.1 Silt Retention Dams Silt Retention Dam is a concrete structure which constitutes of spillway in one side and diversion in the other side. This kind of structure is useful for retaining the silt where discharge is more and the slope is moderate around 100 to 250. Normally a free board of 0.5 m is provided and the cost estimation and dimensions of a typical Silt Retention Dam is provided below- Unit Cost Estimation of Silt Retention Dam Depth of foundation = 1.5 m Height of Dam = 3 m from bed level Top width = 1.5 m Bottom width = 5.5 m
Table 3.25: Unit Cost of Silt retention Dam
Sl. No. Particulars Quantity Units Rate per unit Total Amount (₹) (₹) 1 Earth work 15 m3 120.00 1800.00 2 Cement 180 bags 675.00 121,000.00 3 Steel 20 Quintals 7335 146,700.00 Total 2,69,500.00
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3.11.2 Contour bunding Contour bunding in shallow and medium soil at appropriate vertical interval and horizontal distance across the slopes helps in reduction of soil erosion and conservation of moisture. It consists of constructing narrow based trapezoidal bunds on contours to improve runoff rainwater in such a manner that it percolates and recharges the root profile on either side of the bunds up to 50 to distance between two such terraces. Unit cost of silt retention dam is ₹ 1680. The Schematic representation of contour bund is presented as Figure 3.1.
Figure 3.1: Schematic representation of Contour Bund
3.11.3 Brush Wood Check Dams Gullies are mainly formed on account of physiography, soil type and heavy biotic interferences in an area. The scouring of streams at their peak flows and sediment laden run-off cause gullies. Narrow gully can be treated with brush wood check dams or plots to control gully erosion. Brushwood will be available locally in abundance. The construction will be faster and the catchment can be protected from gulley erosion. Subsequently this will help in reducing sedimentation in the reservoir. Before commencing the construction for the check dam, the sides of the gully at the selected sites are slopped to 1:1.5 and the gully bottom, for the whole length of the dam, is lowered by about 15 cm. Also, 15 cm excavations are carried up into the bank as high as required to give the necessary notch capacity for discharging the
3-27 EMP Report of Dibang Multipurpose Project run-off. The country wood stakes, about 10 cm to 13 cm in diameter are driven 0.90 m apart in two rows to go at least 0.90 m to 1.2 metre in to the hard bed of gully. The distance between the rows will be 0.9 m. The tops of the stakes are kept at such a height as to form a distinct depression in the middle to form a notch of the required waterway to enable the maximum run-off to discharge. The first layer of straw and brushwood is laid across the gully between two rows of wood stakes. Over it long branches of specially selected species are laid lengthwise of the gully and well pressed. The process is repeated till the required height is obtained. The brush is anchored on to the stakes by means of galvanised iron wire. Intermediate stakes of shorter lengths are driven and the brush is anchored on to them to prevent lifting form bed by water. Drawing of a typical Double Row Brush wood Dam is presented in Map-3.15. Cost estimation for the Brushwood Check Dam is placed in Table 3.26. Table 3.26: Unit Cost of Brushwood Check Dam
Amount Particulars Item Quantity Rate (₹) Unit (₹) Survey & Alignment 1 300 Bund 300.00 Purchase & Transport of Wooden 44A 10 48 Nos 480.00 Pegs (size-5 cm diameter 65 cm length) Construction of Bund by fixing 45 10 48 Nos. 480.00 wood pegs At dist. 20 cm in 2 rows & supporting soil & murum Plantation of Bushes at distance 2 75 bush 150.00 of 0.5 m Plantation of trees at distance of 1 150 Plants 150.00 2.5 m Intercultivation 3 times 9 15 Plants 135.00 Total 1695.00 Contingencies 2 % 33.90 Grand Total 1728.90 Say, 1730.00
3.11.4 Loose Bolder Check Dam
Like brushwood check dam, loose boulder check dams can be made of boulder piled up across the gulley if they are locally available. Such structures for damming a gulley or a stream to refine the flow velocity are called loose bolder check dams. The site where the dam is to be erected is cleared and the sides are sloped to 1:1.5. The
3-28 EMP Report of Dibang Multipurpose Project bed of the gully is excavated to a uniform depth of 0.30 m and the dry boulders are packed over pressed straw from that level. In the centre of the dam portion sufficient waterway is allowed to discharge the maximum run-off from the catchment. The boulder filling should go up to 0.30 m to 0.60 m into the stable portion of the gully side to prevent end cutting. The cost estimation for loose boulder check dam is presented in Table 3.27. The schematic view of Loose Boulder Check Dam is given in Figure 3.2.
Table 3.27: Unit Cost of Loose Boulder Check Dam
Rate Amount Particulars Quantity Unit (₹) (₹) Survey & Alignment 1 per bund 30 30 Excavation on both banks 19.6 cu m 70 1372 Excavation for foundation 9.18 cu m 70 643 Bund construction, collection of dry 36.25 cu m 105 3806 rubble Foundation for pitching 2.94 cu m 70 206 Pitching on both Banks 10.9 sq m 125 1363 Transportation charge for dry rubble 18.12 cu m. 210 3805 Galvanized wire mesh 15 X 15 cm 150 sq m 180 27000 wire mash having 3 mm diameter Transportation of wire mesh up to 50 1 ₹ / total Mesh 450 450 km Survey during construction 1 Per bund 300 300 Total 38975 Contingencies 2 % 780 Grand Total 39755
Figure 3.2: Schematic and pictorial representation of loose boulder check dam
3-29 EMP Report of Dibang Multipurpose Project
3.11.5 Gabion Structures If loose boulders are considered not to be stable in a particular reach of the stream, Gabion structure or stone masonry structures can be installed. This is not very much encouraged because the terrain is stiff and the cement has to be carried by human labour. Carrying the cement will be tedious, time consuming and some times cement itself can set damaged during the carriage or while it is stocked at site for use. Therefore with proper judgement about the site conditions these structures may be installed. Cost estimates for the gabion structure construction is given in the following Table 3.28. Table 3.28: Unit Cost of Gabion Structure
S. No. Work Particulars Item Unit Rate Amount A Soil Work 1 Survey Alignment per bund 240 240 Excavation for foundation up to A2 cu m 300 300 2 0.30 m. B Stone Work Below Foundation 1 Refilling of foundation with dry rubble 35 cu m 285 9975 2 To collect dry rubble 45 cu m 225 10125 C. Stone Working above foundation 1 Work to collect & supply dry dubble 35 cu m 186 6510 2 Transporation of dry rubble 35 cu m 180 6300 3 Construction wages 35 cu m 360 12600 4 Stone Header 15 unit 300 4500 D Plantation work 1 Bush plantation 20 Plants 75 1500 Weeding and soil work 20 Plants 36 720 2 (intercultivation) Total 52770 Contingencies 2 % 1055 Grand Total 53825
3.11.6 Biological Measures In order to help reduce the erosion of soil and its transport to the reservoir it is suggested to undertake plantation of shrubs as well as trees, wherever the soil characteristics permit, in the various subwatersheds. The best policy would be to use
3-30 EMP Report of Dibang Multipurpose Project following local shrubs and trees, especially Rosa webbiana,, Macaranga denticulata, Salix sp., Populus sp., Prunus armenacia, Ailanthus grandis, Altingia excelsa, Manglietia insignis, Amoora wallichi, Syzygium sp. Terminalia myriocarpa, Duabanga grandiflora, Toona febrifuga etc. Besides these species, the rare and endangered species that are found in the project area like Aconitum ferox Wallich, Actinodaphne lanata Meissn., Coelogyne mossiae Rolfe, Dendrobium aurantiacum Reichb. f. Paphiopedilum fairieanum (Lindl.) Stein, P. venustum Pfitz., Syzygium manii (King) N. P. Balakrishnan and Vanda coerulea Griff. ex Lindl. will be planted under CAT for their ex-situ conservation and propagation. This would also help overcome the human interference that might occur during the project construction. In the villages that will get affected by the acquisition of land for different project activities provision would also be made for raising horticultural plantation like apricot, pineapples etc. The activity will be taken up on available suitable land in the villages to boost the economy of the locals. A total of 770 ha of land are proposed to be planted by different plant species as mentioned above.
3.12 ADMINISTRATIVE CHARGES An amount of ₹ 250 lakhs will be required to be kept under this head for salary and related activities like engagement of staff on contractual basis to perform specialised activities like salary, draftmanship etc.
3.13 ADMINISTRATIVE SETUP The catchment area treatment project involves intensive and highly technical operations, which require the expertise of technical personnel. It is therefore recommended that the existing forest staff of Dibang Forest Division and Anini Social Forestry Division may look after all the works to be carried out under the CAT plan including plantation and maintenance as all the area to be covered under CAT plan falls under both Dibang Forest Division and Anini Social Forestry Division.
3.14 CONTINGENCY CHARGES This Component will take care of future wage hike, unseen expenses, overflow of other components and other contingencies during implementation. An amount of ₹ 273.35 lakhs has been kept for this purpose.
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3.15 MONITORING, EVALUATION AND MAINTENANCE Monitoring and evaluation will be done as an inbuilt part of the project management. It is most important for assessing the works carried out and the results achieved vis- à-vis eco-restoration, etc. Annual work plan for each range would be prepared well in advance specifying physical and financial targets, sites, locations and beneficiaries of each component of the project activity. Month-wise work schedule of various items of each component for the financial year would also be prepared in advance and its timely implementation would be ensured. The monitoring committee proposed in Chapter-19 (Environmental Monitoring), would monitor the quality and quantity of works carried out under the CAT program.
A sum of ₹ 300 lakhs will be required to be provided for monitoring and evaluation. Under this component, independent agencies /consultants will be engaged to make base line survey, mid-term survey and end of the project survey to find out effectiveness of CAT plan activities in the catchment area. Silt load and run-off rate also will be monitored at practically feasible strategic points.
3.16 COST ESTIMATE The total expenditure on the catchment area treatment plan to be implemented over a period of five years is estimated to be ₹ 1572.36 crore. The details are of cost are presented in Tables 3.29 and 3.30. Table 3.29: Subwatershed-wise break-up of cost estimate (₹ in lakhs) of CAT Plan Gabion Loose Silt Brushwood Contour Structure Bolder Retention Plantation S. Sub - check Dam bunding (@ ₹ Check Dam Dam (@ ₹ (@₹ No Watershed (@ ₹ (@ ₹ 53825/ (@ ₹ 2,69,500/ 100,000/ha) 1730/dam) 1680/bund) structure) 39,755/dam) dam) 1 3A2C4 0.42 0.00 0.00 7.16 0.00 10.00 2 3A2C7 0.21 0.00 0.00 0.00 0.00 6.00 3 3A2D1 6.95 0.40 43.06 96.21 107.80 244.00 4 3A2D2 2.04 0.17 15.07 27.83 37.73 72.00 5 3A2F5 0.03 0.03 0.54 0.00 5.39 1.00 6 3A2G3 0.14 0.00 0.00 0.00 0.00 6.00 7 3A2G4 0.83 0.03 8.61 14.31 5.39 26.00 8 3A2H2 6.64 0.44 40.91 91.44 102.41 232.00 9 3A2H3 4.81 0.30 31.22 68.38 75.46 173.00 Total 22.07 1.38 139.41 305.32 334.18 770.00 Grand Total 1572.36
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Table 3.30: Year-wise estimate of costs on different treatment works
Brush Loose Silt wood Unit Contour Unit Gabion Unit Bolder Unit Plant Total Year Cost Cost Cost Cost Retenti Unit Cost Unit Cost check Rate bunding Rate Structure Rate Check Rate ation Cost No. (Lakh) (Lakh) (Lakh) (Lakh) on Dam Rate (₹) (Lakh) Rate (₹) (Lakh) Dam (₹) (Nos.) (₹) (Nos.) (₹) Dam (₹) (ha) (Lakh) (Nos.) (Nos.) (Nos.)
1st 250 1730 4.33 8 1680 0.13 40 53,825 21.53 126 39,755 50.09 16 2,69,500 43.12 121 1,00,000 121.00 240.20
2nd 350 1730 6.06 20 1680 0.34 67 53,825 36.06 174 39,755 69.17 46 2,69,500 123.97 151 1,00,000 151.00 386.60
3rd 380 1730 6.57 30 1680 0.50 62 53,825 33.37 190 39,755 75.53 34 2,69,500 91.63 236 1,00,000 236.00 443.61
4th 200 1730 3.46 14 1680 0.24 50 53,825 26.91 166 39,755 65.99 20 2,69,500 53.90 168 1,00,000 168.00 318.50
5th 96 1730 1.66 10 1680 0.17 40 53,825 21.53 112 39,755 44.53 8 2,69,500 21.56 94 1,00,000 94.00 183.44
Total 1276 22.07 82 1.38 259 139.41 768 305.32 124 334.18 770 770.00 1572.36
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3.17 COST ESTIMATE FOR CAT PLAN The total cost earmarked for CAT Plan is ₹ 2395.71 lakh. Details of cost of CAT is given below in Table 3.31:
Table 3.31: Total cost of Catchment Area Treatment S. No. Particulars Cost (₹ lakh) 1 CAT Measures 1572.36 2 Administrative Charges 250.00 Subtotal 1822.36 3 Contingency Charges 15% of above 273.35 4 Monitoring & Evaluation including 300.00 maintenance for 3 years Total 2395.71
3-34
CHAPTER 4 FISH MANAGEMENT PLAN
EMP Report of Dibang Multipurpose Project
CHAPTER 4 FISH MANAGEMENT PLAN
4.1 INTRODUCTION
As a result of impoundment of rivers by dams the physical structure of riverbeds may change, physicochemical environment may get impacted, upstream - downstream linkages may get cut. In spite of this the fisheries management concerns were not given due importance in the past while deciding the dam design alternatives. This situation has improved since environmental impact assessment (EIA) became universally mandatory for most types of dam projects and presently all possible measures are taken to make the dam projects, as far as possible, eco-friendly.
4.2 FISH IN DIBANG RIVER As per the survey conducted, fish species recorded at various sampling sites in the Study Area is listed in Table 4.1. Table 4.1: List of Fish species reported in the Study Area Conservation Status S. No. Scientific name Family (IUCN, 2013) 1. Barilius tileo Cyprinidae LC 2. Bariliu barna Cyprinidae LC 3. Crossocheilus latius Cyprinidae LC 4. Cirrhinus mrigala Cyprinidae LC 5. Semiplotus semiplotus Cyprinidae - 6. Garra annandalei Cyprinidae LC 7. Garra gotyla gotyla Cyprinidae LC 8. Garra lamta Cyprinidae LC 9. Garra arupi Cyprinidae - 10. Labeo pangusia Cyprinidae NT 11. Labeo gonius Cyprinidae LC 12. Rasbora elanga Cyprinidae LC 13. Neolissocheilus hexagonolepis Cyprinidae - 14. Puntius ticto Cyprinidae LC 15. Schizothorax richardsonii Cyprinidae VU 16. Schizothoraichthys progastus Cyprinidae LC
4-1 EMP Report of Dibang Multipurpose Project
Conservation Status S. No. Scientific name Family (IUCN, 2013) 17. Schizothorax esocinus Cyprinidae - 18. Tor tor Cyprinidae NT 19. Tor putitora Cyprinidae EN 20. Aborichthys elongates Cobitidae LC 21. Botia dario Cobitidae LC 22. Lepidocephalus annandalei Cobitidae - 23. Exostoma labiatum Sisoridae LC 24. Pseudecheneis sulcatus Sisoridae - 25. Pterocryptis gangelica Siluridae DD 26. Sperata seenghala Bagridae LC 27. Ompok pabda Siluridae NT 28. Mastacembelus armatus Mastacembellidae LC 29. Pseudolaguvia Erethistidae - 30. Chanda nama Chandidae LC 31. Chanda ranga Chandidae LC 32. Parambasis ranga Ambassidae LC 33. Colisa fasciatus Belontidae - 34. Colisa sota Belontidae - 35. Badis assamensis Badidae DD
4.2 CONSERVATION AND MANAGEMENT CONSIDERATIONS OF DIBANG RIVER Fish migration is attributed to the movement of fish from one habitat to another habitat for specific purpose especially for spawning in specific period. Among the fish species mentioned in Table 1 Tor putitora, Tor tor and Neolissocheilus hexagonolepis are considered to be migratory species. These species especially Tor tor and Tor putitora inhabit lower reaches or foothills in Himalayan rivers and take their upstream migration during March and April. They spawn in small tributaries having relatively high temperature from June to September when rivers swell greatly and have high turbidity. After spawning Tor spp. start to descend during September and October. During primary survey, these species could not be located at high fish landing centre and in the tributaries of Dibang basin, however, local fishermen
4-2 EMP Report of Dibang Multipurpose Project revealed the presence of these species, which are known as Jungapithia in the area. Their presence in foothill stretch and middle hills of Dibang basin indicate that they must have breeding grounds as tributaries near dam sites. Some of the tributaries like Emra, Airi Pani, Ashu Pani, Deopani and Iphipani in Lower Dibang Valley can be considered as spawning grounds of Tor spp.
Schizothorax spp. are also considered to perform local migration, though they are found in Dibang river throughout the year. To cope adverse climatic conditions in winter season these species migrate from upper reaches to lower reaches while ascends in the months of May-June. Likewise mahseer (Tor spp.) they do not have specific breeding grounds and spawn in all tributaries of lower and middle reaches and/or even in banks of the main river. During the primary survey we could locate fingerlings and juveniles of Schizothorax spp. in tributaries like Emra, Airi Pani and Ashu Pani.
4.3 MANAGEMENT MEASURES To minimise the impact of damming on the fishery of a river several mitigative measures are generally taken. Ban of Destructive Fishing Methods The responsible authority should stop the killing of fishes by destructive methods like poisoning and use of dynamite in the diverted river channel and pool regions respectively. Such fishing methods not only kill the fries, fingerlings and brood fishes but also destroy the breeding habitats of the fish themselves.
Lack of awareness about the importance of riverine fishery in the local inhabitants is the major problem for the destruction of riverine fishes. Uneducated local fishermen do not understand the destructive nature of the use of poison, dynamite and the importance of natural habitat of fish. So, awareness camp should be organized from time to time for the conservation of fish species among local people.
Ban of Harmful Fishing Implements The fine meshed net like Cast net, Bhureli jal, and mosquito nets which catch fish juveniles must be banned because they reduce the survival rate of fish species. Fish poisons are widely used in diverted river channel, most of which are derived from
4-3 EMP Report of Dibang Multipurpose Project plant parts such as Sapium sp., bark of Myrica esculanta, stem of cacti etc. Public in the area should be made acquainted with the importance of fish conservation and the destructive effects of the poisons.
Dynamiting which is a destructive method killing all the types as well as age groups of fishes. Hence, it must be checked and totally banned.
Hence, all of these harmful means and methods of fishing must be checked and totally banned for the proper conservation and management of fish biodiversity.
Other Measures During this study various alternatives for fish conservation and translocations were discussed with the Fishery officers of Roing and Guwahati. Even though, construction of fishways (fish ladders) of different types in the dam for the up and down movement of the fish is a good option. Keeping in mind the height of the present dam construction of a fish ladder/fish ways is not technically feasible. Another step that could help the fish move up and down of the dam is provision of a fish bypass. However, the local topography of the Dibang makes provision of fish bypass almost impossible and least viable. A third option is the incorporation of a fish lift in the dam structure. The biological uncertainty for its function, as well as the high costs (construction and operation cost and the cost of compensatory release of water) all count against this option.
The main objectives of the mitigation program include: To maintain fish Biodiversity and production in affluent streams entering the reservoir. To maintain fish Biodiversity and production in the riverine environments downstream from the dam. To develop the new fisheries potentials created in the reservoir of the dam.
In spite of the fact that the bypass facilities (Ladders / Bypasses) and Fish lifts won’t be feasible in case of the proposed Dibang Project, the objectives listed above can be realised by adopting fish propagation techniques. The biologically and economically best alternative to compensate for the obstructed migration possibilities of the fish in the river seems to be the option of artificial hatching and
4-4 EMP Report of Dibang Multipurpose Project continuous restocking of the river and the reservoir. It is therefore, recommended to build a Fish hatchery in the Project area.
4.4 RECOMMENDATIONS Creation of a barrier in the form of a dam across the migratory path of some fishes may considerably undermine the survival and breeding of fishes. Hence hatchery in the nearby areas is the most suitable proposition for the fish population. For successful conservation and management of indigenous fish species in the Dibang river the following recommendation are made.
4.4.1 Fish Hatchery The Reservoir which will be formed due to damming may be commercially exploited for fish consumption during the non-breeding seasons and co-operation may be sought from the state fishery department in this regard. However for developing fish culture a Hatchery is proposed in the vicinity of the reservoir.
For the development of cold water fishery in the area, construction of a Hatchery is the most important. The location of the hatchery can be identified somewhere near Etalin in consultation with the State Fisheries Department and State Fishery Colleges. The fish hatchery can be managed by the State Fisheries Department, which may be equipped with the technical know-how for running trout and carp culture fisheries. After rearing the spawn in the hatchery for a stipulated period of time the young fish can be restocked in the reservoir as well as in the river, both upstream and downstream for replenishing the natural population. Both the activities can be managed by an officer of the rank of Fishery Project officer with the help of subordinate staff.
4.4.1.1 Seed Collection One of the main problems faced during the Culture practices is the procurement of the seed, particularly of the indigenous varieties. For procuring the fish seed, the brood fish can be easily collected from the river itself, especially just below the dam. The striped fish can be returned to the natural habitat and the spawn reared in the hatchery constructed for the purpose.
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For the development of fisheries and management of reservoir following steps are necessary:
4.4.1.2 Analysis of Water Quality Prior to seed stocking in the reservoir, detailed study of physical, chemical and biological characteristics of water and the soil of reservoir is required.
4.4.1.3 Seed Stocking The main problem confronting the fisheries developing agencies is whether the resident indigenous species would be able to establish successfully in the lacustrine system. Therefore, it would be worthwhile to introduce rainbow trout and brown trout and a few indigenous species on an experimental basis in the proposed reservoir from the fish stock reared in the proposed hatchery. The total hatchery of 1.5 ha area would require about 15-20 kg seeds for the stocking in the first year.
4.4.1.4 Organization of Fishermen Owing to smaller water spread entire reservoir of Dibang project could be treated as a ringlet beat. The reservoir would support and require an organization of about 20 fishermen in the beginning. The Fishery Department would be advised to allow the use of fishing gears of definite types (cast nets and gill nets, etc.) and proper mesh size to prevent the young and juvenile fish from over-exploitation. Simultaneously, the authorities should initiate a training programme for operating hatchery at the surface and deeper waters.
4.4.1.5 Other Requirements For the control of noxious weeds, harvesting of fishes (for rapid growing fishes and non-cultivable fishes) and maintenance of embankments, the Fishery Department needs some mechanical control devices, boats and chemicals.
4.4.1.6 Conservation of Downstream River Bed Since construction of the dam affects the flow of water in the river, the river bed below the dam site gets invariably affected and many a time a long stretch of river bed down stream of a dam gets affected due to low volume of water. However, in the present case the Power House is to be located very close to the dam and as such
4-6 EMP Report of Dibang Multipurpose Project there are very low chances of the down stream of the dam getting dried up. The construction of dam also will not affect the water requirement of the population residing in the downstream areas. This population generally depends upon the local streams and springs for drinking water and for other domestic uses. There is also no competitive use of water downstream of dam for industrial purposes. Therefore, the impact of damming on the downstream areas is not anticipated.
4.4.2 Management of Reservoir Fisheries 4.4.2.1 Institutional Mechanism The plan is proposed to be implemented through the State Fisheries Department of Arunachal Pradesh, the funds for which will be released periodically by the project to the Fisheries Department. An Advisory Committee is proposed to be instituted which would monitor the implementation aspects, priorities, activities, etc. The committee would offer advice on development of marketing linkages and training programmes, keeping in mind people's participation in fisheries development schemes. Chairman Head of the Project Co-Chairman Head, State Fisheries Department Member Nominee of Fisheries Department Member Two Representative from PAF Member Environment Officer, NHPC Member Local NGO Representative
4.4.2.2 Staffing Pattern For smooth implementation and maintenance of fish farms, staffing pattern has been suggested in Table-4.2.
Table 4.2: Staffing pattern for smooth implementation and maintenance of fish farms S. No. Staff Nos. 1. Farm Superintendent 1 2. Farm Manager 2 3. Farm Assistant 3 4. Fish Farm Attendant 6 5. Chowkidar 1 6. Driver 1
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4.4.2.3 Planning and Monitoring A Farm Superintendent appointed full time on behalf of The Advisory Committee would coordinate and oversee the operation of the proposed fisheries Development and Management Plan. Various terms led by Farm Managers would be constituted to look after activities such as (i) land acquisition, development of fish farm facilities and office at allocated site, (ii) execute fish breeding activity and (iii) marketing of product.
The Farm Superintendent would evaluate/monitor both financial and administrative aspects at the Farm Office. The implementation, monitoring and appraisal of the plan should be reported regularly. After five years of management and maintenance, the fish farms will be handed over to the state fishery department.
The meetings of Advisory Committee would be held once every three months in order to ensure incorporation of preference of the PAFs and resolve logistic problems in plan implementation. The Farm Superintendent with team members would meet every week to ensure the implementation of project on time to time. Six monthly progress reports would be submitted to NHPC for evaluation and disbursement of finance.
4.5 COST ESTIMATE FOR FISH MANAGEMENT PLAN The total cost earmarked for fish management plan is ₹ 648.24 lakh. The details are given in Table 4.3. It does not include the cost of the land required for two hatcheries). Table 4.3: Component wise cost for development of fish seed farm
S. Amount Particulars Qty. Rate (₹) No. (₹ lakh) A. Capital cost (Non-recurring expenditure) 1. Hatchery (20 troughs and 80 trays) 1 Lump sum 10.00 2. Nursery ponds 9 30,000 2.70 (3.0 m x 0.75 m x 0.5m) 3. Rearing ponds 9 50,000 4.50 (10 m x 1.50 m x 0.5m) 4. Stocking ponds 2 1,50,000 3.00 (30 m x 6.0 m x 1.5 m)
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S. Amount Particulars Qty. Rate (₹) No. (₹ lakh) 5. Office, store, hut with infrastructure 4 - 20.00 6. Laboratory 1 - 2.00 7. Water supply (lump sum) - - 2.00 8. Other project cost (Drag nets, wide - - 5.00 mouth earthen pots, miniature hapa, buckets, bamboo poles etc.) (lump sum) Sub-total 49.20 Cost for two hatcheries (A) 2 49.20 98.40 B. Working Capital / year (Recurring expenditure) 1. Salaries i) Farm Manager 1 50,000/month 6.00 ii) Farm Assistants 1 25,000/month 3.00 iii) Farm Attendants 1 15,000/month 1.80 iv) Chowkidars 1 15,000/month 1.80 2. Fish food (rice bran, oil cake, etc.) Lump sum 5.00 3. Brooders 200 150 0.30 kg 4. Ponds manuring i) Cow dung 20 200/tons 0.04 tons ii) Urea 100 10/kg 0.01 kg iii) Potash, phosphate 100 100/kg 0.10 kg 5. Lime 300 10/kg 0.03 kg 6. Training and Research Lump sum 5.00 7. Chemical Lump sum 5.00 8. Maintenance Lump sum 5.00 9. Travel Lump sum 5.00 10 Miscellaneous Lump sum 10.00 Sub-total (B) 48.08 Total recurring expenditure for 10 549.84 years with 10% escalation (B) Total (A+B) 648.24
4-9
CHAPTER 5 GREENBELT DEVELOPMENT PLAN
EMP Report of Dibang Multipurpose Project
CHAPTER 5 GREENBELT DEVELOPMENT PLAN 5.1 INTRODUCTION The forest loss due to the reservoir submergence and construction of other project appurtenances shall compensated as a part of compensatory afforestation. However, it is proposed to develop greenbelt around the perimeter of various project appurtenances, selected stretches along reservoir periphery, etc. The main objectives of creating a green belt around a reservoir are to: Check soil erosion around the reservoir Check landslides and slips around the reservoir Develop the habitat for wildlife particularly avi-fauna
The general consideration involved while developing the greenbelt are: - Trees growing up to 10 m or above in height with perennial foliage should be planted around various appurtenances of the proposed project. - Planting of trees should be undertaken in appropriate encircling rows around the project site. - Generally fast growing species should be planted. - Since, the tree trunk is normally devoid of foliage up to a height of 3 m, it may be useful to have shrubbery in front of the trees so as to gives coverage to this portion.
5.2 PLANTATION The tree plantation will be done at a spacing of 2.5 x 2.5 m. About 1600 trees per ha will be planted. The maintenance of the plantation area will also be done by the project proponent. The treated waste water and the manure generated by composting of solid waste generated for labour camps will be used for the greenbelt development. The species recommended for greenbelt development are given in Table 5.1. Table 5.1: Species recommended for greenbelt development
Common/ Local Name Botanical Name Trees Black Siris Albizia odoratissima
5-1 EMP Report of Dibang Multipurpose Project
Common/ Local Name Botanical Name Chalta Dillenia indica Bhut-vriksha Oroxylum indicum Horse Chestnut Aesculus assamica Butterfly tree Bauhinia purpurea Hollock Terminalia myriocarapa Bahera Terminalia bellerica Siris tree Albizia lebbeck Koroi Albizia procera Palash Butea monosperma Dhale Katus Castanopsis indica Magnolia Magnolia hodgsonii Nahor Mesua ferrea Shrubs Wild Rhea Debregeasia longifolia Sisal Agave sisalanaa Jatropha Jatropha curcas Cassava Manihot esculenta Nirgundi Vitex negundo Satavar Asparagus racemosus Palmae Calamus spp. Himalayan Pinanga palm Pinanga gracilis Herbs Cogon grass Imperata cylindrica Devil's Horsewhip Achyranthes aspera Safed Musli Chlorophytum arundinaceum Lemon Grass Cymbopogon flexuosum Scented Grass Chrysopogon gryllus Elephant Grass Pennisetum purpureum
5.3 COST ESTIMATE FOR GREEN BELT DEVELOPMENT The cost of plantation per hectare is estimated at ₹ 1,00,000 per ha which includes sapling cost, nursery cost, labour cost, cost of manure, weeding etc. It is proposed to afforest about 200 ha of land as a part of Greenbelt development. The total cost works out to be ₹ 200 lakh.
5-2
CHAPTER 6 GEO-ENVIRONMENTAL MANAGEMENT PLAN (PLAN FOR CONTROL OF LANDSLIDES)
EMP Report of Dibang Multipurpose Project
CHAPTER 6 GEO-ENVIRONMENTAL MANAGEMENT PLAN (PLAN FOR CONTROL OF LANDSLIDES)
6.1 INTRODUCTION Geo-environmental management plan is formulated to protect and/or improve the reservoir zone and to provide stability to the reservoir. The important issues, which need considerations from the environmental point of view, are discussed in this chapter. In the vicinity of the reservoir area around 60 nos. of landslide zones / unstable slopes have been identified.
6.2 LANDSLIDE CONTROL The total numbers of landslides in the project area are classified into small, medium and large categories based on their dimension and area. The details are given in Table 6.1.
Table 6.1: Categories and types of landslides encountered in the reservoir area of Dibang Multipurpose Project
Approximate Size of Approximate Dimension No. of Type of Material Landslide area in sq m (width × height) Landslides (sq m) Small Up to 1250 25 x 50 10 Mostly in overburden. Few in rock Medium 1250 to 25 x 50 38 Both rock and 20,000 to overburden 100 x 200 Large More than More than 12 Rock in general 20, 000 100 x 200
6.2.1 Landslide Control Measures:
The following control measures can be adopted to stabilize the landslide. 1. Capture and drainage of surface water flowing into the slide area or emerging in the head scarp area. 2. Pumping of water from all wells in the slide area and from any undrained depressions.
6-1 EMP Report of Dibang Multipurpose Project
3. Filling and compacting of the fill in all open cracks, which could be entered by, surface water. This particularly concerns deep cracks which develop during slope movement and which reach down to the slide plane. 4. In the case of slow, creep-like slope movements, the packing of open cracks may also have an impeding effect, because it can hinder upslope propagation of slope deformation.
The scheduling of corrective measures must pay due regard to weather conditions. The individual operations should be scheduled with action so that the remedial works would not remain unfinished. In such a case it is better to postpone the operations to spring time.
All corrective installations must be regularly checked and maintained. If regular maintenance is not carried out, or if the agreed programme for developing and using the slide area is not adhered to, then extensive and costly corrective measures may come to naught and within a short period new movements may start up. The schedule of inspection and the maintenance work should be included in the overall planning of the corrective measures.
6.2.2 Treatment of slope conformation The stability of a slope may be increased either by reducing the volume at the head or by expanding the volume at the toe.
The presence of a lower layer possessing a large shear strength angle makes building up of the toe more advantageous because a small extra weight may be sufficient to stabilize the slope foot. On the other hand if the strength of the bottom place layer is low (e.g. in unconsolidated surface layers), it is also possible to place a fill in front of the slope, as is frequently done in open pit coal mines. An important factor, which gives a good buttressing effect from the fill, is proper drainage of its base, particularly if the fill rests on clayey material. The best drainage can be accomplished with a gravel layer of 0.6 to 1 m thick.
The use of the drained fill also works well in the toe areas of moving slopes, where saturation of soils is the chief problem. Generally, there is insufficient time for
6-2 EMP Report of Dibang Multipurpose Project installing horizontal drainage boreholes, whereas the fill can be dumped in a very short time, even overnight. Owing to the velocity of the movement, the gravel fill may need to be placed some distance from the current position of the toe of the slide. The overt rusting material at the front of the sliding mass becomes drained and cessation of the movement follows. A successive treatment of the sliding mass with horizontal boreholes can therefore be postponed.
A protective fill dumped on the surface of slopes excavated in clays is another effective measure, if carried out in good time. The coefficient of initial lateral stress is assumed to be unity and the presence of ground-water was assumed. Therefore, the sooner the protective fill is put in place, the greater is the safety of the slope. This is a point that needs to be emphasized in engineering-geological remediation. The design of the protective gravel fill should take into account of the foregoing considerations, and therefore the fill should be designed as a self-supporting beam. Thicker protective fills work well where the banks of reservoirs are concerned.
6.3 DRAINAGE OF LANDSLIDE AREAS i) Surface drainage The surface of any area affected by sliding is generally uneven, hummocky, and traversed by deep fissures. In the depressions and fissures water accumulates and wet ground develops. Therefore one of the remedial measures is the surface drainage of the slide areas. Although surfaced drainage by itself is seldom sufficient to stabilize a slope which is in motion, it can contribute substantially to the drying out, and thus also to the control of the landslide.
First of all, all streams and temporary watercourses are diverted from the threatened area. In addition, all springs issuing within the slide area, especially those at its head, must be contained and diverted away from the slide. For an immediate, provisional diversion of flowing water any available pipes may be used. In the first stages of a landslide when the movement and changes in the relief are appreciable, surface pipes have the advantage of being easy to move and they are inexpensive. In winter, however, they prove less suitable because they do not protect the drainage water from freezing.
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After partial stabilization of the landslide, open ditches of adequate dimensions and gradient are excavated for discharging rain-water. At the same time, the ground surface is leveled and undrained depressions filled along with all cracks so that a continuous run-off of surface water is ensured. During these operations the grass cover must not be disturbed unnecessarily, since grass reduces the tendency of water to percolate down into the slope.
The arrangement of ditches depends on the soil type; their banks and floors must be sufficiently firm so as to resist erosion. They are paved either with natural stone of suitable properties, or with concrete tiles set in a sand foundation, the joints being sealed with cement or sod. Water infiltration into the sand bed is directed along the ditch by establishing low steps. In sandy soils, the ditch sides and bottom may be consolidated with asphalt, bitumen or oil sprinkle.
In some cases ditches of reinforced concrete have proved suitable for surface drainage. These tiles are slightly narrowed at one end so that they can be inserted into one another. Compared with paving, gutters of reinforced concrete have the advantage of being less pervious; they can withstand slight movements of the slope. Wooden troughs, which are occasionally used, can easily be set out and then repositioned if necessary, but with frequent moistening and drying out, the wood deteriorates and becomes more leaky.
In addition to ditches constructed in the slide area, peripheral ditches above the head scarp are sometimes dug so as to divert surface water flowing down adjacent slopes into the potentially unstable area. They must be provided with impervious paving and have a uniform gradient to prevent deposition of material on the bottom the slope, and may seriously upset the stability, even in the case of a slide which is temporarily at rest. ii) Subsurface drainage As ground water is one of the major causes of slope instability, subsurface drainage is a very effective form of remedial treatment. It complements or may even render unnecessary the shape adjustment of slopes, since a drained slope may be stable at a steeper angle than an un drained one. The disadvantage of subsurface drainage is
6-4 EMP Report of Dibang Multipurpose Project that the drainage system cannot be designed until after geological and hydro- geological research has been completed, with the result that it come into operation somewhat belatedly.
Drainage galleries are conventional deeply situated structures such as were built in the first railway construction schemes of the last century. They have several advantages, first of all serving as a means of investigating water percolation through the rock, and thus helping to ascertain precisely the hydro-geological conditions of the slope. They are capable of discharging a large amount of water. Their effectiveness may be increased by making long or short drainage borings in the walls, floor or roof of the gallery. Thus, galleries can be constructed below the slide plane for the purpose of collecting water from the overlying layers through vertical boreholes. If the water seems to derive from the more permeable bed in the floor of the gallery, a shaft or a trench may be dug. The course of the gallery may be changed so as to follow the influx of water, or to make contact with the lower ends of vertical drainage boreholes. The diameter of galleries is generally so large that they discharge water even when partly disturbed.
In spite of these disadvantages, galleries still represent an indispensable method of draining deep slides in which the distances to be drained are greater than 250 m. Boreholes were drilled inside the gallery in order to drain saturated pockets of terrace gravel. The cost borehole is largely reduced on account of the shorter construction time which depends upon suitable machinery being available, and almost no need for pumping costs compared with pumping wells. There are four drawbacks involved in drainage borings: (a) It is difficult to guarantee that a borehole will contact those water-bearing beds in which the pressure of the ground-water is responsible for impairing the stability of the slope. (b) Even if an appropriate layer is contacted, the reduction achieved in the uplift force may not be sufficient to increase the shear resistance. (c) The maximum length of effective borings is 250 to 300 m, tended position by several metre. Fine sands or sandy gravel often do not permit the drilling of boreholes longer than 100 m, because the fine grains jam the drilling tool. (d) Drainage boreholes have a limited useful life.
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As far as items (a), (b) and (c) are concerned, the following observations may be made: Unless the most permeable layer within the slope has been reached, the drainage process will not be fully effective. Effective drainage by attacking the less permeable talus loams requires several times the number of boreholes that would otherwise be needed for draining the underlying rock debris or permeable bedrock. In the entire reservoir area overall 60 number of active landslide zones forming unstable slopes has been identified.
6.4 MITIGATION MEASURES Following are the Mitigation Measures suggested for controlling the Landslide in the Project area Rock anchoring, carving out of slopes, shot creting etc. should be planned. The impact of landslide on the project could be managed by arresting the potential landslides zones through suitable engineering treatments, afforestation etc. Landslide Control with Coir-Geotextile
Looking into the nature of the landslide in the Dibang Project Site Following technique is suggested for the landslides.
If an area roughly measuring 20 m x 31 m along the slope is chosen the slope length is divided by constructing two unbounded stone masonry walls of 22 m long and with a maximum height of 1.20 m at the bases of the steep slopes. This is to be carried out to arrest the debris movements and yet to provide sufficient drainage.
The installation procedure is generally similar to that used for other types of geo- textile materials for surface erosion control. However due to the steepness of slope and the changes of high runoff occurrence and additional precautionary measure should be used. This includes typing the coir netting in the position using coir ropes, which are anchored, into the ground. The detailed procedure of installation is as follows:
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The soil on the surface of slope is first graded to remove the unevenness present, where possible. There may still some patches of exposed rock/boulders. Wedge shaped trenches of 30 cm x 30 cm is to be dug to anchor the coir nets at the top and the bottom (Figure 6.1). The area may be seeded with very limited quantity of Pennisetum sp. / Vetiveria sp., grasses known for quick and easy growth and have root depth nearly equaling the existing soil cover, i.e. around 40 to 50 cm.
Rolls of the coir matting is first anchored in the top trench and then unrolled along the slope. Each slope is given an overlap of minimum 15 cm with the adjacent ones and anchored firmly into the ground by mild steel staple, spaced to form a grid of 2 m in either direction. Coir ropes of 20 mm diameter were used to tying the coir matting, which is anchored in tension in a criss-cross pattern at around an angle of 90o, making a grid of 1m size. Steel staples are driven at each joint of the coir rope (Figure 6.2) type. Matting is used on the upper half having a slope of 60o and type B matting were used on bottom half with 40o slope. Culms of locally growing bamboos species may also be used for anchoring the jute net / geo-textile. Over a period of time the roots from the bamboo will develop and will further provide stability to the slope.
For the medium and large category of landslides the retaining wall method along with concrete slab will be used for landslide control. The Schematic diagram for restoration of various landslides is given in Figures 6.3 to 6.5.
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Figure 6.1: Wedge shaped trenches
Figure 6.2: Coir Rope
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Photo 6.1: Landslide L 60 near Airi Pani confluence with Dibang river (about 2 km u/s of Dam axis)
Figure 6.3: Schematic view of restoration plan for landslide L 60
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Photo 6.2: Landslide L 39 on left bank of Dibang at the confluence of Ithun and Dibang river
Figure 6.4: Schematic view of restoration plan for landslide L 39
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Photo 6.3: Landslide L 13 on left bank of Dibang about 1.2 km downstream of Enne nala
Figure 6.5: Schematic view of restoration plan for landslide L 13
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The cost estimate for the Geo-textile is presented in the following Table 6.2.
Table 6.2: Cost estimate for Geo-textile Area to be treated with geo- Rate (₹ / sq m) S. No. Amount (₹ in lakh) textiles (Geo-textile) 1. Geo-textile – 1400.00 175.00 1250 sq m x 10 small landslides 2. Plantation of Pennisetum sp. / 1000.00 125.00 Vetiveria sp., 1250 sq m x 10 small landslides Total 300.00
6.5 COST ESTIMATE FOR GEO-ENVIRONMENTAL MANAGEMENT PLAN An amount of ₹ 2312.63 lakh has been earmarked for control of landslides. The details are given in Table 6.3.
Table 6.3: Financial outlay for Geo-environmental Management Plan S. No. Item Cost (₹ lakh) 1. Construction of retaining wall 1845.00 2. Construction of drain 30.00 3. Geo-textile measures 300.00 4. Turfing 7.50 5. Contingencies 20.00 Sub-total (A) 2202.50 6. Maintenance cost @ 5% of (A) 110.13 Total 2312.63
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CHAPTER 7 MUCK DISPOSAL PLAN
EMP Report of Dibang Multipurpose Project
CHAPTER 7 MUCK DISPOSAL PLAN
7.1 GENERAL The proposed Dibang multipurpose project would involve a number of civil engineering activities leading to production of large quantities of muck. This muck would be excavated from the HRTs & TRTs during the tunnelling, construction of desilting arrangement, underground power house complex, approach roads etc. Even though some of the muck will be utilized for back filling, yet a large quantity of the excavated material will need to be relocated and dumped in such a manner that it does not impose any negative impact on terrestrial and aquatic environment.
7.2 MUCK DISPOSAL AREAS The total excavation quantity likely to be generated at the project will be around 177 lakh cum, out of which 59 lakh cum will be common excavation. Effectively, total rock excavation will be 117.8 lakh cum. Out of 117.8 lakh cum of total rock excavation, approximately 35 lakh cum will be used for production of aggregate and remaining 82.84 lakh cum will have to be disposed of. Adding 25% to 60% bulkage factor for common excavation and rock excavation, the quantity to be disposed of would be 198 lakh cum. The detailed calculation is in Table 7.1. Table 7.1: Quantum of Muck to be disposed S. No. Description Quantity (cum) 1. Total Excavation (TE) 17686800 2. Common Excavation (CE) 5902440 3. Total Rock Excavation(TRE)=TE-CE 11784360 4. Reusable Quantity (for use as Aggregate) (RQ) 3500000 5. Disposable rock mass 8284360 6. Taking swelling factor of 60% for rock, disposable rock 13254976 muck 7. Back fill/ fill quantity (BQ) 673600 8. Disposable common muck=CE-BQ 5228840 9. Taking swelling factor of 25% for common disposable 6536050 muck 10. Total muck to be disposed(10)=(6)+(9) 19791026 Say, 198 lakh cum
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Three muck disposal areas have been identified for accommodating 198 lakh cum of muck generated. However, the capacity of the three dumping sites is 200.81 lakh cum, the details are given in Table 7.2.
Table 7.2: Details of Muck Disposal Areas
Average Distance Description of Muck Disposal Area Capacity S. No. from Dam Area (ha) (lakh cum) area (km) 1. Muck Disposal Area - 1 near 20 1 4.00 Pothead Yard (R/Bank) 2. Muck Disposal Area - 2 between 40 5 60.00 Thar Pahar & Pathar Camp (R/Bank) 3. Muck Disposal Area - 3 between 52.621 7 136.81 Aka Korong & Aya Korong (R/Bank) Total 112.621 200.81
7.3 RESTORATION OF MUCK DISPOSAL SITES The unused material (198 lakh cum of muck) would be piled at an angle of repose at the proposed dumping sites. For the stabilization of dumped materials various engineering and phyto-remedial measures are being proposed in the management plan.
7.3.1 Engineering Measures Individual plans and cross sections of the three muck disposable areas, including protection measures are placed as Maps 7.1 to 7.15.
7.3.2 Phyto-remediation of Muck Disposal Areas The work plan formulated for re-vegetation of the muck disposal areas through “Integrated Biological and Biotechnological Approach” is based on following parameters: 1. Depending upon the quality of muck material formulation of appropriate blends of organic waste and soil to enhance the nutrient status of rhizosphere.
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2. Isolation and screening of specialized strains of rnycorrhizal fungi, rhizobium, azotobacter and phosphate solubilizers (bio-fertilizers inoculum) suitable for the dumped material. 3. Mass culture of plant specific bio fertilizer and mycorrhizal fungi to be procured from different institutions/organizations which are engaged in the phyto-remediation activity of degraded areas. 4. Plantation of dumping sites/areas using identified blend and bio fertilizer inoculum. The afforestation with suitable plant species of high ecological and economic value, which can adapt to local habitat, will be undertaken.
Areas of approximately 112.621 ha (Refer Table 7.3) would require phytoremediation measures. The cost for remediation includes the cost of turfing of slopes, preparation of ground, spreading of manure, providing 5 cm of soil cover, provision of retaining wall and transportation and carriage etc. It also includes the cost of fencing, watch and ward, irrigation, etc.
Table 7.3: Area for Remediation of muck disposal sites Total Area S. No. Description of Muck Disposal Area (ha) 1. Muck Disposal Area - 1 near Pothead Yard (R/Bank) 20 2. Muck Disposal Area - 2 between Thar Pahar and 40 Pathar Camp (R/Bank) 3. Muck Disposal Area - 3 between Aka Korong and Aya 52.621 Korong (R/Bank) Total 112.621
Proper dumping shall be done over the designated dumping sites. The waste material dumped at spoil tips would comprise mainly of loose rock fragments that would be mechanically compacted and properly levelled with suitable safe slopes and retaining walls/crate walls shall be constructed so that in no case the dumped material is washed away into the river. Construction material like stones, sand, etc. required for the construction of road should be obtained mostly from the excavated material to minimize the environmental damage. The efforts shall be made to utilize maximum dumped material for the project activities and backfilling. In the streams, box culverts will be provided to prevent the erosion of stream bed.
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Map 7.1: Muck Disposal Area near Switch Yard (Pot yard) – Site 1
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Map 7.2: Muck Disposal Area between Thar Pahar & Aka korong – Site 2
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Map 7.3: Muck Disposal Area between Aka korong & Aya korong
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EMP Report of Dibang Multipurpose Project
7.3.2.1 Re-vegetation of Spoil Tips After proper dumping of the muck all three dumping sites shall be rejuvenated using bio-technological approach. The area shall be restored through plantation and turfing on the slope.
7.3.2.2 Soil Working and Plantation Techniques Isolation and screening of specialised strains of mycorrhizal fungi, rhizobia, azotobacters and phosphate solubilizers (biofertilizer inoculum) in accordance with the suitability for the spoil tips will be done at site, based on following: Inoculation of plants with specific biofertilizers and mycorrhizal strains. Periodical evaluation of rhizosphere development for physical, chemical and microbiological parameters. Monitoring of growth response in different plant species periodically and identification of corrective measures, if necessary. Mass culture of plant specific biofertilizers and mycorrhizal fungi.
The pitting details are as follows: Total No. of pits : 1800 per hectare Size of each pit : 0.6 m x 0.6 m Spacing between pits : 2.5 m x 2.0 m
The excavated material from the pits will be mixed with 43.2 litre of external soil, 10 kg of apple peel and 5 kg of farmyard manure, and 2 kg of vermi-compost. The pit will be refilled with the mixture, 10-15 gm of mycorrhizal inoculum near the root system is to be added. After this, plant saplings already inoculated with biofertilizers (Rhizobium and Azotobacter bacteria) would be planted and refilling will be done to cover the entire plant root system. The schematic technique of plantation is shown in Figure 7.1 Turfing (sodding) and suitable shrubs will be grown at slopes. About 5 cm of thick layer external soil will be spread on the slope area. Sod patches (40 cm x 20 cm) will be grown per square meter. Before sowing, the area will be properly amended with the manure @ of 2 kg/m2.
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1. Excavate in spoil dump pit of size 60 cm x 60 cm x 60 cm
2. Mix 43.2 litres of soil, 10 kg of apple peel compost, 5 kg of farm yard manure and 2 kg of vermi-compost with excavated spoil (Soil : Spoil = 1:4)
3. Refill the pit with Mixture 4. 10 –15 g of Mycorrhizae inoculum near the root system
5. Plantation of sapling inoculated with biofertilizers (Rhizobium + Azotobactor) and refilling
Figure 7.1: Schematic representation of plantation using VAM technique
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7.3.2.3 Species for Plantation Afforestation with suitable plant species of high ecological and economic value and adaptable to local conditions like Populus spp., Rosa spp., Hibiscus spp., Pinus spp., Alnus nepalensis, Betula alnoides etc. will be undertaken at the rate of 1000 trees per hectare in accordance with canopy cover requirement.
7.3.2.4 Irrigation Facility Generally, afforestation programme in the vicinity is not supplemented with any irrigation modalities and depends on rains. However, in order to ascertain quick greenery and growth in the spoil tip areas, irrigation, especially during the drought period is to be provided. For this, water-harvesting tanks will be constructed to supplement the drip irrigation facility in the downstream for the horticultural crops. Research trenches will also act as water harvesting structures to facilitate irrigation for the cash crops.
7.3.2.5 Fencing All the sites will be properly fenced to protect the area from human and animal interference. About 4400 m of fence would be required at all the sites.
7.3.2.6 Watch and Ward It is proposed that 5 guards would be deployed for protection and maintenance of sites for three years. The duties will include replacement of casualties, weeding, watering, repair of fence line etc.
7.4 RECOMMENDATIONS Following recommendations for smooth implementation of the Muck Disposal Plan are delineated below:
Selection of species having faster growth, and helpful in stabilizing the dump sites Project authorities should ensure frequent meetings with the project team to enable smooth implementation of the Plan
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7.5 COST ESTIMATE FOR MUCK DISPOSAL PLAN An amount of ₹ 648.40 lakh has been earmarked for stabilization of muck disposal sites. The details are given in Table 7.4.
Table 7.4: Summary of cost required for muck disposal
Amount S. No. Cost (₹ in lakh) 1. Plantation on spoil tips (plain area) including bio- 180.00 fertilizer cost 2. Turfing on slopes (@ ₹ 100,000/- per ha taking into 45.00 account 40% of total area of muck disposal i.e. 45 ha to be earmarked for turfing) 3. Fencing cost for 4400 m (@ 500/- per running m) 22.00 4. Retaining Wall (lump sum) 300.00 5. Cost of two portable water pumps, (flow 20 cum/hr, 15.00 20m head, along with 200 m pipe, 100 mm dia., HDPE) 6. Watch & Ward (2 persons @ ₹ 10,000/month/for 8 27.45 years considering 10% escalation per year Sub-total (A) 589.45 Contingencies (10% of A) 58.95 Total Cost 648.40
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CHAPTER 8 RESTORATION PLAN FOR QUARRY AREAS
EMP Report of Dibang Multipurpose Project
CHAPTER 8 RESTORATION PLAN FOR QUARRY AREAS
8.1 QUARRY SITES Three rock quarries namely DBR-1, DBR-2 and DBR-4 located within 5 km upstream of dam axis were explored as a part of the investigation for the project. The possibility of utilising excavated muck likely to be generated during excavation from dam abutments, powerhouse and tunnels (DBR-3, DBR-5 & DBR-6) was also explored to minimize the extraction of construction material from rock quarries.
Three shoals / fan deposits namely DBG-1, DBG-2 &DBG-3, located within 13.5 km downstream of dam axis have been identified and were explored extensively to establish the suitability of the same for use as coarse and fine aggregate for concrete.
To meet the requirement (0.26 lakh cum) of impervious material, out of the three soil borrow areas identified, investigated and tested for suitability, one (i.e. Munli camp impervious soil deposit – DBC-1) located within a distance of 1 km upstream of dam axis has been selected. Epali impervious soil deposit (DBC-2) is proposed to be kept as reserve.
The requirement of 0.74 lakh cum of shell material shall be met from the excavated material from left side of Dam abutment (DBR-5).
The materials from these borrow areas/rock quarries were tested for their suitability as shell and impervious material, coarse and fine aggregate. The materials were tested in North Eastern Hydraulic and Allied Research Institute, Guwahati for physical and index properties. In addition, for evaluation of concrete aggregate for alkali aggregate reactivity potential, the representative samples from various borrow areas were tested in National Council of Buildings, Ballabhgarh using Mortar bar test. The location, distance with respect to dam axis and quantity available from these borrow areas/rock quarries / impervious is given in Map 8.1.
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The details of proposed borrow areas/excavated rock material for dam and underground structures, to be utilized given in Table 8.1.
Table 8.1: Proposed borrow areas/excavated rock material for dam and underground structures
Distance S. Index from Available Location Remarks No. No. Dam qty. axis (km) Shoal/Fan deposit 1. Aya Korong fan DBG-1 8.5 190.00 To be utilized for deposit coarse aggregate & crushed sand. 2. Eme river fan DBG-2 10.5 75.00 To be utilized for deposit natural & crushed fine sand. 3. Nizam Ghat DBG-3 13.5 130.00 To be utilized for shoal & Sirki coarse & crushed river/ fan sand. deposit Rock Quarry excavated material 4. Right bank Ilu DBR-1 5.0 100.00 Material suitable for Pani rock quarry coarse aggregate only. (u/s) 5. Left bank Ilu DBR-2 5.5 111.00 Pani rock quarry - Do- (u/s) 6. Excavated DBR-3 0.5 3.00 To be utilized for material of coarse & fine power house aggregate. cavern 7. Airi Pani rock DBR-4 2.5 163.50 Material suitable for quarry coarse aggregate only. 8. Excavated DBR-5 0 16.00 To be utilized for material from coarse aggregate and left side of Dam shell material only. abutment 9. Excavated DBR-6 0 16.00 To be utilized for material from coarse and fine right side of aggregate. Dam abutment Impervious borrow area 10. Munli camp DBC-1 1.0 0.28 To be utilized for core impervious soil material deposit 11. Epali impervious DBC-2 13.5 2.50 To be kept as reserve soil deposit at
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Distance S. Index from Available Location Remarks No. No. Dam qty. axis (km) Epali area
12. Yagang DBC-3 30.0 14.00 - impervious soil deposit at Yangang area
Coarse and fine aggregates For the construction of concrete dam, power house and other allied civil structure of the project about 193 lakh cum of coarse aggregate and 96.5 lakh cum fine aggregates will be required for production of concrete. Coarse, crushed sand and fine aggregate samples collected from river bed/fan deposit and rock quarry were tested for various physical parameters. Based on the test result, borrow areas and rock quarries have been selected and short listed for meeting the requirement of coarse and fine aggregates.
(A) Availability of concrete aggregate from Rock quarries The total requirement of 193 lakh cum of coarse aggregate can be met from DBR-1, DBR-2 & DBR-4 located 5.0, 5.5 and 2.5 km upstream of dam axis, containing estimated quantities of 100, 111 and 163 lakh cum respectively. However, all efforts shall be made to maximize the utilization of suitable excavated material from dam, powerhouse and HRT (DBR-3, DBR-5 & DBR-6) to reduce the extraction of material from quarries for coarse and fine aggregate.
It is pertinent to mention here that detailed tests reveal that material from major quarries viz. DBR-1, DBR-2 and DBR-4 located upstream of dam axis are not found suitable for use as fine aggregate and eventually the same shall have to be transported from the major downstream quarries viz.DBG-2 and DBG-1.
The entire rock quarries that were investigated for establishing the availability of suitable construction material are located within 5 km upstream of the dam defined by steep rocky escarpment within submergence. In view of steep gradient, large-
8-3 EMP Report of Dibang Multipurpose Project scale mining of the rock by blasting may cause instability problem around the reservoir rim, which is observed to be infested with number of active slides.
(B) Availability from riverbed/fan deposit Against the total requirement of 193 lakh cum coarse aggregate for the various structure, 168.5 lakh cum and 24.5 lakh cum of suitable coarse aggregate has been proposed to be utilized from DBG-1 and DBG-3 respectively, located downstream of dam axis.
Against the requirement of 96.5 lakh cum of fine aggregate, 75.0 lakh cum consisting of 20 lakh cum of suitable natural sand and 55 lakh cum suitable crushed sand have been estimated to be available from Eme river bed deposit (DBG-2). The balance 21.5 lakh cum suitable coarse material shall be made available for production of crushed fine aggregate from Aya Korang deposit (DBG-1).
It is observed that during monsoons, the active local nala such as Eme and Sirki brings down a large volume of riverine/nallah fan material each year and replenish the area. However, such additional quantity has not been considered at present while estimating available quantity of construction material. It is pertinent to be mentioned here that these borrow areas are formed due to a continuous draining of loose nallah fan material derived from the in situ rock occupying higher levels. Being distantly away from the active river channel, utilization of this material is not likely to affect the existing river dynamics adversely. On the contrary removal of the loose material from the up slope would possibly reduce spilling over of this material towards the river during rains when all the local nallahs are active. Therefore, it would invariably reduce the possibility and intensity of flash floods due to sudden chocking of the river caused by local blockages. Thus, material utilization of river borne/fan deposit from DBG-1, DBG-2 and DBG-3 has been proposed.
Impervious Soil Three identified borrow areas namely DBC-1, DBC- 2 and DBC-3 were considered for investigation exploration keeping in view the location, distance from the dam axis and availability of quantities. Impervious soil samples collected from these borrow area are tested for engineering and index properties for its suitability. Against the
8-4 EMP Report of Dibang Multipurpose Project requirement of 0.26 lakh cum for the construction of embankment of cofferdams, 0.28 lakh cum suitable material is proposed to be used from Munli camp borrow area (DBC-1) located at 1.0 km upstream of dam axis. DBC-2 is proposed to be kept as reserve.
Shell material The requirement of 0.74 lakh cum of shell material shall be met from the material from left bank (DBR-5).
8.2 STABILIZATION OF QUARRY SITES Most of the quarry sites are located upstream of the Dam which will be submerged after the commissioning of the project. Only two quarry sites i.e. Epali Impervious soil deposit site DBC -2 (located 13.5 km downstream of Dam between Aya Korong fan deposit and Eme river), and Yagang Impervious soil deposit DBC-3 (30 km downstream of Dam) will only require restoration (Maps 8.2 & 8.3).
8.2.1 Stabilization through Phytoremediation The quarry slopes after excavation of the construction material needs to be stabilized. It is suggested that quarry slopes should be maintained at a slope 1:1. The slope should then be covered with topsoil of at least 30 cm. It is suggested that for stabilization, grass, herbs & shrubs should be grown over these slopes.
Afforestation with suitable plant species of high ecological and economic value along with turfing by suitable grass species can be undertaken over the two quarry sites after providing required slope and laying top soil over the slopes. Wherever required proper engineering measures like construction of retaining wall etc. would also be constructed for proper slope stabilisation.
An area of 82 ha will be required to be restored through engineering and biological measures. The plantation could be proposed over 60% of the quarry area to be restored i.e 49.2 ha or say 49 ha. Remaining area i.e. 33 ha may be taken up for turfing. The budget earmarked for phyto-remediation of quarry sites is ₹ 189.62 lakh. The details are given in Table 8.2.
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Map 8.2: Epali Impervious Soil Deposit
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Map 8.3: Yagang Impervious Soil Deposit
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Table 8.2: Cost Estimate for Restoration of Quarry Sites
S. Amount Remedial measures proposed Rate (₹) No. (₹ in lakhs) 1. Plantation over 49 ha. 100,000 /ha* 49.00 2. Turfing over 33 ha 50,000/ha** 16.50 3. Retaining Wall of 15 m each 40,000/ 15 m 80.00 (200 Nos.) i.e. 3000 m length 4. Training of slopes including labour 30,000/ha 24.60 cost and laying down of top soil 5. Fencing over quarry areas (4000 r m) 350 / rm 14.00 Sub total 184.10 6. Contingency cost (3%) 5.52 Total 189.62
Notes: * The rate is inclusive of sapling cost, manure cost, nursery cost, labour cost, tending, weeding, etc. ** The rate is inclusive of sapling cost, manure cost, nursery cost, labour cost etc.
8.3 COST ESTIMATE FOR RESTORATION PLAN FOR QUARRY AREAS The total cost earmarked for restoration of quarry sites is estimated as ₹ 189.62 lakh.
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CHAPTER 9 LANDSCAPING AND RESTORATION OF CONSTRUCTION AREAS AND ENVIRONMENTAL MANAGEMENT IN ROAD CONSTRUCTION
EMP Report of Dibang Multipurpose Project
CHAPTER 9
LANDSCAPING AND RESTORATION OF CONSTRUCTION AREAS AND ENVIRONMENTAL MANAGEMENT IN ROAD CONSTRUCTION
9.1 RESTORATION OF CONSTRUCTION SITES Due to various construction activities viz., construction of working areas, office and residential complexes, etc. will disturb the natural environment of the project area. Engineering and biological measures are suggested for the stabilization and beautification of the disturbed area. Following measures should be adopted for the restoration and landscaping of colony areas and construction sites. 1) During the construction phase, proper roads and lanes would be provided inside the colony area. Open area in the colony and working area would be planted with various plant species. Ornamental plants and avenue plantation should be done along the roads and lanes and in open places in the colonies, offices, powerhouse area, dam area and adits. 2) Patch plantation may be done at all vacant sites in and around colony area, officers, adits, working areas etc. with plantation in 2-3 or even more rows wherever possible. 3) The choice of the tree species for plantation will depend on agro-climatic conditions of the area. 4) Retaining walls should be built to avoid landslides and slips. Proper drainage would be provided inside colony for the outlet of the domestic/rain water. 5) Parks and play grounds with all play implements will be developed in the colony areas during the construction phase and at vacant spaces after completion of the work. 6) Green areas would be developed in front of offices, hospital, officers club, field hostels, guest houses etc. during the construction phase.
9.2 POST PROJECT CONSTRUCTION LANDSCAPING After the completion of all the construction activity, the construction sites and other temporary settlements would be removed and area covered with the top soil to support the growth of plant species. These plant species which grow first are considered ecological pioneers and would initiate the process of succession and colonization. Areas close to colony and suitable areas will be landscaped to develop
9-1 EMP Report of Dibang Multipurpose Project children parks, gardens, skating ring etc. The maintenance of the area will be done by the project in O&M stage for the life of the project. Rest of the area will be vegetated and restored. A detail plan in this regard is to be formulated by consultant. A lump sum provision of ₹ 300 lakhs has been kept for this works.
9.3 COST ESTIMATE FOR RESTORATION OF COSNTRUCTION AREAS The cost for landscaping and restoration is estimated as ₹ 415 lakh. The details are given in Table 9.1. Table 9.1: Cost Estimate for Restoration of Construction Areas and Landscaping
S. Amount Item of Work No. (₹ lakh) A Colony Area, Office Complexes (i) Engineering measures (a) Retaining Walls 30.00 (b) Levelling the area 10.00 (ii) Bio-engineering measures (a) Covering the slopes with geo-textiles 15.00 (b) Mulching 10.00 (iii) Biological measures (a) Planting of trees and shrubs 35.00 (b) Planting of flowering plants and other herbs 15.00 Sub-total (A) 115.00 B Post project construction landscaping 300.00 Total 415.00
9.4 ENVIRONMENTAL MANAGEMENT IN ROAD CONSTRUCTION The approach roads will have to be constructed as a part of the access to the construction site. In a pristine and relatively undisturbed environment like Arunachal Pradesh, construction of roads disturbs the scenic beauty of the area. In addition, hilly terrain, landslides are often triggered due to road construction because of the loosening of rocks by water trickling from various streams. Steeply sloping banks are liable to landslides, which can largely be controlled by provision of suitable drainage. The basic principle is to intercept and divert as much water as possible, before it arrives at a point, where it becomes a nuisance. The other erosion hazard is that of surface erosion of the bank, which is best controlled by vegetation. However, in a steeply sloping terrain, difficulty lies in growing vegetation on steeply sloping
9-2 EMP Report of Dibang Multipurpose Project banks. Engineering solutions such as surface drainage, sub-surface drainage, toe protection and rock bolting can be used. Landslides can be stabilized by several methods - engineering or bio-engineering measures alone or a combination of these. The cost required for implementation of various measures has already been incorporated in the overall budget earmarked for construction of roads. In hilly terrain, road construction often generates significant quantity of wastes (muck) due to the stripping of the rocks to make way for the roads. The stripped muck is generally cleared by dumping the material along the slopes. These dumped materials finally flow down to the valleys and ultimately finds it way to the river. This practice is not acceptable and more systematic approach needs to be adopted. The stripped material will have to be collected and dumped in the designated muck disposal area which will have check dams to prevent the muck to flow down into the river. After disposal operation is complete at a dump site, the dump yard will be contoured and vegetated. A network of new roads is required to facilitate completion of the project as per anticipated time schedule. The various aspects to be considered while making the project road are briefly described in the following paragraphs:
9.4.1 Design - Where the road is in cutting, half cut and half fill type selection which involves least disturbance to the natural ground should be adopted subject to considerations of economy and road stability being satisfied. - The cut slopes should be made stable for the type of strata in the initial construction stage itself by adoption of appropriate slopes with benches, etc. including the use of stabilizing structures like breast walls, pitching, etc.
9.4.2 Construction - Area for clearing and grubbing should be kept to the minimum subject to the technical requirements of the road. The clearing area should be properly demarcated to save trees and shrubs and to keep tree cutting to the minimum. - Where erosion is likely to be a problem, clearing and grubbing operations should be so scheduled and performed that grading operations and permanent erosion control of features can follow immediately thereafter, if the
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project conditions permit; otherwise temporary erosion control measures shall be provided between successive construction stages. Under no circumstances, however, should very large surface area of erodible earth material be exposed at any one time by clearing and grubbing. - The method of balanced cut and fill formation should be adopted to avoid large difference in cut and fill quantities. - The cut slopes should be suitably protected by breast walls, provision of flat stable slopes, construction of catch water and intercepting drains, treatment of slopes and unstable areas above and underneath the road, etc. - Where rock blasting is involved, controlled blasting techniques should be adopted to avoid over-shattering of hill faces. - Excavated material should not be thrown haphazardly but dumped duly dressed up in a suitable form at appropriate places where it cannot get easily washed away by rain, and such spoil deposits may be duly turfed or provided with some vegetative cover.
9.4.3 Drainage - Drainage of the water from hill slopes and road surface is very important. All artificial drain must be linked with the existing natural drainage system for which separate detailed engineering survey may be carried out and planning done. - The surface drains should have gentle slopes. Where falls in levels are to be negotiated, check dams with silting basins should be constructed and that soil is not eroded and carried away by high velocity flows. - Location and alignment of culverts should also be so chosen as to avoid severe erosion at outlets and siltation at inlets
9.4.4 Grassing and Planting - Deforestation and road construction should be bare minimum and strict control must be exercised in consultation with the forest department. Equivalent amount of new trees must be planted as integral part of the project within the available land and if necessary, separate additional land may be acquired for this purpose.
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- Depending on the availability of land and other resources, afforestation of roadside land should be carried out to a sufficient distance on either side of the road.
9.4.5 Control of Landslides along the Roads Steeply sloping banks are liable to landslides, which can be controlled by drainage. The basic principle is to intercept and divert as much water as possible, before it arrives at a point, where it becomes a nuisance. The erosion hazard that of surface erosion of the bank is best controlled by vegetation, but the difficulty lies in growing vegetation on steeply sloping banks. Engineering solutions such as surface drainage, sub-surface drainage, toe protection and rock bolting can be used. Landslides can be stabilized by several methods – engineering or bio-technical measures alone or a combination of these.
9.4.6 Species Recommended for Plantation The list of floral species recommended for plantation is given in Table 9.2.
Table 9.2: Some important plant species for roadside plantations
Botanical name Family
Trees 1 Alangium chinense Alangiaceae 2 Artocarpus heterophyllus Moraceae 3 Bombax ceiba Bombacaceae 4 Butea monosperma Fabaceae 5 Castanopsis tribuloides Fagaceae 6 Cinnamomum tamala Lauraceae 7 Erythrina stricta Fabaceae 8 Morus indica Moraceae 9 Parkia timorina Mimosaceae 10 Terminalia bellirica Combretaceae Shrubs 1 Cassia tora Caesalpiniaceae 2 Caesalpinia bonduc Caesalpiniaceae 3 Clerodendrum viscosum Verbenaceae 4 Desmodium velutinum Fabaceae 5 Rosa sericea Rosaceae Herbs 1 Cymbopogon flexuosus Poaceae 2 Erangium foetidum Apiaceae 3 Houttuynia cordata Saururaceae
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4 Pennisetum purpureum Poaceae 5 Themeda arundinacea Poaceae 6 Urena lobata Malvaceae
9.4.7 Cost Estimate for Environmental Management in Road Construction An amount of ₹ 300.00 lakh has been earmarked for implementation of measures to mitigate adverse impacts due to construction of roads. The details are given in Table 9.3.
Table 9.3: Details of expenditure for implementation of measures for management of Impacts due to construction of roads
S. No. Item Cost (₹ lakh) 1. Construction of retaining walls 40.00 2. Stream bank stabilization 50.00 3. Provision of drainage system along roads 100.00 4 Carpeting the slopes with coir, jute or local fibres 20.00 5 Mulching 10.00 6. Roadside plantation, Jute matting etc. 20.00 7 Development of Nursery (4 ha) 10.00 8 Maintenance of Nursery (5 years) 25.00 9 Manpower to maintain the nursery 25.00 Total 300.00
9.5 RESTORATION OF COLONY AND OFFICE COMPLEX As a part of the project, land will be disturbed due to construction of colony area, office colony, crusher and batching plant and workshop etc. The following measures are recommended for the restoration and landscaping of colony areas and construction sites. Proper roads and lanes would be provided inside the colony area. Open area should be covered with vegetation. Ornamental plants and avenue trees should be planted along the roads and lanes. Retaining walls shall be built in areas prone to landslides slips. Proper drainage would be provided inside colony for disposal of sewage and storm water.
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After the completion of all the construction activity, the construction sites and other temporary settlements would be covered with the top soil from the quarry site which would support the growth of plant species. As a part of various project related activities it is also proposed to develop nature parks, Children parks, gardens, and other recreation facilities near the project area once the construction activities of the project are over. It is proposed to earmark a provision of ₹ 80 lakh for this purpose. An amount of ₹ 162.76 lakh has been earmarked for restoration of colony and office complexes. The details are given in Table 9.4.
Table 9.4: Cost required for restoration of Colony Area, Office Complexes Amount S. Item of Work Unit Quantity Rate/unit (₹ in No. lakh) (i) Engineering measures (a) Retaining walls cum 100 18000 18.00 (b) Leveling the area sq m 87500 25.0 21.88 (ii) Bio-engineering measures (a) Covering the slopes with geo- sq m 17500 150 26.25 textiles (b) Grass seeding ha 87.5 4000 3.50 (iii) Biological measures (a) Planting of trees and shrubs No. 10500 100 10.50 (b) Planting of flowering plants and No. 5250 50 2.63 other herbs (c) Construction of parks, playgrounds 80.00 etc. Total 162.76
9.6 COST ESTIMATE FOR LANDSCAPING & RESTORATION OF CONSTRUCTION AREAS AND ENVIRONMENTAL MANAGEMENT IN ROAD CONSTRUCTION Total cost estimate proposed for landscaping and restoration of construction areas and environmental management in road construction including restoration of colony and office complex is (₹ 415.00 lakh + ₹ 300.00 lakh + ₹ 162.76 lakh) i.e. ₹ 877.76 lakh.
9-7
CHAPTER-10 PUBLIC HEALTH DELIVERY SYSTEM
EMP Report of Dibang Multipurpose Project
CHAPTER-10 PUBLIC HEALTH DELIVERY SYSTEM 10.1 GENERAL The creation of a huge and an artificial water body will certainly change the micro- climate of the surrounding area, particularly raising the humidity levels. These changes are likely to reflect in creating conditions for human diseases directly and indirectly. Direct causes include water-borne diseases, while indirect causes include breeding grounds for carriers and vectors. Malaria could be the major vector-borne disease in the area.
The existing medical facilities in the around the project area are listed as below: District Hospital (at Roing) - 1 Community Health Centre - 1 Primary Health Centres - 3 Health Sub-centre - 7 Health Units - 1 Dispensaries - 2
10.2 MOSQUITO CONTROL MEASURES 10.2.1 Reservoir Operation The Reservoir basin should be cleared and prepared prior to filling for removing unwanted materials in the reservoir, which may lead to unhealthy condition giving rise to breeding ground to mosquito. It involves removal of trees, undergrowth, etc. and clearance of shoreline subjected to erosion to the extent to which the wave action is anticipated. It also involves clearance of mats of logs and other floating debris, so that it does not provide mosquito-breeding sites.
10.2.2 Residential Colonies for the Workers The site selected for habitation of workers should be properly planned and should not be in the path of natural drainage. Adequate drainage system to dispose storm water drainage and sewage water from labour colonies shall be provided.
Strict procedures will be followed in importing labour force from outside the state. Quarantine measures will be adopted and any possibility of importing any communicable diseases would be eliminated by keeping close vigil on the potential
10-1 EMP Report of Dibang Multipurpose Project carriers. A thorough medical screening of the labour population migrating in the area will be conducted.
10.2.3 Other Measures The project authorities would ensure that all preventive measures and norms are strictly enforced to avoid outbreak of any such eventuality. Surface sprays on the reservoir waters to eliminate breeding of disease bearing insects, like mosquitoes, etc. will be made from time to time. These sprays will be intensified particularly during hot and humid season. - Adequate vaccination and immunization facilities shall be provided for workers at the construction site. - The labour camps and resettlement sites shall be at least 2 to 3 km away from a main water body or quarry areas.
10.3.1 Traditional Medicinal Practices In the remote areas of Arunachal Pradesh the traditional medicinal practices are prevalent and the rural population used to adopt and get cured various illness by using the traditional medicines. These practices may be given a formal boost up by the project authorities by keeping at least one practitioner in the hospital. This kind of practitioner in rural terms is called “Bamunies”. By providing these facilities the rural population’s medicinal faith also will be kept intact.
10.4 DEVELOPMENT OF MEDICAL FACILITIES Labour colonies will be developed for the construction work. It is estimated that a population of about 5800 is likely to congregate during construction phase. The labour population will be concentrated at two or three sites. It is recommended that one Dispensary shall be developed at a site, which is easily accessible from the three labour colonies. The details of manpower, infrastructure requirement for this dispensary are given as below:
10.4.1 Manpower 2 Doctors of having M.B.B.S./M.D qualification can be employed in the dispensary and it is advisable that the doctors reside in the staff quarters adjacent to the dispensary. The Para-medical staff required for assistance to these doctors is given
10-2 EMP Report of Dibang Multipurpose Project in Table 10.1.
Table 10.1: Details of Para-medical staff for Dispensary
Para medical staff Numbers Auxiliary Nurses 5 Male Multipurpose Health workers 2 Attendants 2 Driver 2 Total 11
In addition to above, one dresser and health assistant shall also be posted at each first-aid post.
10.4.2 Proposed Health Facilities at Construction sites and labour camp It is possible that during the construction work, the technical staff operating different equipment is not only exposed to the physical strain of work but also to the physical effects of the environment in which they are working. The workers and other technical staff may come up with common manifestations such as insect bites, fever, diarrhoea, work exhaustion and other diseases, which they are suffering. In addition they may invariably come up with injuries caused by accidents at work site. Under all circumstances, workers need immediate medical care.
At least three first-aid posts are to be provided at each of the major construction sites, so that workers are immediately attended to in case of an injury or accident. This first-aid post will have at least the following facilities: - First aid box with essential medicines including ORS packets - First aid appliances-splints and dressing materials - Stretcher, wheel chair, etc.
The first aid post can be housed in temporarily erected structure and should be managed by one Health Assistant and assisted by one dresser/first aid attendant. Doctors from the dispensary can attend First Aid post regularly every day at a fixed time. Communication to establish link between the dispensary and then first-aid post, so as to enable doctors from dispensary to reach the work site in case of an
10-3 EMP Report of Dibang Multipurpose Project emergency shall be developed. The first-aid post shall have facilities such as fire fighting equipment; telephone connection, one vehicle or ambulance van for effective functioning.
10.5 SURVEILLANCE In water resources schemes it is imperative to develop a proper surveillance system. If facilities for diagnosis and treatment of parasitic diseases are available, then the data obtained should be reported systematically and reviewed at higher levels, where operational decisions on specific interventions can be made. The systematic surveillance may be followed as per the following:
10.5.1 Malaria control activities One of the doctors may be designated as “Medical Officer for Malaria” and will be permanently posted at the dispensary. It is suggested that the anti-malarial campaign be carried out under his immediate personal supervision. A systematic campaign should be conducted amongst the labour population in the months of March and September, which are the breeding months of mosquito. Surveillance for malaria is very important as during construction phase, stagnant pools for water, wastewater, etc. are created which can lead to greater incidence of malaria. One male multi-purpose health worker along with one attendant will visit the labour camps and surrounding areas once a fortnight and will inquire: - Whether there is a case of fever in the house - Whether there was a case of fever in the house between his previous visit and the present visit.
If the answer to either of these two questions is 'yes' then the health worker will collect a blood sample and a single dose of chloroquine (600 mg for adults and proportionate dose for others) as a presumptive treatment. The blood sample is then sent to laboratory at the dispensary for testing. If the test is positive then infected person is administered a course of Radical Treatment.
There shall be regular fumigation and sprays of insecticides in the areas where water is likely to be stagnant, to prevent the growth of malarial larvae. Expert opinion may be seeked by project authority before selecting the appropriate insecticide for
10-4 EMP Report of Dibang Multipurpose Project malaria control. The frequency of monitoring could be decided once the insecticide is selected. For this purpose a special van may be arranged.
10.5.2 Vaccination and Health Check-up Camps Regular health check-up will be held at the construction sites for the labourers in order to assess general health conditions and any other communicable diseases. Vaccination camps also will be held for the labourers as well as their family members in the labour colonies. A provision for adequate quantity of medicine distribution also will be kept for the requirement of the labourers. Sufficient stock of medicines also will be ensured for meeting the requirement in case of epidemic situation.
10.5.3 Health Extension Activities The health care activities proposed in the plan shall also be extended to the PAPs and the locals residing in project area. It is important to inculcate hygienic habits of environmental sanitation especially with respect to water pollution by domestic wastes. There would be possibility of the transmission of communicable diseases due to migration of labour population from other areas at the construction site. The doctors from dispensary will make regular visits to these villages and organize health promotional activities with the active participation of the local village leaders, NGOs and available local health functionaries. The health functionaries would undertake the following tasks as a part of health promotional activities: - Collect water samples to ascertain the potability of water from different sources so as to monitor regular disinfections of drinking water sources. - Surveillance of incidence of communicable diseases in these villages. - Maintain close liaison with the community leaders and health functionaries of different departments, so that they can be mobilized in case of an emergency.
10.6 COST ESTIMATE FOR PUBLIC HEALTH DELIVERY SYSTEM The expenditure involved in establishing a health care system will have two major components. One is the fixed cost of construction and other is the recurring cost. The total cost for implementation of various measures under Public Health Delivery System shall be ₹ 1021.34 lakh. The details are given as under:
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10.6.1 Fixed Cost (Non-recurring) Infrastructure (a) Dispensary The project authority has proposed to construct a hospital at the colony which will be located nearby the project site. The construction area proposed for the same is estimated as 1000 sq m (plinth area 500 sq m; double storey) and the estimated cost of cost of construction and land cost is ₹ 90 lakhs as per DPR.
(b) First-Aid Posts Three first-aid posts are proposed to be developed at appropriate locations so as to provide easy and immediate access to the laborers. The first-aid posts shall be built up only for the construction phase and hence may be of temporary nature and will be constructed with asbestos sheets, bamboo, etc. It will cost @ ₹ 2,00,000/First Aid Post. The total cost for constructing of three (3) First Aid Posts shall ₹ 6.0 lakhs.
(c) Miscellaneous i) ₹ 24,00,000/- for two (2) Vehicles (Closed Jeep) @ 12,00,000/- ii) ₹ 200,000/- Furniture etc. iii) ₹ 15,00,000/- for one (1) Van for mosquito control spray
10.6.2 Variable Cost (Recurring) Rate Amount S. No. Particulars (₹ per month) (₹ in lakh) a) Sprays for control of insecticides, 1,00,000 12.00 drugs and medicine b) Malaria control-dosage of 50,000 6.00 chloroquine, spray for mosquito control, blood testing etc. Sub-total (A) 18.00 c) Expenditure in manpower utilization 1) Doctors (2 Nos.) 1,00,000 24.00 2) Nurses (5 Nos.) 30,000 18.00 3) Multipurpose health workers 30,000 7.20 (2 Nos.) 4) Health workers / attendants 15,000 3.60 (2 Nos.) 5) Drivers (2 Nos.) 15,000 3.60
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6) Health assistants (3 Nos.) 20,000 7.20 7) Dressers (3 Nos.) 10,000 3.60 Sub-total (B) 67.20 Total (A) + (B) 85.20
Note: For salary, the rules of State Government shall be followed.
10.6.3 Overall Expenditure
S. No. Particulars Amount (₹ in lakh) Non-recurring Expenditure 1. Infrastructure (Construction of 3 First Aid Posts) 6.00 2. Vehicles 39.00 3. Furniture 2.00 Sub-total (A) 47.00 Recurring expenditure 1. Expenditure for 1 year 85.20 2. Expenditure for 8 years with 10% escalation per year 974.34 Sub-total (B) 974.34 Total (A + B) 1021.34
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CHAPTER 11 PLAN FOR SOLID WASTE MANAGEMENT PLAN & SANITATION FACILITIES IN LABOUR CAMPS
EMP Report of Dibang Multipurpose Project
CHAPTER 11 PLAN FOR SOLID WASTE MANAGEMENT PLAN & SANITATION FACILITIES IN LABOUR CAMPS
11.1 INTRODUCTION The residential colonies of the Dibang project will be located on the right and left bank of the Dibang River. The colonies will be of two types, one for the NHPC employees and their families, with an approximate population of 800, and, the other for labourers, with an approximate population of 5000 (peak labour requirement). In addition to this, during construction stage it is expected that about 100-200 people from nearby villages will visit project site every day for commercial purposes and constitute the regular floating population. This floating population may also generate solid waste.
11.2 QUANTITY OF SOLID WASTE GENERATION The quantity of waste generated in Indian cities reported to be in the range of 0.2-0.6 kg/capita /day as per the “Manual on Solid Waste Management” prepared by Central Public Health & Environment Engineering Organisation (CPHEEO), Ministry of Urban Development, Govt. of India. The Waste Generation pattern is very much dependant on the living style of the population. As the major share of the population is labour force will stay in Dibang, the waste generation factor of 210 g/capita/day has been taken into consideration.
Solid waste generation will be the leading problem among the negative impacts assuming that huge quantity of municipal waste that would be generated from residential colony, labour camps and office buildings when the project is constructed. Huge amount of sewage will also be generated from the similar sources during the construction and operation phase of the proposed project. The major generation sources for sewage and municipal wastes would be as follows: Municipal waste from residential colony, labour camps, office buildings Sewage from residential colony, labour camps, office buildings Hazardous wastes (i.e. Bio-Medical wastes) from primary health centre and hospitals
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It is also expected that if proper management measures for solid waste are not adopted, it will degrade the nearby environment, create hazards for labour and staff that would be posted in the project area during construction/ operation period of the project. Therefore, all the problems due to origination of solid waste require proper management facilities. The types of wastes, its composition and major generation sources during the construction/ operation of proposed Project are indicated in Table 11.1.
Table 11.1: Expected typical composition of waste in proposed project Sources of waste Waste Type Composition of waste generation Municipal waste Food wastes, plastics, paper, From residential and sewage, glass, vegetables waste. labour camp areas Construction waste Empty cement begs, dust, debris, From construction site demolition and construction and crusher etc. wastes, scrap, dust and ashes etc. Bio-medical waste Syringes, cotton, bandages, glass From primary health tubes, etc. centres.
11.3 COMPOSITION OF MUNICIPAL SOLID WASTES The composition of garbage in India indicates lower organic matter and high ash or dust contents. It has been estimated that recyclable content in solid waste varies from 13 to 20% and compostible materials is about 80-85%. A typical composition of municipal solid waste is given below in Table 11.2.
Table 11.2: Typical composition of municipal solid wastes expected in the proposed project Description Percentage by weight Vegetable, leaves 40.15 Grass 3.80 Paper 0.81 Plastic 0.62 Glass/ceramics 0.44 Metal 0.64
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Description Percentage by weight Stones/ashes 41.81 Miscellaneous 11.73 Source: Central Pollution Control Board
Chemical composition of solid waste is another important aspect for evaluating alternative processing and energy recovery point of view. The details of typical chemical composition of municipal wastes in India are given in Table 11.3.
Table 11.3: Chemical components of municipal solid wastes expected in the proposed project
Component C (%) H (%) O (%) N (%) S (%) Ash (%) Food wastes 48 6.4 37.6 2.6 0.4 5 Paper 43.5 8 44 0.3 0.2 6 Card board 44 5.9 44.6 0.3 0.2 5 Plastic 60 7.2 22.8 - - 10 Textiles 55 6.6 31.2 4.6 0.15 2.5 Rubber 78 10 - 2 - 10 Leather 60 8.0 11.6 10 0.4 10 Garden trimming 47.8 6 38 3.4 0.3 4.5 Wood 49.5 6 42.7 0.2 0.1 1.5 Dirt, ashes, brick etc 26.3 3 2 0.5 0.2 68 Source: Central Pollution Control Board
11.4 ADMINISTRATIVE SET UP Administratively, a Solid Waste Management Committee (SWMC) comprising of the project representatives will look after the management of solid waste. The SWMC may comprise of the following:
- In-charge of civil works, at least of the rank of Senior Manager/Manager (1 No.) - Supervisors/JEs (2 Nos.)
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The SWMC will be supported by sanitary workers, sweepers etc., the number of which may be decided by the SWMC after assessing the work requirement.
11.5 SOLID WASTE MANAGEMENT PLAN A solid waste management system works on four basic principles viz. segregation & primary storage at the source, collection, transportation, treatment and disposal.
11.5.1 Segregation at source Segregation of waste is one of the critical activities in the Solid Waste Management as it saves undue efforts on transportation and disposal of recyclable or inert wastes. The segregation of such wastes, before they are transported to the processing/ disposal site, should be carried out. Waste segregation cannot be introduced without public awareness and should be implemented in a phased manner. In order to achieve this, the following strategy may be adopted for promoting public awareness: i. The residents shall be educated about appropriate use of biodegradable waste like kitchen & garden wastes. ii. Extensive awareness campaigns have to be organized by SWMC for educating the public on the aspects related to impacts of solid waste on environment and health, ill effects of littering and burning of wastes, segregation of municipal solid wastes, proper primary storage within their house premises, etc. The awareness can be spread through posters, distribution of pamphlets etc. SWMC may involve NGOs for organizing awareness programs at project school, hospital etc. iii. Residents may be advised to develop the habit of segregating the biodegradable waste material like kitchen and garden waste and store in a separate bag or a bin installed at their respective houses. The SWMC would educate its sanitary workers about the revenue earning potential of recyclable waste and various options to earn revenue. The sanitary workers should be advised to collect such waste separately. To encourage collection of recyclables, SWMC may think of devising a plan which can provide some revenue opportunities for the sanitary workers. Market potential with respect to the forward linkages for effective disposal
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of recyclable waste is to be identified and exploited by the SWMC for the purpose. Collection and segregation of hazardous wastes from the workshops viz. used batteries, transformer oil, used oil, metal scraps etc. and selling them to CPCB registered vendors having Environmentally Sound Management (ESM) system. The operator of waste processing/disposal facility should be advised to carry out inspection of waste received to further segregate recyclables and sell them to recyclers. If it is not feasible to segregate recyclables on their own, the processing/disposal facility operator may allow registered scavengers to enter the premises of the compost plant and pick recyclable waste. This would ensure reduction in rejects, reducing burden on processing plant as well as landfill. SWMC may register the names of recyclers for the recyclables such as plastics, newspapers, glass, metals etc. from residential and commercial sources and the names of registered recyclers should be published or made known to the public residing in the project / labour colonies / labour sheds. SWMC may associate and involve residents, shop owners, hospital & school staff and NGOs/ Voluntary Organizations of the area working in the field of waste management in increasing awareness among the people to segregate recyclable material at source and hand it over to a designated waste collector identified by SWMC.
11.5.2 Primary Storage of Wastes It is recommended to segregate waste into two categories & store the segregated wastes in two different containers: One container (Green Coloured) for the “Biodegradable Waste” or the “Wet Waste” Other container (Blue Coloured) for the “Non-biodegradable Wastes” or the “Dry Waste”. Wet waste (Biodegradable) includes the following:
11-5 EMP Report of Dibang Multipurpose Project
Kitchen waste including food waste of all kinds, cooked and uncooked, including eggshells and bones Flower and fruit waste including juice peels and house-plant waste Garden sweeping or yard waste consisting of green/dry leaves Sanitary wastes Green waste from vegetable & fruit vendors/shops Waste from food & tea stalls/shops etc. Dry waste (Non-biodegradable) includes the following: Paper and plastic, all kinds Cardboard and cartons Containers of all kinds excluding those containing hazardous material Packaging of all kinds Glass of all kinds Metals of all kinds Rags, rubber House sweeping (dust etc.) Ashes Foils, wrappings, pouches, sachets and tetra packs (rinsed) Discarded electronic items from offices, colonies viz. cassettes, computer diskettes, printer cartridges and electronic parts. Discarded clothing, furniture and equipment The wet and dry wastes are to be stored in two different containers as mentioned above. As the biodegradable waste degrades and generates liquid, it is advisable to use non-corrosive container with lid for the storage of bio- degradable/wet waste. A Green coloured container of 10 liters capacity for a family of about 5-6 members would generally be sufficient for wet waste. However, it is advisable that a household should keep larger container or standby container to store the additional wastes produced in 24 hours. The household may have a spare capacity of 100% to meet unforeseen delay in clearance or unforeseen extra loads. Dry waste can be stored in another Blue coloured container of 10-12 litre capacity or plastic bag/Jute Bag/plastic/polymer containers.
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The containers are to be procured by SWMC and provided to individual households in the project colonies & labour colonies/camps. Some containers of bigger capacity (0.5 m 3) will also be kept at public places, as community bins, like offices, workshops, shops, community centre, school, canteens/ mess, guest houses etc. The places where community bins have to be placed away from drinking water sources and preferably on elevated areas where water stagnation is not there during rainy days. For the project hospital, separate storage bins are to be arranged, the wastes of which are to be disposed of through incinerators. In addition to the above wastes, another type of waste called “Domestic Hazardous Waste” may also be generated at household level. These include used aerosol cans, batteries, household kitchen and drain cleaning agents, car batteries and car care products, cosmetic items, chemical-based insecticides/rodenticides, light bulbs, tube-lights and compact fluorescent lamps (CFL), paint, oil, lubricant and their empty containers. These wastes are to be stored separately, whenever generated and sold for recycling or handed over to the sanitary workers who come for house-to-house collection. To enforce successful implementation, necessary rules/by-laws should be framed by SWMC to make segregation and storage at source compulsory and also to avoid littering and burning of wastes at the project sites.
11.5.3 Collection of Solid Wastes It is recommended to have a mechanism for door to door collection of waste from the staff/ labour colonies and labour sheds. The sanitary workers / sweepers) will have tricycle with containers or containerized handcarts having ringing bell and will go for waste collection from individual house at a fixed time every day. The sanitary workers would ring the bells at the time of reaching the particular area/locality, giving a signal for waste collection to the residents. In labour colonies also, the door-to-door collection of waste would be carried out. The containerized rickshaws or handcarts would be employed for collection of wastes. The labourers should be strictly advised to store the wastes in available plastic containers of suitable size. The waste bins
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including community bins are to be cleaned daily by the sanitary workers at an informed timing. During collection of wastes from the bins, care shall be taken to avoid waste spillage and it shall be the responsibility of the sanitary workers to clean & maintain hygienic conditions at the places where community bins are kept.
11.5.4 Waste Handling As per Municipal Solid Waste (Solid Waste Management & Handling) Rules, 2000; the manual handling of waste has to be avoided. As per the recommended system, the waste from their source of generation is either collected by sanitary workers during door-to-door collection from the colonies or from community bins. The sanitary workers, after primary collection, will transport the waste to the storage depots from where it will be lifted by dumper placers and transported to the processing & disposal sites. The community bins of size 0.5 m3 are to be lifted manually and unloaded into the containers kept in the transportation vehicles. The sanitary workers involved in manual lifting are to be provided with gloves and masks and shall be instructed to use them compulsorily while handling waste. It will be the responsibility of the sanitary supervisors to monitor the proper use of personnel protective equipment by the workers.
11.5.5 Transportation of Solid Wastes It is recommended to use tricycles/push carts/containerized handcarts, for primary collection of waste from the individual households, offices and other public places, as described above, up to the waste storage depots. The sufficient number of tri-cycles / push carts/containerized handcarts shall be arranged for effective door-to-door collection system. The wastes collected from the street sweeping and drain cleaning is to be shifted to the waste storage depots using tricycles/handcarts. The transportation of waste from the waste storage depots to the processing and disposal sites will be done in the covered trucks/dumpers etc. so that the waste is not exposed to the human population and there is no spillage of waste on the roads during transportation.
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To take care of certain unavoidable circumstances, if it is required to lift waste from some open place, front-end loaders and tractor trolleys may be used. However, the waste in tractor trolley has to be covered with LDPE sheet during its transport.
11.6 DISPOSAL OF SOLID WASTE (NON-DEGRADABLE PORTION) As per the requirements of the Municipal Solid Waste (Solid Waste Management & Handling) Rules 2000, land filling would be restricted to non-biodegradable, inert waste and other waste that are not suitable either for recycling or for biological processing. Land filling shall be done following proper norms and landfill sites shall meet the specifications as given in these rules. The quantum of solid waste to be disposed for landfill is given in Table 11.4.
Table 11.4: Estimation of Quantity of waste to be disposed to landfill S. No. Description Data 1. Per capita MSW generation at present 0.21 kg per capita per day 2. Population during construction stage of the project 5800 3. Total Solid Waste (SW) generation at the rate of 1218 kg/day 0.21 kg/capita/day 4. Considering the fraction of bio-degradable waste 548 kg/day as 45 % of total SW generated, total quantity of bio-degradable waste to be generated (for vermi- composting) 5. Inorganic waste for disposal (48% of total waste) to 585 kg/day landfill (considering that recyclable waste in form of paper, glass, metals, plastic etc. constitute 7 % of total waste) 6. Quantity of rejects generated from the compost 165 kg/day plant to be disposed to landfill, assuming the rejects as 30% of waste going to compost plant 7. Hence total waste to be disposed in landfill at 750 kg/day
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S. No. Description Data present 8. Waste to be disposed to landfill, annually 274 tons/year 9. Waste to be disposed to landfill in 8 years 2192
The details of landfill site are given as below: Length 32 m Width 20 m Depth of fill 5 m
A provision of 15% of the total area, for accommodating infrastructure facilities has also been included while working out requirement of space. The liner system will comprise of the following layers below the waste: 0.30 m thick drainage layer comprising of coarse sand or gravel (stone dust with no fines) 0.2m thick protective layer of sandy silt 1.50mm thick HDPE geomembrane 1.0 m thick clay layer/amended soil layer, amended soil layer comprising of local soil + bentonite is to be provided).
11.7 TREATMENT OF SOLID WASTE (DEGRADABLE PORTION) Considering the fraction of bio-degradable waste as 45 % of total SW generated, total quantity of bio-degradable waste to be generated (for vermi-composting), which amounts to about 0.8 m3/day. The vermi-composting the process takes around 60 days to mature. Thus the total capacity of pits required would be (60 X 0.8) 48 cu m.
A pit of 2 m x 1.5 m x 1.3 m deep (0.3m freeboard) size can take 3.0 cu m of compostable waste. Thus the no. of pits required shall be 16. The total area will be almost three times the pit area as some area in between pits will be required for transportation and stacking of waste. Hence, total area required will be 150 m2. The pits will be covered with GI sheets. Additional 80 sq m would be kept for storage for compost plus screening and other activities.
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The pits to be constructed will have around 25 cm of bottom lining consisting of about 5 cm thick stone grit over which 15 cm thick coarse sand followed by 15 cm thick earth lining will be done. The refuse along with animal dung will have to be laid in layers of 5 to 10 cm thickness. The pit will be then watered on alternate days. Thereafter waste is laid in 5 to 10 cm thick layers twice in a week till the whole pit is filled up. Every week the waste will need to be turned up and water will have to be sprinkled every day to keep adequate moisture. The process will take around 45 to 60 days where after the composted waste from the pit is taken out and after drying it is screened with screens having 2 mm diameter holes. The screened compost would be filled in plastic bags and used as good manure especially for cultivation of vegetables and flowers.
11.8 SANITATION FACILITIES IN LABOUR CAMPS
11.8.1 INCREASE IN LABOUR POPULATION The project construction is likely to last for a period of 8 years. About 800 technical staff and 5000 labour population shall be involved in construction phase. The total increase in population shall be about 5,800. The aggregation of large number of workers in the project area during the construction phase is likely to put considerable stress on the prevailing biotic and abiotic environment of the area. The stress could be on account of increased water demand, sewage and solid waste generation, fuel requirements etc. The aim of this EMP is to minimize these stresses.
11.8.2 FACILITIES IN LABOUR CAMPS a) Housing It shall be made mandatory for the contractor involved in the construction activities to provide adequate facilities for water supply and sanitation. It is recommended that the contractor provides living units to each of the labour family involved in the construction activities. The units should have proper ventilation. b) Water supply As mentioned earlier, about 5800 workers and technical staff (including family) are likely to congregate during project construction phase. The domestic water
11-11 EMP Report of Dibang Multipurpose Project requirement of the labour/employee population is expected to be of the order of 0.41 mld @ 70 Ipcd. Appropriate water supply sources need to be identified. Proper infrastructure for storage and if required treatment e.g. disinfection or other units, shall also be provided. c) Sewage treatment The domestic water requirement shall be of the order of 0.41 mld. It is assumed that about 80% of the water supplied will be generated as sewage. Thus, the total quantum of sewage generated is expected to be of the order of 0.33 mld. The BOD load contributed by domestic sources will be about 261 kg/day. The sewage generated from labour camps shall be treated prior to disposal.
The labour population is proposed to be situated in existing colonies. One community toilet shall be provided for 20 persons. The sewage from the community toilets can be treated in a Sewage Treatment Plant (STP) comprising of aerated lagoon and secondary settling tank. The treated sewage can be used for meeting irrigation requirements of areas being afforested under greenbelt development. The total cost required for implementation of sanitation facilities in labour camps shall be ₹ 166 lakh. The details are given in Table 11.5.
Table 2.1: Cost estimate for sanitation facilities in labour camps
Item Unit Number Total cost (₹ in lakh) Community toilet ₹ 40,000/community toilet 290 116.00 Aerated lagoon & Lump sum 50.00 Secondary settling tank Total 166.00
The dimensions of the various units of sewage treatment plant are given as below:
Aerated lagoon Length : 40 m Width : 16 m Depth : 3 m
Secondary Settling tank Diameter : 4.0 m Depth : 2.5 m
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11.9 GENERAL SANITARY MEASURES Sweeping of Streets, Public Spaces & Drain Cleaning
In the project colonies, office complexes etc. sweeping should be carried out by the sanitary workers daily. Sweeping should be carried out between 6 to 8 am in the morning and between 2 to 4 pm in the afternoon. The Sanitary workers will be allotted some specified area and after sweeping they would collect the waste in the form of heaps on the street side. These heaps would be loaded into handcarts and these handcarts will be emptied at waste collection points. For proper solid waste Solid Waste Management, suitable tools, equipment & vehicles in sufficient numbers are necessary for handling, lifting and transportation of waste. The equipment required for Solid Waste Management are mentioned under cost estimation table.
The sanitary workers involved in drain cleaning may be given tools like seamless handcarts and shovels. It is also recommended to maintain separate roster for cleaning of drains.
Burning of waste causes hazardous/toxic gaseous pollutants and must be avoided. The SWMC will discourage burning of waste along the roadside and/or on public places.
11.10 COST ESTIMATE FOR SOLID WASTE MANAGEMENT PLAN The total cost required for solid waste management is ₹ 554.78 lakh. The details are given in Table 11.5.
Table 11.5: Cost Estimate for Solid Waste Management and Sanitation Facility in Labour Camps
S. No. Item Cost (₹ in lakh) 1. Waste bins & Community Bins 2.00 2. Waste Storage Depots 2.50 3. Vehicles 7.00 4. Cost of land for land filled vermin-composting sites 30.0 5. Reclamation and stabilization cost of landfill and 15.0 vermin-composting sites 6. Two covered trucks for conveyance of solid waste to 120.0 landfill and vermin-composting site @ ₹ 3 million per
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S. No. Item Cost (₹ in lakh) truck 7. Manpower cost for 10 persons @ ₹ 10,000/ month for 137.28 8 years including 10% escalation/year 8. 05 tractors with trolleys @ ₹ 500,000/ per tractor with 25.0 trolley 9. Awareness programme 10.0 10. Water facility & Toilet facilities at landfill and vermin- 8.0 composting site 11. Tools & Implements 10.0 12. Yard lighting maintenance store room lighting, 2.0 Monitoring station @ 5000 / fixture x 40' 13. Periodical Training & Medical Check-up 20.0 14. Sanitation Facilities in Labour Camps 166.00 Total 554.78
11-14
CHAPTER 12 SAFETY PRACTICES DURING CONSTRUCTION PHASE
EMP Report of Dibang Multipurpose Project
CHAPTER 12 SAFETY PRACTICES DURING CONSTRUCTION PHASE
12.1 INTRODUCTION The following aspects have been covered in this chapter: Traffic management during construction phase Measures to be taken during excavation of earth Safety practices during construction phase Fire protection in labour camps and staff colonies
12.2 TRAFFIC MANAGEMENT DURING CONSTRUCTION PHASE Temporary diversions will be constructed with the approval of the Engineer. Detailed Traffic Control Plans will be prepared and submitted to the Engineer for approval, at least 5 days prior to commencement of works on any section of road. The traffic control plans shall contain details of temporary diversions, details of arrangements for construction under traffic, details of traffic arrangement after cessation of work each day, safety measures for transport of hazardous material and arrangement of flagmen.
The Contractor will ensure that the diversion/detour is always maintained in running condition, particularly during the monsoon to avoid disruption to traffic flow. He shall inform local community of changes to traffic routes, conditions and pedestrian access arrangements. The temporary traffic detours will be kept free of dust by frequent application of water.
12.3 MEASURES TO BE TAKEN DURING EXCAVATION OF EARTH While planning or executing excavation the contractor shall take all adequate precautions against soil erosion, water pollution etc and take appropriate drainage measures to keep the site free of water, through use of mulches, grasses, slope drains and other devices. The contractor shall take adequate protective measures to see that excavation operations do not affect or damage adjoining structures and water bodies.
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The recommended measures are listed as below: Ensure unobstructed natural drainage through proper drainage channels / structures. Dispose surplus excavated earth at identified sites. Ensure minimum hindrance to locals. All excavations will be done in such a manner that the suitable materials available from excavation are satisfactorily utilized as decided upon beforehand. The excavations shall conform to the lines, grades, side slopes and levels shown in the drawings or as directed by the engineer.
12.4 SAFETY PRACTICES DURING CONSTRUCTION PHASE The Contractor is required to comply with all the precautions as far as possible for safety of the workers. The contractor will supply all necessary safety appliances such as masks, ear plugs, etc., to the workers and staff. The contractor shall comply with all regulation regarding, working platforms, excavations, trenches and safe means of entry and egress.
In order to guarantee construction safety, efficient lighting and safety signs shall be installed on temporary roads during construction and adequate traffic regulations shall be adopted and implemented for temporary roads.
12.5 FIRE PROTECTION IN LABOUR CAMP AND STAFF COLONIES It has been envisaged that the fire protection planning shall be taken up in the following manner: a) Construction of Camps etc. and placement of fire protection equipment.
It has been planned that all facilities to be constructed shall be fully equipped with the fire protection equipments as per IS standards. The analysis of fire hazard in the construction of labour camps, colonies and other facilities along with management measures is summarized in Table 12.1.
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Table 12.1: Analysis of fire hazard in the construction of labour camps, colonies and other facilities
S. Stage Potential hazard Remedial Measures No 1. Construction Fire prevention and By Water Resources Department of Camp/ firefighting not While construction of Field hostels, colony considered in design Guest House/office and other In adequate fire facilities owned by NHPC Ltd. protection measures The project proponent shall provide during construction the fire protection system as per IS Standards for Fire code. Proper housekeeping will also be ensured and maintained during these facilities to protect them from any fire related incidents. It will be ensured that the firefighting equipment are placed at common place also including work place preferably within 15 meters of work place. By Contractors Clear term of reference will be given to contractor at tendering stage for incorporating fire code as per IS Standard. Firefighting equipment will be placed at all common places ( within 15 meters of work place)
b) Maintenance of fire protection equipment as the safety measures thorough dedicated EHS Team.
During construction, it has been envisaged to set up fully fledged Environment Health & Safety (EHS) department reporting directly to Head of the Project. This department shall also take care of the adequacy of Fire Safety measures set up in all facilities created either owned by NHPC Ltd. or any of its Contractors. The analysis of responsibility for this EHS team in respect of Fire protection system is outlined in Table 12.2. Table 12.2: Analysis of responsibility for this EHS team S. Stage Potential hazard Remedial Measures No 1. During Fire incident due to Residential complex will be Occupation electrical short constructed as per the approved circuit/LPG design and will be checked for
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S. Stage Potential hazard Remedial Measures No Leakage/ Improper completeness on fire aspect before handling of allotment to residents flammable Each Block Colony/ camp will be liquids/lack of provided with rated estimated trip precaution off circuit braker will be installed on Improper access to each block. and from the All residents are made aware of fire location hazard by training, regular In adequate fire campaigns and by placing posters fighting and signs arrangements LPG Cylinders/Flammable liquids Lack will stored at designated storage communication area . The storage will be well Lack of Knowledge protected, ventilated with adequate on fighting fire and provision of fire equipment. handling fire Each bloc of the colony will be equipment provided with 10 kg DCP fire Inadequate extinguishers. Emergency Additionally fire point containing fire response buckets, CO2 extinguishers, DCP Extinguisher will be provided at the common place covering four residential blocks in labour Camp. Placement of written posters of preventive measures in each accommodation block Regular EHS inspection of the camp site Placement of placard of emergency numbers to be contacted in case of Emergency Dedicated phone line will be provided in labour camps for effective communication. Ensure proper access is maintained around and to the residential blocks Identification of emergency Muster points at safe distance
Responsibility Project In charge is responsible for implementation of plan through his authorized representative on site. Site EHS Team shall monitor the implementation of plan and report non-compliance to site management.
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Training and awareness Training of employees on fire prevention and firefighting is important to prevent occurrence of fire incident in project area. All employees will be given brief overview of fire prevention, firefighting procedure and response process at the time EHS Induction training. Project proponent will also carry out regular campaigns on fire prevention around the site. EHS Department is responsible for providing required training.
12.6 COST ESTIMATE FOR SAFETY PRACTICES DURING CONSTRUCTION PHASE Implementation of this plan will be mandatory for all contractors. Requirements of this plan will be part of contract agreement.
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CHAPTER 13 ENERGY CONSERVATION MEASURES
EMP Report of Dibang Multipurpose Project
CHAPTER 13 ENERGY CONSERVATION MEASURES 13.1 INTRODUCTION Various construction and other activities of the proposed Dibang Multipurpose Project would lead to increased demand for fuel wood and fodder in the project area and its vicinity and would therefore exert pressure on forest areas located around the project. The major source of energy in the villages of the project area is fuel wood, acquirement of which is one of the main causes of ecological degradation and human drudgery. It is estimated that during the construction of the project, which would last for about 8 years, around 5800 labourers (including their family members) will be working. Majority of the labour force will be outsiders and it will be very important to meet their energy requirement in an ecologically sustainable manner.
To provide an alternate for the energy requirement of the workers, contractor/s will be made responsible to provide subsidized kerosene/LPG to their workers which will in turn discourage them from illegal tree felling and removal of fuel wood and timber from the adjoining forests. Further, community kitchen facilities would also be provided to the labourers by the contractors. In addition to above, efforts would be made towards energy conservation by installing non-conventional energy sources as discussed in the subsequent paragraphs.
13.2 ENERGY CONSERVATION DURING CONSTRUCTION PHASE 13.2.1 Construction of LPG depots & LPG Connection Wood is main source of energy in affected villages. To minimize the pressure on the adjoining forests from illegal felling and removal of timber the Project Authority, as a part of the contract, will make it mandatory for the contractors to provide community kitchen facilities to their labourers. The fuel used for cooking in these kitchens shall be LPG. However, there will be a small percentage of labour population who will be employed by small contractors. It will not be possible for these small contractors to run community kitchen for the labour employed by them. The project authorities are suggested to establish a LPG depot near project area and would provide one time grant to poor labourer families as well as households of affected villages for LPG connection including stoves. The depot would fulfil the requirement of about 2000
13-1 EMP Report of Dibang Multipurpose Project connections (1000 labourer families and about 1000 affected families). For construction of LPG depot budget has been kept under K-Building of DPR. Total budget for LPG connections to 2000 families @ ₹ 5000 per family would be ₹ 100.00 lakhs.
13.2.2 Other Energy Conservation measures during construction phase The following energy conservation measures would be undertaken during construction works: Efficient work scheduling and methods that minimize equipment idle time and double handling of material Throttling down and switching off construction equipment when not in use Switching off truck engines while they are waiting to access the site and while they are waiting to be loaded and unloaded Switching off site office equipment and lights and using optimum lighting intensity for security and safety purposes Careful design of temporary roads to reduce transportation distance Designing roads on site to reduce transportation distances. Regular maintenance of equipment to ensure optimum operations and fuel efficiency The specification of energy efficient construction equipment.
13.3 ENERGY CONSERVATION DURING OPERATION PHASE The following energy conservation measures would be implemented during operation phase: Use of CFL lights up to maximum possible extent. Awareness about the use of CFL lights by locals. Employing renewable energy sources such as day lighting and passive solar heating.
13.4 ENERGY SAVING MEASURES FOR POPULATION IN STUDY AREA 13.4.1 Distribution of Kerosene oil stoves Conventional Kerosene oil Stoves is a good substitute for fuel wood and it is proposed
13-2 EMP Report of Dibang Multipurpose Project that kerosene oil stoves would be distributed amongst the workers and the locals in the affected villages. Total budget for distribution of 2000 kerosene oil stoves @ ₹1000 per stove would be ₹ 20.00 lakh.
13.4.2 Distribution of Pressure Cookers The distribution of the pressure cookers may also be taken as one of the attractive option for energy saving. The energy required for food preparation in pressure cookers is less than conventional cooking in pot. Therefore, to save burning of firewood, pressure cookers would be given at subsidized rates to the labourers for cooking needs. It will also help in reducing energy consumption. The total budget for distribution will be ₹ 20.0 lakh.
13.4.3 Solar Cookers Solar cookers utilize sunrays, one of the abundant sources of pollution free natural energy. Barring cloudy days in rainy season, it can be used in sunny days to cook and thereby conventional fuels to a significant amount. It, however, supplements the cooking fuel and cannot replace it in total. Solar energy is abundantly available in India. On clear sunny days, it is possible to cook noon meal for 4 to 5 people in a normal Box solar cooker and if one desires either full or part evening meal could also be cooked in it. Concentrating Cookers can cook food for large number of people faster than box solar cookers.
Solar cookers are available both with and without electrical back up in different sizes and features. These can be procured from manufacturers /suppliers/district and head offices of state agencies. Cooker with an electrical back up has the advantage of cooking food during non-sunshine hours/cloudy days with very nominal consumption of electricity. The cost of the cooker is of the order of ₹ 5000 depending on its size and features. A normal size family cooker is sufficient for a family of 4 to 5 members. It has a life of 15 to 20 years and pays back the cost in 3 to 4 years. Community box solar cookers are also being manufactured by some of the manufacturers, which can cook food for 20 to 25 people. The total budget for distribution of 500 solar cookers @ ₹5000 per cooker for PAFs / locals would be ₹ 25.00 lakh.
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13.4.3 Installation of Improved Chulhas Improved chulhas are scientifically designed for optimal regulation of heat flow and better fuel utilization. Improved chullhas not only economies fuel wood consumption but also help in keeping the house clean, i.e. free from smoke and also help in preventing eye ailment due to smoke. Provisions may be made to make smokeless chullhas available to the workers and villagers. Varieties of energy efficient chullhas are available such as durable fixed type chullhas with chimney, portable type and High altitude chullhas. The total budget for distribution of 500 smokeless chullhas @ ₹ 1000 would be ₹ 5.00 lakh.
13.5 COST ESTIMATE FOR ENERGY CONSERVATION MEASURES An amount of ₹ 170.00 lakh has been earmarked for distribution of energy saving measures amongst population in the Study Area. The details are given in Table 13.1.
Table 13.1: Estimated Cost for Energy Conservation Management Plan
S. No. Particulars Cost (₹ lakh) 1. LPG Connections 100.00 2. Distribution of Kerosene oil stoves 20.00 3. Distribution of Pressure Cookers 20.00 4. Distribution of Solar Cookers 25.00 5. Distribution of Improved Chullhas 5.00 Total 170.00
13-4
CHAPTER 14 RESETTLEMENT AND REHABILITATION PLAN
EMP Report of Dibang Multipurpose Project
CHAPTER 14 RESETTLEMENT AND REHABILITATION PLAN
14.1 EXISTING GUIDELINES FOR RESETTLEMENT PROGRAMME IN ARUNACHAL PRADESH As per the Memorandum of Agreement between NHPC and Govt. of Arunachal Pradesh, Resettlement and Rehabilitation (R & R) of project affected families is to be implemented on the basis of National Policy on Resettlement and Rehabilitation (NPRR) 2003. Government of India has subsequently revised this policy on 31st October 2007 and came up with National Rehabilitation and Resettlement Policy (NRRP) 2007.
However, this policy does not seem adequate to fulfill the aspirations of people due to different cultures, traditions, languages and different climatic conditions, in different states of the Indian union. As a result, some states have come up with their own Rehabilitation and Resettlement Policies, which not only provides a better relief package but takes care of the regional issues and aspirations.
Arunachal Pradesh being a mountainous State, heavily forested and drained by numerous rivers and streams, availability of cultivable land is less. So, suitable agricultural land is a scarce resource. This coupled with the fact that the economy of the State is largely dependent on agriculture and forests; diversion of any piece of cultivable land for a project is bound to have more adverse effect upon tribal community of Arunachal Pradesh than that envisaged in the NRRP-2007. As a result, Government of Arunachal Pradesh decided to come up with its State Rehabilitation and Resettlement Policy 2008 which would cater to loss of rights over Unclassed State Forests and other privileges of the tribal community. The Policy, is although, based on NRRP-2007, certain definitions viz. ‘community’, ‘Affected area’ and ‘Jhum’ and benefits have been included to recognize various customary and cultural rights of the tribal population. R & R Policy of Arunachal Pradesh also has special provisions with respect to community and jhum land.
14-1 EMP Report of Dibang Multipurpose Project
The R & R Plan for Dibang Multipurpose Project is prepared in line with the State Rehabilitation and Resettlement Policy 2008 of Arunachal Pradesh.
14.2 OBJECTIVES OF R & R PLAN The successful implementation and running of a mega project would depend on addressing the grievances of the local people which might emerge out of the setting up of the project and involving the local people into the project in different capacities in the spirit of participatory development. All affected landowners will be entitled to a combination of compensation packages and resettlement assistance, depending upon the nature of ownership of their land and the scope of impacts, including socio- economic vulnerability of the affected persons and measures to support livelihood restoration if livelihood impacts are envisaged.
The objectives of the Resettlement and Rehabilitation Plan envisaged for Dibang Multipurpose project are to: provide assistance and other support to the PAFs so that they regain their previous standard of living; even improve if possible, within a reasonable transition period. pay compensation for the loss of land, houses and all other immovable properties to the PAFs as per the State Rehabilitation and Resettlement Policy, 2008 of Arunachal Pradesh. improve the overall quality of life of affected population through better infrastructure medical and educational facilities, etc. assist PAFs in regaining their economic status in the initial stages in such a way that they can sustain on their own and do not have to depend on the project authorities for long. The project authorities can slowly phase-out their assistance and leave the PAFs to depend on their own economic activities and social lifestyle. provide adequate compensation to the project affected tribal community for extension of tradition right and privilege of USF land use and collection of forest produce.
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The Rehabilitation component primarily means to assist the affected population so that every individual could regain or improve lifestyle and socio-economic condition. This is done primarily by imparting skills and/or vocational training to the PAPs. Resettlement on the other hand, primarily involves the physical relocation of the affected population to new residential sites. The Rehabilitation package is conceptualized around a development strategy to bring about a positive socio- economic transformation of the PAFs, so as to improve the quality of their life and also to facilitate harmonious relationship between the project proponent and project affected people.
R & R benefits for Dibang Multipurpose Project are primarily based on the State Rehabilitation and Resettlement Policy 2008 of Arunachal Pradesh.
14.3 DEFINITIONS The various terms which are relevant to the proposed project are described in following paragraphs. The definition of the various expressions used in this policy is the same as defined under State R&R Policy 2008 of Arunachal Pradesh. (a) Administrator for Rehabilitation and Resettlement It means an officer not below the rank of District Collector or commissioner in a State appointed for the purpose of rehabilitation and resettlement of affected persons. (b) Affected family (i) is a family whose primary place of residence or other property or source of livelihood is adversely affected by the acquisition of land for a project or involuntary displacement for any other reason or (ii) any tenure holder, tenant, lessee or owner of other property, who on account of acquisition of land (including plot in the abadi or other property) in the affected area or otherwise, has been involuntarily displaced from such land or other property; or (iii) any agricultural or non-agricultural labourer, landless person (not having homestead land, agricultural land, or either homestead or agricultural land), rural artisan, small trader or self-employed person; who has been residing or engaged in any trade, business, occupation or vocation continuously for a period of not less than three years preceding the date
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of declaration of the affected area, and who has been deprived of earning his livelihood or alienated wholly or substantially from the main source of his trade, business, occupation or vocation because of the acquisition of land in the affected area or being involuntarily displaced for any other reason. (c) Affected area It means area of village or locality notified by the state government under paragraph 7.1.2 of State R & R Policy. (d) Agricultural labourer Primarily a resident of the affected area for a period of not less than three years immediately before the declaration of the affected area who does not hold any land in the affected area but who earns his livelihood principally by manual labour on agricultural land therein immediately before such declaration and who has been deprived of his livelihood. (e) Agricultural land It includes land being used for the purpose of (i) agriculture or horticulture; (ii) dairy farming, poultry farming, pisciculture, breeding of livestock or nursery growing medicinal herbs; (iii) raising of crops, grass or garden produce; and (iv) land used by an agriculturist for the grazing of cattle, but does not include land used for cutting of wood only; (f) Appropriate Government (i) in relation to the acquisition of land for the purposes of the Union, the Central Government; (ii) in relation to a project which is executed by the Central Government agency or undertaking or by any other agency on the orders or directions of the Central Government, the Central Government; (iii) in relation to the acquisition of land for purposes other than (i) and (ii) above, the State Government; and (iv) in relation to the rehabilitation and resettlement of persons involuntarily displaced due to any other .reason, the State Government;
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(g) BPL family The below poverty line (BPL) families shall be those as defined by the Planning Commission of India from time to time and included in a BPL list for the time being in force.
(h) Commissioner for Rehabilitation and Resettlement It means the Commissioner for Rehabilitation and Resettlement appointed by the State Government not below the rank of Commissioner' or of equivalent rank of that Government. (i) Family It includes a person, his or her spouse, minor sons, unmarried daughters, minor brothers, unmarried sisters, father, mother and other relatives residing with him or her and dependent on him or her for their livelihood; and includes "nuclear family" consisting of a person, his or her spouse and minor children. (j) Holding It means the total land held by a person as an occupant or tenant or as both. (k) Land acquisition or acquisition of land It means acquisition of land under the Land Acquisition Act, 1894 (1 of 1894), as amended from time to time, or any other law of the Union or a State for the time being in force. (l) Notification It means a notification published in the Gazette of India or, as the case may be the Gazette of a State. (m) Project It means a project involving involuntary displacement of people, irrespective of the number of persons affected; (n) Requiring body It means a company, a body corporate, an institution, or any other organisation for whom land is to be acquired by the appropriate Government, and includes the appropriate Government if the acquisition of land is for such Government either for its own use or for subsequent transfer of such land in public interest to a company, a body corporate, an institution, or any other organization, as the case may be, under lease, license or through any other system of transfer of land;
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(o) Community It means the residents of a village as a whole, clan, sub-clan or kindred. (p) Jhum Land It means jhum land as defined in Section 2(b) of the Balipara/Tirap/Sadiya Frontier Tract Jhum Land Regulation, 1947.
14.4 RESETTLEMENT AND REHABILITATION GRANTS
14.4.1 Compensation for land along with rights and privileges: The process of land acquisition will be dealt by NHPC along with PAFs and Government of Arunachal Pradesh. Land for various components involves Unclassed State Forest (USF), community land without forest cover and land under wet rice cultivation (WRC). PAFs shall be compensated as per the norms of State Government for the community land. The community shall be compensated @ ₹ 1.56 lakhs/ ha for loss of customary rights and privileges of tribal people to collect and use forest produce (traditional land use) from USF. In addition to this, the community will be paid a sum equivalent to 25 % of Net Present Value (i.e. 25% of ₹ 39581.21 lakh) of the USF. Community land without forest cover and land under WRC will be paid @ ₹ 1.75 lakhs/ha. Compensation for crops will be paid @ ₹ 1.25 lakhs/ha for land under jhum cultivation and ₹ 1.5 lakhs/ha for land under WRC. Detailed financial outlay is provided in the following Table 14.1:
Table 14.1: Detailed financial outlay for land compensation along with rights & privileges
Solatium Quantity Amount Rate 25% of (30% of Cost of Total (₹ Land of land (₹ in per ha NPV land crops/ha in lakhs) (in ha) lakhs) value/ha) USF 4577.84 1.56 7141.43 9895.30 -- -- 17036.73 Community 876.63 land (@ ₹ 701.30 1.75 1227.28 -- 368.18 2472.09 without 1.25 forest cover lakhs/ha) 105 Land under (@ ₹ 70.00 1.75 122.50 -- 36.75 264.25 WRC 1.50 lakhs/ha) Total 5349.14 -- 8491.21 9895.30 404.93 981.63 19773.07
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Note: 1. The property value above is calculated based on land compensation only. In case of USF/Community Forest land 25 % NPV and in case of Community Jhum Land/Community agricultural Land, 30 % solatium of land value would be paid additionally. 2. The cost arrived is based on the socio economic survey, however, the final actual compensation shall be paid as per the actual property survey to be conducted by the State Government which may increase/decrease the cost arrived at as referred above.. 3. Compensation for trees and cost of Crops standing on the acquired agricultural land would be payable to the entitled land owner families as per the valuation by the State Government. DC / Administrator (R&R) is to constitute a committee for the same so that the compensation payable to PAFs is worked out. 4. The cost of NPV for the USF/ community land may undergo a change as per the Forest Proposal, which is still under approval at the level of MoEF, GoI. 5. Cost of the properties standing on the land and cost of Govt. Properties & communities assets is still to be firmed up by the District Authority / Administrator (R&R).
14.4.2 Housing benefit and compensation: Each family who is fully affected and losing house shall be allotted free of cost house and a plot for the house site to the extent of actual loss of area of the acquired house but not more than 250 sq m (0.025 ha) of land. The size and design of house will be decided by the State Authority in consultation with the project affected community and project authority. 115 families, getting affected in 5 fully affected villages, are eligible for this benefit.
Provided that any such affected family which opts not to take the house offered at the resettlement site, shall get one-time financial assistance for house construction and the amount shall be ₹ 2 lakh and his claim for free of cost plot at the resettlement site shall stand forfeited.
14.4.3 Land allotment and compensation: Each affected family owning agriculture land in the affected area and whose entire land has been acquired or lost shall be
14-7 EMP Report of Dibang Multipurpose Project allotted agricultural land or cultivable waste land to the extent of actual land lost in the name of the adult member of the subject to a maximum of 1 ha of irrigated land or 2 ha of cultivable un-irrigated land subject to the availability of government land in or near the resettlement area. The affected family will be compensated for the remaining cultivable land monetarily @ ₹ 1.75 lakhs / ha. 115 families are eligible for this benefit.
14.4.4 Ex Gratia for the landless: Each affected family who is rendered landless shall be provided an ex gratia grant of ₹ 50,000. This benefit shall be extended to 115 fully affected families.
14.4.5 Ex gratia for those affected families who are left with less than 1 ha of land: Each of the affected families who are left with less than 1 ha of land after acquisition shall be provided an ex gratia grant ₹ 40,000.
14.4.6 Land Development Assistance: In case of allotment of wasteland or degraded land in lieu of acquired land, the senior most adult member in the affected household shall get one time financial assistance ₹ 25000/ha for land development. This benefit shall be extended to 115 fully affected families.
14.4.7 Livelihood grant for landless: An amount equivalent to 1000 days Minimum Agricultural Wages (MAW) @ ₹ 100/day or the prevailing agricultural labour wage whichever is higher shall be paid to each of the affected families who have been rendered landless after land acquisition. This benefit shall be extended to 115 fully affected families.
Each PAF would be given the option for taking up to 20% of his livelihood grant amount in the form of shares & debentures.
14.4.8 Livelihood grant for those who have been left with less than 1 ha of land: An amount equivalent to 750 days Minimum Agricultural Wages (MAW) @ ₹ 100/day or the prevailing agricultural labour wage whichever is higher shall be paid to each of the affected families who are left with less than 1 ha land after land acquisition.
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Each PAF would be given the option for taking up to 20% of his livelihood grant amount in the form of shares & debentures.
14.4.9 Financial Assistance for self-employed: Each affected person who is a rural artisan, a small trader or self-employed person and who has been displaced shall get a one-time financial assistance of such amount as the State Authority may decide but not less than ₹ 25000 for construction of working shed or shop.
14.4.10 Transportation grant: Each affected family that is displaced shall get financial assistance of such amount as the State Authority may decide but not less than ₹ 20,000 for transportation of their household goods, cattle, etc to the resettlement site. This benefit shall be extended to 115 fully affected families.
14.4.11 Assistance for construction of cattle shed: Each affected family that is displaced and has cattle shall get financial assistance of such amount as the State Authority may decide but not less than ₹ 15000 for construction of cattle shed. This benefit shall be extended to 115 fully affected families.
14.4.12 Subsistence allowance: Each affected family that is displaced will be given monthly allowance equivalent to 25 days MAW for a period of 1 year from the date of displacement. This benefit shall be extended to 115 fully affected families.
14.4.13 Pension for life for vulnerable affected persons: The project authorities shall, at their cost, arrange for annuity policies that will pay a pension of ₹ 500/- per month for life to the vulnerable affected persons as indicated at paragraph 7.1.6 (iv) of State R&R Policy 2008 of Arunachal Pradesh This provision will be applicable for those who will be identified by the District Administration during final survey.
14.4.14 Scheduled tribe family grant: Each Scheduled Tribe affected family shall get an additional one-time financial assistance equivalent to 500 days MAW for loss of customary rights or usages of forest produce or ₹ 50,000/- whichever is higher. This will be applicable for 859 affected families.
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14.4.15 Training for Livelihood: Suitable training would be provided for skill development so as to make provisions for employment at a rate not lower than the minimum wages, to at least one member from the project affected family.
14.4.16 Free electricity: The project developers will provide to each of the project affected family the benefit of 100 units of electricity per month free of charge for a period of 10 years from the date of commissioning of the project. In case the affected family does not consume 100 units of electricity in a month, the cost of balance unused units shall be made available to the family in cash.
14.4.17 Special provisions . There shall be an option of acquiring entire agriculture land, if 75% of land holdings are required for acquisition. . The land or house allotted to the affected families shall be free from all encumbrances. . The tribal families residing in the project areas having fishing rights in the river shall be given fishing rights in the reservoir area. . The PAFs resettled out of the district / Anchal will get 25% higher R&R benefits in monetary terms.
14.5 Financial Outlay for R & R Benefits: The budgetary provision of R & R benefits is presented in the following Table 14.2:
Table 14.2: R & R Benefits with budget S Amount Benefits Criteria No. (₹ in lakhs) 1. Homestead land Max. 0.025 ha @ Rs 1.75 5.00 lakhs /ha for 115 PAFs 2. House construction 2 lakhs/PAF for 115 PAFs 230.00 grant
3. Stamp duty and @ 8% 18.80 registration for homestead land and house 4. Compensation for land ₹ 1.75 lakhs/ha for 2 ha for 402.50 115 PAFs
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S Amount Benefits Criteria No. (₹ in lakhs) 5. Ex-gratia payment for Rs 50,000/PAF for 57.50 landless 115PAFs 6. Ex gratia payment for ₹ 40000/PAF for 744 PAFs* 297.60 those who are left with less than 1 ha of land 7. Land development ₹ 25,000/PAF for 115 PAFs 28.75 assistance 8. Livelihood grant for 1000 days MAW @ Rs 115.00 landless 100/day for 115 PAFs 9. Livelihood grant for 750 days MAW @ Rs 558.00 those who are left with 100/day for 744 PAFs* less than 1 ha of land 10. Financial assistance for Lump sum 20.00 self-employed persons 11. Transportation grant ₹ 50000/PAF for 115 PAFs 57.50
12. Assistance for ₹ 25000/PAF for 115 PAFs 28.75 construction of cattle shed 14. Subsistence allowance Rs 3000/month 12 months 41.40 for 115 PAFs 15. Scheduled Tribe Family Rs 50,000/PAF for 859 429.50 Grant PAFs 16. Provision of annuity Lump sum 30.00 policies for pension for life to vulnerable affected persons @ ₹ 500/ month 17. Training for livelihood Lump sum 30.00
18. Free electricity @ 100 Lump sum 50.00 units per PAF per month Total 2400.30
*Exact number of PAFs left with less than 1 ha of land would be identified by District Administration during implementation of R&R Plan. Note: Initially the R & R Benefits were prepared in line with the State Rehabilitation and Resettlement Policy 2008 of Arunachal Pradesh / NRRP 2007. However, it has now been revised on the basis of RTTFC in LARR 2013.
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14.6 APPLICATION FOR GRANT AND GRANT DISTRIBUTION The Commissioner / District Magistrate or his/her representative not below the rank of ADM/ SDM from Dibang and Lower Dibang Valley District will be the sanctioning authority for the rehabilitation grant, which shall be provided by the project authorities. Affected family/ person will apply on a general prescribed form, which will furnish the information of the village, details of his/her land acquired, family status, etc. The form will be submitted to the project office and evaluated by Land Acquisition Officer and General Manager of NHPC Ltd. After receiving the list of PAFs by District Magistrate, the options will be invited from head of affected family on stamp paper and this will be routed through SDM concerned. District Magistrate shall be the final authority to sort out the disputes between affected families and the project authorities. All stamp duty and fees of registration shall be borne by the project developers. After submitting all the necessary documents, R&R cell would disburse the compensatory amount to the affected person. If there is any dispute between affected person and the project, Commissioner / DM can interfere to sort out the disputes. Alternatively, if GoAP directs NHPC for distribution of grant then the R&R cell of NHPC would distribute the grants by any other means as agreed upon by the Administrator (R&R).
14.7 INFRASTRUCTURE FACILITY AT RESETTLEMENT SITE / COLONY Project Affected Families will be resettled to a new location. New Resettlement sites shall be finalized by the Administrator (R&R) in consultation with PAFs and it will be developed with all the basic infrastructural facilities well before the filling of reservoir. Fully affected families shall be resettled in a group to maintain their socio-cultural compatibility. The basic amenities to be provided in the resettlement colonies are given as below:
Access roads, passages and easement rights, proper drainage and sanitation facilities; Assured water supply capable of yielding enough water to meet the demand of at least sixty litre per capita per day (lpcd); Building for Panchayat Ghar and Community Hall; Building for a Village level Post Office;
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Building for setting up an appropriate seed-cum-fertilizer store as per requirement; Primary health facilities; Primary education facilities; Promotion of institutional arrangements for availing of financial assistance under the Central/State Government’s schemes/Bank schemes; Electricity connections, if possible. The payment to the concerned electricity supply agency in respect of electricity to be consumed shall be the responsibility of the PAFs; Place of worship; Public cremation ground/burial ground; Separate land earmarked for traditional tribal institutions; Suitable public transport facility Anganwadi with child and mother supplemental nutritional services. Any other additional facility extended by NHPC as and when considered necessary; Produces and common property resources, if available in the vicinity of the new place of settlement. Veterinary service centre.
14.7.1 Financial Outlay for Infrastructural Facilities: The budgetary provision earmarked for providing various infrastructural facilities are presented in the Table 14.3. Table 14.3: Financial Outlay for providing infrastructural facilities
S. Total Cost Parameter Criteria No. (₹ in lakhs.) 1. Water supply Lump sum 60.00 2. Community toilets Lump sum 30.00 3. Development of sewage Lump sum 60.00 treatment system including drainage system 4. Electrification and Street lights Lump sum 100.00 6. Construction of shopping Lump sum 30.00 complex
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S. Total Cost Parameter Criteria No. (₹ in lakhs.) 7. Construction of community Lump sum 100.00 centre 8. Construction of vocational activity Lump sum 60.00 centre 9. Children's park Lump sum 40.00
10. Avenue plantation & block Lump sum 20.00 plantation 11. Internal roads in the resettlement Lump sum 250.00 colony 12. Link roads to the resettlement Lump sum 4000.00 colony 13. Irrigation facilities to PAFs Lump sum 175.00 14. Construction of Hospital Building Lump sum 150.00 15. School Complex including play Lump sum 150.00 ground 16. Place of worship Lumpsum 20.00 17. Anganwadi Lumpsum 30.00 18. Public Transportation facility Lumpsum 30.00 19. Separate land for traditional tribal 1 ha of land @ 1.75 institution Rs 1.75 lakhs /ha 20. Veterinary service centre Lumpsum 50.00 22. Miscellaneous Lump sum 100.00 Total 5456.75
Note: Initially the facilities proposed to be provided in Resettlement Colony were prepared in line with the State Rehabilitation and Resettlement Policy 2008 of Arunachal Pradesh. However, it has now been revised on the basis of RTTFC in LARR 2013. Further, the provision of land for Resettlement Colony has been kept under B-Land in DPR.
The above-mentioned facilities will also be available to the host population and the neighboring community in the Resettlement colonies/sites. The responsibility of project authority shall be limited to incurring one-time capital cost for creation of these facilities. Efforts will be made to involve PAPs in creation of these infrastructure facilities by giving contracts to their co-operative societies or otherwise
14-14 EMP Report of Dibang Multipurpose Project for construction works to the extent possible. This will also help in developing a sense of ownership among the PAPs regarding these facilities.
14.8 LUMP SUM CASH ASSISTANCE All the affected families shall be given an option to take a lump sum cash amount in lieu of one or more the benefits specified in the R&R package, depending upon their entitlement. 14.9 MONITORING AND EVALUATION Six monthly progress report of implementation of R & R plan will be sent to Corporate R & R cell, NHPC Ltd which will be monitored by the Executive Director (Planning). The committee to oversee this will have the following members.
a) Executive Director (Planning) Chairman b) General Manager (Project), NHPC Ltd. Member c) Head of R & R Cell, NHPC Ltd. Member Secretary d) A representative from Corporate Finance Member Division
In addition to an internal committee as above, it is suggested to constitute another committee in order to avoid any dispute between project authorities and the affected persons. The committee will include representatives of District Administration, elected members, project authority, panchayat, member, etc. The committee shall comprise the following members:
a) District Magistrate, or his/her representative Chairman b) SDM(s), concerned Member c) Panchayat members of affected villages Member d) Woman (social worker) from the affected area Member e) Representative of well known NGO in the area Member f) General Manager (Project), NHPC Ltd. Member Secretary g) Head of the R & R Cell, NHPC Ltd. Member h) Land Acquisition Officer of the Project Member
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The financial budget for the day to day expenditure of the committee would be ₹ 50.00 lakhs only.
14.10 COST ESTIMATE FOR R&R PLAN Total financial package for R & R Plan would be ₹ 7907.05 lakhs. It includes R & R benefits amounting to ₹ 2400.30 lakhs, ₹ 5456.75 lakhs for providing infrastructural facilities in the resettlement colony and ₹ 50 lakhs for monitoring and evaluation. In addition, ₹ 19773.07 lakhs will be paid towards the compensation of land, and rights and privileges against loss of unclassified forests and community land.
Table 14.4: Summary of Budget for Resettlement & Rehabilitation Plan
S. Total Cost Parameters No. (₹ in lakhs.) I. R & R Plan (i) R&R Benefits 2400.30 (ii) Infrastructural facilities in the resettlement 5456.75 colony (iii) Monitoring & Evaluation 50.00 Total 7907.05 II. Compensation of land and rights and privileges 19773.07 (including 25% of NPV)
Note: Recently, “The Right to Fair Compensation, Transparency in Land Acquisition, Rehabilitation and Resettlement Act, 2013” (RTTFC in LARR) has become effective from January 1, 2014. The Act has provisions to provide fair compensation and resettlement and rehabilitation benefits to those whose land is acquired for construction of projects. The R&R Plan of Dibang Multipurpose Project has been revised in line with the provisions kept in RTTFC in LARR. As per the Act the R&R Plan is to be prepared by the State Govt. by appointing Administrator (R&R) / Commissioner (R&R). The compensation in lieu of the private land / other properties to be acquired shall be paid at market price as decided by the State Govt.
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CHAPTER 15 COMMUNITY & SOCIAL DEVELOPMENT PLAN
EMP Report of Dibang Multipurpose Project
CHAPTER 15 COMMUNITY & SOCIAL DEVELOPMENT PLAN
15.1 COMMUNITY AND SOCIAL DEVELOPMENT PLAN (CSDP) Community and Social Development Plan (CSDP) will be taken up by the project for social and community development activities in and around project affected areas including vocational training for self-employment, infrastructure development in affected area including approach roads, community buildings, health and hygiene facilities, water supply, programmes to encourage students/entrepreneurship etc. Detailed CSDP will be framed in association with District Administrations and by taking inputs from PAFs, senior citizens, Panchayat leaders and Gram Budhas of the local area. A provision of ₹ 7000 lakhs has been proposed for CSDP.
15.1.1 Aim of CSDP CSDP will aim principally to support and facilitate training programmes to create self-employment amongst the communities in the affected zone viz. in computer application, poultry farming, animal husbandry, dairy, handicrafts, knitting, tailoring, etc. Vocational trainings would be imparted based on literacy, basic aptitude and skill level of the affected PAPs, local products available and scope for developing a sustainable market. The selection of candidates for various training and the associated procedures will be decided by the CSDP execution committee which will include representatives of district administration, elected members, project authority, panchayat members etc.
15.1.2 Objectives of CSDP The objective of CSDP is to enable affected population as well as population of local area to have a wider range of choices and opportunities in the economic, social and political spheres so they can improve their own well-being and that of their households. A list of objectives is given below: Programmes to support and strengthen Self Help Groups will be taken up which would provide them with access to financial services, fostering linkages with banks and supporting microfinance institutions.
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It will evolve strategies based on participatory approaches for community development Its strategies will supplement state development projects and schemes at the local and state level and it will address capacity building of PAFs and host community. It will aim to diffuse competition for resources among PAFs, neighbouring communities and host population. It will plan sensitization and capacity building of concerned NHPC officers at the project office level towards identifying and facilitating need based and resource sensitive community based interventions and support for PAFs and neighbouring communities and host populations.
15.2 CONCERNS RAISED DURING PUBLIC HEARINGS
During public consultation prior to public hearing and during public hearings of Dibang Multipurpose Project held on 11th March 2013 at Roing, Lower Dibang Valley District and on 13th March 2013 at New Anaya, Dibang Valley District, various issues were raised by the Public through memorandums, speeches which have Financial Implication. There was demand of financial assistance for various infrastructural works in both Lower Dibang Valley and Dibang Valley Districts. These demands are enumerated below:
1. Flood control of Eze (Deopani) river to protect the Roing township. 2. Upgradation of Roing District Hospital to a referral hospital with multi- speciality provisions. 3. Upgradation of Anini District Hospital infrastructure to modern structure with modern amenities. 4. Upgradation of infrastructure of Govt. Higher Secondary Schools of Roing and Anini along with hostels and playground. 5. Provision of financial assistance for Govt. Degree College, Roing. 6. Provision of financial assistance for Govt. Polytechnic College, Simari village, Roing.
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7. Provision of financial assistance to all Govt. institutions and schools in the district for better infrastructure development with basic modern amenities. 8. Provision of financial assistance for multipurpose cultural cum museum centre at Roing with multi-storeyed building for community activities and sort stay accommodation. 9. Starting of ITI at Anini. 10. Provision of fund to complete 3 km road from 173 km point of BRTF road to Anelih village. 11. Provision of funds for renovation of ME School, Anelih. 12. Provision of funds for maintenance of Inspection Bungalow (IB) at Anelih (Dibang Valley District)
A lump sum provision of ₹ 1200 lakhs is proposed to be kept to meet part financial assistance for implementation of Infrastructural works. The proposals and plans will be prepared by Govt. of Arunachal Pradesh. The part financial assistance may be considered by NHPC through Govt. of Arunachal Pradesh.
There was demand of downstream people to take up construction of embankment on both sides of river in downstream of dam to give them protection against dam break / flood. To meet out this demand, wire crate wall / concrete walls as per design requirement and as per requirement of location are proposed to be constructed along the river banks. A lump sum provision of ₹ 5000 lakhs is kept for this purpose.
Construction of earthen raised platforms of 200 m X 200 m is proposed at 11 locations near villages falling in inundation area. The platforms will be of different heights as per inundation depth as per distance from dam. The average height of platforms is considered as 7 m. A provision of ₹ 10400 lakhs is proposed to be kept for construction of platforms including cost of land and rip rap.
For works of providing CGI sheets shelter on platform for providing boat and helicopter for evacuation of people, a lump sum provision of ₹ 17100 lakh is proposed to be kept. The details are given in Table 15.1.
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Table 15.1: Financial outlay for Community and Social Development Plan
Amount S. No. Description (₹ in lakh) 1. Implementation of infrastructural works 1200 2. Construction of raised platform including land cost and 10400 rip rap 3. Wire crate walls at selected locations as per design 5000 requirement for protection against flood 4. Arrangement of boats at platform, construction of shelter 500 at platform and other miscellaneous activities e.g. helicopter etc. for evacuation Total 17100
During public hearings, the public took assurance from NHPC that the concerns of implementation of infrastructural works and downstream protection works raised during public hearings / public consultation / through various memorandums shall be brought to the notice of MoEF for their consideration / approval.
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CHAPTER16 PLAN FOR PROTECTION OF CULTURAL IDENTITY OF LOCALS
EMP Report of Dibang Multipurpose Project
CHAPTER 16
PLAN FOR PROTECTION OF CULTURAL IDENTITY OF LOCALS
16.1 INTRODUCTION
NHPC Ltd. has decided to frame a policy / guidelines for the preservation cultural identity of the local tribal with the following objectives in view to: preserve the cultural identity of the local tribal outside the project area from interaction and contact with the labourers/ staff of NHPC as well as contractors while they are not socially and culturally prepared for such interface; preserve the social organization, mode of subsistence and cultural identity of the Indigenous people community outside the project area from impact of different culture and unacceptable demographic sift; conserve the tradition and culture of the indigenous community outside the project area and strengthen support systems in order to enable the indigenous people pursue their traditional modes of subsistence and way of life; sensitise the officials and staff of NHPC as well as contractors for the protection and preservation of tradition and culture of the local tribal community outside the project; and educate the officials and staff of NHPC as well as contractors about the need to preserve this ancient tradition and culture of the indigenous community and to value their unique culture and lifestyles.
16.2 STRATEGIES/GUIDELINES NHPC Ltd., with the above objectives in view, have framed the following strategies / guidelines for the preservation of the cultural identity of the indigenous people outside the project area from any adverse effects of intervention and contact with the labourers / staff of NHPC as well as contractors.
16.3 PROTECTION OF CULTURAL IDENTITY OF LOCAL TRIBAL a) The way of life of the indigenous people outside the project area shall be considered and treated as a unique cultural heritage.
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b) An approach of only essential interaction with the indigenous people outside the project area shall be adopted by the NHPC Ltd. so that there shall be no impact of different culture and people in social and cultural life of the indigenous people. c) The requisite interaction with indigenous people will be managed with care and sensitivity through local personnel, in consultation with Gaon Burah (traditional headman of the village).
16.4 PROTECTION OF THE NATURAL HABITAT OF LOCAL TRIBALS a) No exploitation of natural resources in and around the project area by the labourers / staff of NHPC as well as of contractors will be allowed by the project authority. b) Necessary measures shall be initiated to curb any form of extraction of resources from the village outside the project area by the labourers / staff of NHPC as well as of contractors. c) The project area shall be fully and effectively demarcated and fenced. d) Necessary arrangements to ensure that any form of intervention does not take place in indigenous community will also be made. e) It shall be ensured that no labourer other than people from indigenous community is allowed to enter the village outside the project area by any means unless he/she is permitted by the competent authority designated by the project for this purpose. f) No such permission shall be granted unless the person is proceeding on bonafide work relating to the project activities. g) The project will not allow any visitor to visit / interact with the indigenous people outside the project area so that curious intrusions are avoided.
16.5 REGULATION OF TRAFFIC ON ROAD a) Traffic on road will be regulated strictly by limiting the traffic to the project works and to ensure that that no intervention take place in indigenous community. b) Vehicles on road will be allowed to move under notified speed limit to avert possible road accidents.
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c) The traffic on road will be strictly monitored to ensure that there is no interaction between the indigenous people and the labourers/ staff of NHPC as well as contractors. Check gates at different locations shall be installed.
16.6 INSTITUTIONAL ARRANGEMENTS a) The project authority shall be responsible for the implementation of the aforesaid policy. It shall lay down detailed tasks for each unit of the project in connection with preservation of the indigenous community. b) The project authority assisted by local administration having knowledge and experience in indigenous community affairs will enforce and monitor implementation of the policy. c) Essential interaction with the indigenous people will take place with the consultation of local administration, Gram Budhas, panchayat leaders and prominent citizens etc. d) The project authority shall be responsible for taking up all necessary efforts in consultation with local administration, Gram Budhas, panchayat leaders and prominent citizens to ensure that the tradition and culture identity of the indigenous people is maintained. e) Periodic review of this policy will be done so that the policy is dynamic and takes into account changing needs and circumstances.
16.7 ACTION PLAN All efforts would be made by NHPC in consultation with the State Govt. and local public representatives to maintain the cultural identity of the people. The requirement of labourers will be in a phased manner. All efforts would be made to keep the labour population to the minimum. Maximum deployment would be only during peak construction period. All statutory guidelines will be followed during influx of labour population. Further, Project area of Dibang Multipurpose project is isolated from local inhabitants. Nearest village / town is about 25 km from the dam site. All precautionary measures shall be taken by the project with the help of District Administration to avoid demographic changes. Also, the labour colonies will be constructed separately.
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The project area of Dibang Multipurpose Project is situated in Lower Dibang Valley District of Arunachal Pradesh. The spread and lay out of the project is such that the project area can be enclosed with the barbed wire fencing or other suitable boundary. Following action will be implemented to check and preserve the cultural identity of the local. The project area shall be fenced to prevent unauthorized trespassing. Limited number of opening / check post shall be installed to guard the unauthorized entry/exist from the project area. All workers / officers shall be provided with the identity card. No worker shall be allowed to leave the project without any specific and genuine reason and permission. Specific pass shall be issued to the worker leaving the project area. Strict action shall be taken against the worker/officials not adhering the norms and regulations. A committee with participant of local leaders/prominent person shall be constituted to deal with the problems arising due to any illegal activities by the workers.
16.8 SURVEILLANCE MEASURES During construction and operation phases, it is proposed to construct 6 (six) check posts to prevent unnecessary inter-mingling of labour population with the locals. Each check post will have two guards and will report directly to a supervisor. The staff manning these check posts have adequate communication equipment. For this an amount of ₹ 20 lakh has been earmarked. The infrastructure including check- posts, watch towers, accommodation, etc. is proposed. For watch tower and accommodation an amount of ₹ 50 lakh has been earmarked. An amount of ₹ 20 lakh has been earmarked for purchase of vehicles.
16.9 SUPPORT TO CULTURAL HERITAGE / PROGRAMMES The local tribes i.e. Idu-Mishmi and Adi have rich diversity of religious customs, local traditions, ethnic lifestyle, art and craft etc. To promote their culture and customs etc., a sum of ₹ 50 lakh has been kept for a period of 8 years.
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16.9 COST ESTIMATE OF PLAN FOR PROTECTION OF CULTURAL IDENTITY OF LOCALS An amount of ₹ 327.03 lakh has been earmarked for protection of cultural identity of locals. The details are given in Table 16.1 below:
Table 16.1: Summary of Cost Estimate of Plan for Protection of Cultural Identity of Locals
S. No. Particulars Amount (₹ in lakh) 1. Salary Guards (12 nos.) @ Rs.8000 per month 11.52 Supervisor (1 no.) @ Rs.20,000 per month 2.40 Total cost for one year 13.92 Total Salary for 8 years @ 10% increase per 159.19 year) 2. Communication equipment 20.00 3. Infrastructure 50.00 4. Purchase of Vehicles 20.00 5. Support to Local Cultural Heritage 50.00 Total 327.03
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CHAPTER 17 CONTROL OF WATER, AIR AND NOISE POLLUTION
EMP Report of Dibang Multipurpose Project
CHAPTER 17 CONTROL OF WATER, AIR AND NOISE POLLUTION
17.1 WATER POLLUTION CONTROL 17.1.1 Control of Water Pollution during Construction Phase During project construction phase, sufficient measures need to be implemented to ameliorate the problem of water pollution from various sources. The sewage generated from various labour camps should be treated in septic tanks and disposed by discharging into nearest water body. However, efforts shall be made to discharge the treated effluent only in these water bodies, which are not used for meeting domestic water requirements.
The construction activities would require a crusher to crush large lumps of rocks to the requisite size for coarse as well as fine aggregates. The effluent generated from these crushers will have high-suspended solids. The effluent needs to be treated before disposal. Settling tanks of appropriate size for treatment of effluent from various crushers should be provided.
During tunneling work ground water flows into the tunnel along with construction water, which is used for various works like drilling, shortcreting, etc. The effluent thus generated in the tunnel contains high suspended solids. Normally, water is collected in the side drains and drained off into the nearest water body without treatment. It is recommended to construct a settling tank of adequate size to settle the suspended impurities. The sludge from the various settling tanks can be collected once in 15 days and disposed at the site designed for disposal of municipal solid wastes from the labour camps. The sludge after drying could also be used as cover material at landfill disposal site. An amount of Rs. 20.0 lakh has been earmarked for construction of various settling tanks.
17.1.2 Control of Water Pollution during Operation Phase In the project operation phase, a plant colony with 100 quarters is likely to be set up. It is recommended to provide a suitable Sewage Treatment Plant (STP) to treat the sewage generated from the colony. The cost required for construction of sewage
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STP in the project colony has already been covered in the budget earmarked for construction of the project colony. Hence, the cost for the same has not been included in the cost for implementing EMP.
17.2 AIR POLLUTION CONTROL 17.2.1 Control of Emissions Minor air quality impacts will be caused by emissions from construction vehicles, equipment and DG sets, and emissions from transportation traffic. Frequent truck trips will be required during the construction period for removal of excavated material and delivery of select concrete and other equipment and materials. The following measures are recommended to control air pollution: The contractor will be responsible for maintaining properly functioning construction equipment to minimize exhaust. Construction equipment and vehicles will be turned off when not used for extended periods of time. Unnecessary idling of construction vehicles to be prohibited. Effective traffic management to be undertaken to avoid significant delays in and around the project area. Road damage caused by sub-project activities will be promptly attended to with proper road repair and maintenance work.
17.2.2 Control of Air Pollution due to DG sets The Central Pollution Control Board (CPCB) has issued emission limits for generators upto 800 KW. The same are outlined in Table 17.1, and are recommended to be followed.
Table 17.1: Emission limits for DG sets prescribed by CPCB
Parameter Emission limits (gm/kwhr)
NOx 9.2 HC 1.3 CO 2.5 PM 0.3 Smoke limit* 0.7 * Light absorption coefficient at full load (m-1)
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The above standards need to be followed by the contractor operating the DG sets. The other measures are recommended as below:
Location of DG sets and other emission generating equipment should be decided keeping in view the predominant wind direction so that emissions do not effect nearby residential areas. Stack height of DG sets to be kept in accordance with CPCB norms, which prescribes the minimum height of stack to be provided with each generator set to be calculated using the following formula: H = h+0.2x √KVA H = Total height of stack in metre h = Height of the building in metres where the generator set is installed KVA = Total generator capacity of the set in KVA
17.2.3 Dust Control The project authorities will work closely with representatives from the community living in the vicinity of project area to identify areas of concern and to mitigate dust- related impacts effectively (e.g., through direct meetings, utilization of construction management and inspection program, and/or through the complaint response program). To minimize issues related to the generation of dust during the construction phase of the project, the following measures have been identified: Identification of construction limits (minimal area required for construction activities). When practical, excavated spoils will be removed as the contractor proceeds along the length of the activity. When necessary, stockpiling of excavated material will be covered or staged offsite location with muck being delivered as needed during the course of construction. Excessive soil on paved areas will be sprayed (wet) and/or swept and unpaved areas will be sprayed and/or mulched. The use of petroleum products or similar products for such activities will be strictly prohibited. Contractors will be required to cover stockpiled soils and trucks hauling soil, sand, and other loose materials (or require trucks to maintain at least two feet of freeboard). Contractor shall ensure that there is effective traffic management at site. The number of trucks/vehicles to move at various construction sites to be fixed.
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Dust sweeping - The construction area and vicinity (access roads, and working areas) shall be swept with water sweepers on a daily basis or as necessary to ensure there is no visible dust.
17.3 NOISE CONTROL MEASURES 17.3.1 Control of noise from construction equipment The contractors will be required to maintain properly functioning equipment and comply with occupational safety and health standards. The construction equipment will be required to use available noise suppression devices and properly maintained mufflers. vehicles to be equipped with mufflers recommended by the vehicle manufacturer. staging of construction equipment and unnecessary idling of equipment within noise sensitive areas to be avoided whenever possible. notification will be given to residents within 100 m of major noise generating activities. The notification will describe the noise abatement measures that will be implemented. monitoring of noise levels will be conducted during the construction phase of the project. In case of exceeding of pre-determined acceptable noise levels by the machinery will require the contractor(s) to stop work and remedy the situation prior to continuing construction.
17.3.2 Control Noise from DG sets The following Noise Standards for DG sets are recommended for the running of DG sets during the construction: The maximum permissible sound pressure level for new diesel generator sets with rated capacity up to 1000 KVA shall be 75 dB(A) at 1 m from the enclosure surface. Noise from the DG set should be controlled by providing an acoustic enclosure or by treating the enclosure acoustically. The Acoustic Enclosure should be made of CRCA sheets of appropriate thickness and structural/ sheet metal base. The walls of the enclosure should be insulated with fire retardant foam so as to comply with the 75 dBA at 1m sound levels specified by CPCB, Ministry of Environment & Forests.
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The acoustic enclosure/acoustic treatment of the room should be designed for minimum 25 dB (A) Insertion Loss or for meeting the ambient noise standards, whichever is on the higher side. The DG set should also be provided with proper exhaust muffler. Proper efforts to be made to bring down the noise levels due to the DG set, outside its premises, within the ambient noise requirements by proper siting and control measures. A proper routine and preventive maintenance procedure for the DG set should be set and followed in consultation with the DG set manufacturer which would help prevent noise levels of the DG set from deteriorating with use.
17.3.3 Control Noise from crushers Based on literature review, noise generated by a crusher is in the range of 79-80 dB(A) at a distance of 250 ft or about 75 m from the crusher. Thus, noise level at a distance of 2 m from the crusher shall be of the order of 110 dB (A). The exposure to labour operating in such high noise areas shall be restricted upto 30 minutes on a daily basis. Alternatively, the workers need to be provided with ear muffs or plugs, so as to attenuate the noise level near the crusher by atleast 15 dB (A). The exposure to noise level in such a scenario is to be limited up to 4 hours per day.
It is known that continuous exposure to noise levels above 90 dB(A) affects the hearing of the workers/operators and hence has to be avoided. Other physiological and psychological effects have also been reported in literature, but the effect on hearing acuity has been specially stressed. To prevent these effects, it has been recommended by international specialist organizations that the exposure period of affected persons be limited as specified in Table 17.2.
Table 17.2: Maximum Exposure Periods specified by Occupational Safety and Health Administration (OSHA)
Maximum equivalent continuous Unprotected exposure period per day noise level dB(A) for 8 hrs/day and 5 days/week 90 8 95 4 100 2 105 1
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110 ½ 115 ¼ 120 No exposure permitted at or above this level
17.4 IMPLEMENTING AGENCY Various management measures needs to be implemented for Control of air pollution control need to be included in the Tender Document for the Contractor involved in construction activities. The same shall be monitored on a regular basis by the project proponents. A provision of ₹ 35 lakh has been proposed for miscellaneous expenditure for the maintenance of air, water and noise quality.
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CHAPTER 18 DISASTER MANAGEMENT PLAN
EMP Report of Dibang Multipurpose Project
CHAPTER 18 DISASTER MANAGEMENT PLAN
18.1 DAM BREAK ANALYSIS The study of catastrophic flooding that may occur in the event of a dam failure is of great concern and importance because of the risk of life and property in the potentially inundated reaches downstream of the structure. Some of the recent disasters have focused attention on the requirement of conducting needful analysis of such cases, however remoter they may be, in order to assess probable damage and also to plan necessary measures for mitigating the losses. The studies will have to identify the inundated area, flood depth, flow velocity and travel time of the flood waves. In fact the evaluation or determination of the submersion wave of dam break due to extreme flood events is an initiative needed for defining the risk of submergence of areas located downstream of the existing dams and consequently to prepare protective measures, both active (reservoirs, dikes) and passive (emergency and evaluation plans) in the areas affected.
Floods due to failure of dams induce widespread damage to life and property due to its high magnitude and unpredictable sudden occurrence. Such flood is required to be simulated to determine the inundated area, flood depth, and travel time of the flood waves so that adequate safety measures can be provided. The review of the past works reveals that dam break problem remains a topic of continued interest since Ritter (1892) attempted its first analytical solution for a horizontal frictionless rectangular channel. Investigations are still going on (i) to evaluate performance of different forms of Governing Equations, (ii) for developing analytical solution of these equations for different situations and (iii) for developing better and suitable numerical schemes for addressing complexities of natural rivers. Over the years different investigators have developed both one dimensional (Hicks F.E. et al (1997), Sanders B. F.(2001), Macchione F, Viggiani G. (2004) ) and two dimensional models (Katopodes N.D. (1984), Hromadka (1985) Akanbi, A. A. et al (1988), Zhao D.H. et al (1996), Sarma, A.K. (1999) Zoppou .C. and Roberts S. (2000)) using both conservative and non-conservative form
18-1 EMP Report of Dibang Multipurpose Project of governing equations for simulating dam break flood. Although computation of dam break flood has been a topic of interest for more than hundred years, numerical simulation of dam break flow in relatively simple channels is found more often compared to real river flood simulation. Natural channels with steep slopes and wide flood plains offer numerous complexities and make the computation very challenging. These channels are highly non-prismatic in nature with significant variations in bed width, bed slope and roughness characteristics. Selection of proper and suitable governing equations and use of efficient numerical scheme are some of the important issues of model development for simulating dam break flood.
Many commercial types of software developed for dam break analysis use implicit scheme, which though advantageous from stability point of view may lead to erroneous result if time step and space discretization are not done properly. Experiences has shown that Explicit Finite Difference schemes with conservative formulation of the Governing equation give reliable solution for dam break analysis for complex natural channel like that of Dibang (Sarma and Das, 2006). This being a case of disaster mitigation of an area resided by a large number of people, it was decided to carryout the analysis by three different FD schemes, namely, first order Diffusive, second order Modified Two-step Predictor Corrector, and TVD MacCormack Predictor Corrector using Van Leer Flux limiter, to have more confidence on the computed results. Validity and applicability of the numerical models in different flow conditions, i.e., subcritical, supercritical and mixed flow condition, are assessed by comparing the computed flow profiles with experimental data of Das (1978), Barr and Das (1980), Bellos (1990), and Bellos et al (1992) in terms of water depth. A hypothetical situation of instantaneous failure of the proposed dam on the river Dibang has been considered to simulate the worst possible scenario. The reservoir extends approximately up to 40,000 m upstream of the dam and the channel meets the river Brahmaputra 64,000 m downstream of the dam. The elevation of the channel bed changes from 545 m to 127 m. Change in the channel width ranges from 300 m to 5650 m and Manning’s roughness coefficient at different sections are taken as 0.03, 0.032, and 0.035 based on the channel and floodplain characteristic of the river.
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18.1.1 Governing Equations To obtain the basic equations of fluids in motion following philosophy are followed: (i) To choose the appropriate fundamental physical principles i.e., conservation of mass, momentum and energy. (ii) To apply these physical principles to suitably model the flow (iii) To deduce the mathematical equations to represent the flow considered. If a solid body is in translational motion, the velocity of each part of the body is same, but if the fluid is in motion, the velocity may be different at each location within the fluid. Hence to represent a moving fluid and to apply the fundamental physical principles one of the following models is used.
(i) Non-conservative form When the governing equations i.e. the continuity and momentum equations for the unsteady flow are deduced considering the fluid element which is moving along with the fluid such that same fluid particles are always inside it, the formulation is known as non- conservative form.
(ii) Conservative form: In conservative formulation the mathematical model is represented considering the fluid element fixed in space with fluid moving through it. The movement of the wave in the dam-failure situation is governed by gradually varied unsteady flow equation in open channel, i.e., the Saint-Venant (1871) equations. This can be written in non-conservative form as follows: A V A A 0 ……………………………………………………………… (1) x x t g A V V V fb )SS(g ……………………………………………………. (2) bm x x t And in conservative form as follows: U )U(F )U(S …………………………………………….……………… (3) t x Where:
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A U …………………………………………………………………...... (4) Q
Q F(U) = Q2 ………………………………… …………………………………………… (5) gI A 1
0 S(U)= ……………………………………………………………………... (6) gA )SS(gI 2f0 x = direction parallel to the river, t = time, A= cross-sectional flow area, Q = discharge, V
= Depth averaged flow velocity, bm = mean cross sectional width, g = acceleration due to gravity, S0 = bed slope, and Sf = friction slope.
)x(h 1 d),x(b])x(h[I ………………………...... (7) 0
)x(h b ])x(h[I d …………………………………………………………. (8) 2 x 0 hh o
I1, I2 = cross-sectional moment integrals; = integration variable representing the vertical distance to the bottom of the section; b = cross-sectional width at height ; h = water depth above the bottom.
NUMERICAL SCHEMES Numerical schemes have been developed with conservative form only as conservative formulation gives reliable result for non-prismatic channel like that of Dibang First order Diffusive Scheme When diffusive scheme is applied to (3), the following equation is obtained (Chunge et al., 1980):
n n 1n n 1i UU 1i n n n )1(UU )FF( tS ………………………………...... (9) i i 22 2i 1i i 0 1 Where, τ= t ………………………………………………………………………….….. (10) x
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Macchione et al. (2003) found in their numerical investigation that diffusive scheme gives increasingly accurate results as the value of coefficient increases. For = 0.75, the results are only slightly less accurate than those obtained through Roe’s First-Order Upwind Scheme. Hence = 0.75 have been considered here.
Second order two Step schemes In this study, following two-step second order schemes are examined: 1. Modified Predictor Corrector i.e., the well-known MacCormak scheme in a slightly modified form, and 2. Total Variation Diminishing (TVD) MacCormack scheme.
A number of explicit Second-order two-step schemes exist which have been collected by Lerat and Peyret under the following general structure (Peyret and Taylor 1990) (The well known MacCormack scheme belongs to this same family)
n n n n Predictor: i i 1i 1i i )FF(UU)1(U tSi ……………………………………..… (11)
1n n 1 n n n n n Corrector: i i )2(UU [( 1i i 1i i FF(F)1(F)12(F) 1i )] St i ………... (12)
In MacCormack scheme (1969), =1, =0 The Mac Cormack scheme is recommended by different investigators (Garcia et al. (1986), Garcia N. P. et al (1992), Fennema, R.J.(1990) et al, Rahman, M. et al (1998), and Aureli F. et al (2004)) for unsteady gradually varied flow computations.
Modified Predictor Corrector: The well-known Mac Cormack scheme in a slightly modified form has been used here. The set of governing equations used for modeling purpose has an inherent property of signal propagation i.e., in case of sub-critical flow the information comes both from upstream and downstream, while the information comes only from upstream if the flow is super-critical. Numerical investigations have shown that better results are produced if the direction of differencing in the predictor step is the same as that of the movement of wave front (Choudhury M H 1990).
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In the sub-critical region backward F.D. approximation is used for predictor step and forward F.D. approximation is used in the corrector step. In the super-critical region as the control is always on the upstream side, use of forward F.D. approximation in the corrector step is omitted to eliminate erroneous influence of downstream flux on the computed values. This simple technique has made application of the scheme possible in the mixed flow regions also. When it is applied to (3), the predictor step is given as: Predictor:
n n n n UPi i i i 1i )FF(U tSi ……………………………………..…………………..(13) Corrector step is applied to each node on the basis of the following conditions:
If Vi gh i , for sub-critical flow
n 1i i, Corrector: UC i i i -U FP - FP i )t(SP ………………………………………… (14)
If Vi gh i , Corrector step for super-critical flow is omitted, and thus
UCi=UPi……………………………………………...... (15) Finally, the U vector containing value of primitive flow variables in the next time step is calculated as
UCUP ii U 1n ………………………………... ………………………………………. (16) i 2
TVD MacCormack scheme Among the Second-order two-step family, TVD MacCormak with Van Leer’s Limiter is reported (Macchione et al (2003)) to demonstrate excellent behavior. Here the value of n+1 Uii given by the corrector step (12) is corrected by adding the following TVD term:
n n 2/1i 2/1i )TT( ………………………………………………………………………… (17) Where:
2 n )k( )k( )k( 2/1i 2/1i 2/1i rwDT 2/1i …………………………………… (18) 1k
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j The term D i+1/2 which can be considered an artificial dissipation term, has the following expression:
j 1 j Di [( 1()1 )]i ………………………………………………... (19) 2/1 2 2/1
In which = limiter allowing the TVD condition to be satisfied. The limiter is calculated as a function of the ratio of the characteristic variations
w 2/1i )sgn(2/1i 2/1i ………………………………………………………………….. (20) w 2/1i In The present study the Van Leer limiter is considered:
)( …………...... ………………………………………………….. (21) 1
The variations w(1)(2) at the point( i+1/2) are expressed as follows:
Q 2/1i ……………………………………… (22) 1( )( )2 1i1i )QQ(w i1i2/1i )AA(c A 2/1i
)j( r are the approximate Jacobian matrix eigenvectors. For the construction of such a matrix for the case of system (3) the following averaged variables should be considered for each cell (i,i+1) (Garcıa Navarro11 et al. 1992):
2/1i AAA 1ii ……………………………………………………………………………. (23)
1ii QAQA i1i Q 2/1i ………………………………………………………………… (24) i AA 1i The averaged celerity is computed as follows: II 1 1i 1i gc When Ai+1 Ai …………………………………………………………. (25) AA i1i
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1 i1i )AA(g c 2 When A =A 1 i+1 i )bb( 2 i1i or II( )( 0)AA ………………………………………………………………….. (26) i1i i1i11 So that the approximate Jacobian matrix is characterized by the following eigen values and eigenvectors: Eigenvalues: Q 1 c ……………………………………………………………………...... (27a) A Q 2 c ……………………………………………………………………...... (27b) A
)1( 1 T Eigenvectors: r 1 ],1[ ………………………………………………………….. (28a) c2
)2( 1 T r 2 ],1[ ………………………………………………………………...... (28b) c2 Stability is assured by the Courant–Friedrichs–Lewy condition: v cmax C 1…………………………………………………………………………. (29) r x/ t
Where Cr is the Courant number, v is the velocity, c is celerity = gh and c)vmax( stands for the maximum value over the whole range of grid points
18.2 SALIENT FEATURES The salient features of the dam are as given below: Location Country: India State: Arunachal Pradesh District: Lower Dibang Valley District Dam Site: Latitude: 28°20’07” N and Longitude: 95°46’38” E Hydrology Catchment area: 11276 km2
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Location of Catchment: Latitude: 28°11’50” N to 29°25’59” N Longitude: 95°14’47” E to 96°36’49” E Average annual rainfall: 4405 mm Reservoir Dam top level: EL 540 m Full reservoir level: EL 530.3 m Length of reservoir: 43 km
18.3 REQUIREMENT OF FIELD DATA The basic field data required for the flow analysis are: (i) Terrain profile – for the bed elevation and channel breadth, (ii) Topographic characteristic of the downstream area – for using appropriate value of resistance parameter, (iii) Height of the Dam.
18.3.1 Field Survey Reconnaissance of the entire area was carried out by both aerial and ground survey during 10th to 12th of January 2006. The survey was carried out basically to have an understating of the terrain to determine roughness characteristic of different river reaches and to suggest the appropriate methodology for collecting Bathymetry data. GERMIN Global Positioning System (GPS) was used for collecting the location information of various points in World Geodetic System, 1984 (WGS84).
18.3.2 Topographic Characteristics The topographic characteristic varies significantly within the computation domain. Fig. 18.1 shows the different terrain condition through which the river Dibang passes during its course from hills of Arunachal to the plains of Assam. The river passes through deep gorges, terrains with pebbles and boulders and then through alluvial plains. Most of the portion on downstream of the dam lies in the plains. While it was possible to rely on the satellite based DEM data (Developed from Stereo pair) for elevation value of the hilly
18-9 EMP Report of Dibang Multipurpose Project portion lying upstream side of the dam, it was not advisable to use elevation data derived from the stereo pair for the plain area. As such the concerned organization was requested to conduct cross-sectional survey using TOTAL STATION to acquire the required elevation data.
Fig. 18.1: Different terrain condition 18.3.3 Channel Roughness Choosing a correct roughness coefficient is quite important in unsteady flow simulation in a natural channel. Standard values of Manning’s roughness coefficient “n” for natural streams has been given by Chow, V.T. ( ) and Choudhary H.M.( ) as given below. (i) As complied from Chow Type of the channel “n” value Clean and Straight 0.030
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Bottom gravels, cobbles and boulders 0.040 Bottom cobbles with large boulders 0.050
(ii) As given by Chaudhry MH. (1993) “Open-channel flow”. Prentice-Hall. India Pvt.Ltd. M-97, New-Delhi. Type of Channel “n” Left bank Right bank bottom value Slime covered cobble Cemented cobbles Cobble set in gravel 0.024 and gravel Sand and clay Smooth and free Smooth and free 0.030 vegetation vegetation Smooth Smooth Smooth 0.032 Cobble“d10=0.15m” Cobble“d10=0.15m” Cobble“d10=0.15m” Gravel and Overhanging bushes Trees 0.036 boulders“d10=1.72m” Boulders“d10=1.4m” Gravel, boulders and Gravel, boulders and 0.041 trees trees Angular Angular Angular 0.050 Boulders“d10=0.70m” Boulders“d10=0.70m” Boulders“d10=0.70m” Boulders“d10=2.10m” Boulders“d10=2.10m” Boulders“d10=2.10m” 0.060 Fine sand Sand, silt with heavy Sand, silt with heavy 0.070 growth of trees growth of trees Boulders“d10=2.20m” Boulders, bushes, trees Boulders, bushes, trees 0.075
Based on these tables, it has been found that value ranging from 0.03 to 0.035 can be considered for different reaches of the entire channel under consideration.
18.3.4 Numerical Applications Numerical models formulated have been applied in the natural river Dibang. Performances of these models under different flow conditions have been tested against laboratory data to ensure their validity and applicability.
Application in Dibang River The numerical application analyzed here concerns the instantaneous and total removal of a large dam placed across the non-prismatic channel of river Dibang. The expected flood due to the failure of the proposed dam has been analyzed.
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Input data Initially the cross section data of Dibang River obtained earlier from NPC was used to compute the flow profile. Variation of channel width along the channel reach is presented in the Fig. 18.2. Longitudinal profile of the channel bed along with the computed flow profiles is presented in the Fig. 18.3. The input data in the programme is given in the form of regularly spaced grids. To accomplish it, the actual data acquired at convenient chainage points on the riverbed is linearly interpolated. The total channel reach is represented with a total no of 1000 grid points.
Fig. 18.2: Graph showing variation of channel width along the channel reach
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Fig. 18.3: Channel bed and computed flow profiles
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Initial and Boundary Conditions In this problem, the upstream boundary coincides with the upstream extremity of the reservoir at 40,000m and the downstream one with its confluence with River Brahmaputra, at 64,000m from the dam site. At upstream of the dam the initial profile has been considered as the surface of the still water stored in the reservoir at maximum storage level. For computational advantage, a water depth of 0·1 m is assumed in the dry downstream portion. To start the numerical computation an initial profile computed by Ritter’s equation after elapse of 1 sec, since failure of the dam, has been introduced. Boundary values are obtained with the help of method of characteristics.
Analysis of the results The numerical simulations with the above-mentioned explicit FD schemes are done for the conservative formulations of unsteady flow. Fig. 18.3 illustrates that the conservative formulation of all the FD methods taken here, results excellent flow profiles. Form practical point of view considering factors such as wave propagation time, depth of flow; and peak arrival time, simulated flood profiles by these FD schemes are quite comparable to one another.
Fig. 18.4 represents the plot of flow variables up to 200 second since dam failure at three different cross-sections; one at dam site, one 2496 m upstream of the dam and another 2706 m downstream the dam. It is clear from this plot that the changes in discharge and velocity with respect to spatial distance and time are quite less compared to the flow area. The shapes of the flow area hydrographs at the three different sections are observed to be completely contrasting. At upstream the flow area decreases with time with a reducing rate while at downstream it increases gradually with time. At dam site first it rises sharply with time and then falls down gradually to a more or less constant value. But in case of discharge and velocity hydrographs, similar pattern is maintained in all the three sections. Therefore numerical models with non-conservative formulation, where the variation of cross sectional area with space is computed separately, becomes unstable for dam break flow in such non-prismatic natural channel, as error associated with the calculation of area gets compounded with time. It shows
18-14 EMP Report of Dibang Multipurpose Project that, as rightly used in this project, the numerical formulations of such flow problem should be in conservative form.
It has been reported (Choudhury M. H.1990, Jin et al 1997) that applicability of the numerical schemes are difficult when sub critical and super critical flows are present either simultaneously in different parts of the channel or if they occur in the same section in sequence at different times. Models developed in this study using conservative form have exhibited their capability of handling mixed flow region. Fig. 18.4 illustrates the flow conditions in the entire flow domain considered in this study. Here mixed flow condition has been observed, where sub critical flow changes to high supercritical, with a moving sub/super critical interface. This of course is obviously an expected case for a real large dam break case. The Diffusive scheme which is simplest among FD schemes; also provides excellent results even in complex flow situations when it is formulated in conservative form with small spatial grid points to maintain the high non prismatic nature of the complex real river channel.
Fig. 18.4: Flow conditions at different time, i.e., Froud number of the flow
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Implementation effort The flood in the real cases has to be simulated for a quite long period of time over river stretches of several kilometers long for proper flood management. Therefore, the runtime of the numerical formulation is one of the most important parameters to be considered. Among the above three FD method the diffusion scheme is the easiest to implement and most advantageous even from runtime point of view. The modified predictor corrector takes 146% that of diffusive scheme runtime. The runtime in case of TVD MacCormack is 380% of the diffusive scheme, as TVD correction requires calculation of Jacobian matrix. But there is no significant difference among the flow depths and time of wave propagations when schemes are formulated in conservative form.
18.3.5 Need of Considering Extended Width The flood depth computed by considering the limited width of the cross sectional area has shown that the channel will not be sufficient to contain the flow within that limit. Thus the depth computed by these data cannot be considered logical, as flow will spread beyond this limit. Therefore, the concern organization was requested to collect terrain data beyond this limit up to the required distance as assessed from the first study. On receiving these data it has been found that the terrain can be approximated as a parabolic channel. The channel width thus obtained is presented in the Fig. 18.5. The main channel of Dibang is also shown in this figure. In fact several channels are there in the entire width shown in the plan view. In case of dam failure flood as the depth will be quite high all these channel will merge and will flow as a single channel covering the required width to carry the flow volume. Using the FD Diffusive scheme in conservative form the flow was computed keeping other boundary conditions same as before. The flow depth computed by this procedure has been found to be quite logical and accepted for the computing submerged area due to instantaneous failure of the dam.
18-16 EMP Report of Dibang Multipurpose Project
Plan of Dibang River
N Survey of India 63km control point,situated Road Bolung at Pathar Camp Bridgepoint Kundil River Deopani River Helipad.The Kundil river Deopani river 11km Iphipani river Kerim River Iphipani River Dibang Spherical Lohit river Dibang Dibang Dibang Dibang Dibang Value of the control point is - Dibang Lat 28° 18'40.01250"N, Dense forest Gongo River Gongo River Sisiri River Long Gango river Gango river 95°44'20.19474 "E, El 285.170M Siba river Siba river Siba River Siba River Sisiri River Siang River Siang river Siang River Siang River Barguli Village
Fig. 18.5: Plan of Dibang River
The channel sections for the entire width presented in the fig 15.5 have been approximated as parabolic channel for the purpose of computing dam break flow passing over the terrain. Fig. 18.6 shows the way of representing the cross section for computation purpose. Fig. 18.7a 18.7b & 18.7c, show the computed flow depth considering the parabolic channel representing the entire cross-section. Fig. 18.8 shows the difference in flow depth computed by the (i) concept of rectangular channel of limited width and (ii) concept of parabolic channel of entire cross section. From the comparison it is clear that the flow depth computed by considering the parabolic channel is realistic as the depth drops with the expansion of the channel, which is logical. However, for making disaster management plan we suggest to increase the depth by 10% than that computed by the parabolic section, as the channel section has been approximated. Fig. 18.9 represent the peak arrival time, which is quite vital for mitigation measures. Fig. 18.10 shows the maximum flow velocity, which is helpful for
18-17 EMP Report of Dibang Multipurpose Project assessing the extent of intensity of damage to the existing structures. Fig. 18.11a & 18.11b show the submerged area without considering the additional 10% depth. In Fig.18.11c the graph showing maximum probable depths at different distance from dam axis at downstream (d/s) is presented.
Assumed Channel section for computations at 29 km downstream the dam considering the whole terrain
channel section at 29km d/s
Least square parabolic curve for the 215 computational channel bottom Terrain profile 210
205 Assumed parabolic 200 channel in computations 195 Dibang 190 River elevation(m) 185 y = 5E-07x2 - 0.0057x + 199.94 180 175 -1000 1000 3000 5000 7000 9000 11000 13000 15000 lateral distance(m)
Fig. 18.6: Approximated channel section
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Fig. 18.7a: Flow at 40 km d/s
Fig. 18.7b: Flow C/S at 52Km d/s
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Fig. 18.7c: Flow C/S at 60 km d/s
Fig. 18.8: Comparison of Flow depth
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Time of Peak Arrival at various sections D/S
Time of peak arrival vs the downstream distance
2000
1500
1000
500 Timeof peak arrival (seconds)
0 0 10000 20000 30000 40000 50000 60000 Downstream Distance(m)
Fig. 18.9: Peak arrival of time
Maximum Probable Velocity
The maximum velocity d/s the dam
45 40 35 30 25 20 15 10
d/s the dam (m/seconds) (m/seconds) the dam d/s 5 Maximum probable velocity velocity probable Maximum 0 0 10000 20000 30000 40000 50000 60000 downstream distance(m)
Fig. 18.10: Maximum velocity
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Maximum Probable Submergence
Maximum submergence computed at the grid points
550 Reservoir 500 submergence 450 ground elevation 400 Dam 350 300 250
Elevations metres in 200 150 100 0 200 400 600 800 1000 Grid points
Fig. 18.11a: Sectional view of maximum Submergence
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Fig. 18.11b: Plan view of flooded area at different time without considering additional 10%
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80
70 67.64
60
50
40 36.99
30
20 10.18 9.52 Maximum Probable Depth (m) Depth Probable Maximum 8.3 10 6.57 4.45 4.74 4.37 4.23 3.78 2.2 0 5082.35 10058.82 15035.30 20011.77 25094.12 30070.59 35047.06 40023.53 45000.00 50082.36 55058.83 60035.30 Distance from Dam Axis at d/s (m)
Fig. 18.11c: Graph showing maximum probable depths at different distance from dam axis at downstream (d/s)
18.4 EMERGENCY ACTION PLAN
The important purpose of the dam break study is to prepare an Emergency Action Plan that will lessen or mitigate its impact upon human habitations and properties. The thrust area of action plan will be as follows:
i. To prepare an inundation map, ii. To evaluate risk at downstream habitations, potential areas etc., and iii. To prepare a disaster management plan
18.5 DISASTER MANAGEMENT PLAN In the event of any breach, it is to be ascertained that losses to lives and properties could be kept at minimum by administering the feasible measures. To achieve this, non-structural measures are found to be substantially effective. The important measures are:
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i. To provide flood forecasting services and quick dissemination of forecasts to important and heavily populated towns, villages, including other potential areas. ii. To formulate flood proof communication system, and iii. To form a disaster mitigation network/system, including relief fund. along with the above, few important structural measures, like (i) time to time verification of gates, sluices etc. (ii) human dwelling, animal shelter and storage of essential commodities on raised structures/platforms (above maximum depth of inundation) and (iii) to improve drainage system pertaining to railway lines, National Highways etc. against any possible contestation; are to adopted.
The area downstream of the dam will remain vulnerable to a large-scale disaster either due to high volume release of water from the reservoir compounding the flood scenario downstream or due to passage of dam break flood. The environmental management plan therefore has taken cognigence of such eventualities and has dealt with various aspects of disaster management.
18.5.1 Dimension of disaster and area/population likely to be affected The area as shown in Fig. 18.11b is the basis of the preparing for disaster management plan. Areas on bath north bank and south bank are likely to be prone to disaster caused by high floods. Various components of Disaster Mitigation Plan is described below –
Planning The purpose of disaster management planning is to anticipate future situations and requirements and establish the frame work to meet them. The plan should include all disaster related activities in the pre disaster period, during a disaster and afterward events. But it never goes exactly as envisaged in a plan during an actual disaster. No disaster plan, even well thought out, will provide all the necessary answers to every problem to be faced. But the mental discipline entailed in preparing and practicing will enable a better grasp and help to cope much more effectively whenever it happens.
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Levels of Planning It is suggested that the project authorities should prepare something like a mission plan which can be called as master plan setting out the overall frame work within well laid policies.
Plans at lower levels like districts, sub division should be worked out in consultation with local administration and communities. At this level it should be tailor made to more specific confidences. The higher level mission plan will support the district & sub division level plan.
Disaster management drills Practice or drills to manage disaster should be conducted to orient the concerned organisations and personnel on annual basis. This will help in getting immediate response. Materials and facilities like boats, ropes, medicines, first aid etc. should be kept ready with the onset of monsoon every year. The following aspects should be considered in the disaster management plans: Needs 1. Evacuation 2. Food 3. Shelter 4. Drinking water 5. Health care 6. Sanitation
Safety measures The buildings, electrical distribution infrastructure, communication infrastructure like telecommunication and road to the disaster prone area should be planned and built to withstand worst kind of disaster in the prone area.
Shelters Raised platforms can be constructed as part of the strategy to meet the disasters environment. These platforms should be higher than maximum expected flood water level, safe from erosion by the recurring floods and should be located near health centres having communication to the extent possible.
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Inundation Map and Risk at Down Stream Habitation/Potential Areas
An inundation map depicts the downstream areas vulnerable to inundation by the dam break flood. An inundation map is prepared on the basis of analysis result and is shown in Fig. 18.11b. In the present study, the inundation map was prepared up to 63 km downstream of dam site. Several villages viz. Nizamghat area, Bomjir, Nogpok, Borguli, Bijari, Seram, Anpum, Namsing, Bango, Mer, Amarapur and Puglam are likely to be come in inundation zone.
18.6 FINANCIAL OUTLAY FOR DISASTER PREPAREDNESS AND MITIGATION Occurrence of Disaster due to high flood and disaster like situation cannot be ruled out in this project. The project area being under seismic Zone-V disaster management gains much importance both due to earth quake, change of river courses and floods. The financial provisions included under EMP are discussed below.
18.6.1 Financial Outlay for Installation of VSAT Communication System The cost of deployment and maintenance of a telecommunication system in disaster prone areas is not as important as the availability, reliability and quick restoration of the system. The cost of both satellite bandwidth and the ground components of the satellite communication system has been decreasing rapidly like that of V-SAT (Very Small Aperture Terminal) based systems supporting a couple of voice and data channels. Some highly superior communication systems in VSAT without time delay are marketed by National agencies like HECL, HFCL and HCL Connect. There are two different types of systems with the above mentioned capabilities available in the market viz. SCPCDAMA and TDMA. However, the first one named SCPCDAMA has been recommended. The estimated cost of installation of such a communication system has been given in Table 18.1.
Table 18.1: Estimated cost of setting up of a satellite communication system
S. Amount Product No. (₹ lakh) 1. Product Name: SCPCDAMA (4 sites) @ ₹ 35.00 lakhs per site 140.00 a) Antenna 4 x 2.4 M b) RF 4 x 2 W
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c) Modem 4 x 1 No. 2. Generators 4 x 1 No. (21KVA) 30.00
3. UPS 4 x 1 No. (2KVA) 30.00
4. Installation and maintenance of system, 140.00 maintenance and running cost of UPS, generators, etc. for 7 years @ 10% of the total cost Total 340.00
18.6.2 Evacuation Plans Emergency Action Plan includes evacuation plans and procedures for implementation based on local needs. These are: . demarcation/prioritization of areas to be evacuated, . notification procedures and evacuation instructions, . . safe routes, transport and traffic control. . shelter areas, and . functions and responsibilities of members of evacuation team.
The flood prone zone in the event of dam break of Dibang shall be marked properly at the village locations with adequate, factor of safety. As the flood wave takes sufficient time in reaching these villages, its population shall be informed well in time through wireless and sirens etc. so that people may take shelter at some elevated place beyond the flood zone which has been already marked as safe.
18.6.3 Notification Notification procedures are an integral part of any emergency action plan. Separate procedures shall be established for slowly and rapidly developing situations and in case of failure. Notifications will include communications of either an alert situation or an alert situation followed by a warning situation. An alert situation will indicate that although failure or flooding is not imminent a more serious situation can occur unless conditions improve. A warning situation will indicate that flooding is imminent as a result of an impending failure of the dam. It will normally include an order for evacuation of delineate inundation areas. For a regular watch on the flood level situation, it is necessary that two or more people man the flood cell so that in alternative person Is available for notification round the clock.
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The copies of the Emergency Action Plan should also include the inundation map which would be displayed at prominent locations and in the rooms and locations of the personnel named in the notification chart. Inundation maps will be displayed in the Village Panchayats nearby the project area and also of the villages falling under flood prone zone. For speedy and unhindered communication, a wireless system will be a preferable mode of communication. Telephones would be kept as backup, whenever required. t is also preferred that all the flood cells if more than one, are tuned in the same wireless channel. It will ensure communication from the dam site to the control rooms. An amount of ₹ 50.00 lakhs has been allocated in the project cost for undertaking notification and publication procedures.
In addition, a few guidelines to be generally followed by the inhabitants of flood prone areas, which form part of public awareness for disaster mitigation include: . listen to the radio for advance information and advice, . disconnect all electrical appliances and move all valuable personal and household goods and all clothing out of reach of floodwater, . move vehicles, farm animals and movable goods to the highest ground nearby, . move all dangerous pollutants and insecticides out of reach of water, and . do not enter floodwaters on foot, if it can be avoided.
18.7 COST ESTIMATE FOR DISASTER MANAGEMENT PLAN An amount of ₹ 590 lakh has been earmarked for implementation of Disaster Management Plan. The details are given in Table 18.2.
Table 18.2: Summary of Cost Estimate for Disaster Management Plan
S. Particulars Amount No. (₹ in lakhs) 1. Installation of alert systems, setting-up of control room, etc. 200.00
2. Setting up of VSAT communication system 340.00 3. Notification and publication procedures, miscellaneous, etc. 50.00 Total 590.00
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18.8 CONCLUSION The Dam break analysis has been done for the worst situation that may arise due to failure of Dibang dam. The dam break flood has been routed through the Channel of Dibang River up to the confluence of Brahmaputra River. It has been observed that the reservoir become empty much before the flood wave reaches the confluence. It has also been observed that a large volume of released water will be retained in the Dibang Basin and will return to the main stream of Dibang quite later. Therefore, the effect of this dam failure on the flow of the River Brahmaputra has not been considered in this study. However, if the dam-break-flood-wave reaches the River Brahmaputra simultaneously with a natural flood wave of the Brahmaputra itself, a situation worse than that of the estimated one may occur. However, simultaneous occurrence of such event i.e., the time of dam break flood reaching the confluence and time of a natural flood of Brahmaputra reaching the confluence of Dibang being same, that too with a complete instantaneous failure, is definitely a very rare one.
The Dam break analysis of Dibang dam has been carried out using three different FD schemes. Out of all these schemes the most convenient one, namely the FD Diffusive scheme has been tested for its validity with laboratory data generated elsewhere and then adopted for computing various information, required for preparation of disaster management plan to mitigate flood hazard in the event of failure of the dam. Computed result has shown that several villages located at the downstream side of the dam is expected to be flooded in the event of instantaneous failure. The inundation area shown in the fig will be more by 10% in terms of depth of submergence. This has to be taken into consideration as a safety margin, while preparing the actual disaster management plan for any eventuality of breaking of the DAM.
18-30
CHAPTER 19 ENVIRONMENTAL MONITORING PROGRAMME
EMP Report of Dibang Multipurpose Project
CHAPTER 19 ENVIRONMENTAL MONITORING PROGRAMME
19.1 THE NEED Monitoring is an essential component for sustainability of any water resources project. Monitoring of environmental indicators signal potential problems and facilitate timely prompt implementation of effective remedial measures. It is an integral part of any environmental assessment process. Monitoring becomes essential to ensure that the mitigation measures planned for environmental protection function effectively during the entire period of project operation. It will also allow for validation of the assumption and assessments made in the present study. Any water resources development project introduces complex inter-relationships in the project area between people, various natural resources, biota and the many developing forces. Thus, a new environment is created. It is very difficult to predict with complete certainty the exact post-project environmental scenario. Hence, monitoring of critical parameters is essential in the post-project phase. The data so generated can serve as a data bank for prediction of post project scenarios in similar projects.
19.2 ENVIRONMENTAL MONITORING CELL An Environmental Monitoring Cell (EMC) will be formed in order to assess and review the progress of the various mitigation measures suggested in the Environmental Management Plan. The committee will consist of representatives of MoEF, experts from the concerned State Government Departments, representatives of project affected families/villages, local NGOs and NHPC. The committee will sit at predetermined intervals for verifying progress and reporting the same. The project authority shall depute a Senior Officer to coordinate with the monitoring committee.
19.2.1 Monitoring Mechanism The project authority will engage neutral agency or organization for supervision and monitoring of the environmental management components as discussed below. The project authority will also depute a full time Sr. Officer to look and co-ordinate the progress of the environmental management activities. The independent supervising
19-1 EMP Report of Dibang Multipurpose Project agency will work closely with the project environmental cell and will carry out necessary laboratory analysis, collection of data’s and information regarding the progress and will prepare the progress report in every two months and will present to the Monitoring Committee through the environmental cell. For any major comments or obstacles the independent agency may call a meeting where representatives from independent agency, project authority and environmental committee will be present and any issue may be discussed in the meeting. The major progress report will be with respect to:
Progress of Catchment Area Treatment works, fish management etc. Status of protection measures, sausage / gabion walls etc. at the dumping and quarry sites. Whether dumping is done so as to avoid spillage of muck into the river, especially during rains. Levelling and slope stabilization works at dumping sites. Status of afforestation / turfing works on the dumping/quarry sites.
19.3 AREAS OF CONCERN Based on the findings of the Environmental Impact Assessment study in various Environmental Management Plan the important parameter viz. Catchments Area Treatment, Biodiversity Conservation & Management, Public Health Delivery System, Fish Management, Restoration of Dumping Sites, Quarry areas, Landscaping and Restoration of Construction Area, Green Belt Development etc. have been proposed.
19.4 WATER QUALITY Construction Phase It is proposed to monitor the effluent before and after treatment from oxidation ditch. The frequency of monitoring could be once per month. It is assumed that 3 STPs shall be constructed to treat the sewage generated from five labour camps. A total of (3 STPs X 12 months X 2 samples, i.e. before and after treatment) 72 samples/year need to be analysed. The parameters to be monitored include pH, Bio-chemical Oxygen Demand, Total Suspended Solids and Total Dissolved Solids. The cost of analysis of one sample is expected to be ₹ 2,000. Thus, total cost for analysis of 72
19-2 EMP Report of Dibang Multipurpose Project samples is expected to be ₹ 1.44 lakh/year. The analysis work can be done by a laboratory recognized by the State Pollution Control Board.
Operation phase The surface water quality of river Dibang and proposed reservoir needs to be monitored thrice a year. The proposed parameters to be monitored are as follows: pH, temperature, electrical conductivity, total suspended solids, turbidity, total dissolved solids, calcium, magnesium, total hardness, chlorides, sulphates, nitrates, DO, COD, BOD, Iron, Zinc and Manganese. The sampling sites shall be: - 1 km upstream of the reservoir site. - Reservoir water. - 1, 3 and 5 km downstream of the dam site
The total cost of analysis will be ₹0.75 lakh per year. This analysis shall be done throughout the entire life of the project. The analysis work can be conducted by a reputed external agency recognized by State Pollution Control Board.
During project operation phase, a Sewage Treatment Plant (STP) is proposed to be set up to treat the effluent from the project colony. Once every week, it is envisaged to analyse a sample after treatment from STP. The parameters to be analysed include pH, Biochemical Oxygen Demand, Chemical Oxygen Demand, Total Suspended Solids and Total Dissolved Solids. The cost of analysis of 104 samples @ ₹ 2000 per sample works out to ₹ 2.08 lakh/year. Thus, total cost for analysis in project operation works out to ₹ (0.75 + 2.08) = ₹ 2.83 lakh/year.
19.5 AIR QUALITY AND METEOROLOGY Project Construction Phase The ambient air quality monitoring during construction phase can be carried out by an external agency, approved by State Pollution Control Board at four stations close to construction sites. Every year monitoring is to be done for the following three seasons: - Winter - Summer - Post-monsoon
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The frequency of monitoring could be twice a week for four consecutive weeks at each station for each season. The parameters to be monitored are Particulate Matter less than 2.5 microns (PM2.5), Particulate Matter less than 10 microns (PM10),
Sulphur dioxide (SO2) and Nitrogen dioxide (NO2).
Every year, ambient air quality is to be monitored for (4 stations x 2 days/week x 4 weeks x 3 seasons) = 96 days. A total cost of ₹ 5.76 lakh/year @ ₹ 6,000/day can be earmarked for this purpose.
A meteorological laboratory can be set up at one of the ambient air quality monitoring stations. Automatic recorders for temperature, humidity, wind speed & direction, rainfall needs to be commissioned at the site. An amount of ₹10.00 lakh can be earmarked for this purpose.
19.6 NOISE Project Construction Phase Noise emissions from vehicular movement, operation of various construction equipment may be monitored during construction phase at major construction sites. The frequency of monitoring could be once every three months. For monitoring of noise generators an Integrating Sound Level Meter will be required. An amount of ₹ 1.00 lakh has been earmarked for the purpose.
Project Operation Phase No major impact due to noise is observed in operation phase.
19.7 ECOLOGY Project Construction Phase A detailed ecological survey covering forestry, fisheries, wildlife is recommended during entire construction phase. The survey can be conducted once in each season for three seasons every year for the entire construction period. The various aspects to be covered include: - Qualitative and Quantitative assessment of flora and fauna. - Monitoring of restoration of muck disposal area.
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Monitoring of aquatic ecology will be essential to achieve sustainable yield of fish. Some of the parameters to be monitored are phytoplanktons, zooplanktons, benthic life and fish composition, etc. The monitoring can be conducted by a reputed external agency, for which an amount of ₹18.00 lakh/year can be earmarked.
Project Operation Phase Status of afforestation programmes, changes in migration patterns of the aquatic and terrestrial fauna species should be studied. The study could be undertaken with a frequency of once in each season for three seasons per year till the entire design life of the project. A provision of ₹ 18.00 lakh/year can be kept for this purpose. The monitoring can be conducted by a reputed external agency.
19.8 INCIDENCE OF WATER-RELATED DISEASES Project Construction Phase Identification of water-related diseases, adequacy of local vector control and curative measures, status of public health are some of the parameters which should be closely monitored three times a year with the help of data maintained in the government dispensaries/hospitals. Implementation : Public Health Department, and Dispensary constructed for labour camps Cost per annum : ₹ 5.00 lakh
Project Operation Phase
Increased prevalence of various vector borne diseases and adequacy of local vector control and curative measures need to be monitored. The monitoring can be done three times in a year. Implementation : Nearby Dispensary/PHCs Cost per annum : ₹ 5.00 lakh
19.9 LANDUSE PATTERN Project Operation Phase During project operation phase, it is proposed to monitor land use pattern once every year. An amount of ₹ 5.00 lakh can be earmarked for this purpose.
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19.10 SUMMARY OF ENVIRONMENTAL MONITORING PROGRAMME The details of environmental monitoring programme are given in Tables 19.1 and 19.2 respectively. Table 19.1: Summary of Environmental Monitoring Programme during Project Construction Phase S. Item Parameters Frequency Location No. 1. Effluent from STPs pH, BOD, COD, TSS, Once Before and after TDS every treatment from month each STP 2. Water-related Identification of water Three Labour camps diseases related diseases, times a and colonies adequacy of local vector year control and curative measure, etc. 3. Noise level Equivalent noise level Once in At major (Leq) three construction sites. months 4. Ambient Air quality PM2.5, PM10, SO2 and Once At major NO2 every construction sites season 5. Meteorological Wind direction & velocity Once At one of the aspects temperature humidity, every ambient air rain season quality sampling sites 6. Ecology Status of afforestation Once programmess of green every belt development, season Terrestrial Flora and fauna and aquatic ecology 7. Aquatic ecology Phytoplanktons, Once zooplanktons, benthic every life, fish composition season
Table 19.2: Summary of Environmental Monitoring Programme during Project Operation Phase S. Items Parameters Frequency Location No. 1. Water pH, Temperature, EC, Once every 1 km upstream of TSS,Turbidity, Total season submergence site Dissolved Solids, Submergence area Calcium, Magnesium, 1, 3 and 5 km Total Hardness, downstream of dam Chlorides, Sulphates, site Nitrates, DO. COD, BOD, Iron, Zinc, Manganese 2. Effluent pH, BOD, COD, TSS, Once every Before and after
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S. Items Parameters Frequency Location No. from TDS week treatment from Sewage Sewage Treatment Plant (STP) Treatment Plant (STP) 3. Ecology Status of afforestation Once every - programmess of green season belt development, Terrestrial Flora and fauna and aquatic ecology 4. Water- Identification of water- Once every Villages adjacent to related related diseases, sites, season project sites diseases adequacy of local vector control measures, etc. 5. Aquatic Phytoplanktons, Once every 1 km upstream of ecology zooplanktons, benthic season reservoir site life, fish composition Submergence area 1, 3 and 5 km downstream of dam site
6. Landuse Landuse pattern using Once in a Catchment area satellite data year
19.11 COST ESTIMATE FOR ENVIRONMENTAL MONITORING PROGRAMME The cost required for implementation of the Environmental Monitoring Programme is of the order of ₹ 406.37 lakh. A 10% annual price increase may be considered for every year. The construction period for estimation of cost for implementation of Environmental Monitoring programme during construction phase has been taken as 8 years. Moreover, a provision of ₹ 50.00 lakh has also been kept for Environmental Study. The details are given in Table 19.3.
The cost required for implementation of the Environmental Monitoring Programme in operation phase is of the order of ₹ 30.83 lakh/year. The details are given in Table 19.4.
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Table 19.3: Cost for Implementing Environmental Monitoring Programme during construction phase Total cost for construction Cost period S. Item (₹ of 8 years with 10% No lakh/year) escalation per year (₹ in lakh) 1 Water quality 1.44 16.47 2 Ambient Air quality 5.76 65.87 3. Set-up of Meteorological Lab Lump sum 10.00 4. Noise meter Lump sum 1.00 5. Ecology 18.00 205.85 6. Incidence of water related 5.00 57.18 diseases 7. Budget earmarked for Lump sum 50.00 Environmental Study Total 406.37
Table 19.4: Cost for Implementing Environmental Monitoring Programme during operation phase S. Cost Item No. (₹ in Lakh/year) 1. Water quality 2.83 2. Ecology 18.00 3. Incidence of water related diseases 5.00 4. Land use pattern 5.00 Total 30.83
19-8
CHAPTER 20 ASSESSMENT OF ENVIRONMENTAL FLOW
EMP Report of Dibang Multipurpose Project
CHAPTER 20 ASSESSMENT OF ENVIRONMENTAL FLOW
20.1 ENVIRONMENTAL FLOW IN THE DIVERTED STRETCH OF ABOUT 1.2 KM BETWEEN DAM AND TRTS OF POWER HOUSE
The study on estimation of depth on account of release of Environmental Flows has been studied using HEC-RAS 4.1 in between dam and TRTs of Power House. The L-section of the stretch between Dam and TRT outlet is presented in Fig. 20.1. The study has been done using cross-sections. The Manning's value (n = 0.04) has been kept constant throughout the entire reach.
The Ashupani contribution of 1.55 cumec (discharge data of Ashu Pani is given in Annexure 20.1) has also been taken at 1400 m d/s of dam and the Plunge pool portion is up to 700 m d/s of dam. Depth and velocity of water in the river due to release of three alternatives of environmental flow i.e. 15 cumecs, 20 cumecs and 25 cumecs have been calculated with four scenarios: 1) Contribution of Ashupani & Backflow 2) Contribution of Ashupani but no contribution from Backflow 3) No Contribution of Ashupani & No Backflow 4) Contribution of Backflow but no contribution from Ashupani
The depth and velocity for various scenarios for release of 15 cumecs, 20 cumecs and 25 cumecs in the stretch between plunge pool of Dam and TRT outlet t is given in Tables 20.1 to 20.3.
20-1 EMP Report of Dibang Multipurpose Project
Fig. 20.1: L-section of the stretch between Dam and TRTs
20-2 EMP Report of Dibang Multipurpose Project
Table 20.1: Depth and Velocity due to 15 cumecs discharge between plunge pool of Dam and TRT Outlet
Location Bed Contribution of Contribution of No Contribution of Contribution of Level Ashupani & Ashupani but no Ashupani & No Backflow but no (m) Backflow contribution Backflow contribution from Backflow from Ashupani Depth Velocity Depth Velocity Depth Velocity Depth Velocity (m) (m/sec) (m) (m/sec) (m) (m/sec) (m) (m/sec) 700 m d/s 287.02 1.33 0.62 1.33 0.62 1.33 0.62 1.33 0.62 800 m d/s 286.88 1.10 1.69 1.10 1.69 1.10 1.69 1.10 1.69 900 m d/s 286.14 1.38 1.08 1.38 1.08 1.38 1.08 1.38 1.08 1000 m d/s 285.96 1.23 1.07 1.23 1.07 1.23 1.07 1.23 1.07 1100 m d/s 285.53 0.79 1.99 0.79 1.99 0.79 1.99 0.79 1.99 1200 m d/s 284.90 1.05 0.65 1.05 0.65 1.05 0.65 1.05 0.65 1300 m d/s 284.76 0.81 1.39 0.81 1.38 0.78 1.44 0.78 1.49 1400 m d/s 284.12 1.25 0.64 1.14 0.76 1.09 0.75 1.21 0.61 (Ashupani Confluence) 1500 m d/s 284.00 1.31 0.49 1.18 0.56 1.14 0.53 1.28 0.46 1600 m d/s 283.92 1.37 0.36 1.21 0.45 1.17 0.44 1.34 0.34 1700 m d/s 283.59 1.65 0.50 1.45 0.65 1.41 0.62 1.63 0.47 1800 m d/s 283.68 1.48 0.64 1.10 1.23 1.06 1.20 1.46 0.59 1900 m d/s 283.55 1.59 0.26 0.86 0.80 0.83 0.77 1.58 0.24
Table 20.2: Depth and Velocity due to 20 cumecs discharge between plunge pool of Dam and TRT Outlet
Location Bed Contribution of Contribution of No Contribution Contribution of Level Ashupani & Ashupani but no of Ashupani & Backflow but no (m) Backflow contribution from No Backflow contribution from Backflow Ashupani Depth Velocity Depth Velocity Depth Velocity Depth Velocity (m) (m/sec) (m) (m/sec) (m) (m/sec) (m) (m/sec) 700 m d/s 287.02 1.48 0.68 1.48 0.68 1.48 0.68 1.48 0.68 800 m d/s 286.88 1.24 1.77 1.24 1.77 1.24 1.77 1.24 1.77 900 m d/s 286.14 1.53 1.18 1.53 1.18 1.53 1.18 1.53 1.18 1000 m d/s 285.96 1.36 1.17 1.36 1.17 1.36 1.17 1.36 1.17 1100 m d/s 285.53 0.88 2.10 0.88 2.10 0.88 2.10 0.88 2.10 1200 m d/s 284.90 1.16 0.72 1.16 0.72 1.16 0.72 1.16 0.72 1300 m d/s 284.76 0.92 1.44 0.92 1.45 0.90 1.52 0.90 1.52 1400 m d/s 284.12 1.36 0.70 1.28 0.79 1.24 0.78 1.33 0.68 (Ashupani Confluence) 1500 m d/s 284.00 1.41 0.59 1.31 0.64 1.27 0.62 1.38 0.56 1600 m d/s 283.92 1.46 0.42 1.34 0.49 1.30 0.48 1.43 0.40 1700 m d/s 283.59 1.73 0.60 1.58 0.72 1.54 0.70 1.71 0.57 1800 m d/s 283.68 1.52 0.78 1.20 1.33 1.17 1.30 1.51 0.74 1900 m d/s 283.55 1.63 0.33 0.93 0.88 0.91 0.86 1.62 0.31
20-3 EMP Report of Dibang Multipurpose Project
Table 20.3: Depth and Velocity due to 25 cumecs discharge between plunge pool of Dam and TRT Outlet
Location Bed Contribution of Contribution of No Contribution Contribution of Level Ashupani & Ashupani but no of Ashupani & No Backflow but no (m) Backflow contribution from Backflow contribution Backflow from Ashupani Depth Velocity Depth Velocity Depth Velocity Depth Velocity (m) (m/sec) (m) (m/sec) (m) (m/sec) (m) (m/sec) 700 m d/s 287.02 1.60 0.73 1.60 0.73 1.60 0.73 1.60 0.73 800 m d/s 286.88 1.37 1.83 1.37 1.83 1.37 1.83 1.37 1.83 900 m d/s 286.14 1.65 1.27 1.65 1.27 1.65 1.27 1.65 1.27 1000 m d/s 285.96 1.47 1.26 1.47 1.26 1.47 1.26 1.47 1.26 1100 m d/s 285.53 0.97 2.18 0.97 2.18 0.97 2.18 0.97 2.18 1200 m d/s 284.90 1.26 0.78 1.26 0.78 1.26 0.78 1.26 0.78 1300 m d/s 284.76 1.02 1.49 1.01 1.52 0.99 1.57 1.00 1.55 1400 m d/s 284.12 1.46 0.74 1.40 0.81 1.37 0.80 1.43 0.73 (Ashupani Confluence) 1500 m d/s 284.00 1.50 0.67 1.42 0.71 1.39 0.69 1.47 0.65 1600 m d/s 283.92 1.54 0.47 1.45 0.52 1.42 0.51 1.52 0.46 1700 m d/s 283.59 1.80 0.68 1.69 0.77 1.65 0.76 1.78 0.65 1800 m d/s 283.68 1.57 0.90 1.28 1.41 1.26 1.39 1.56 0.86 1900 m d/s 283.55 1.67 0.39 1.00 0.95 0.98 0.93 1.66 0.37
It can be seen from Table 20.1 that even for a discharge of 15 cumecs from dam, a minimum depth of 0.78 m is available at a distance of 1300 m downstream of dam with no contribution of Ashu Pani and no contribution from backflow. Thus, even for worst case scenario, sufficient depth is available in the stretch between plunge pool of Dam and TRT Outlet.
Similarly, from Table 20.2 it is clear that for a discharge of 20 cumecs from dam, a minimum depth of 0.88 m is available at at a distance of 1100 m downstream of dam with no contribution of Ashu Pani and no contribution from backflow. Further, for a discharge of 25 cumecs from dam, as clear from Table 20.3, a minimum depth of 0.97 m is available at at a distance of 1100 m downstream of dam with no contribution of Ashu Pani and no contribution from backflow.
The minimum depth required for sustenance of fish species, observed in the study area, is 0.5 to 0.7 m. The depth available in the stretch between plunge pool of dam and TRT outlet, by releasing the environmental flow of 15 cumecs from dam, is appropriate and neet the depth required by fish population.
20-4 EMP Report of Dibang Multipurpose Project
20.2 RELEASE OF MINIMUM FLOW AFTER TRT The minimum flow after TRT for Dibang Multipurpose Project has been compared with the extant norms of Ministry of Environment & Forests (MoEF). The required minimum flow on the basis of discharge in 90% dependable year for the proposed Dibang Multipurpose project is given in Table 20.4.
Table 20.4: Minimum Flows required as per extant norms of MoEF
Discharge (cumecs) Minimum Required Average Month in 90% dependable Flow Minimum Flow Discharge year Criteria (cumecs) June 1548.6 July 603.2 936.9 30% 281.1 August 1111.5 September 484.1 October 799.6 739.4 25% 184.9 November 462.7 December 310.4 377.4 20% 75.5 January 352 February 384.5 March 502.4 April 817.2 739.4 25% 184.9 May 838.5
The hydrograph, which has been formulated using the extant norms, simulates the natural conditions in the river to fulfil the different flow regimes present throughout the year. The identification and incorporation of these important flow characteristics will help to maintain the river’s channel structure, diversity of the physical biotopes.
Detailed power potential studies with three alternatives of environmental flow i.e. release of 15 cumecs, 20 cumecs and 25 cumecs and with a condition that at least one turbine shall be operated 24 hours in full / part load throughout the year have been undertaken. The results of the studies are summarized in Table 20.5. The annual energy generation from the project in the above three alternatives i.e., release of 15 cumecs, 20 cumecs and 25 cumecs and with a condition that at least one turbine shall be operated 24 hours throughout the year will be 10767 MUs, 10690 MUs and 10612 MUs, respectively. The comparison of required Flows with respect to flows proposed to be released after TRT with environmental flow of 15 cumecs, 20 cumecs and 25 cumecs from dam is given in Table 20.6.
20-5 EMP Report of Dibang Multipurpose Project
Table 20.5: Proposed release of water after TRT considering 15 cumecs, 20 cumecs and 25 cumecs of environmental flow from dam in 90% dependable year
15 cumecs 20 cumecs 25 cumecs Minimum Minimum Minimum Discharge at Discharge at Discharge at discharge at discharge at discharge at Month TRT outlet Average Peaking TRT outlet Average Peaking TRT outlet Average Peaking TRT outlet TRT outlet TRT outlet during peak Discharge hours during peak Discharge hours during peak Discharge hours during non- during non- during non- hours (cumecs) (hr) hours (cumecs) (hr) hours (cumecs) (hr) peak hours peak hours peak hours (cumecs) (cumecs) (cumecs) (cumecs) (cumecs) (cumecs) June I 124.16 1529.27 1198 18.34 129.16 1534.30 1203 18.34 134.15 1539.32 1208 18.34 II 123.62 1533.13 1210 18.49 128.62 1538.15 1215 18.49 133.62 1543.18 1220 18.49 III 123.62 1533.13 1210 18.49 128.62 1538.15 1215 18.49 133.62 1543.18 1220 18.49 July I 122.79 669.74 288 7.23 127.79 669.02 289 7.16 132.78 668.31 291 7.08 II 122.79 669.74 288 7.23 127.79 669.02 289 7.16 132.78 668.31 291 7.08 III 122.79 669.74 288 7.23 127.79 669.02 289 7.16 132.78 668.31 291 7.08 August I 123.28 1250.70 820 14.84 128.28 1249.98 818 14.76 133.27 1249.27 816 14.69 II 122.74 615.90 257 6.52 127.73 614.45 258 6.44 132.73 613.00 260 6.35 III 114.43 1039.15 625 13.25 119.41 1039.11 625 13.18 124.40 1039.06 624 13.11 September I 111.71 554.38 232 6.52 116.70 553.60 234 6.44 121.70 552.82 236 6.35 II 111.89 555.42 232 6.52 116.89 554.62 234 6.44 121.88 553.82 236 6.35 III 112.09 556.51 233 6.52 117.08 555.69 235 6.44 122.08 554.88 237 6.35 October I 112.30 557.67 233 6.52 117.29 556.84 235 6.44 122.28 556.00 237 6.35 II 109.05 539.54 226 6.52 114.04 538.90 228 6.44 119.03 538.26 230 6.35 III 106.01 750.88 377 10.10 111.01 750.45 378 10.01 116.00 750.01 378 9.93 November I 104.48 514.04 216 6.52 109.47 513.69 218 6.44 114.47 513.35 220 6.35 II 104.49 514.11 216 6.52 109.49 513.77 218 6.44 114.49 513.44 220 6.35 III 104.50 514.17 216 6.52 109.50 513.86 218 6.44 114.50 513.54 220 6.35 December I 104.51 514.25 216 6.52 109.52 513.95 218 6.44 114.52 513.65 220 6.35 II 106.01 522.60 219 6.52 111.02 522.24 221 6.44 116.03 521.87 223 6.35 III 107.64 531.67 223 6.52 112.65 531.23 225 6.44 117.66 530.78 227 6.35 January I 109.59 542.57 227 6.52 114.61 542.03 229 6.44 119.62 541.48 231 6.35 II 111.09 550.91 231 6.52 116.10 550.29 233 6.44 121.12 549.67 235 6.35 III 112.72 560.00 234 6.52 117.74 559.29 236 6.44 122.76 558.58 238 6.35 February I 114.68 570.95 239 6.52 119.70 570.13 241 6.44 124.72 569.31 242 6.35 II 116.26 579.76 242 6.52 121.28 578.84 244 6.44 126.30 577.92 246 6.35 III 118.16 590.37 246 6.52 123.19 589.39 248 6.44 128.22 588.41 250 6.35 March I 120.42 602.95 252 6.52 125.45 601.83 253 6.44 130.47 600.71 255 6.35 II 121.23 607.51 253 6.52 126.26 606.30 255 6.44 131.28 605.09 257 6.35 III 122.15 612.60 255 6.52 127.16 611.29 257 6.44 132.17 609.98 259 6.35 April I 123.27 618.87 258 6.52 128.27 617.43 259 6.44 133.27 615.99 261 6.35 II 118.20 590.59 247 6.52 123.19 589.39 248 6.44 128.18 588.19 250 6.35 III 114.52 570.08 238 6.52 119.51 569.08 240 6.44 124.50 568.08 242 6.35 May I 111.53 1236.59 890 16.61 116.52 1231.42 881 16.46 121.50 1226.30 873 16.31 II 114.72 1601.36 1431 21.24 119.66 1606.16 1436 21.26 124.60 1610.95 1442 21.27 III 123.42 947.82 496 10.84 128.42 947.11 495 10.76 133.41 946.40 495 10.69 Annual Energy 10767 10690 10612 Generation (MU)
20-6 EMP Report of Dibang Multipurpose Project
Table 20.6: Comparison of required Minimum Flows vis-à-vis proposed release of water after TRT considering 15 cumecs, 20 cumecs and 25 cumecs of environmental flow from dam in 90% dependable year
Required Minimum 15 cumecs 20 cumecs 25 cumecs Flow considering Month 90% Average Average Average dependable Discharge Discharge Discharge year (cumecs) (cumecs) (cumecs) (cumecs) June I 281.1 1198 1203 1208 II 281.1 1210 1215 1220 III 281.1 1210 1215 1220 July I 281.1 288 289 291 II 281.1 288 289 291 III 281.1 288 289 291 August I 281.1 820 818 816 II 281.1 257 258 260 III 281.1 625 625 624 September I 281.1 232 234 236 II 281.1 232 234 236 III 281.1 233 235 237 October I 184.9 233 235 237 II 184.9 226 228 230 III 184.9 377 378 378 November I 75.5 216 218 220 II 75.5 216 218 220 III 75.5 216 218 220 December I 75.5 216 218 220 II 75.5 219 221 223 III 75.5 223 225 227 January I 75.5 227 229 231 II 75.5 231 233 235 III 75.5 234 236 238 February I 75.5 239 241 242 II 75.5 242 244 246 III 75.5 246 248 250 March I 184.9 252 253 255 II 184.9 253 255 257 III 184.9 255 257 259 April I 184.9 258 259 261 II 184.9 247 248 250 III 184.9 238 240 242 May I 184.9 890 881 873 II 184.9 1431 1436 1442 III 184.9 496 495 495
20-7 EMP Report of Dibang Multipurpose Project
From Table 20.6, it is clearly observed that the project shall maintain discharge higher than the required Minimum Flow, as per the extant norms, throughout the year.
The depths of flow in the river at various distances by release of water after TRT considering 15 cumecs of environmental flow from dam in 90% dependable year are presented in Tables 20.7.
Table 20.7: Depth of water by releasing average flow during the day from TRT considering 15 cumecs of environmental flow from dam in 90% dependable year Depth Average Depth of Depth of Depth of Depth of of flow Flow flow (m) flow (m) flow (m) flow (m) (m) Month during the 12 km d/s 24 km d/s 48 km d/s 60 km d/s 36 km day of dam of dam of dam of dam d/s of (cumecs) (m) (m) (m) (m) dam (m) June I 1198 1.90 3.12 1.87 2.29 1.90 II 1210 1.90 3.13 1.88 2.30 1.90 III 1210 1.90 3.13 1.88 2.30 1.90 July I 288 1.14 1.98 1.19 1.42 1.14 II 288 1.14 1.98 1.19 1.42 1.14 III 288 1.14 1.98 1.19 1.42 1.14 August I 820 1.66 2.76 1.66 2.02 1.66 II 257 1.10 1.91 1.14 1.36 1.10 III 625 1.50 2.53 1.52 1.84 1.50 September I 232 1.06 1.84 1.11 1.32 1.06 II 232 1.06 1.84 1.11 1.32 1.06 III 233 1.06 1.85 1.11 1.32 1.06 October I 233 1.06 1.85 1.11 1.32 1.06 II 226 1.05 1.83 1.10 1.31 1.05 III 377 1.26 2.15 1.29 1.55 1.26 November I 216 1.03 1.80 1.08 1.29 1.03 II 216 1.03 1.80 1.08 1.29 1.03 III 216 1.03 1.80 1.08 1.29 1.03 December I 216 1.03 1.80 1.08 1.29 1.03 II 219 1.03 1.81 1.09 1.29 1.03 III 223 1.04 1.82 1.09 1.30 1.04 January I 227 1.05 1.83 1.10 1.31 1.05 II 231 1.05 1.84 1.11 1.32 1.05 III 234 1.06 1.85 1.11 1.32 1.06
20-8 EMP Report of Dibang Multipurpose Project
Depth Average Depth of Depth of Depth of Depth of of flow Flow flow (m) flow (m) flow (m) flow (m) (m) Month during the 12 km d/s 24 km d/s 48 km d/s 60 km d/s 36 km day of dam of dam of dam of dam d/s of (cumecs) (m) (m) (m) (m) dam (m) February I 239 1.07 1.86 1.12 1.33 1.07 II 242 1.07 1.87 1.12 1.34 1.07 III 246 1.08 1.88 1.13 1.34 1.08 March I 252 1.09 1.89 1.14 1.35 1.09 II 253 1.09 1.90 1.14 1.36 1.09 III 255 1.09 1.90 1.14 1.36 1.09 April I 258 1.10 1.91 1.15 1.37 1.10 II 247 1.08 1.88 1.13 1.35 1.08 III 238 1.07 1.86 1.12 1.33 1.07 May I 890 1.70 2.84 1.70 2.07 1.70 II 1431 2.02 3.30 1.98 2.43 2.02 III 496 1.38 2.35 1.41 1.70 1.38
As stated in the preceding paragraph, the minimum depth required for the sustenance of fish species, observed in the study area, is 0.5 to 0.7 m. From Table 20.7, it is clear that the depth of water at various distances from the dam site by releasing average flow during the day from TRT and 15 cumecs of environmental flows from dam in various seasons in 90% dependable year is much higher than the depth required for sustenance of riverine fish species.
20-9 EMP Report of Dibang Multipurpose Project
Annexure 20.1: Ashu Pani Discharge Data (Cumecs) 1985- 1986- 1987- 1988- 1989- 1990- 1991- 1992- 1993- 1994- 1995- 1996- 1997- 1998- 1999- 2000- MONTH 86 87 88 89 90 91 92 93 94 95 96 97 98 99 2000 2001 1-10 9.42 10.15 13.72 10.17 17.85 11.75 10.17 10.17 7.26 8.64 13.63 6.20 8.94 9.73 8.09 13.11 JUNE 11-20 11.06 11.91 16.10 11.94 20.96 13.80 11.94 11.94 8.52 10.14 16.00 7.27 10.50 11.43 9.50 15.39 21-30 11.05 11.90 16.09 11.92 20.93 13.78 11.92 11.92 8.51 10.13 15.98 7.26 10.49 11.41 9.49 15.37 1-10 10.45 9.24 15.85 10.03 15.99 14.12 8.18 4.67 8.75 3.95 6.15 19.28 6.48 17.12 8.19 9.04 JULY 11-20 10.08 8.91 15.30 9.68 15.43 13.62 7.89 4.51 8.44 3.81 5.94 18.60 6.25 16.52 7.91 8.72 21-31 9.35 8.27 14.20 8.98 14.32 12.64 7.32 4.18 7.83 3.53 5.51 17.26 5.80 15.33 7.34 8.09 1-10 6.77 9.16 11.50 10.25 8.46 9.78 9.05 4.26 7.88 6.05 9.20 7.09 3.59 14.68 5.81 8.38 AUGUST 11-20 8.54 11.55 14.50 12.93 10.66 12.34 11.42 5.37 9.94 7.63 11.60 8.95 4.53 18.52 7.33 10.57 21-31 7.90 10.68 13.42 11.96 9.87 11.41 10.56 4.97 9.20 7.06 10.73 8.28 4.19 17.13 6.78 9.78 1-10 7.99 8.32 8.29 8.43 14.31 12.11 9.27 6.59 5.00 4.54 9.43 8.22 8.51 10.97 5.58 9.07 SEPTEMBER 11-20 4.51 4.69 4.68 4.76 8.07 6.83 5.23 3.71 2.82 2.56 5.32 4.64 4.80 6.19 3.15 5.12 21-30 3.39 3.54 3.52 3.58 6.08 5.15 3.94 2.80 2.12 1.93 4.01 3.49 3.61 4.66 2.37 3.85 1-10 5.52 4.47 4.16 3.85 10.43 6.89 5.45 3.03 3.87 5.48 5.41 4.99 2.59 5.26 3.20 4.54 OCTOBER 11-20 4.54 3.68 3.42 3.17 8.57 5.67 4.48 2.49 3.18 4.51 4.45 4.10 2.13 4.32 2.63 3.73 21-31 4.98 4.04 3.75 3.47 9.41 6.22 4.92 2.74 3.49 4.95 4.88 4.50 2.34 4.74 2.89 4.10 1-10 2.12 2.20 2.15 2.17 3.18 2.07 2.18 2.03 2.23 3.00 2.09 2.23 2.10 2.10 2.83 2.42 NOVEMBER 11-20 2.05 2.12 2.08 2.10 3.08 2.00 2.11 1.96 2.16 2.90 2.02 2.16 2.03 2.70 2.73 2.34 21-30 1.94 2.00 1.96 1.98 2.90 1.89 1.99 1.85 2.04 2.74 1.90 2.04 1.92 2.55 2.57 2.20 1-10 2.11 1.95 2.16 1.96 2.20 1.98 1.99 1.92 2.00 1.97 2.02 2.00 1.95 2.21 2.41 2.10 DECEMBER 11-20 2.14 1.98 2.19 1.99 2.23 2.01 2.02 1.95 2.03 2.00 2.05 2.03 1.98 2.24 2.45 2.13 21-31 1.98 1.83 2.02 1.84 2.06 1.86 1.86 1.80 1.87 1.84 1.89 1.87 1.82 2.07 2.26 1.97 1-10 2.00 1.90 2.25 2.42 3.08 2.92 2.27 2.22 2.31 2.22 2.36 2.09 1.85 1.94 2.27 2.05 JANUARY 11-20 2.00 1.90 2.25 2.41 3.07 2.91 2.26 2.21 2.30 2.22 2.36 2.08 1.84 1.93 2.27 2.04 21-31 1.93 1.83 2.17 2.33 2.96 2.81 2.18 2.14 2.22 2.14 2.27 2.01 1.77 1.87 2.19 1.97 1-10 2.60 2.81 2.50 2.59 4.20 2.67 2.67 2.48 2.67 2.33 2.17 3.96 2.36 2.01 2.39 2.05 FEBRUARY 11-20 2.60 2.81 2.50 2.58 4.19 2.66 2.66 2.47 2.66 2.33 2.16 3.95 2.36 2.01 2.39 2.05
20-10 EMP Report of Dibang Multipurpose Project
21-28 2.83 3.07 2.73 2.82 4.57 2.91 2.91 2.70 2.91 2.54 2.36 4.32 2.58 2.19 2.61 2.24 1-10 2.31 2.97 2.28 3.57 3.14 2.28 2.52 2.06 2.37 3.06 2.31 2.41 3.46 1.88 2.53 2.43 MARCH 11-20 2.17 2.79 2.14 3.36 2.95 2.15 2.37 1.94 2.23 2.88 2.17 2.26 3.25 1.76 2.38 2.28 21-31 2.58 3.32 2.54 3.99 3.50 2.55 2.81 2.30 2.65 3.42 2.57 2.69 3.86 2.09 2.83 2.71 1-10 2.48 2.57 2.51 3.12 4.35 2.45 2.51 1.55 2.04 3.57 2.10 1.68 4.99 3.78 6.12 3.01 APRIL 11-20 3.88 4.01 3.91 4.87 6.78 3.82 3.91 2.42 3.18 5.57 3.27 2.63 7.78 5.90 9.55 4.69 21-30 4.26 4.41 4.30 5.35 7.45 4.20 4.30 2.66 3.49 6.12 3.60 2.88 8.55 6.48 10.49 5.15 1-10 7.91 7.68 6.21 8.98 5.82 5.89 6.21 5.15 4.79 5.14 5.57 9.99 6.48 7.39 6.90 3.65 MAY 11-20 6.87 6.68 5.40 7.80 5.06 5.12 5.40 4.48 4.16 4.47 4.84 8.68 5.63 6.42 6.00 3.17 21-31 9.18 8.92 7.21 10.43 6.76 6.84 7.21 5.98 5.56 5.97 6.46 11.60 7.53 8.58 8.02 4.24
20-11
CHAPTER 21 SUMMARY OF COST ESTIMATES
EMP Report of Dibang Multipurpose Project
CHAPTER 21 SUMMARY OF COST ESTIMATES
21.1 COST FOR IMPLEMENTING ENVIRONMENTAL MANAGEMENT PLAN The total amount to be spent for implementation of Environmental Management Plan (EMP) is ₹ 63942 lakh. The details are given in Table 21.1.
Table 21.1: Cost of Environmental Management Plans
S. No. EMP Component Amount (₹ in lakh) 1. Biodiversity Conservation and Management Plan 1785.10 2. Catchment Area Treatment Plan 2395.71 3. Fish Management Plan 648.24 4. Green Belt Development Plan 200.00 5. Geo-Environmental Management Plan 2312.63 6. Muck Disposal Plan 648.40 7. Restoration Plan for Quarry Areas 189.62 8. Landscaping & Restoration of Construction 877.76 Areas and Environmental Management in Road Construction 9. Public Health Delivery System 1021.34 10. Plan for Solid Waste Management & Sanitation 554.78 Facilities in Labour Camps 11. Energy Conservation Measures 170.00 12. a) Resettlement and Rehabilitation Plan 7907.05 b) Compensation of Land and Rights and 19773.07 Privileges 13. a) Community and Social Development Plan 7000.00 b) Concerns raised during Public Hearing 17100.00 14. Plan for Protection of Cultural Identity 327.03 15. Maintenance of Air, Water and Noise Quality 35.00 16. Disaster Management Plan 590.00 17. Environmental Monitoring Programme (during 406.37 construction phase) Total 63942.10 Say ₹ 63942 lakh
21-1 EMP Report of Dibang Multipurpose Project Annexure 18.1
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
0, 179.434016228438, 38.4010000000003
105.882361, 177.249845101045, 44.7010000000004
211.764722, 173.224182088301, 50.4010000000005
317.647083, 169.577493217734, 55.5010000000005
423.529444, 166.324082713056, 60.0010000000006
529.411805, 163.190004092772, 64.5010000000006
635.294166, 160.375508927567, 68.6010000000004
741.176527, 157.645511371781, 72.5010000000002
847.058888, 155.065856809326, 76.201
952.941249, 152.617625458612, 79.9009999999997
1058.82361, 150.285173051477, 83.4009999999995
1164.705971, 148.336939839355, 86.700999999993
1270.588332, 145.920034639946, 90.0009999999992
1376.470693, 144.14064072426, 93.100999999999
1482.353054, 141.893248155393, 96.0009999999988
1588.235415, 140.253597814132, 99.1009999999986
1694.117776, 138.150539337095, 102.000999999998
1800.000137, 136.556843081633, 104.700999999998
1905.882498, 134.402452629903, 107.400999999998
2011.764859, 132.742701838161, 110.100999999998
2117.64722, 131.136413803872, 112.800999999998
2223.529581, 129.583157418982, 115.300999999998
2329.411942, 128.083496237308, 117.800999999998
2435.294303, 126.639129827466, 120.500999999997
2541.176664, 124.940481111215, 122.800999999997
2647.059025, 123.591128257315, 125.300999999997
1 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
2752.941386, 119.421201066789, 127.800999999997
2858.823747, 115.508182379078, 130.100999999997
2964.706108, 111.829764865867, 132.600999999997
3070.588469, 108.366165062524, 134.900999999997
3176.47083, 105.099705526604, 137.200999999996
3282.353191, 102.014612724814, 139.500999999996
3388.235552, 99.0967395661833, 141.800999999996
3494.117913, 96.3333922937284, 143.900999999996
3600.000274, 93.7130905091887, 146.200999999996
3705.882635, 91.2254816725024, 148.300999999996
3811.764996, 88.8611805351033, 150.600999999996
3917.647357, 86.6116986883341, 152.700999999996
4023.529718, 84.4692670927775, 154.800999999995
4129.412079, 82.4268257578615, 156.900999999995
4235.29444, 80.4779317490761, 158.800999999995
4341.176801, 78.6166840889028, 160.900999999995
4447.059162, 76.8376451985741, 163.000999999995
4552.941523, 75.1358815002616, 164.900999999995
4658.823884, 73.5067879629294, 166.800999999995
4764.706245, 71.9461568934147, 168.700999999995
4870.588606, 70.4500993891508, 170.600999999995
4976.470967, 69.0150153128962, 172.500999999994
5082.353328, 67.6375710438234, 174.200999999994
5188.235689, 66.3146974316606, 176.100999999994
5294.11805, 65.0435075934805, 177.800999999994
2 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
5400.000411, 63.8213435345404, 179.500999999994
5505.882772, 62.6457297017519, 181.200999999994
5611.765133, 61.5143529667074, 182.900999999994
5717.647494, 60.4250486371101, 184.600999999994
5823.529855, 59.3758172130087, 186.100999999994
5929.412216, 58.364758764336, 187.600999999994
6035.294577, 57.3901169307822, 189.100999999994
6141.176938, 56.4502383683355, 190.600999999993
6247.059299, 55.5435642085439, 192.100999999993
6352.94166, 54.66864173374, 193.400999999993
6458.824021, 53.8240927167631, 194.700999999993
6564.706382, 53.0086338659705, 196.000999999993
6670.588743, 52.2210479963344, 197.300999999993
6776.471104, 51.4601786501571, 198.600999999993
6882.353465, 50.7249514085973, 199.700999999993
6988.235826, 50.0143347343199, 200.800999999993
7094.118187, 49.327363510782, 201.900999999993
7200.000548, 48.6631152802581, 203.000999999993
7305.882909, 48.0207291492116, 203.900999999993
7411.76527, 47.3993691159563, 204.800999999993
7517.647631, 46.7982586798646, 205.700999999993
7623.529992, 46.2166516944172, 206.600999999993
7729.412353, 45.6538303081064, 207.500999999993
7835.294714, 45.1091365410969, 208.200999999992
7941.177075, 44.5819128253125, 208.900999999992
3 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
8047.059436, 44.0715504791102, 209.600999999992
8152.941797, 43.5774630363167, 210.300999999992
8258.824158, 43.099100014943, 210.800999999992
8364.706519, 42.6359252861645, 211.500999999992
8470.58888, 42.1874432312579, 212.000999999992
8576.471241, 41.7531692450877, 212.500999999992
8682.353602, 41.3326563675217, 213.000999999992
8788.235963, 40.9254836353628, 213.500999999992
8894.118324, 40.5312593592156, 214.000999999992
9000.000685, 40.1496381576484, 214.300999999992
9105.883046, 39.7802975608206, 214.800999999992
9211.765407, 39.422957261673, 215.300999999992
9317.647768, 39.0774204040918, 215.600999999992
9423.530129, 38.7435080413978, 216.100999999992
9529.41249, 38.4211463036626, 216.400999999992
9635.294851, 38.1103415366541, 216.900999999992
9741.177212, 37.8111915325013, 217.400999999992
9847.059573, 37.523934206023, 217.900999999992
9952.941934, 37.2489609165438, 218.200999999992
10058.824295, 36.9868279348076, 218.900999999992
10164.706656, 36.7383220960904, 219.400999999992
10270.589017, 36.5044664952496, 219.900999999992
10376.471378, 36.2865915987601, 220.600999999992
10482.353739, 36.0864064051463, 221.100999999992
10588.2361, 35.9060275083115, 221.800999999992
4 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
10694.118461, 35.7480722866755, 222.700999999992
10800.000822, 35.6157743575935, 223.400999999992
10905.883183, 35.513019921946, 224.300999999992
11011.765544, 9.53014555076344, 225.200999999991
11117.647905, 9.43627376509783, 226.100999999991
11223.530266, 9.34696305693162, 227.000999999991
11329.412627, 9.2619357057333, 228.100999999991
11435.294988, 9.1809322085666, 229.200999999991
11541.177349, 9.10371171917375, 230.300999999991
11647.05971, 9.03004575810155, 231.400999999991
11752.942071, 8.95972372260109, 232.700999999991
11858.824432, 8.8925494042696, 234.000999999991
11964.706793, 8.82834557507796, 235.300999999991
12070.589154, 8.76694582602583, 236.600999999991
12176.471515, 8.70819434847822, 237.900999999991
12282.353876, 8.65195326836424, 239.400999999991
12388.236237, 8.59809694184713, 240.900999999991
12494.118598, 8.54651669368843, 242.400999999991
12600.000959, 8.49711436760959, 243.90099999999
12705.88332, 8.44980250626121, 245.40099999999
12811.765681, 8.40450889421136, 247.10099999999
12917.648042, 8.36117928342338, 248.60099999999
13023.530403, 8.31977008089227, 250.30099999999
13129.412764, 8.28024955105729, 252.00099999999
13235.295125, 7.76334893816104, 253.70099999999
5 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
13341.177486, 7.31460248792749, 255.60099999999
13447.059847, 6.92143177570791, 257.30099999999
13552.942208, 6.57417130277528, 259.20099999999
13658.824569, 6.26525788099698, 261.100999999991
13764.70693, 5.98885854489405, 261.100999999991
13870.589291, 5.74004183350706, 263.000999999991
13976.471652, 5.51480815123307, 264.900999999992
14082.354013, 5.30993687298756, 266.800999999992
14188.236374, 5.1227572320867, 268.900999999993
14294.118735, 5.27629110656426, 270.800999999993
14400.001096, 5.43676026501471, 272.900999999994
14505.883457, 5.60462806663469, 275.000999999994
14611.765818, 5.78041067947589, 276.900999999995
14717.648179, 5.96466863986142, 279.000999999995
14823.53054, 6.15802368341424, 281.100999999995
14929.412901, 6.36116490227104, 283.200999999996
15035.295262, 6.57485736306186, 285.300999999996
15141.177623, 6.79995943706672, 287.600999999997
15247.059984, 7.03742026785049, 289.700999999997
15352.942345, 7.15457049991163, 292.000999999998
15458.824706, 7.27401788141618, 294.100999999998
15564.707067, 7.39582858523504, 296.400999999999
15670.589428, 7.5200947711634, 298.500999999999
15776.471789, 7.64690506020781, 300.801
15882.35415, 7.77635953784892, 303.101
6 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
15988.236511, 7.90857092643846, 305.401000000001
16094.118872, 8.04366332690481, 307.701000000002
16200.001233, 8.18177378636815, 310.001000000002
16305.883594, 8.32305406293386, 312.301000000003
16411.765955, 8.17851207233567, 314.601000000003
16517.648316, 8.04130530832497, 316.901000000004
16623.530677, 7.91091969238103, 319.401000000004
16729.413038, 7.78689396510168, 321.701000000005
16835.295399, 7.66878923660135, 324.001000000005
16941.17776, 7.55621785490461, 326.501000000006
17047.060121, 7.44881005781186, 328.801000000006
17152.942482, 7.34623581343874, 331.301000000007
17258.824843, 7.2481745331252, 333.801000000007
17364.707204, 7.15433465403111, 336.301000000008
17470.589565, 7.23468478854219, 338.601000000009
17576.471926, 7.315969066162, 341.101000000009
17682.354287, 7.39821029736893, 343.60100000001
17788.236648, 7.48143264377277, 346.10100000001
17894.119009, 7.56566179316743, 348.601000000011
18000.00137, 7.65092522519625, 351.101000000011
18105.883731, 7.73725250963477, 353.601000000012
18211.766092, 7.82467767037291, 356.301000000013
18317.648453, 7.91323769388801, 358.801000000013
18423.530814, 8.00296770562068, 361.301000000014
18529.413175, 7.99356525180374, 364.001000000014
7 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
18635.295536, 7.98477891756044, 366.501000000015
18741.177897, 7.97658654372952, 369.001000000015
18847.060258, 7.96898361662734, 371.701000000016
18952.942619, 7.96194766216726, 374.401000000017
19058.82498, 7.95547390358857, 376.901000000017
19164.707341, 7.94953840960536, 379.601000000018
19270.589702, 7.94412529360214, 382.301000000018
19376.472063, 7.93922140734065, 384.801000000019
19482.354424, 7.93480408772355, 387.50100000002
19588.236785, 8.00726270310529, 390.20100000002
19694.119146, 8.08041451351254, 392.901000000021
19800.001507, 8.15427471094682, 395.601000000021
19905.883868, 8.22886012671955, 398.301000000022
20011.766229, 8.30418950916275, 401.001000000023
20117.64859, 8.38028382114838, 403.701000000023
20223.530951, 8.45716655749309, 406.401000000024
20329.413312, 8.53486892198424, 409.301000000025
20435.295673, 8.61341779112854, 412.001000000025
20541.178034, 8.69284546080637, 414.701000000026
20647.060395, 8.60414337895871, 417.601000000026
20752.942756, 8.51903500654706, 420.301000000027
20858.825117, 8.43732742701845, 423.201000000028
20964.707478, 8.35883163533754, 425.901000000028
21070.589839, 8.28337545706534, 428.801000000029
21176.4722, 8.21078413082125, 431.70100000003
8 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
21282.354561, 8.14089665913764, 434.40100000003
21388.236922, 8.0735601361125, 437.301000000031
21494.119283, 8.00861897781052, 440.201000000032
21600.001644, 7.94592627530418, 443.101000000032
21705.884005, 8.05734589495858, 446.001000000033
21811.766366, 8.17052858907794, 448.901000000034
21917.648727, 8.28550788209994, 451.801000000034
22023.531088, 8.40231943106196, 454.701000000035
22129.413449, 8.5210013585344, 457.601000000036
22235.29581, 8.64159500823805, 460.701000000036
22341.178171, 8.76414888376432, 463.601000000037
22447.060532, 8.88870718802475, 466.501000000038
22552.942893, 9.01532194077344, 469.401000000038
22658.825254, 9.14405770430448, 472.501000000039
22764.707615, 9.17594120006914, 475.40100000004
22870.589976, 9.20791379525819, 478.50100000004
22976.472337, 9.23995812986905, 481.601000000041
23082.354698, 9.2720706262857, 484.501000000042
23188.237059, 9.30423244581474, 487.601000000042
23294.11942, 9.33643146005025, 490.701000000043
23400.001781, 9.3686573915081, 493.601000000044
23505.884142, 9.40089366948895, 496.701000000044
23611.766503, 9.43312402236119, 499.801000000045
23717.648864, 9.46533219261588, 502.901000000046
23823.531225, 9.48446260712307, 506.001000000047
9 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
23929.413586, 9.50356729393627, 509.101000000047
24035.295947, 9.52262134926406, 512.201000000048
24141.178308, 9.54159810995451, 515.301000000049
24247.060669, 9.56046908859621, 518.401000000049
24352.94303, 9.57920431494183, 521.70100000005
24458.825391, 9.59777463008699, 524.801000000051
24564.707752, 9.61614282869367, 527.901000000052
24670.590113, 9.63427262591262, 531.001000000052
24776.472474,9. 65212905445909, 534.301000000053
24882.354835, 9.82409021746607, 537.401000000054
24988.237196, 9.99983507468515, 540.701000000054
25094.119557, 10.1795110022848, 543.801000000055
25200.001918, 10.3632651991227, 547.101000000056
25305.884279, 10.5512741965699, 550.201000000057
25411.76664, 10.7437169041143, 553.501000000057
25517.649001, 10.9408005718692, 556.601000000058
25623.531362, 11.1427493538175, 559.901000000059
25729.413723, 11.3498079630811, 563.20100000006
25835.296084, 11.5622495630664, 566.50100000006
25941.178445, 11.4538307560846, 569.601000000061
26047.060806, 11.348915963287, 572.901000000062
26152.943167, 11.247331825, 576.201000000063
26258.825528, 11.1489152451902, 579.501000000063
26364.707889, 11.0535126399352, 582.801000000064
26470.59025, 10.9609793085509, 586.101000000065
10 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
26576.472611, 10.871178866362, 589.401000000066
26682.354972, 10.7839827336579, 592.701000000066
26788.237333, 10.6992696759875, 596.001000000067
26894.119694, 10.6169280886664, 599.501000000068
27000.002055, 10.5702806057581, 602.801000000069
27105.884416, 10.5246436761888, 606.101000000069
27211.766777, 10.4799896471358, 609.60100000007
27317.649138, 10.4362940631967, 612.901000000071
27423.531499, 10.3935303300909, 616.201000000072
27529.41386, 10.3516846777435, 619.701000000072
27635.296221, 10.3107347094793, 623.201000000073
27741.178582, 10.2706729665244, 626.501000000074
27847.060943, 10.2314860401648, 630.001000000075
27952.943304, 10.1931680658923, 633.301000000076
28058.825665, 9.98318504032686, 636.801000000076
28164.708026, 9.78398453897246, 640.301000000077
28270.590387, 9.59473544610145, 643.801000000078
28376.472748, 9.41468741657617, 647.301000000079
28482.355109, 9.24316135844719, 650.80100000008
28588.23747, 9.07954125072908, 654.30100000008
28694.119831, 8.92326708490049, 657.801000000081
28800.002192, 8.7738287559637, 661.301000000082
28905.884553, 8.63076075893168, 664.801000000083
29011.766914, 8.49363757091727, 668.301000000083
29117.649275, 8.58975938798782, 672.001000000084
11 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
29223.531636, 8.68697272819388, 675.501000000085
29329.413997, 8.7853513503286, 679.201000000086
29435.296358, 8.88497821375019, 682.701000000087
29541.178719, 8.98594619130332, 686.401000000088
29647.06108, 9.08835870995351, 690.101000000088
29752.943441, 9.19233389896096, 693.601000000089
29858.825802, 9.29800220709669, 697.30100000009
29964.708163, 9.40550752577519, 701.001000000091
30070.590524, 9.51501027840917, 704.701000000092
30176.472885, 8.73470763963707, 708.601000000093
30282.355246, 8.07966555771655, 712.301000000094
30388.237607, 7.52198727225879, 716.001000000094
30494.119968, 7.04147931977222, 719.901000000095
30600.002329, 6.62316402659902, 723.601000000096
30705.88469, 6.25569770321058, 727.501000000097
30811.767051, 5.93033216798525, 731.401000000098
30917.649412, 5.64021411946512, 735.101000000099
31023.531773, 5.37989666759983, 739.0010000001
31129.414134, 5.1449967294567, 742.9010000001
31235.296495, 4.93783339251695, 746.801000000101
31341.178856, 4.74863623786781, 750.901000000102
31447.061217, 4.57514680381064, 754.801000000103
31552.943578, 4.41546642508454, 758.701000000104
31658.825939, 4.26798850902297, 762.801000000105
31764.7083, 4.13134509305675, 766.701000000106
12 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
31870.590661, 4.00436078502456, 770.801000000107
31976.473022, 3.88602384506915, 774.701000000108
32082.355383, 3.77545544213582, 778.801000000109
32188.237744, 3.67188971881316, 782.90100000011
32294.120105, 3.68353217594039, 787.00100000011
32400.002466, 3.69499851337391, 791.101000000111
32505.884827, 3.70628638321456, 795.201000000112
32611.767188, 3.71739323122593, 799.301000000113
32717.649549, 3.72831628997648, 803.401000000114
32823.53191, 3.7390525722857, 807.501000000115
32929.414271, 3.74959886503889, 811.601000000116
33035.296632, 3.75995232316553, 815.901000000117
33141.178993, 3.77010919316986, 820.001000000118
33247.061354, 3.7800655115092, 824.301000000119
33352.943715, 3.82803574276348, 828.40100000012
33458.826076, 3.87664425834169, 832.701000000121
33564.708437, 3.92590728692808, 836.801000000122
33670.590798, 3.97584257643428, 841.101000000123
33776.473159, 4.02646756421226, 845.401000000124
33882.35552, 4.07780142735851, 849.701000000125
33988.237881, 4.12986440392658, 854.001000000126
34094.120242, 4.18267787524847, 858.301000000127
34200.002603, 4.23626445385101, 862.601000000128
34305.884964, 4.29064807729283, 866.901000000129
34411.767325, 4.31418919904991, 871.20100000013
13 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
34517.649686, 4.33764108365218, 875.501000000131
34623.532047, 4.36100280801958, 879.801000000132
34729.414408, 4.38427410880661, 884.301000000133
34835.296769, 4.40745412975557, 888.601000000134
34941.17913, 4.43054202844787, 892.901000000135
35047.061491, 4.45353854250819, 897.401000000136
35152.943852, 4.47644238880154, 901.701000000137
35258.826213, 4.49925478346228, 906.201000000138
35364.708574, 4.52197499967389, 910.701000000139
35470.590935, 4.53618785684097, 915.00100000014
35576.473296, 4.55022547837287, 919.501000000141
35682.355657, 4.56408760073817, 924.001000000142
35788.238018, 4.57777445125978, 928.501000000143
35894.120379, 4.59128634804178, 933.001000000144
36000.00274, 4.60462386696402, 937.301000000145
36105.885101, 4.6177872863998, 941.801000000146
36211.767462, 4.63077719442556, 946.301000000147
36317.649823, 4.64359433580948, 950.801000000148
36423.532184, 4.65623976838722, 955.501000000149
36529.414545, 4.64291947092694, 960.00100000015
36635.296906, 4.62957373775685, 964.501000000151
36741.179267, 4.61620003632068, 969.001000000152
36847.061628, 4.60279573551019, 973.501000000153
36952.943989, 4.58935872006704, 978.201000000154
37058.82635, 4.57588574121599, 982.701000000155
14 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
37164.708711, 4.56237383499989, 987.401000000156
37270.591072, 4.54882073348294, 991.901000000157
37376.473433, 4.53522246469592, 996.401000000158
37482.355794, 4.52157688132183, 1001.10100000016
37588.238155, 4.53558507859048, 1005.80100000016
37694.120516, 4.54942286757774, 1010.30100000016
37800.002877, 4.5630894411244, 1015.00100000016
37905.885238, 4.57658442672854, 1019.70100000016
38011.767599, 4.58990821460303, 1024.20100000016
38117.64996, 4.60306048786134, 1028.90100000016
38223.532321, 4.61604137701246, 1033.60100000016
38329.414682, 4.62885129094594, 1038.30100000015
38435.297043, 4.64149081359589, 1043.00100000015
38541.179404, 4.65396071640819, 1047.70100000014
38647.061765, 4.67869476275747, 1052.40100000014
38752.944126, 4.70341683694442, 1057.10100000013
38858.826487, 4.7281307705181, 1061.80100000013
38964.708848, 4.75284085760589, 1066.50100000013
39070.591209, 4.77755188265924, 1071.20100000012
39176.47357, 4.80226914874466, 1075.90100000012
39282.355931, 4.82699850634108, 1080.60100000011
39388.238292, 4.85174666601425, 1085.50100000011
39494.120653, 4.87652073967553, 1090.2010000001
39600.003014, 4.90132811827545, 1094.9010000001
39705.885375, 4.85906085832205, 1099.8010000001
15 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
39811.767736, 4.81748995567013, 1104.50100000009
39917.650097, 4.77659283397764, 1109.40100000009
40023.532458, 4.73634761024178, 1114.10100000008
40129.414819, 4.69673334101392, 1119.00100000008
40235.29718, 4.65772930531852, 1123.90100000007
40341.179541, 4.61931634364556, 1128.60100000007
40447.061902, 4.58147504127174, 1133.50100000006
40552.944263, 4.544186900215, 1138.40100000006
40658.826624, 4.50743406062889, 1143.30100000006
40764.708985, 4.48230363664197, 1148.00100000005
40870.591346, 4.45735354064672, 1152.90100000005
40976.473707, 4.43257873141413, 1157.80100000004
41082.356068, 4.40797431747092, 1162.70100000004
41188.238429, 4.38353541767549, 1167.60100000003
41294.12079, 4.35925715207546, 1172.50100000003
41400.003151, 4.33513468902816, 1177.60100000002
41505.885512, 4.31116324998151, 1182.50100000002
41611.767873, 4.28733777599942, 1187.40100000002
41717.650234, 4.26365330019007, 1192.30100000001
41823.532595, 4.25994998994921, 1197.20100000001
41929.414956, 4.25610009415333, 1202.301
42035.297317, 4.25210423712105, 1207.201
42141.179678, 4.24796315040737, 1212.30099999999
42247.062039, 4.24367810340595, 1217.20099999999
42352.9444, 4.2392492405681, 1222.10099999998
16 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
42458.826761, 4.23467778984665, 1227.20099999998
42564.709122, 4.22996379257637, 1232.30099999997
42670.591483, 4.22510836267595, 1237.20099999997
42776.473844, 4.22011145212474, 1242.30099999997
42882.356205, 4.20206357486195, 1247.20099999996
42988.238566, 4.18402363798363, 1252.30099999996
43094.120927, 4.16598893773157, 1257.40099999995
43200.003288, 4.14795691395164, 1262.50099999995
43305.885649, 4.12992499942181, 1267.40099999994
43411.76801, 4.11189018688452, 1272.50099999994
43517.650371, 4.09384930586752, 1277.60099999993
43623.532732, 4.07579910132868, 1282.70099999993
43729.415093, 4.05773613299681, 1287.80099999992
43835.297454, 4.03965677171758, 1292.90099999992
43941.179815, 4.06922168320542, 1298.00099999992
44047.062176, 4.09904747207368, 1303.10099999991
44152.944537, 4.12914221785659, 1308.20099999991
44258.826898, 4.15951442088362, 1313.3009999999
44364.709259, 4.1901730299221, 1318.4009999999
44470.59162, 4.22112747153387, 1323.50099999989
44576.473981, 4.25238768123779, 1328.60099999989
44682.356342, 4.28396413657721, 1333.70099999988
44788.238703, 4.3158680597484, 1339.00099999988
44894.121064, 4.34811106454754, 1344.10099999987
45000.003425, 4.36673135467686, 1349.20099999987
17 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
45105.885786, 4.38536830105779, 1354.30099999986
45211.768147, 4.40402509748414, 1359.60099999986
45317.650508, 4.42270459693189, 1364.70099999985
45423.532869, 4.441410051878, 1370.00099999985
45529.41523, 4.46014543167528, 1375.10099999985
45635.297591, 4.47891407768033, 1380.20099999984
45741.179952, 4.49772041028236, 1385.50099999984
45847.062313, 4.5165685169862, 1390.60099999983
45952.944674, 4.53546326324413, 1395.90099999983
46058.827035, 4.53163643628444, 1401.00099999982
46164.709396, 4.52767308629808, 1406.30099999982
46270.591757, 4.52357389552354, 1411.60099999981
46376.474118, 4.51934021196513, 1416.70099999981
46482.356479, 4.51497299667308, 1422.0009999998
46588.23884, 4.51047318919179, 1427.3009999998
46694.121201, 4.50584200232726, 1432.40099999979
46800.003562, 4.50108050491561, 1437.70099999979
46905.885923, 4.49618959569844, 1443.00099999978
47011.768284, 4.49117032606856, 1448.30099999978
47117.650645, 4.48602373529736, 1453.60099999977
47223.533006, 4.48075092395502, 1458.70099999977
47329.415367, 4.47535286734213, 1464.00099999976
47435.297728, 4.46983049416028, 1469.30099999976
47541.180089, 4.46418478381359, 1474.60099999975
47647.06245, 4.45841669703178, 1479.90099999975
18 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
47752.944811, 4.45252717431024, 1485.20099999974
47858.827172, 4.44651713425971, 1490.50099999974
47964.709533, 4.44038747186188, 1495.80099999974
48070.591894, 4.43413905662788, 1501.10099999973
48176.474255, 4.42777273065697, 1506.40099999973
48282.356616, 4.42128930659197, 1511.70099999972
48388.238977, 4.4146896620002, 1517.20099999972
48494.121338, 4.4079744992126, 1522.50099999971
48600.003699, 4.4011444951789, 1527.80099999971
48705.88606, 4.39420032104918, 1533.1009999997
48811.768421, 4.38714260664235, 1538.4009999997
48917.650782, 4.37997201072059, 1543.90099999969
49023.533143, 4.37268915846574, 1549.20099999969
49129.415504, 4.3652943917265, 1554.50099999968
49235.297865, 4.35053699216015, 1559.80099999968
49341.180226, 4.33571700999268, 1565.30099999967
49447.062587, 4.32083394313389, 1570.60099999967
49552.944948, 4.30588711854729, 1575.90099999966
49658.827309, 4.29087598719373, 1581.40099999966
49764.70967, 4.27579976725375, 1586.70099999965
49870.592031, 4.26065736044938, 1592.00099999965
49976.474392, 4.24544788215407, 1597.50099999964
50082.356753, 4.23017006114426, 1602.80099999964
50188.239114, 4.21482242031252, 1608.10099999963
50294.121475, 4.22707786580175, 1613.60099999963
19 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
50400.003836, 4.23933399412705, 1618.90099999962
50505.886197, 4.25159274135928, 1624.40099999962
50611.768558, 4.26385627250569, 1629.70099999961
50717.650919, 4.27612645201467, 1635.00099999961
50823.53328, 4.28840567097992, 1640.5009999996
50929.415641, 4.30069623092452, 1645.8009999996
51035.298002, 4.31300046429143, 1651.10099999959
51141.180363, 4.32532118430588, 1656.60099999959
51247.062724, 4.3376609851038, 1661.90099999958
51352.945085, 4.31265004165873, 1667.20099999958
51458.827446, 4.28770274163571, 1672.70099999957
51564.709807, 4.26281558025638, 1678.00099999957
51670.592168, 4.23798487122328, 1683.30099999956
51776.474529, 4.21320685819249, 1688.60099999956
51882.35689, 4.18847767788365, 1694.10099999955
51988.239251, 4.16379321733019, 1699.40099999955
52094.121612, 4.13914910920791, 1704.70099999955
52200.003973, 4.11454087841586, 1710.00099999954
52305.886334, 4.08996385474698, 1715.30099999954
52411.768695, 4.0926074760293, 1720.60099999953
52517.651056, 4.09512931261318, 1725.90099999953
52623.533417, 4.09752680661658, 1731.20099999952
52729.415778, 4.09979726598669, 1736.50099999952
52835.298139, 4.10193797848272, 1741.60099999951
52941.1805, 4.10394595073001, 1746.90099999951
20 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
53047.062861, 4.10581800763816, 1752.2009999995
53152.945222, 4.10755105697194, 1757.3009999995
53258.827583, 4.10914167057839, 1762.60099999949
53364.709944, 4.11058636079266, 1767.70099999949
53470.592305, 4.06963459329416, 1773.00099999948
53576.474666, 4.02907538384728, 1778.10099999948
53682.357027, 3.98889247820888, 1783.20099999947
53788.239388, 3.94906992323519, 1788.30099999947
53894.121749, 3.90959180639416, 1793.40099999946
54000.00411, 3.87044223986928, 1798.50099999946
54105.886471, 3.83160534507431, 1803.60099999946
54211.768832, 3.79306537077922, 1808.50099999945
54317.651193, 3.75480643348765, 1813.60099999945
54423.533554, 3.71681263090054, 1818.50099999944
54529.415915, 3.72684971361506, 1823.60099999944
54635.298276, 3.73677009761159, 1828.50099999943
54741.180637, 3.74656561504592, 1833.40099999943
54847.062998, 3.75622779396414, 1838.30099999942
54952.945359, 3.76574771298819, 1843.20099999942
55058.82772, 3.7751160219105, 1847.90099999942
55164.710081, 3.7843230387742, 1852.80099999941
55270.592442, 3.79335825771155, 1857.50099999941
55376.474803, 3.80221112736627, 1862.4009999994
55482.357164, 3.81087023546159, 1867.1009999994
55588.239525, 3.77994805255825, 1871.80099999939
21 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
55694.121886, 3.74890341333377, 1876.50099999939
55800.004247, 3.71772434705767, 1881.00099999938
55905.886608, 3.68639861109642, 1885.70099999938
56011.768969, 3.65491335021971, 1890.20099999938
56117.65133, 3.62325558807834, 1894.90099999937
56223.533691, 3.59141192288992, 1899.40099999937
56329.416052, 3.55936842976259, 1903.70099999936
56435.298413, 3.52711095002697, 1908.20099999936
56541.180774, 3.49462464267727, 1912.70099999936
56647.063135, 3.46333277601192, 1917.00099999935
56752.945496, 3.43174585737413, 1921.30099999935
56858.827857, 3.39984799049362, 1925.60099999934
56964.710218, 3.36762269569916, 1929.90099999934
57070.592579, 3.33505289023111, 1934.20099999934
57176.47494, 3.30212108904051, 1938.30099999933
57282.357301, 3.26880901195193, 1942.40099999933
57388.239662, 3.23509796040051, 1946.50099999933
57494.122023, 3.2009685401353, 1950.60099999932
57600.004384, 3.16640063791926, 1954.70099999932
57705.886745, 3.11377401179727, 1958.60099999931
57811.769106, 3.06135498198746, 1962.70099999931
57917.651467, 3.00911087424872, 1966.60099999931
58023.533828, 2.95700900348816, 1970.3009999993
58129.416189, 2.9050167074619, 1974.2009999993
58235.29855, 2.85310129714557, 1977.9009999993
22 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
58341.180911, 2.80123011193566, 1981.60099999929
58447.063272, 2.74937040793964, 1985.30099999929
58552.945633, 2.69748923700631, 1989.00099999929
58658.827994, 2.6455534112807, 1992.70099999928
58764.710355, 2.59833985361966, 1996.20099999928
58870.592716, 2.55075619842861, 1999.70099999928
58976.475077, 2.50277252966368, 2003.20099999927
59082.357438, 2.45435836199219, 2006.50099999927
59188.239799, 2.40548225878138, 2009.80099999927
59294.12216, 2.35611228283155, 2013.10099999926
59400.004521, 2.30621565320951, 2016.40099999926
59505.886882, 2.25575871666531, 2019.70099999926
59611.769243, 2.20470705092447, 2022.80099999926
59717.651604, 2.18450704225352, 2022.80099999926
59823.533965, 2.2, 2022.80099999926
59929.416326, 2.2, 2022.80099999926
60035.298687, 2.2, 2022.80099999926
60141.181048, 2.2, 2022.80099999926
60247.063409, 2.2, 2022.80099999926
60352.94577, 2.2001020403401, 2022.80099999926
60458.828131, 2.20060471645854, 2022.80099999926
60564.710492, 2.20175759862404, 2022.80099999926
60670.592853, 2.20456464717789, 2022.80099999926
60776.475214, 2.21024179111586, 2022.80099999926
60882.357575, 2.21274148019283, 2022.80099999926
23 EMP Report of Dibang Multipurpose Project
D/s distance (m), Max. Probable Depth (m), Time of Occurrence (sec)
60988.239936, 2.21528056680623, 2022.80099999926
61094.122297, 2.21806546578621, 2022.80099999926
61200.004658, 2.22143547866682, 2022.80099999926
61305.887019, 2.22586223439865, 2022.80099999926
61411.76938, 2.23187228507638, 2022.80099999926
61517.651741, 2.2400758304496, 2022.80099999926
61623.534102, 2.25122550631678, 2022.80099999926
61729.416463, 2.266314626242, 2022.80099999926
61835.298824, 2.28671703471761, 2022.80099999926
61941.181185, 2.250055216024, 2022.80099999926
62047.063546, 2.22352246693356, 2022.80099999926
62152.945907, 2.20827149964473, 2022.80099999926
62258.828268, 2.2018042891502, 2022.80099999926
62364.710629, 2.2, 2022.80099999926
62470.59299, 2.2, 2022.80099999926
62576.475351, 2.2, 2022.80099999926
62682.357712, 2.2, 2022.80099999926
62788.240073, 2.2, 2022.80099999926
62894.122434, 1.08166666666667, 2022.80099999926
63000.004795, 1.08166666666667, 2022.80099999926
24