Vennar Environment By

GOVERNMENT OF TAMILNADU PUBLIC WORKS DEPARTMENT WATER RESOURCES DEPARTMENT TRICHY REGION, TRICHY. ADB IND(44429):CLIMATE ADAPTATION THROUGH SUB-BASIN DEVELOPMENT PROGRAM PROJECT OF VENNAR SUB-BASIN OF CAUVERY BASIN DETAILED PROJECT REPORT Infrastructure Improvements and Reconstruction Works Contents – Volume I Chapter Title Page Check List 1 Salient Features 9 Introduction 19 1.1 Background 19 1.2 Water Resources Issues in the Cauvery Delta 20 1.2.1 Introduction 20 1.2.2 Cauvery River 21 1.2.3 Availability of Water Resources 22 1.2.4 Water Resources Management 24 1.2.5 Climate Change 26 1.3 State Government Responses to Water Resources 27 Issues 1.3.1 IAMWARM Project 27 1.3.2 Cauvery Modernisation Proposal 28 1.3.3 Climate Adaptation through Sub basin Development 28 Programme 1.4 The Design of CASDP 29 1.4.1 Rationale 29 1.4.2 Impact 30 1.4.3 Outcome 30 1.4.4 Outputs 30 1.4.5 Implementation of CASDP 33 1.4.6 Execution of this Project 35 1.4.7 Execution of CASDP follow on project 37 1.5 River Basins 39 1.5.1 India 39 1.5.2 TamilNadu 40 1.6 The Cauvery Basin 42 1.6.1 Description 42 1.6.2 Drainage Area 42 1.6.3 Population 46 1.6.4 Tributaries of Cauvery 47 1.6.5 Unique Feature of Cauvery 47 1.6.6 Upper Anicut 47 1.6.7 Grand Anicut 48 1.6.8 The delta 48 1.6.9 Tailend Regulator 48 1.6.10 Rainfall 49 1.6.11 Soils 51 1.6.12 Development of Irrigation 52 1.6.13 Storage in the Cauvery Basin 53 1.7 The Cauvery Basin in TamilNadu 58 1.7.1 Extent 58 1.7.2 Irrigation Development 59 1.7.3 Irrigation in 1901-02 63 1.7.4 Irrigation in 1928-29 64 1.7.5 Development between 1928 and 1956 64 1.8 Cauvery Delta System 67 1.8.1 Brief narrative report 67 1.8.2 Land holdings 68 1.8.3 Rainfall 69 1.8.4 Barrage on the Cauvery 69 1.8.5 Grand Anicut 70 1.8.6 Improvements to the Origional structure (G.A) 71 1.8.7 Monsoons and their influence 77 1.8.8 Floods and Drainage on the Delta 78 1.8.9 Floods from the catchment lying between upper anicut and 78 grand anicut 1.9 Vennar Basin 81 1.9.1 A brief narration 81 1.9.2 Details of Main drain and stages of drains during the flood 83 1.9.3 Need and necessity of the scheme 86 1.9.4 Vedharanyam Canal 86 1.9.4 The straight cuts 86 1.9.6 Pumping schemes 87 2 Hydrology 96 2.1 Rainfall 96 2.2 River Flow 96 2.3 Droughts 99 2.4 Climate Change 99 3 Reservoir 103 4 Barrages (Anicuts) 104 5 Land Potential 105 5.1 Soils 105 5.2 Land Use 110 6 Cropping Pattern and crop water Requirements 111 6.1 Details of current cropping pattern and crop calendar 111 6.1.1 Current cropping pattern 111 6.1.2 Paddy cultivation in the vennar system 112 6.1.3 Rice water requirements and productivity 112 6.2 Details of original cropping pattern and crop calendar 114 6.3 Future Cropping Patterns 114 6.4 Assessment of Effective Rainfall and Crop Water Requirements 115 6.4.1 Potential evaporation and effective rainfall 115 6.4.2 Agro-climatic zone 118 6.4.3 Water requirement and irrigation schedule 119 6.5 Assumed conveyance efficiecies 120 6.6 Irrigation water requirments 120 7 Aquaculture 121 7.1 Introduction 121 7.2 Area of Shrimp Farming 121 7.3 Water use 123 7.4 Future Development of Shrimp 123 7.5 Best Management Practices 123 8 Horticulture 124 9 Others 125 10 Water Demand 126 10.1 State level 126 10.2 Basin level 126 10.3 Agricultur Demand inVennar system 127 10.4 Water demand for Aquaculture 131 10.4.1 Present water Use 131 10.4.2 Future water Use 131 10.5 Power Generation 132 10.6 Industry 132 10.7 Return flow from Domestic, Commercial and Industrial 133 Water Use 10.8 Drinking water Demand 133 10.9 Summary of Demand 134 11 Impact of Proposed Works 135 11.1 Project and Adjoining Area 135 11.2 Project Description and Proposed works 136 11.3 Aims and objectives of the proposed works 136 11.4 Inter – State Aspects 137 11.5 Impact on Upstream Area 137 11.6 Impact on Downstream Area 137 12 International / Interstate Aspects 138 12.1 Agreements 138 12.2 Cauvery Fact Finding Committee 139 12.3 Cauvery water Disputes Tribunal 139 13 Canal System 146 13.1 Climate Resilient Adaptations in the Vennar System 146 13.1.1 Description of the Vennar Irrigation and Drainage System 146 13.1.2 Floods 151 13.1.3 Coastal Zones 158 13.1.4 Impact of Climate Change 162 13.1.5 Proposed Measures to Improve the Performance of Six 163 Project-1 Rivers 13.2 Design 165 13.2.1 Design Process 165 13.2.2 Design Criteria 165 13.2.3 Topographic Survey 166 13.2.4 Asset Survey 168 13.2.5 Analysis of Rainfall Data and Climate Changes 168 13.2.6 SWAT Rainfall – Runoff Model 168 13.2.7 Hydraulic Model 171 13.3 Proposals for Adaptation to Climate Change in the Six 174 Project -1 Rivers 13.3.1 Introduction 174 13.3.2 Adappar 175 13.3.3 Harichandra 189 13.3.4 Vellaiyar 203 13.3.5 Pandavaiyar 216 13.3.6 Valavanar 220 13.3.7 Vedaraniyan Canal 235 13.4 Surface Water Pumping Schemes 246 13.4.1 Description of Pumping Schemes 246 13.4.2 Project – 1 Pumping Schemes 248 13.4.3 Findings of Survey and Recommendations for this Project 251 Pumping Schemes Volume - II 14 Power 254 15 Navigation 255 16 Ground Water 256 16.1 Introduction 256 16.2 Depth of Ground Water 256 16.3 Assessment of the Ground Water Potential in the command 260 Area 16.4 Quality of Groundwater 261 16.5 Assessment of Possible Impact on Ground Water Recharge 263 due to Canal Lining 16.6 Groundwater Modelling 265 16.7 Cost Estimate for Modelling 267 17 Drainage and Land Reclamation 268 18 Land Acquisition, Rehabilitation and 269 Resettlement 18.1 Introduction 269 18.2 Scope of Resettlement 269 18.3 Policies of the Government and ADB 270 18.4 Screening and Categorisation 270 18.5 Eligibility and Entitlements 271 18.5.1 Eligibility 271 18.5.2 Entitlements 271 18.6 Monitoring 271 18.7 Cost Estimate and Budget 272 19 Water Management and Maintenance 274 19.1 Management of this Project Rivers 274 19.1.1 Management of Irrigation flows 274 19.1.2 Management of Flood flows 275 19.1.3 Maintenance of irrigation canals 275 19.2 Analysis of Current Decision Making 276 19.3 Proposed Decision Support System 277 19.3.1 Management of Irrigation Flows 277 19.3.2 Management of Flood Flows 278 19.3.3 Initial Simple DSS 279 19.3.4 Training of WRD Staff 280 19.4 Costs of the DSS 281 19.4.1 Initial Simplified DSS 281 19.4.2 Monitoring Equipment and Hardware and Database Software 281 19.4.3 Calibration of Regulator Discharges 282 19.4.4 Water Schedule Calendar 282 19.4.5 Summary of DSS Costs 283 20 On Farm Development works 284 21 Construction Programme 285 21.1 Project Area 285 21.2 Major Works 285 21.2.1 Nature of works 285 21.3 Estimated Costs 286 21.4 Project Duration 287 21.5 Procurement of Works 288 21.6 Implementation Schedule 296 22 Construction Organisation 298 22.1 Background 298 22.2 Project Management Unit 300 22.3 Project Consultants 310 22.4 Preparation of CASDP follow on project 318 22.4.1 Approach to the Preparation of follow on project 318 23 Environment, Ecology and Forest Aspects 323 23.1 Anticipated Environmental Impacts and Mitigation Measures 323 23.1.1 Methodology 323 23.1.2 Mitigation Hierarchy 324 23.2 Impacts and Mitigation Measures 325 23.2.1 Ambient Air Environment 325 23.2.3 Soil Environment 326 23.2.4 Water Resources and Quality 327 23.2.5 Wildlife, Biodiversity and Reserved Forest 328 23.2.6 Tree Plantation 328 23.2.7 Land use 329 23.2.8 Archaeological Remains 329 24 Economic Evaluation 349 24.1 Cost Estimates for River Improvements 349 24.2 Cost Estimates for Pumped Irrigation Scheme Improvements 349 24.3 Estimates of Cost 351 24.4 Project Benefits 354 24.4.1 Benefits from Project-1 Improvement Works 354 24.4.2 Agricultural Benefits 355 24.4.3 Flood Protection Benefits 356 24.5 Operation and Maintenance Charges 357 24.5.1 Water Rates for Irrigation 357 24.5.2 Betterment Levy 357 24.5.3 O & M Costs of Pumping Schemes 358 24.5.4 O & M Costs of Groundwater Irrigation 358 24.5.5 Flood Protection Costs 358 24.5.6 Annual Cost of Project-1 358 24.6 Cropping Patterns and Annual Crop Net Benefits 359 24.7 Benefit Cost Ratio 363 24.8 Baseline Survey 363 25 Administrative and Legislative Provisions 365 26 Training 368 27 Conclusion 370 Annexures Annexure A CPM Table and Activity Network Annexure B Soil Analysis Reports Annexure C Testing Results of River Water Annexure 1 Cropping patterns Annexure 2 Details of Works Annexure 9 Data and Analysis for Economic Analysis Annexure 9.1 Certified Flood damage Data, Thiruvarur Annexure 9.2 Certified Flood Damage Data, Nagapattinam Annexure 9.3 Data and Analysis used for Calculating the Cost-Benefit Ratio Annexure 9.4 ADB Cost Abstracts Contents Volume - II 14 Power 254 15 Navigation 255 16 Ground Water 256 16.1 Introduction 256 16.2 Depth of Ground Water 256 16.3 Assessment of the Ground Water Potential in the command 260 Area 16.4 Quality of Groundwater 261 16.5 Assessment of Possible Impact on Ground Water Recharge 263 due to Canal Lining 16.6 Groundwater Modelling 265 16.7 Cost Estimate for Modelling 267 17 Drainage and Land Reclamation 268 18 Land Acquisition, Rehabilitation and 269 Resettlement 18.1 Introduction 269 18.2 Scope of Resettlement 269 18.3 Policies of the Government and ADB 270 18.4 Screening and Categorisation 270 18.5 Eligibility and Entitlements 271 18.5.1 Eligibility 271 18.5.2 Entitlements 271 18.6 Monitoring 271 18.7 Cost Estimate and Budget 272 19 Water Management and Maintenance 274 19.1 Management of this Project Rivers 274 19.1.1 Management of Irrigation flows 274 19.1.2 Management of Flood flows 275 19.1.3 Maintenance of irrigation canals 275 19.2 Analysis of Current Decision Making 276 19.3 Proposed Decision Support System 277 19.3.1 Management of

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