India: Climate Adaptation Through Sub-Basin Development Program (Financed by the Technical Assistance Special Fund)
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Technical Assistance Consultant’s Report Project Number: 44429 October 2014 India: Climate Adaptation through Sub-Basin Development Program (Financed by the Technical Assistance Special Fund) Prepared by Mott MacDonald Delhi, India For Water Resources Department, Public Works Department, Government of Tamil Nadu This consultant’s report does not necessarily reflect the views of ADB or the Government concerned, and ADB and the Government cannot be held liable for its contents. (For project preparatory technical assistance: All the views expressed herein may not be incorporated into the proposed project’s design. Climate Adaptation through Sub-Basin Development Program PPTA Final Report October 2014 Asian Development Bank Climate Adaptation through Sub-Basin Development Program PPTA Final Report Issue and revision record Revision Date Originator Checker Approver Description Click here to enter text. A 14 April 2014 PPTA Team I Hogg P Ede First Draft B 17 September 2014 PPTA Team I Hogg P Ede Second Draft C 10 October 2014 PPTA Team I Hogg P Ede Final Information Class: Standard This document is issued for the party which commissioned it We accept no responsibility for the consequences of this and for specific purposes connected with the above-captioned document being relied upon by any other party, or being used project only. It should not be relied upon by any other party or for any other purpose, or containing any error or omission used for any other purpose. which is due to an error or omission in data supplied to us by other parties. This document contains confidential information and proprietary intellectual property. It should not be shown to other parties without consent from us and from the party which commissioned it. D324440/ID /IDC/1/B 10 October2014 Final Report Final V1 Climate Adaptation through Sub-Basin Development Program PPTA Final Report Contents Chapter Title Page Executive Summary i 1 Rationale for CASDP 1 2 Execution of the PPTA 3 2.1 PPTA Consultants and Contractors _____________________________________________________ 3 2.2 ToR for Program Preparation __________________________________________________________ 3 2.3 Deliverables from the Main Consultancy _________________________________________________ 4 2.4 Reporting and Review Missions ________________________________________________________ 5 3 The Project Area 8 3.1 The Cauvery River Basin _____________________________________________________________ 8 3.2 Water Development _________________________________________________________________ 9 3.2.1 The Cauvery River Basin _____________________________________________________________ 9 3.2.2 The Cauvery River Sub-Basin in Tamil Nadu _____________________________________________ 11 3.2.3 The Vennar Irrigation and Drainage System _____________________________________________ 12 4 Due Diligence 17 4.1 Water Resources Issues ____________________________________________________________ 17 4.2 Availability of Surface Water __________________________________________________________ 17 4.3 Avai lability of Groundwater ___________________________________________________________ 18 4.3.1 Aquifers _________________________________________________________________________ 18 4.3.2 Groundwater Quality________________________________________________________________ 21 4.3.3 Groundwater Development ___________________________________________________________ 23 4.4 Water Demand ____________________________________________________________________ 24 4.4.1 Agriculture _______________________________________________________________________ 24 4.4.2 Aquaculture ______________________________________________________________________ 24 4.4.3 Power Generation__________________________________________________________________ 25 4.4.4 Industry __________________________________________________________________________ 25 4.4.5 Drinking Water ____________________________________________________________________ 26 4.4.6 Return flow _______________________________________________________________________ 27 4.4.7 Summary of Demand _______________________________________________________________ 27 4.5 Water Balance Model _______________________________________________________________ 27 4.6 Irrigation Infrastructure ______________________________________________________________ 29 4.7 Inefficient Water Use _______________________________________________________________ 31 4.8 Flooding _________________________________________________________________________ 31 4.9 Droughts _________________________________________________________________________ 33 4.10 Climate Change ___________________________________________________________________ 33 4.11 Water Resources Management _______________________________________________________ 34 4.11.1 Institutions _______________________________________________________________________ 34 4.11.2 Policy ___________________________________________________________________________ 35 4.11.3 Legislation _______________________________________________________________________ 37 4.11.4 Government Projects _______________________________________________________________ 38 4.12 Agricultural Systems ________________________________________________________________ 40 4.12.1 Climate __________________________________________________________________________ 40 324440D /ID /IDC/1/B 10 October2014 Final Report Final V1 Climate Adaptation through Sub-Basin Development Program PPTA Final Report 4.12.2 Climate Change ___________________________________________________________________ 40 4.12.3 Soils ____________________________________________________________________________ 40 4.12.4 Tamil Nadu Agricultural Policies and Programs ___________________________________________ 40 4.12.5 Agricultural Practices and Issues ______________________________________________________ 41 4.12.6 Current Cropping Pattern, Yields and Net Returns _________________________________________ 41 4.12.7 Scope for Water Saving Technologies __________________________________________________ 42 4.12.8 Procurement Capacity Assessment ____________________________________________________ 43 4.12.9 Financial Management Assessment ____________________________________________________ 44 5 Formulation of CASDP 46 5.1 Context __________________________________________________________________________ 46 5.2 Impact and Outcome _______________________________________________________________ 46 5.3 Outputs __________________________________________________________________________ 46 5.3.1 Output 1: Integrated Programs and Infrastructure for the Management of Surface Water, Groundwater and Salinity _______________________________________________________________________ 47 5.3.2 Output 2 - Improved Systems for Management of Water Resources, Flood Risk and Flood Events ___ 47 5.4 New Design Guidelines for Drainage Infrastructure ________________________________________ 50 5.5 Feasibility Studies for Structural Drainage Improvements ___________________________________ 52 5.6 Feasibility Studies for Upgrading Pumped Irrigation Schemes ________________________________ 53 5.7 Social Safeguards _________________________________________________________________ 54 5.8 Environmental Safeguards ___________________________________________________________ 55 5.9 Economics _______________________________________________________________________ 55 5.10 Hydrologic and Hydraulic Modelling ____________________________________________________ 56 5.10.1 Hydrologic Modelling _______________________________________________________________ 57 5.10.2 Hydraulic Model ___________________________________________________________________ 59 5.11 Groundwater Model ________________________________________________________________ 70 5.12 Conjunctive Use of Groundwater ______________________________________________________ 73 5.13 Groundwater Recharge _____________________________________________________________ 74 5.14 Coastal Processes _________________________________________________________________ 75 5.14.1 East Coast Outlets _________________________________________________________________ 75 5.14.2 South Coast Outlets ________________________________________________________________ 76 5.15 Management of Flood Risk, Events and Disasters _________________________________________ 77 5.15.1 Flood Event Management ___________________________________________________________ 77 5.15.2 Flood Risk Management _____________________________________________________________ 78 5.15.3 Flood Disaster Management _________________________________________________________ 79 5.16 Improved Management of Flood Risk, Events and Disasters _________________________________ 80 5.16.1 Structural Measures ________________________________________________________________ 80 5.16.2 Non -Structural Measures ____________________________________________________________ 81 5.17 Road Map to Integrated Water Resources Management ____________________________________ 82 5.18 Decision Support System (DSS)_______________________________________________________ 87 5.19 Detailed Project Reports and Initial Procurement Packages _________________________________ 89 5.20 CASDP Appraisal Documentation _____________________________________________________ 89 5.21 Implementation ____________________________________________________________________ 90 5.22 Program Management ______________________________________________________________ 90 5.22.1 Project Management Unit 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