Environmental Impact Assessment Project TA No.: 9242-REG Status: Initial Draft (revised) Date: February 2020 Samoa: Alaoa Multi-purpose Dam Project Volume 1: EIA Report Prepared by Electric Power Corporation of Samoa This environmental impact assessment is a document of the borrower. The views expressed herein do not necessarily represent those of the ADB’s Board of Directors, Management, or staff, and may be preliminary in nature. In preparing any country program or strategy, financing any project, or by making any designation of or reference to a particular territory or geographic area in this document, the Asian Development Bank does not intend to make any judgments as to the legal or other status of any territory or area. Alaoa Multi-Purpose Dam Project - Environmental Impact Assessment Revision No: 3.1 E307132 10-Feb-20 Document information Document title Alaoa Multi-Purpose Dam Project Initial Environmental Impact Assessment Client organisation Asian Development Bank Client contact Woo Lee ConsultDM number E307132 Project Manager Richard Herweynen Project number P513660 Revision history Revision 3.0 Revision description Initial draft EIA document issued to ADB Prepared by Entura Team: Andrew Taylor William Elvey Cedric Schuster Tim O’Meara Sam Sesega Other support: Pilgrim J. Stirnemann R. L. Reviewed by Andrew Taylor Approved by Richard Herweynen (name) (signature) (date) Woo Lee Asian Development Bank Distributed to Jean Williams Asian Development Bank (name) (organisation) (date) Revision 3.1: Including comments of ADB (23-Jan-20) and revisions 10-Feb-20 2 | P a g e Alaoa Multi-Purpose Dam Project - Environmental Impact Assessment Revision No: 3.1 E307132 10-Feb-20 Contents 1 Introduction 1 1.1 Overview of the document 1 1.2 Definition of the project area 3 1.3 Confidence in the safety of a dam against failure 7 1.4 Ecological importance of the project Area 7 1.4.1 Avifauna - ma’oma’o / mao 7 1.4.2 Avifauna - Manumea 8 2 Legal, Administrative and Policy Framework 10 2.1 Institutional Arrangements 10 2.1.1 Executing and implementing agencies 10 2.1.2 Other relevant institutions 10 2.2 Country safeguard system 12 2.2.1 Lands, Surveys and Environment Act 1989 12 2.2.2 Planning and Urban Management Act 2004 12 2.2.3 Environmental Impact Assessment Regulations 2007 12 2.2.4 Water Permit and Water Management Act 14 2.2.5 Forest Act 14 2.2.6 Security and Emergency Disaster and Emergency Management Act 2007 14 2.2.7 Protection of Wildlife Regulations 2004 15 2.3 Policies for Samoa 15 2.3.1 Cultural and Natural Heritage Conservation Policy 2004 15 2.3.2 Planning for Climate Change Policy 15 2.3.3 Policy Statement on Biological Diversity 15 2.3.4 Samoa Codes of Environmental Practice 2006 15 2.3.5 Statement of Economic Strategy (SES) 2000 – 2001 16 2.3.6 Strategy for the Development of Samoa 2017 - 2020 16 2.3.7 Energy Sector Plan 2012 - 2016 17 2.4 Relevant International Agreements 18 2.5 Relevance of Legal, Policy, and Administrative Frameworks 19 2.6 Safeguard Policy Statement 19 2.6.1 Environmental Requirements 19 3 Description of the Project 21 3.1 Project components 21 3.2 Proposed project delivery mechanism 25 4 Alternatives 26 4.1 Overview 26 4.2 Technological - Alternative to a dam 26 4.3 Location and site alternatives 26 4.3.1 Different dam types and sizes 26 4.3.2 Hydropower options 28 i | P a g e Alaoa Multi-Purpose Dam Project - Environmental Impact Assessment Revision No: 3.1 E307132 10-Feb-20 4.3.3 Storage options 28 4.4 Ecological considerations 29 4.4.1 Environmental Flow 29 4.4.2 Species migration past Samsoni Weir 29 4.5 No project 30 5 Description of Existing Environment (Baseline) 31 5.1 Physical Environment 31 5.1.1 Geography and topography 31 5.1.2 Geology and Soils 32 5.1.3 Climate 35 5.1.4 Climate Change 38 5.1.5 Hydrology 40 5.1.6 Tectonic setting / Seismology 45 5.1.7 Geomorphology 47 5.1.8 River sediment charatcter, transport and deposition 52 5.2 Biological Environment 53 5.2.1 Overview of ecology 53 5.2.2 Overview of flora 53 5.2.3 Overview of avifauna and fauna 54 5.2.4 Overview of protected areas and key biodiversity areas 54 5.2.5 Apia Catchment KBA and the project area 56 5.2.6 Habitat in the project area 60 5.2.7 Terrestrial habitat value and threat status 64 5.2.8 Avifauna – Mao 65 5.2.9 Avifauna - Manumea 68 5.2.10 Other terrestrial species 70 5.2.11 Aquatic fauna 70 5.2.12 Previous aquatic surveys of the Vaisigano River 71 5.2.13 Ecology and status of migratory climbing species 72 5.2.14 Migration requirements 78 5.2.15 Priority biodiversity: natural and critical habitat 80 5.3 Environmental Flow 84 5.3.1 Current hydropower development in the Vaisigano River catchment 84 5.3.2 Changes in flow with the new flood protection dam 87 5.4 Socio-economic Environment 90 5.4.1 Population and demography 90 5.4.2 Communities in the project area 92 5.4.3 Livelihoods and Employment 93 5.4.4 Overview of land use and land ownership 93 5.4.5 Land tenure in the project area 94 5.4.6 Economy and economic infrastructure 96 5.4.7 Cultural heritage and resources 98 5.4.8 Ambient noise 99 5.4.9 Traffic movements 103 ii | P a g e Alaoa Multi-Purpose Dam Project - Environmental Impact Assessment Revision No: 3.1 E307132 10-Feb-20 6 Consultation and Information Disclosure 105 6.1 Overview 105 6.2 Stakeholder Identification and Engagement 105 6.3 Consultations Undertaken 106 6.4 Information disclosure 109 6.5 Process for Consultation During Implementation 111 6.6 Grievance redress mechanism 112 6.6.1 Overview 112 6.6.2 GRM during construction phase 113 6.7 Outcomes and Conclusions of the Consultations 116 6.7.1 Benefits 116 6.7.2 Costs/adverse impacts 116 7 Assessment of Impacts 117 7.1 Overview of Assessment 117 7.1.1 A structured approach to critical habitat impact assessment 118 7.1.2 Risk matrix approach for impact assessment 119 7.2 Pre-construction impacts 120 7.2.1 Potential impacts on terrestrial critical habitat 120 7.2.2 Potential impacts on aquatic critical habitat 121 7.2.3 Potential impacts on natural habitat 122 7.2.4 Residual impacts on terrestrial critical habitat 136 7.2.5 Residual impacts on aquatic critical habitat 137 7.2.6 No net loss/net gain approach 143 7.2.7 Updating the EIA, development consent application and bid & contract documentation 147 7.2.8 Identifying suitable material sources 148 7.2.9 Biosecurity and introduction of invasive and/or alien species 149 7.2.10 Worker code of conduct 149 7.3 Construction Impacts on Physical Environment 150 7.3.1 Degradation of landscapes and soil erosion 150 7.3.2 Soils, geology and hydrogeology 151 7.3.3 Climate change – reservoir GHG emissions 152 7.3.4 Climate change – adaptation and resilience of the Project 154 7.3.5 Natural hazards 157 7.3.6 Air quality – dust and other emissions 158 7.3.7 Hydrology and water quality 160 7.3.8 Borrow pits and quarry sites 161 7.3.9 Waste and Materials 162 7.4 Construction Impacts on Biological Environment 164 7.4.1 Biodiversity - potential impacts on critical and natural habitat 164 7.4.2 Vegetation removal and forest clearance during construction 164 7.5 Construction Impacts on Socio-economic Environment 165 7.5.1 Labour conditions 165 7.5.2 Workplace and Community Health and Safety 165 7.5.3 Utilities and Infrastructure 167 7.5.4 Site Construction Access Routes 167 iii | P a g e Alaoa Multi-Purpose Dam Project - Environmental Impact Assessment Revision No: 3.1 E307132 10-Feb-20 7.5.5 Construction camps 167 7.5.6 Construction Noise 168 7.5.7 Vibration 173 7.5.8 Cultural and physical resources 177 7.6 Operation Impacts 178 7.6.1 Operation impacts on the physical environment 178 7.6.2 Operation impacts on biological environment 180 7.6.3 Operation impacts on socio-economic environment 181 8 Environmental Management Plan 182 8.1 Introduction 182 8.2 Institutional Responsibilities 182 8.2.1 Project Management Unit of Electric Power Corporation 182 8.2.2 Construction supervision consultant and supervising engineer 183 8.2.3 Lenders Technical Advisor 183 8.2.4 Design and build contractor 183 8.3 Framework of Environmental Plans 185 8.3.1 Environmental management system 185 8.3.2 Framework of the plans 185 8.3.3 Environmental reporting requirements 195 8.4 Pre-Construction EMP 195 8.5 Construction Phase EMP 199 8.6 Operational Phase EMP 217 8.7 Estimated Costs for Environmental and Social Protection Measures 226 9 Conclusions and Recommendations 229 9.1 Conclusions 229 9.1.1 Critical Habitat issues 229 9.1.2 Environmental Flow issues 231 9.2 Concluding remarks 231 9.3 Requirements and Recommendations 232 9.4 Provisions for Grant Agreement 233 References 236 Appendices Appendix 1 – Environmental documents reviewed in the preparation of this EIA 256 Appendix 2 – Project specific studies prepared as part of EIA process 257 Appendix 4 – Data utilized & calculations undertaken in GHG emissions estimate for the Project 259 Appendix 5 – Construction noise calculations 261 iv | P a g e Alaoa Multi-Purpose Dam Project - Environmental Impact Assessment Revision No: 3.1 E307132 10-Feb-20 List of Figures Figure ES1: Four Branches of Vaisigano River and Location of Alaoa Dam and UNDP flood walls xiii Figure ES2: 3D representation of Dam impoundment and hydro-power station xiii Figure 1.1: Location of Samoa and project area 1 Figure 1.2: Project area for the Project and Apia Catchment key biodiversity area 5 Figure 1.3: Plan of Works – Dam, inundated area, penstock and hydropower station 3 Figure 1.4: Alaoa Dam Project - schematic of existing and post project situation 4 Figure 3.1: The four sub catchments in the Vasigano catchment 20 Figure 3.2: Location of flood protection walls in Apia – in relation to project 24 Figure 3.3: General Arrangement of the preferred dam option 24 Figure 3.4: How water will be stored behind dam for flood protection, water supply and powerError! Bookmark not defined.25 Figure 4.1: The two dam site options considered 27 Figure 5.1: Vaisigano catchment 31 Figure 5.2: Geological map of Upolu 33 Figure 5.3: Digitised version of soil map of Upolu covering the Vaisigano River catchment.