Environmental Impact Assessment Project Number: 52111-001 February 2020 Samoa: Alaoa Multi-purpose Dam Project Volume 2: Assessment of Ecological Effects: Birds and Bats (Part 1 of 9) Prepared by Rebecca Stirnemann and Briar Taylor-Smith for the Asian Development Bank. This environmental impact assessment is a document of the borrower. The views expressed herein do not necessarily represent those of ADB's Board of Directors, Management, or staff, and may be preliminary in nature. Your attention is directed to the “terms of use” section on ADB’s website. 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. 0 Proposed Alaoa Dam Vaisigano River, Upolu, Samoa Assessment of Ecological Effects: Birds and Bats 1 Prepared by Dr Rebecca Stirnemann and Dr Briar Taylor-Smith for the Asian Development Bank Pictures: 1) Manumea 2) MNRE staff Fialelei Enoka and a Mao. Contents 1 Executive Summary 4 2 Introduction 4 2.1 Background 4 2.2 Policy, Legal and Administrative Framework 9 2.3 Critical habitat 10 2.4 Legal protection and international recognition of the site 10 2.5 Relative Importance of the Project Area 11 2.5.1 Ecology and Distribution 11 2.5.2 Manumea 12 2.5.2.1 Ecology and Distribution 12 3 Methods 14 3.1 Assessment of Ecological Effects methodology 14 3.1.1 Evaluating ecological features 14 3.1.2 Assessing potential and actual effects 15 3.1.3 Establishing impact management options 15 3.2 Vegetation mapping 16 3.3 Avifauna surveys 16 3.3.1 Playback surveys 16 3.3.2 Automated recorders 17 3.3.3 Territory determination 17 3.3.4 Targeted habitat identification 17 3.4 Bat surveys 18 4 Description of Existing Ecological Values 19 4.1 Habitat 19 4.3 Habitat value & threat status 22 4.4 Mao 23 4.4 Manumea 27 4.5 Other bird species 29 4.6 Bats 29 5 Project effects 29 5.1 Summary of adverse ecological effects 29 5.2 Effects on vegetation 32 5.3 Effects on avifauna 33 5.4 Effects on bats 38 2 6 Avoidance, remediation, mitigation and offsetting/compensation requirements 38 6.1 Mitigation Strategy 38 6.2 Vegetation mitigation 41 6.3 Avifauna mitigation & monitoring 42 6.3 Bat mitigation & monitoring 43 References 43 Appendix I: Vegetation types - species lists 45 Appendix II 47 3 1 Executive Summary The proposed Alaoa dam site contains habitat for the endangered mao (Gymnomyza samoensis) and the critically endangered manumea (Didunculus strigirostris) as well as habitat for additional range restricted species such as the Samoan fruit bat and other threatened Samoan avifauna. Territories of mao occur within the footprint. The site is defined as critical habitat for both mao and manumea. The Project is categorized as environment Category A, because potential adverse environmental impacts are not only site-specific due to the potential population level on mao and Manumea. Samoan fruit bats and some threatened range restricted bird species will also be impacted and are detailed in this document. Impacts on key species could have significant adverse environmental impacts if mitigation is not carefully designed and implemented. Stringent environmental management will be required for the Alaoa dam project to proceed. Mitigation and environmental management would be needed to be carefully designed to ensure these species are maintained and enhanced by the development. It is critical that there are no significant adverse environmental impacts that are irreversible, diverse, or unprecedented for these populations. An Environmental Management Plan (EMP) would be required should the project proceed. 2 Introduction 1.1.1 2.1 Background The Terrestrial Ecology Study is part of the wider Technical Feasibility and other Scientific Assessments that will provide the information for the resource consenting process for the Alaola Dam Project. The purpose of this Assessment of Ecological Effects (AEE) report is to present the environmental impacts and risks associated with the proposed project and make recommendations regarding measures to avoid, mitigate or offset potential adverse effects. Specifically, the objectives are to: To conduct some additional biodiversity surveys focusing on endangered/critically endangered birds and bats, to map the vegetation of the area and provide qualitative and quantitative data on the presence and abundance of sensitive species. The biodiversity expert will: ● Conduct biodiversity surveys of Samoan endangered birds and bats in the area of influence for the project. ● Conduct botanical surveys of the vegetation present in the area of influence of the project to identify the habitat and the presence of trees/habitat potentially able to sustain the endangered species. ● Delivery of a biodiversity report indicating the presence and abundance of the targeted species, basic habitat mapping of vegetation to determine the habitat value for key species and suggestions on how to mitigate the environmental impacts of the proposed project. The scope of the project is limited to the methodology milestones set out in the Request for Proposal documents from ADB and the extent of physical works and flooding associated with the proposed Alola Dam as shown in the proposed site layout in Figures 1 and 2 below - provided by ADB and Entura. This report does not cover quantification of habitat loss outside of the flood area (within dotted pink Fig. 1) and the dam wall as seen in Figure 1 and the white line seen in Figure 2. Due to the lack of available information at the time the report was drafted the effect of roads and other construction cannot be quantified. 4 5 Figure 1. Proposed dam site layout. The footprint as defined in this document are the areas within the pink dotted line and inclusive of the grey dam wall as seen in this figure and the white line on Figure 2. 6 1.1.2 2.2 Policy, Legal and Administrative Framework The Project shall comply with the requirements of the Planning and Urban Management Act 2004 and the Environmental Impact Assessment (EIA) Regulations 2007. For development of hydropower projects, development consent must be obtained from the Planning and Urban Management Agency (PUMA) within the Ministry of Works, Transport & Infrastructure and from the Ministry of Natural Resources and Environment (MNRE). The development consent application must include an environmental assessment which complies with the Act and Regulation requirements. The Project should also comply with the requirements of the Asian Development Bank (ADB) Safeguard Policy Statement (ADB, 2009) to: (i) avoid adverse impacts of projects on the environment and affected people; (ii) where possible; minimize, mitigate, and/or compensate for adverse project impacts on the environment and affected people when avoidance is not possible; and (iii) help borrowers/clients to strengthen their safeguard systems and develop the capacity to manage environmental and social risks. The environment safeguard requires due diligence which entails addressing environmental concerns, if any, of a proposed activity in the initial stages of project preparation. Proposed projects are screened according to type, location, scale, and sensitivity and the magnitude of their potential environmental impacts, including direct, indirect, induced, and cumulative impacts. The SPS categorizes potential projects or activities into categories of impact (A, B or C) to determine the level of environmental assessment required to address the potential impacts. Projects are assigned to one of the following four categories: (i) Category A: A proposed project is classified as Category A if it is likely to have significant adverse environmental impacts that are irreversible, diverse, or unprecedented. These impacts may affect an area larger than the sites or facilities subject to physical works. An Environmental Impact Assessment is required. (ii) Category B: A proposed project is classified as Category B if its potential adverse environmental impacts are less adverse than those of Category A projects. These impacts are site-specific, few if any of them are irreversible, and in most cases mitigation measures can be designed more readily than for category A projects. An Initial Environmental Examination is required. (iii) Category C: A proposed project is classified as category C if it is likely to have minimal or no adverse environmental impacts. No environmental assessment is required although environmental implications need to be reviewed. (iv) Category FI: A proposed project is classified as category FI if it involves investment of ADB funds to or through a financial intermediary. The Project is categorized as environment Category A, because potential adverse environmental impacts are not only site-specific due to the potential population level on mao (Gymnomyza samoensis) and manumea (Didunculus strigirostris). These effects will affect an area larger than the footprint and will also include sites or facilities subject to physical works. Impacts are likely to have significant adverse environmental impacts if mitigation is not carefully designed and implemented. This EIA has been prepared as the requisite level of assessment to address the potential impacts in line with the SPS. 1.1.3 2.3 Critical habitat Critical habitat is defined by ADB for purposes of informing investment decisions as a subset of both natural and modified habitat that deserves particular attention. Critical habitat includes areas with high biodiversity value, including habitat required for the survival of critically endangered or endangered species; areas having special significance for endemic or restricted-range species; sites that are critical for the survival of migratory species; areas supporting globally significant concentrations or numbers of individuals of congregatory species; areas with unique assemblages of species or that are associated with key evolutionary processes or provide key ecosystem services; and areas having biodiversity of significant social, economic, or cultural importance to local communities (ADB, 2009).