Department of Alternative Energy Development and Efficiency MINISTRY OF ENERGY Initial Environmental Examination of Khlong Ae Mini Hydropower Project Surat Thani Province Final Report (Executive Summary ) Prepared by Macro Consultants Co., Ltd. February 2009 u5Gn u~aT~sfiorsu"a~~nu.i1"11% MACRO CONSULTANTS CO., LTD. 20 SO1 RATCHADAPHISEK 36, RATCHADAPHISEK RD. LADYAO JATUJAK BANGKOK 10900 TEL :939051 1-5,9390518-9,9391950-2 FAX :(662) 9390520 Final Report IEE of Khlong Ae Mini Hydropower Project Acknowledgement Acknowledgement Macro Consultants Co., Ltd. would like to express deepest gratitude to the Department of Alternative Energy Development and Efficiency for giving opportunity to jointly undertake the Initial Environmental Examination of Khlong Ae Mini Hydropower Project, Surat Thani Province.Throughout the course of study, the Consultants received excellent cooperation and support from the Project Supervisory Committee and involved DEDE’s personnel whose contributions in field survey work, sharing effort in public participation meetings as well as providing numerous constructive comments and valuable suggestions to the Consultants, are greatly appreciated. Followings are members of the Committee : 1) Khun Chavalit Jiravichailit 2) Khun Jareerat Satrawaha 3) Khun Pheeraphong Boonsang 4) Khun Wuttipong Apichonnabutr 5) Khun Praphaporn Khursida In the course of study, the Consultants also obtained valuable secondary data with welcome cooperation from the local government agencies in Surat Thani Province namely Khlong Yan Wildlife Sanctuary, Tapee Watershed management Unit, Agriculture Office of Surat Thani, Takuk Tai Subdistrict Administrative Organization, Takuk Nua Subdistrict Administrative Organization, Num Hak Subdistrict Administrative Organization, Takuk Tai Subdistrict Health Center, Num Hak Subdistrict Health Center. In addition, during the periods of holding several public participation meetings in the local communities and the field survey work, warmest cooperation and sincere assistance were received from numerous community chiefs including the Surat Thani Associate Provincial Governor, Vibhavadi District Officer, Khiri Ratthanikhom District Officer, Prime Minister of the Takuk Tai Subdistrict Administrative Organization, Prime Minister of the Takuk Nua Subdistrict Administrative Organization and Prime Minister of the Num Hak Subdistrict Administrative Organization. The above-mentioned excellent cooperation and contributions given and helped the project study accomplished successfully are highly acknowledged. Last but not least, special thanks is extended to Dr. Panich Pongpirodom, the Director General of DEDE who provided moral support and encouragement to the Consultants throughout the study period. - ii - Macro Consultants Co., Ltd Final Report IEE of Khlong Ae Mini Hydropower Project Table of Contents Initial Environmental Examination of Khlong Ae Mini Hydropower Project Surat Thani Province EXECUTIVE SUMMARY Table of Contents Page Transmittal Letter i Acknowledgement ii Table of Contents iii List of Figures vii List of Tables viii Abbreviation and Symbol ix 1. INTRODUCTION 1.1 Project Background and Study Objective 1 1.2 Scope of Study 3 1.2.1 Review of Previous Study Reports 3 1.2.2 Description of Existing Environmental Conditions 3 1.2.3 Assessment of Anticipated Environmental Impacts 3 1.2.4 Mitigate Measures of Adverse Impacts 4 1.2.5 Environmental Monitoring Program 4 1.2.6 Conclusion and Recommendation 4 1.2.7 Priority of Environmental Resources/Values 4 1.2.8 Public Participation and Publicity Program 4 2. REVIEW OF PREVIOUS FEASIBILITY STUDY REPORTS 2.1 Project Features and Components of Previous Study 4 2.1.1 Project Features 4 2.1.2 Project Components 5 2.2 Meteo-hydrology 6 2.2.1 Climatology and Meteorology 6 2.2.2 Rainfall 6 2.2.3 Stream Flow 6 2.2.4 Stream Flow in This Study 7 2.3 Hydropower Generation and Impact to Flow over Water Fall 7 2.3.1 Hydropower Generation 7 2.3.2 Impact to the Discharge over the Water Fall 7 2.3.3 The Study for Stopping of Hydropower Generation for 7 Some Periods of Time 2.4 Project Design 9 2.4.1 Weir and Intake Structure 9 2.4.2 Desander 9 - iii - Macro Consultants Co., Ltd Final Report IEE of Khlong Ae Mini Hydropower Project Table of Contents Table of Contents (Cont’d) Page 2.4.3 Headrace 10 2.4.4 Surge Tank 10 2.4.5 Penstock 10 2.4.6 Power House and Substation 10 2.4.7 Mechanical and Electrical Equipments 10 2.4.8 Tailrace 11 2.4.9 Access Road 11 2.5 Project Construction Cost 25 2.6 Construction and Investment plans 25 2.6.1 Construction Plan 25 2.6.2 Project Investment 25 2.7 Economic and Financial Analyses 25 2.8 Conclusion of Project Features from Update Study 27 3. EXISTING ENVIRONMENTAL CONDITIONS 3.1 Physical Resources 30 3.1.1 Weather and Meteorology 30 3.1.2 Hydrology of Surface Runoff 31 3.1.3 Surface Water Quality 31 3.1.4 Hydrogeology and Ground Water Quality 33 3.1.5 Geology and Seismology 33 3.1.6 Soil Resources 33 3.1.7 Erosion and Sedimentation 34 3.1.8 Noise and Vibration 34 3.2 Biological Resources 34 3.2.1 Aquatic Biology 34 3.2.2 Forestry Resource 35 3.2.3 Wildlife Resource 35 3.2.4 Watershed Quality Area 35 3.3 Human Use Values 36 3.3.1 Land use 36 3.3.2 Transportation 36 3.3.3 Power Supply 36 3.3.4 Water Use 36 3.3.5 Agriculture and Livestock 37 3.3.6 Fishery and Aquaculture 37 3.3.7 Irrigation 37 3.3.8 Drainage and Flood Protection 37 3.3.9 Mineral Deposit 37 3.4 Quality of Life Values 38 3.4.1 Socioeconomics 38 3.4.2 Land and Property Compensation 38 3.4.3 Public Health and Nutrition 38 3.4.4 Historic and Archeological Site 39 3.4.5 Tourist Attraction and Recreation 39 - iv - Macro Consultants Co., Ltd Final Report IEE of Khlong Ae Mini Hydropower Project Table of Contents Table of Contents (Cont’d) Page 4. ENVIRONMENTAL IMPACT ASSESSMENT 4.1 Physical Resources 40 4.1.1 Topography 40 4.1.2 Climatology and Meteorology 40 4.1.3 Air Quality 40 4.1.4 Hydrology of Surface Runoff 41 4.1.5 Surface Water Quality 41 4.1.6 Groundwater 41 4.1.7 Geology and Seismology 42 4.1.8 Soil Resources 42 4.1.9 Erosion and Sedimentation 42 4.1.10 Noise and Vibration 43 4.2 Biological Resources 43 4.2.1 Aquatic Biology 44 4.2.2 Forestry Resource 44 4.2.3 Wildlife Resource 44 4.2.4 Watershed Quality Area 44 4.3 Human Use Values 45 4.3.1 Land use 45 4.3.2 Transportation 45 4.3.3 Power Supply 45 4.3.4 Water Use 46 4.3.5 Agriculture and Livestock 46 4.3.6 Fishery and Aquaculture 47 4.3.7 Irrigation 47 4.3.8 Drainage and Flood Protection 47 4.3.9 Mineral Deposit 48 4.4 Quality of Life Values 48 4.4.1 Socioeconomics 48 4.4.2 Land and Property Compensation 49 4.4.3 Public Health and Nutrition 49 4.4.4 Historic and Archeological Site 49 4.4.5 Tourist Attraction and Recreation 49 4.5 Conclusion of Environmental Impact Assessment 50 4.5.1 Summary of direction of anticipated impacts and 50 severity degrees on the related Environmental Resources/Values 4.5.2 Priority Arrangement of Environmental Resources/Values 50 5. PROPOSED MITIGATIVE MEASURES AND MONITORING PROGRAM 5.1 Protective and Mitigate Measures 53 5.1.1 Physical Resources 53 5.2 Environmental Quality Monitoring Program 54 6. ENVIRONMENTAL ECONOMICS STUDY 56 - v - Macro Consultants Co., Ltd Final Report IEE of Khlong Ae Mini Hydropower Project Table of Contents Table of Contents (Cont’d) Page 7. PUBLIC PARTICIPATION AND PULBIC RELATIONS 7.1 Objectives 57 7.2 Scope of Study and Study Methodology 57 7.3 Conclusion of Public Participation Meeting 59 8. CONCLUSIONS AND RECOMMENDATIONS 8.1 Summarizes the Beneficial and Adverse effects 59 8.2 Conclusions and Recommendations 61 - vi - Macro Consultants Co., Ltd Final Report IEE of Khlong Ae Mini Hydropower Project Table of Contents List of Figures Figure Page 1.1-1 Khlong Ae Mini Hydropower Project Location 2 2.2-1 Daily Flow Duration Curve 8 2.4-1 General Layout Plan Weir and Desander 12 2.4-2 Weir Sections (1) 13 2.4-3 Weir Sections (2) 14 2.4-4 Desander General Lay-Out Plan 15 2.4-5 Desander Sections (1) 16 2.4-6 Desander Sections (2) 17 2.4-7 Power Waterway Hydraulic Arrangement 18 2.4-8 Typical Section of Headrace and O&M Road Miscellaneous Details 19 2.4-9 Surge Tank Plan and Sections 20 2.4-10 Power House General Lay-Out Plan 21 2.4-11 Power House Sections 22 2.4-12 Power House Elevations 23 2.4-13 Tailrace Sections and Details 24 3.1-1 Sampling Locations of Existing Surface Water Quality and 32 Aquatic Ecology 5.2-1 Sampling Locations of Surface Water Quality and Aquatic Ecology 55 Monitoring in Khlong Ae - vii - Macro Consultants Co., Ltd Final Report IEE of Khlong Ae Mini Hydropower Project Table of Contents List of Tables Table Page 2.1-1 Salient Features of Project of Previous Study 5 2.6-1 Project Construction Schedule 26 2.7-1 Economic Evaluation and Energy Production Cost (Discount Rate at 8%) 28 2.8-1 Salient Features of Project after Reviewed Study 29 4.5-1 Summary of Impact Assessment for Khlong Ae Mini Hydropower Project 51 4.5-2 Priority Arrangement of Environmental Resources/Values for 52 Khlong Ae Mini Hydropower Project - viii - Macro Consultants Co., Ltd Final Report IEE of Khlong Ae Mini Hydropower Project Abbreviation and Symbols ABBREVIATION AND SYMBOLS ABBREVIATION DESCRIPTION B/C Benefit-Cost Ratio DBH Diameter at Breast Height EIA Environmental Impact Assessment EIRR Economic Internal Rate of Return FIRR Financial Internal Rate of Return Hr hour IEE Initial Environmental Examination kWh Kilowatt-hour m.