“Darial Energy” LLC Dariali Hydro Power Plant Construction and Operation Project Environmental and Social Impact Assessment Report Executors Scientific Research Firm “Gamma" President : V. Gvakharia “Stucky Caucasus“ LLC General Director : B. Quigley 2011 SCIENTIFIC RESEARCH FIRM “GAMMA 17a. Guramishvili av, 0192, Tbilisi, Georgia tel: +(995 32) 260 44 33 +(995 32) 260 15 27 e-mail: [email protected] EIA-Dariali_HPP 2 / 205 Table of Content 1 Introduction .......................................................................................................................................7 1.1 General Overview ...........................................................................................................................................7 1.2 Basis and Goals of Environmental and Social Impact Assessment Report ...................................................7 2 Legal-institutional framework............................................................................................................8 2.1 Georgian legislation and institutional framework.........................................................................................8 2.1.1 State policy objectives ................................................................................................................................8 2.1.2 Regional and international cooperation ....................................................................................................9 2.1.2.1 Regional cooperation .........................................................................................................................9 2.1.2.2 International agreements.................................................................................................................10 2.1.3 Institutional Framework for Environmental Protection ........................................................................10 2.1.4 Environmental Legislation .......................................................................................................................11 2.1.4.1 Overview of the key environmental legislation acts......................................................................13 2.1.4.2 Environmental Standards ................................................................................................................18 2.1.5 Environmental Impact Assessment Process in Georgia ..........................................................................20 2.2 Environmental and Social Standards of International Financial Institutions ............................................21 2.2.1 Lender Policies and Standards .................................................................................................................22 2.2.1.1 EBRD Environmental and Social Policy, 2008 ...............................................................................22 2.2.1.2 International Financial Corporation Guidelines and Standards ....................................................30 3 Analysis of alternatives for the planned activities............................................................................30 3.1 No Action Alternative ..................................................................................................................................30 3.2 A Seasonal Regulation HPP Construction Alternative ...............................................................................31 3.3 A Riverbed Type HPP Construction Alternative ........................................................................................34 3.4 Diversion type HPP construction alternatives ............................................................................................34 3.4.1 Two-stage run-of-the-river HPPs construction alternative ..................................................................34 3.4.2 One-Stage Diversion HPP Construction Alternative .............................................................................36 3.4.2.1 Alternatives for Headworks ............................................................................................................38 3.4.2.2 Diversion System alternatives .........................................................................................................40 3.4.2.3 Penstock Alternatives ......................................................................................................................44 3.4.2.4 Alternatives for Power Unit ............................................................................................................45 3.5 Comparison of Alternatives..........................................................................................................................46 3.6 Conclusion.....................................................................................................................................................49 4 HPP Construction and Operation Project Description.....................................................................49 4.1 General Review of the Project......................................................................................................................49 4.2 HPP Structure Description ...........................................................................................................................54 4.2.1 Water Intake .............................................................................................................................................54 4.2.1.1 Dam ..................................................................................................................................................54 4.2.1.2 Settling Basin....................................................................................................................................55 4.2.1.3 Fishway.............................................................................................................................................56 4.2.2 Diversion System ......................................................................................................................................56 4.2.2.1 Diversion Pipeline............................................................................................................................56 4.2.2.2 Diversion Tunnel .............................................................................................................................57 4.2.3 Power Unit Facility ..................................................................................................................................58 4.2.3.1 Surge Shaft........................................................................................................................................60 4.2.3.2 Power House ....................................................................................................................................60 4.2.3.3 Tailrace Tunnel and Channel ..........................................................................................................60 4.2.3.4 Cable Duct and Service Tunnel.......................................................................................................60 4.2.3.5 Open Substation...............................................................................................................................61 4.3 Description of Construction Works .............................................................................................................61 4.3.1 Construction camp and Construction sites..............................................................................................61 4.3.1.1 Construction camp...........................................................................................................................61 SCIENTIFIC RESEARCH FIRM “GAMMA EIA-Dariali_HPP 3 / 205 4.3.1.2 Construction Sites ............................................................................................................................62 4.3.1.3 Power Supply ...................................................................................................................................62 4.3.2 HPP Construction Works.........................................................................................................................62 4.3.2.1 General Provisions ...........................................................................................................................62 4.3.2.2 Headwork .........................................................................................................................................63 4.3.2.3 Diversion Pipeline............................................................................................................................63 4.3.2.4 Diversion Tunnel .............................................................................................................................64 4.3.2.5 Surge Shaft and Power House .........................................................................................................64 4.3.3 Machinery Requirements for Construction Operations .........................................................................64 4.3.4 Water Supply and Sanitation ...................................................................................................................65 4.3.4.1 Water Supply ...................................................................................................................................65 4.3.4.1.1 Drinking and Domestic Water Supply.......................................................................................65