LAO PEOPLE’S DEMOCRATIC REPUBLIC PAKLAY HYDROPOWER PROJECT Feasibility Study Report FINAL (Chapter 1) DEVELOPER: CONSULTANT: March, 2017 Contents NO. CHAPTER 1 Executive Summary 2 Hydrology 3 Engineering Geology 4 Project Planning 5 Project Layout and Main Structures 6 M&E Equipment and Hydraulic Steel Structures 7 Construction Organization Design 8 Project Management Plan 9 Environmental and Social Impact Assessment 10 Project Cost Estimation 11 Economic Evaluation 1 Executive Summary Contents 1 General Description ..................................................................................................... 1-1 1.1 Overview ............................................................................................................... 1-1 1.2 Hydrology .............................................................................................................. 1-6 1.3 Engineering Geology ........................................................................................... 1-14 1.4 Project Planning .................................................................................................. 1-32 1.5 Project layout and main structures ...................................................................... 1-55 1.6 Electromechanical and Metal Structures ............................................................. 1-94 1.7 Construction Organization Design ..................................................................... 1-114 1.8 Project Management Plan .................................................................................. 1-129 1.9 Cost Estimate ..................................................................................................... 1-130 1.10 Economic Evaluation ...................................................................................... 1-132 1.11 Main Conclusions and Suggestions ................................................................. 1-133 1.12 Project Characteristics ..................................................................................... 1-136 1.13 Attached Drawings .......................................................................................... 1-141 1 General Description 1.1 Overview 1.1.1 Geographical Location of Project Located on the middle Mekong River in Laos, Paklay Hydropower Station is the fourth hydropower station (from upstream to downstream) of the 11 Hydropower Stations planned for the main stream of Mekong River. Sayaburi Hydropower Station is located upstream of it while Sanakham Hydropower Station is located downstream. The dam site of Paklay Hydropower Station is located at 1829km (to the estuary) on the main stream of Mekong River, about 31km upstream from Paklay County and about 241km from Vientiane, the capital city of Laos. The control drainage area at the dam site is about 278,400 km2. See Fig. 1.1-1 for the geographical location of Paklay Hydropower Station. 1- 1 Fig. 1.1-1 Geographical Location of PAKLAY Hydropower Station 1.1.2 River Planning As a famous international river in Southeast Asia, Mekong River, known as Lancang River within the Chinese territory, is originated from the north piedmont of Tanggula Mountains in China, passes Qinghai, Tibet and Yunan Provinces (autonomous regions) and leaves China at Mengla County, Xishuangbanna Prefecture, Yunnan Province, from where it is called Mekong River, passes Myanmar, Thailand, Laos and Cambodia from north to south and converges in the South China Sea in Ho Chi Minh City, Vietnam. With a drop of about 480m, Mekong River has a total length of about 2720km and a control drainage area of 621,000 km2. The mean annual discharge at estuary is 15062m3/s 1- 2 and annual runoff is 475 billion m3. According to statistics of relevant data, the reserve of waterpower resources of Mekong River is about 58,000MW in theory, of which the exploitable waterpower resources are about 37,000MW. The exploitable waterpower resources of Mekong River mainly concentrates in Laos and Cambodia, accounting for 51% and 33% respectively, as well as in other countries (Myanmar, Thailand and Vietnam) accounting for 16%. At present, the exploited waterpower resources of Mekong River accounts for only 1% of the total. In accordance with the Study on Development of Run-of-River Hydroelectric Projects on Mekong River Main Stream released by Mekong River Commission Secretariat in 1994, 11 hydropower stations are planned on the main stream of Mekong River, including five hydropower stations in Laos, namely, Pak Beng, Luang Prabang, Sayaburi, Paklay and Sanakham. See Table 1.1-1 for the planned technical indicators of the 11 hydropower stations. 1- 3 Table 1.1-1 Major Technical Indicators in the Proposal of 1994 for Planning of Run-of-River Hydroelectric Projects on Mekong River Item Location Distance from Catchment Area of Mean Annual Discharge Normal Pool Installed Mean Annual Annual Operation Hours of Inundated Arable Relocated Estuary Dam Site at Dam Site Level Capacity Energy Output Installed Capacity Land Population Unit km 103 km2 m3/s m MW 109 kWh h km2 Person (s) PakBeng Laos 2188 218.0 3170 345 1230 5.67 4610 5 1670 Luang Laos 2036 230.0 3810 320 1410 7.38 5234 5 6580 Prabang Sayaburi Laos 1930 272.0 3990 270 1260 5.99 4754 0 1720 (Sayabouly) Paklay Laos 1818 283.0 4030 250 1320 6.46 4894 10 11780 Chiang Laos 1772 292.0 4160 230 570 3.21 5632 10 12950 Khan Pamong Border between Laos 1651 295.5 4310 207.5 2030 8.87 4369 10 23260 and Thailand BanKoum Border between Laos 928 419.0 8520 120 2330 10.23 4391 5 2570 and Thailand Don Border between Laos 719 553.0 10310 70~72 240 1.64 6833 0 0 and Cambodia Sabong Stung Cambodia 670 635.0 13710 55 980 4.87 4969 80 9160 Treng Sambor Cambodia 560 646.0 13950 40 3300 14.87 4506 150 5120 Tonle Sap Cambodia 362 710.0 13820 10 140 0.31 2214 0 0 Total 14810 69.5 4693 275 74810 Notes: The names in the brackets are what adopted in water level coordination report. 1- 1 Paklay Hydropower Station is the fourth hydropower station (from upper to lower) of the 11 hydropower stations planned for the main stream of Mekong River with Sayaburi Hydropower Station located in the upstream and Sanakham Hydropower Station located in the downstream. Paklay Hydropower Station is a large hydroproject with the main function of power generation and concurrently other multiple functions such as navigation. In the planning report of 1994, the normal pool level of Paklay Hydropower Station is 250m and the installed capacity preliminarily proposed is 1320MW. Since there is overlap and contradiction in the planned water levels of hydropower stations in the planning report of 1994, the Lao government entrusted the Compagnie Nationale du Rhône (referred to as CNR) of France to carry out recheck and re-demonstration about planning of the 5 hydropower stations (Pak Beng~Sanakham) in Laos. In September of 2009, CNR put forward the final research report Optimization of Mekong Main Stream Hydropower. The suggested normal pool levels of the hydropower stations are shown in Table 1.1-2. Table 1.1-2 Normal Pool Level of Hydropower Stations Planned, Demonstrated and Recommended by CNR in 2009 Luang Chiang Khan Name Pak Beng Sayaburi Paklay Prabang (Sanakham) Distance to the estuary (km) 2188 2036 1930 1818 1737 Highest normal pool level 340.00 312.50 275.00 245.00 220.00 Lowest normal pool level 337.50 310.00 275.00 240.00 217.50 Notes: The dam site of Chiang Khan Hydropower Station, now called Sanakham Hydropower Station, moves 35km downward from the 1994 planned site. 1.1.3 Brief Description of Design Process On June 11, 2007, the joint venture of Sinohydro Corporation Limited and China National Electronics Import-Export Corporation (referred to as "joint venture") signed an investment and development memo (MOU) for BOT items of PAKLAY Hydropower Station with the Lao government. In November, 2007, the joint venture officially entrusted Hydrochina Zhongnan to carry out the feasibility study on the project of Paklay Hydropower Station. 1- 1 In November, 2007, Hydrochina Zhongnan began to move in the site to carry out field survey and investigation. In May, 2008, we finished the field survey and investigation as well as field experiment of this stage. On August 26, 2009, the Lao government gave a notice to the joint venture by letters requiring that the normal pool level of the Paklay Hydropower Station should not be higher than 240.00m. On March 25, 2010, the joint venture made it clear by letters that the feasibility work is carried out based on normal pool level 240.00m as basic water level and required that relevant results of comparison with a normal pool level of 245.00m should be provided at the same time. In July, 2010, Hydrochina Zhongnan completed the feasibility study on Paklay Hydropower Station as required above and submitted to the joint venture the relevant results of the following recommended dam sites. On April 28, 2011, the joint venture held the Technical Review Meeting about Feasibility study Report on Laos Paklay Hydropower Station in Beijing, in which technical review of the feasibility report submitted by Hydrochina Zhongnan in July, 2011 was carried out. The main conclusion and comments of the review are as follows: a) The report has reached the design depth of feasibility stage. The design is generally rational and feasible. b) It is required to give up the lower dam site scheme which has better economic indicators and choose the upper dam site as the recommended one. The report compared the schemes for lower and upper dam sites from two aspects, i.e. technical