UNITED REPUBLIC OF TANZANIA MINISTRY OF WATER Lake Nyasa Basin Water Board PREPARATION OF AN INTEGRATED WATER RESOURCES MANAGEMENT AND DEVELOPMENT PLAN FOR THE LAKE NYASA BASIN Hydropower Report May 2013 United Republic of Tanzania Ministry of Water Hydropower Report Date: May 2013 This report has been prepared for the Ministry of Water of the United Republic of Tanzania in accordance with the terms and July 2012 conditions of Contract: ME 011/2010/2011/C/08 Consultancy Services for preparing the Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin. Funds are made available by the International Development Association (IDA) and the United Republic of Tanzania. The opinions expressed are those of the authors and may not represent the views of the IDA or those of the United Republic of Tanzania. SMEC International Pty Ltd cannot accept any responsibility for any use of or reliance on the contents of this report by any third party. Table of Contents ABBREVIATION and ACRONYMS ................................................................................ ii 1 INTRODUCTION .................................................................................................. 1 1.1 Literature Search, Data Collection ........................................................................ 2 1.2 Data and Information Review ................................................................................ 2 1.3 Consultations, Workshop and Field Visits ............................................................. 3 1.4 Software Programs ............................................................................................... 3 2 HYDROPOWER SITUATION REVIEW ................................................................ 4 2.1 Nyasa Basin .......................................................................................................... 4 2.2 Preview for Tanzania Power Sector ...................................................................... 5 2.3 Existing Hydropower in Nyasa Basin .................................................................... 7 3 HYDROPOWER WATER PLAN........................................................................... 8 3.1 Water Demand ..................................................................................................... 8 3.2 Water Demand Management ............................................................................... 9 3.3 Planning Objectives, Development Plan ............................................................. 10 3.4 Reservoir Operating Rules.................................................................................. 10 4 POTENTIAL HYDROPOWER DEVELOPMENT SCHEMES ............................. 12 4.1 Potential Hydropower in Nyasa Basin ................................................................. 12 4.2 Prioritized Projects (PSMP 2009)........................................................................ 13 4.3 Other Identified Potentials (mini grid) .................................................................. 16 5 FINDINGS and RECOMMENDATIONS ............................................................. 17 APPENDICES ............................................................................................................... 18 Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page i TABLES Table 1 - Thermal Power Plants in Tanzania Power Grid ................................................ 6 Table 2 - Hydropower Plants in Tanzania Power Grid ..................................................... 6 Table 3 - Water Abstraction Certificates/Applications ...................................................... 8 Table 4 - Potential Hydropower in Nyasa Basin ............................................................ 12 Table 5 - Prioritized Future Hydropower Projects under PSMP 2009 (Nation Wide) ....... 13 Table 6 - Other Potentials in Nyasa Basin ..................................................................... 16 FIGURES Figure 1 - Lake Nyasa Basin and its Rivers ................................................................... 4 Figure 2 - Tanzania Power Generation Mix ................................................................... 5 Figure 3 - Existing Basin Hydropower Contribution to National Power Grid .................. 7 Figure 4 - Basins’ Future Hydro Contribution in MW to the Electric Grid ..................... 12 Figure 5 - Basins’ Future Hydro Contribution in % to the National Grid ....................... 13 Figure 6 - Illustrative Diagram for Upgraded Rumakali Hep Concept .......................... 14 Fig App B1 - Rumakali River Rating Curve......................................................Appendix B Fig App B2 - Ruhuhu at Masigira Rating Curve ...............................................Appendix B Fig App B3 - Songwe River at Kasumulu Rating Curve ...................................Appendix B APPENDICES Appendix A - Photo Documentation Appendix B - Rating Curves Appendix C - Map Licensed Hydropower Plants, Prioritized Projects (PSMP 2009) Appendix D - License Holders for Hydropower Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page i ABBREVIATIONS AND ACRONYMS CRC Cumecs CWS CWSS EF FAO FRG GWh HEP IPP ITCZ Km kW kWh = critical rule curve = cubic meter per seconds (m3/sec) = Community Water Supply and Sanitation = Commercial Water Supply and Sewerage = Environmental Flows = Food and Agriculture Organization of the United Nations = Federal Republic of Germany = Giga Watt hour = Hydro Electric Power = Independent Power Producer = Inter-Tropical Convergence Zone = kilometer = kilo Watt = kilo Watt hour LNBWB = Lake Nyasa Basin Water Board LocClim m.a.s.l. MDGs Mm3 MoEM MoW MW NEMC NyM Ppt Ph.D PSMP NORPLAN REA SHP SMEC TANESCO ToR URT WRMD WSDP = Local Climate Estimator = meters above sea level = Millennium Development Goals = Million Cubic Meters = Ministry of Energy and Minerals (Tanzania) = Ministry of Water (Tanzania) = Megawatt = National Environmental Management Council = Nyumba ya Mungu = Precipitation = Doctor of Philosophy = Power System Master Plan = Norway based consulting firm = Rural Electrification Agency = Small Hydro Power = Snowy Mountains Engineering Corporation = Tanzania Electric Supply Company Limited = Terms of Reference = United Republic of Tanzania = Water Resources Management and Development = Water Sector Development Program Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page ii 1 INTRODUCTION The Government of Tanzania is presently implementing the Water Sector Development Program (WSDP) 2006 - 2025. The WSDP targets four areas in the water sector, namely: (i) Water Resources Management and Development (WRMD), (ii) Community Water Supply and Sanitation (CWSS), (iii) Commercial Water Supply and Sewerage (CWS) and (iv) Sector Institutional Strengthening and Capacity Building. The development of an IWRMD Plan is a key objective of the WRMD component whose conceptual framework for IWRMD consists of four main components: Water Supply & Sanitation Energy (Hydropower) Irrigation & Drainage Environmental Services Other Uses including Industry & Navigation This report looks at the Hydropower component. It makes an assessment of the hydropower situation in the basin, water demand, management and development and the potential for hydropower (Chapter 3-4). Chapter 5 presents the key findings and recommendations. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 1 1.1 Literature Search, Data Collection A desk study was undertaken and a number of key stakeholders were visited. These are: TANESCO, MEM, REA and the MAJI offices in Dar es Salaam. Other offices including the LNBWO in Tukuyu were visited as well, for data and information collection. The following data and reports were collected from various institutions/offices in Dar es Salaam and elsewhere: Basin Hydrological Report, LNBWO, December 2010 The Water Resources Management Act 2009, GoT, 15th May 2009. Power System Power Master Plan, MEM/TANESCO, August 2009 A List of Mini Hydropower Potential Sites in Tanzania, TANESCO, August 1996 Topographical Maps, 1:50,000 for the area. Hydrological Year Book 1950-1959, Ministry of Agriculture, Republic of Tanganyika, 1963 Hydrological Year Book 1965-1970, Ministry of Water Development and Power, United Republic of Tanzania, 1976 Hydrological Year Book 1971-1980, Ministry of Water, URT, 1980 Water Master Plans for Iringa, Ruvuma and Mbeya Regions, Hydrology Volume 7, Carl Bro et al 1982 Implementation of Water Master Plan for Iringa, Ruvuma and Mbeya Regions, Hydrology – Low Flow Gaugings, Reginal Hydrologists, 1988 1.2 Data and Information Review The following data were reviewed: Topography and hydrological data and information mainly based on previous studies/reports. Identification reaches of streams/rivers with potential for hydropower development. Relevant stream/river gauging stations. Matching these with the corresponding catchment/sub-catchments. Identify time series for the gauging stations and compute its mean values (monthly and annually) using commercially available computer software programs. Identify relevant rainfall stations and their time series runoffs were studied to compute monthly/annual averages for the corresponding catchments to give averages discharges. These rainfall averages will be compared and used fill gaps identified in the discharge time series for the flows of the same catchments. Based on these and other key information (head) from the existing reports preliminary power and energy output were estimated. During the study period, some interviews to ascertain quality, gaps of data and information were held with different officials of LNBWO. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 2 1.3 Consultations, Workshop and Field Visits Consultations Prior to the basin visit, consultations and discussions with the following officers/institutions were held with the aim of understanding the government planning objectives related to the energy sector: Ministry of Energy and Minerals: Assistant Commissioner (Renewable), Mr. Edward Leonard Ishengoma Senior Energy Engineer, Mr. Leonard Masanja Senior Energy Engineer, Mr. Juma Mkobya TANESCO: Senior Manager Hydropower Generation – Eng. Costa Rubagumya Principal Planning Engineer – Eng. Evalder Munisi Rural Energy Agency: Director Technical services – Eng. Bengiel Msofe Workshop A training workshop on Hydropower in Nyasa was held in December 2012 in Tukuyu with participants from LNBWO and TANESCO. Information was gathered from the LNBWO/TANESCO staff: Basin Water Officer – Witgal Nkondola Basin Environmental Engineer – Innocent Lyamuya Lake Nyasa Hydrologist – Damas Mbaga TANESCO Officer – Richard Ngwada The workshop included presentations which were structured and delivered as an interactive session enabling the participants to discuss and brainstorm on key issues of serious concerns and challenges facing the basin encompassing issues on IWRMD. Field Visit Field visits with the LNBWO counterparts were conducted in December 2013 to inspect nearby hydrological river gauging and meteorological stations. Also during the same period, the Bugema Micro Hydropower Plant at Busoka village run by a local Church was visited. Discussions/explanations on the facility were held at site during the tour (see also Appendix A). 1.4 Software Programs During this study, an assessment and evaluation of the rainfall spatial distribution within the basin was carried out using the New LocClim 1.10 program developed by DWD/FAO 2005. New LocClim is a tool for spatial interpolation of agroclimatic data and specially designed for the interpolation of agroclimatic data, offering the possibility of producing climate maps from user provided station data. However, where such station data is unavailable, New LocClim is also capable of producing climate maps of the average monthly climate conditions taken from the agroclimatic database of the Agromet Group of the Food and Agriculture Organisation of the United Nations. For free copies and technical details of this software, the reader is directed to contact agromet@fao.org or gpcc@dwd.de. Also, for hydrological assessment and evaluation, free software program was used. Hydrological time series processing software called Hydrognomon, version 4.1.0 was used in the exercise. Details on this free software program may be obtained from http://hydrognomon.org. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 3 2 HYDROPOWER SITUATION REVIEW 2.1 The Basin The study area is comprised of 10 major rivers whose catchments have a total area of about 27,600 km2 as shown in Figure 1 below. The Lake Nyasa is a shared lake between Tanzania, Malawi and Mozambique with a total drainage area of about 98,700 km2. The Lake Nyasa Basin is located in the south western part of Tanzania and drains into the Indian Ocean via Lake Nyasa through Shire River System into the Zambezi River in Mozambique. The major rivers that drain into Lake Nyasa are Ruhuhu, Songwe, Kiwira, Lufirio, and Lumbira. Name Lake Nyasa Malawi Mozambique Mbawa Mchuchuma Ruhuhu Nkiwe Songwe Mbaka Lumbira Rumakali Lufirio Kiwira total Tanzania catchment LN Area Land Area (sqkm) (sqkm) 30,898 62,906 62,906 8,182 8,182 1,878 671 14,211 1,881 2,490 747 2,153 693 1,012 1,888 27,623 98,711 Figure 1 - Lake Nyasa Basin and its Rivers Basin Topography The Tanzania portion of the basin is generally mountainous and hilly, with Rungwe, Kipengere Mountains being the highest of peaks over 2,000 metres above sea level. The lowest land is around the Lake Nyasa which is 470 metres above sea level on the average. The mountainous areas in the Ruvuma region are of lesser altitudes than those of the Iringa and Mbeya regions and most of the region is covered by undulating hills. The characteristic features of the basin, apart from the Rift Valley system, are the surrounding uplifted and warped plateaus, covering nearly 90 percent of the total basin area. The plateaus represent by far the most common land form. They are dissected by fault-lines and ravines which are the result of steady erosion that has taken place since the late Jurassic period. The oldest plateaus are found at the highest levels from 1,800 to 3,000 m above sea level (i.e. the Mporoto and Kipengere ranges) while the remaining parts of the basin are occupied by areas where deposition of the material has taken place notably in the Rungwe Volcanics, in and around Rungwe district. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 4 The Rungwe Volcanics, with the Rungwe Mountain (2,960 m.a.s.l.) at its centre of eruption, forms an area of pronounced topographical relief. The craters, lava flows and volcanic ash covers make the volcanic area completely different from the rest of the Basin. Climate The climate of the Basin is tropical, displaying wet and dry seasonal patterns. It is significantly affected by the location of the ITCZ. During December to February this zone is located south of the Basin and the dry and warm north-east monsoon pre-dominates. From March the zone moves northwards and is located over the Basin and results in the heaviest rainfall of the year. By June the zone has moved north of the Basin and the colder but dry south-east air streams predominate. The convergence zone then moves south again, although more rapidly than its northward journey, and by November it is again situated over the Basin giving rise to some light rains. Run-off Streams starts rising in November-December, experience a maximum flow in March-April, and have their recession period from May to October-November with annual rainfall below 500-800 mm and the mean annual runoff is generally below 2 l/s/km2. At the other part of the Basin where annual rainfall is in the range of 1,000-2,500 mm, streams and rivers are perennial, and the mean annual runoff exceeds 10 l/s/km2. Exceptional high mean annual runoff can be found in areas like Kiwira River (40 l/s/km2) from the 1,660 km2 catchment at Kyela. The available hydrological records of several stream flows gauging station were reviewed. However, this report will not deal with detailed hydrological assessment as the subject will be handled in a separate report prepared. However, typical river characteristics in terms of river flows patterns for some selected rivers are given in Appendix B. 2.2 Tanzania Power Sector Electricity generation players in Tanzania are both the Public (TANESCO) and Private Sector (IPPs). A significant portion of generation is also supplied through RENTAL Units system. TANESCO’s generation system consists mainly of hydro and fossil fuel based generation. The total interconnected system installed capacity from TANESCO, IPPs and RENTAL Units generation assets amount to about 1,436 MW as per 2012. Figure 2 - Tanzania Power Generation Mix The Tanzania power generation mix is shown in Figure 2. Details of each segment are shown in Tables 1 and 2. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 5 Table 1 - Thermal Power Plants in Tanzania Power Grid (2012) Thermal Plant Fuel Songas 1 Songas 2 Songas 3 Tegeta IPTL Subtotal 1 Gas Gas Gas HFO Ubungo T Tegeta T Subtotal 2 Gas Gas Symbion I Agreko Symbion II Subtotal 3 Total (1+2+3) # units IPPs 2 3 1 10 TANESCOs 10 RENTALS Gas/JetA1 5 HFO 100 HFO Installed (MW) Available Capacity (MW) 40 120 40 103 303 38 110 37 90 275 102 45 147 100 43 143 120 100 205 425 875 112 100 205 417 835 Available Energy (GWh) Available Capacity * 8760* 1 (for max plant 1 factor) The national grid system constitutes hydropower of about 561 MW installed capacity. Fossil fuel generating capacity forms the rest, mainly from IPPs (875 MW). Hydro contributes the largest share of TANESCO’s own power generation. Table 2 - Hydropower Plants in Tanzania Power Grid (2012) Plant name Capacity (MW) Mtera 80 Avg Annual energy (GWh) 429 Firm Annual energy (GWh) 195 Commis sioned Date Age in 2013 (years) 1988 25 Kidatu Hale* Lower Kihansi New Pangani Falls Nyumba Ya Mungu 204 21 180 68 8 1,111 91 694 341 36 601 54 492 201 20 1975 1964 2000 1995 1968 38 49 13 18 45 Total 561 2,704 1,564 The total generation from TANESCO own sources in 2008 was 2,985,275,264 kWh out of which 2,648,911,352 kWh or 90% was from Hydro Power Plants. Total country demand as per 2008 records was 4,425,403,157 kWh, of which 33% was supplied by IPPs. Available energy in GWh equals the formula → (Available Capacity in MW) x (hours in a year) x (plant factor). The latter has been given the maximum of 1 (or 100%) following the PSMP 2009. 1 Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 6 2.3 Existing Hydropower in Nyasa Basin Currently, the Lake Nyasa basin does not have any hydropower generation plant connected to the national grid such as Rufiji (83%) and Pangani (17%) basins do, as shown below. Figure 3 - Existing Basin Hydropower Contribution (%) to National Power Grid However, Lake Nyasa basin is a home to existing mini-hydropower plants with an installed capacity totaling of about 290 MW according to the source from LNBWO. These are isolated and off-grid hydropower plants developed by private institutions mostly church missions and dioceses. Appendix C and D shows a map with list of license holders for water abstractions for the mini/micro hydropower plants as well as the prioritized projects under PSMP 2009 . Currently, the Basin office is updating the status of these license holders. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 7 3 HYDROPOWER WATER PLAN 3.1 Water Demand The Lake Nyasa Basin is currently underutilized in terms of hydropower generation in respect to the huge amount of water resources it is bestowed with. The major water use in the basin is for domestic use, irrigation, livestock, industrial use and hydro power. The Basin has about 364 water abstractions out of which 68% have been granted with a water permit for domestic use. Hydromil plants are said to be quite popular in the Basin especially in the Mbinga district, Ruvuma region. Existing mini-hydropower plants are scattered throughout the Basin and generate electric power of most of them less than 1,000 kW, to serve communities. Table 5 - Water Abstraction Certificates/Applications No. 1 2 3 4 5 6 7 8 9 10 Uses Domestic Hydropower Irrigation Fish & Farming Hydromill Domestic & Irrigation Domestic & Livestock Industrial Livestock Dom/Irr/Livestock Total Ruvuma Certif. Appl. 39 7 4 0 6 0 1 1 0 2 60 67 20 1 3 1 0 9 0 0 0 101 Mbeya Certif. Appl. 48 2 24 1 0 0 0 14 0 0 89 30 3 4 1 0 0 0 14 1 5 58 Iringa Certif. Appl. 51 9 7 0 0 8 1 1 0 0 77 22 3 1 4 0 1 0 1 0 0 32 Total 257 40 41 9 7 9 11 31 1 7 364 Source: LNBWO Hydrology Report 2010 Details of the 40 hydropower license holders are contained in the Appendix B without figures for quantities of water granted under the licenses. This information was not immediately available from LNBWO. The total of installed capacity of all the hydropower licence holders is 290 MW. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 8 3.2 Water Demand Management Water resources within Lake Nyasa River basin are being managed by LNBWB which was established in 2002 in accordance with the Water Utilization (Control and Regulation) Act No. 42 of 1974 and its subsequent amendments. This act was repealed and replaced by the Water Resources Management Act No. 11 of 2009. The LNBWB comprises of 11 members, drawn from the public institutions and private sector (including representatives of catchment water committees, LGAs, UWSAs, MoW, private sector water users and water related sectors). According to the Water Resources Management Act of 2009, the Basin Water Board is a financially and administratively autonomous body. It is charged to ensure that water resources are managed sustainably, through water governance and integrated water resources management principles. The Lake Nyasa Water Basin Board in its duties, it has the following activities: Data Collection There is an extensive river flow monitoring network in the Basin. The management of data collection activities and maintenance of the network infrastructure are however beset with difficulties. Different software is used like HYDATA, MS Access for processing and data base management. The basin has 18 weather stations which are operational although some of them need replacement of missing/or old instruments such as cylinders, thermometers, evaporation pans, etc. Apart from that the basin has 31 flow gauging stations and two automatic monitoring devices located at Ruhuhu Masigira and at Kiwira, Ipyana. Only the one at Ruhuhu is operational. Data collection is primarily carried out by gauge readers or meteorological observers who submit the data to the respective basin sub-offices for further processing, analysis, storage and dissemination at every end of each month. Water Allocation More than 364 abstractions have been registered with provisional or final water use permits. Currently the water supply is considered sufficient to meet demand. There are procedures for registering water use permits according to the Water Act of 2009 and its regulations. Applications from applicants received are analyzed and reviewed after field visits (where hydrographical reports are prepared). Other information is obtained the District Authorities. Applications are announced in the official gazette and District’s notice boards. Fiinally, the application is forwarded to LNBWB for approval or rejection. After approval, provisional or final grants will be issued. Coordination of preparation of IWRMD plan The current policy aims at comprehensive, integrated and holistic management of water resources, with a basin as the unit for planning. It is intended that the planning process will be participatory and considers fully all of the environmental, ecological and socio-economic concerns of the basin stakeholders. LNBWO will coordinate the establishment of participatory planning procedures, provide guidance and coordination, and provide technical support for the actual preparation of the IWRMD plan by the local stakeholders. The planning assumption of this activity is 25 years. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 9 Other activities of the LNBWO includes but are not limited to Water Resources Assessment which includes surface water, groundwater, water pollution monitoring and control, borehole monitoring stations, water quality, sediment loads as well as water demand. 3.3 Planning Objectives, Development Plan Power generation expansion national plans are drawn up by the Ministry of Energy and Minerals in collaboration with TANESCO on behalf of the Government and they are usually presented in the Power System Master Plan which is being updated regularly. Currently, the PSMP which is still in force is 2009 Update. The author of this report is well informed that this PSMP 2009 is currently being revised by the MEM/TANESCO team. There are three planning horizons for the power generation expansion plans as follows: 1. Short term: The short-term plan to 2014 which is considered as fixed, since there are other options presently available. In this short term plan, there is no major hydropower project that has been included but the Songwe project (340 MW, 170 MW for TZ) which is a shared resource between Malawi and Tanzania. Project has been commissioned and preparations are underway as project site coordinators have been mobilized to the site by both countries. This is a five year plan which seemed to have been pegged from 2009 as per PSMP 2009 update. 2. Medium term: The proposed mid-term plan as per 2009 PSMP is for the period from 2015 to 2019 and is mainly based on cost and availability of options. Rumakali Hydro (initially 222 MW) is included in this medium term plan by the Government. Usually, for the midterm (i.e., 6 years to 15 years) the least cost plan will be selected for implementation. 3. Long term: This is for the period beyond 2020 where the proposed plan includes the Stiegler´s Gorge hydro complex (Rufiji Basin) as well as Masigira Hydropower 118 MW (Lake Nyasa Basin) among others projects. Appendix B presents rating curves for three gauging stations for the three rivers each. 3.4 Reservoir Operating Rules There are a number of major hydropower projects under consideration at various levels by different developers. The two projects that are currently under pre-investment review studies are Rumakali 520 MW and Songwe 340 MW. NEMC and Lake Nyasa Basin Water Office need to collaboratively work with those developers to establish acceptable reservoir operating rules first so to sustain the environmental management of the rivers concerned. In such environment where rules are inexistent, the most logical step to do is to convene and establish a stakeholders’ working group with representatives from NEMC, Project Developers TANESCO, LNBWB, District Councils, Irrigation department and other relevant departments/stakeholders. A set of rules/principles to manage and operate the reservoirs and associated works would be to: Ensure integrity of the head works system; Meet entitlement holder’s needs in accordance to with their entitlements; Enhance environmental benefits including reserve flows Manage water quality; Deliver safe and reliable water supply; Maximize community benefits. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 10 It is important to understand that where a reservoir is required for water supply purposes (including storage and releases of environmental water), the benefits of flood mitigation and recreation cannot always be guaranteed as supply will always take priority. For Environmental Flows (EF), it is always a challenge how to allocate the environmental flows out of the available water in the river. However, the basis on which to build the reserve is not particularly clear to many of us in the water resources fraternity. EF describes the quantity, timing, and quality of water flows required to sustain freshwater and estuarine ecosystems and the human livelihoods and well-being that depend on these ecosystems. The formulas for calculation of EF are many and their numbers tend to increase day by day. This demonstrates that there is no consensus found so far. Some of the methods are based on hydrologic or statistic values. Examples are: 1. One method group refers to the average flow rate (MQ) of the river at a given cross section. The resulting reserved flow varies from 2,5 % of MQ for the Cemagref method applied in France to 60% for Montana (USA) method applied in the case where fisheries have a high economic importance. Typically, a figure of 10 % of the average flow is used for reserved flow. 2. 2nd method group refers to the minimum mean flow (MNQ) in the river. The reserved flow calculated when applying these methods varies from 20% (Rheinland-Pfalz, Hessen [D]) to 100% (Steinbach [A]) of MNQ. 3. 3rd method group refers to the prefixed values on the Flow Duration Curve (FDC). In this group a large variety of values are chosen as reference: i. NMQ7 (the lowest mean value of flow rate in the seven months with the higher natural discharges), ii. NMQAug (the minimum mean flow in August), Q84%, Q361, Q355 and so on. The author of this report feels it is fair to adopt the method of average flow rate utilizing time series data of the river. Typically, a figure of 10% of the average flow would be appropriate for reserved flow as this has been used in similar hydropower projects elsewhere in the country. However, relevant the Basin authority should take a lead and collaboratively work with key stakeholders to formulate and establish operational rules even at this stage when various projects are being designed. Principles and objectives mentioned under this chapter will be worth reviewing and can be of help and guidance to set the operational rules. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 11 4 POTENTIAL HYDROPOWER 4.1 Potential Hydropower Lake Nyasa Basin The full potential of hydropower in Nyasa basin adds up to 1,072 MW (Table 4) which is about 29% of the projected hydropower generation in the future for Tanzania. Figure 4 and 5 shows Nyasa’s share in hydropower contribution to the national grid2. Project/Scheme Masigira Rumakali Songwe (340 MW, 170 for TZ) Nkiwe River Lumbira/Luyagala Kiwira at natural bridge Lower Kiwira Total Potential Capacity (MW) 118 520 170 110 100 14 40 1,072 River Masigira/Ruhuhu Rumakali Songwe Nkiwe Lumbira/Luyagara Kiwira Kiwira Source: Power System Master Plan 2009 and The Hydropower and Irrigation Study of Western Tanzania 1976 Table 4 - Potential Hydropower Nyasa Basin Figure 4 - Basin Future Hydro Contribution in MW to the National Grid 2 The total potential for hydropower nationwide is assessed at 3,748 MW. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 12 Figure 5 - Basin Future Hydro Contribution in % to the National Grid 4.2 Prioritized Projects (PSMP 2009) Under the PSMP 2009, GoT and TANESCO have given hydropower development in Nyasa basin a high priority as can be seen from Table 5. The prioritized Songwe, Rumakali and Masigira projects have an anticipated total capacity of 808 MW out of 3,243 MW nationwide prioritizsed project. Table 5 - Prioritized Future Hydropower Projects under PSMP 2009 (Nation Wide) Plant/site Kakono 53 Avg Annual Energy (GWh) 404 Rusumo 90MW (30 MW for TZ) 30 148 Kagera Upper Kihansi 120 69 Kihansi Mpanga 144 955 Mpanga Ruhudji 358 1,928 Ruhudji 1,200 340 5,259 1,832 Rufiji Mnyera Taveta 145 850 Mnyera Rumakali (222 MW upgrade) 520 1,475 Rumakali Songwe 340 MW (170 MW for TZ) Masigira 170 118 1,669 664 Songwe Ruhuhu Malagarasi Stage III 45 187 Malagarasi Steiglers Gorge Ikondo Total Power MW River Kagera Basin Lake Victoria Rufiji Lake Nyasa (808 MW) Lake Tanganyika 3,243 Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 13 Under PSMP three projects with a total of 808 MW has been listed. Two of them are at an advanced stage of design. - Rumakali Project. The river is a major tributary of the Lufirio. The current plan has been under review for a possible upgrade from 222 MW to 520 MW by Studio Pietrangeli, Rome. Its new approach design offer has been under discussion since beginning September 2012. - Songwe Project. The other, is a multipurpose project shared between Malawi and Tanzania on the Songwe River. This has been studied to a detailed feasibility level by NORPLAN in association with COWI and DHI Consulting Engineers. The feasibility study was concluded in December 2003. Rumakali Project and Inter-Basin Water Transfer The concept of upgrading Rumakali 222 MW from an earlier designed arrangement in a study carried out by SWEDPOWER/NORCONSULT in 1997/1998 has been gaining pace. A new design concept to bring Rumakali to 520 MW is based on Interbasin Water Transfer as shown in the schematic drawing below (Figure 6). Figure 6 - Illustrative Diagram for Upgraded Rumakali HEP Concept The new Rumakali Hydropower project is envisaged to exploit five catchments for a total of more than 717 km2, namely Rumakali (406 km2); Nyithule + basin 2220 North (113 km2); Kikugu (139 km2); Rumbira (46 km2) and basin 2220 North. The main catchment (Rumakali) will receive the water transferred from the other basins to the main reservoir of the Rumakali dam through artificial water ways (canals, tunnels and pipelines). With respect to the Rumakali reservoir: o the two northern rivers are located at a higher elevation and therefore the waters drain by gravity towards the Rumakali reservoir, while o The two eastern rivers are located at a lower elevation and the waters shall therefore be pumped to the Rumakali reservoir. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 14 Each of the five catchments contributes to the supply of a total annual flow of 22.7m3/s, as follows: o 12.5 m3/s from the Rumakali basin; o 0.5 m3/s from basin 2220 North of Rumakali Reservoir; o 4.0 m3/s from Nyitule basin North of Rumakali Reservoir; o 4.3 m3/s from Kikugu basin East of Rumakali Reservoir; o 1.4 m3/s from Rumbira basin East of Rumakali Reservoir. The following aspects should be noted and included in the E&SIA of the scheme: − the two northern basins are bordering the escarpment of the Lufirio river valley with a main one originating from Nyituli (a western tributary of the Rumakali river but joining downstream of the proposed dam; − the two other catchments on the eastern side from the Kikugu and Rumbira rivers flow directly to Lake Nyasa without flowing into Rumakali River; − allocation of reserved flows/environmental flows for the rivers; − all stakeholders/beneficiaries must be identified; assessment of impact of diverting flows. Possible consequences to be considered: Large volumes are transferred to another flow regime without returns to the same water regime; Rich biodiversity river sections shall be denied of regular water flow; As a result, ground water level along those river embankment will decrease proportionately; As a result, decline in the receptive capacity of the Natural Habitat along the drained rivers; As a result, this will further cause loss of biodiversity and a decline in perennial vegetation. Clearly, this inter-basin water transfer project must include a comprehensive E&SIA study that addresses all social, economic and ecological impacts that may be caused by the project implementation. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 15 4.3 Other Identified Potentials (mini grid) In addition to the three prioritized projects under PSMP 2009, hydropower potential is identified in another nine locations in the basin with a total of 122 MW for off/mini grid connections. These are listed in Table 6. However, the information is outdated (List of Hydropower and Irrigation Study of Western Tanzania, MEM, April 1976) and must be reassessed as the source of this data/info is more than 40 years ago. Table 6 - Other Potentials in Lake Nyasa Basin Name of Site Yungu River at Liuli 20 0.5 Potential Installed Power (kW) 90 Mbawa 200 1 1,800 Luwika 200 0.8 1,400 Luaita Hanga 30 40 0.6 5.2 190 550 Lilondo at Mahanje Mission 150 0.95 1,400 Kitiwaka (Mhangasi River) 50 10.5 5,100 Malisa 75 1.8 1,250 Nkiwe river (stage I-IV) 585 ? 110,000 Total Head (m) Avg Flow (m3/s) 121,780 kW or 122 MW Compiled from “List of Hydropower and Irrigation Study of Western Tanzania, MEM, April 1976 Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 16 5 FINDINGS AND RECOMMENDATIONS Lake Nyasa basin is endowed with plenty of water resources aided by the presence of the Rift controlled terrain which makes the area suitable for hydropower development. At present, despite this endowment, the resources are yet to be exploited fully. Currently, the basin contributes 0% hydropower generation to the national electric grid. There are 364 water rights license holders issued by LNBWB for mainly water supply, hydropower, and irrigation of which 40 for small hydropower systems. Total quantity figures of water flows granted by LNBWB are not available. At present there are no large dams/reservoirs existing within the basin and so there are no Reservoir Operating rules. However, there are major dam projects under consideration at various levels by different developers. In the future, hydropower contribution from the Lake Nyasa Basin will likely be about 29% of the anticipated national hydropower contribution. Both anticipated future grid and off grid power generation are estimated in the order of 1,200 MW. The two projects that are currently under pre-investment review studies are Rumakali 222/520 MW and the Multipurpose Songwe Project 340 MW. This then calls for LNBWO to take the lead, work collaboratively with other relevant governmental authorities to coordinate with the project developers to ensure Reservoir Operating rules are established and in-built in the design and get approved for future application when these reservoirs come into operation. For the Rumakali Hydropower site, a water right has been granted by LNBWB to Mufindi Wood Plantation & Industries Ltd (ref#.:LNBWB/MAKE/0207) for the design capacity of 222 MW. ` Currently a parallel effort is made by both TANESCO and MoEM to carry out the studies that propose the plant to be upgraded from 222 MW to 520 MW by an interbasin water transfer approach. These studies were carried out by the TANESCO commissioned consultant SWEDPOWER/NORCONSULT in 1998. This gives rise to concern whether there is an efficient mechanism for notification to the general public on the intent of granting WR. More importantly, there has to be coordination among relevant key intergovernmental departments/authorities to avoid confusion. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 17 APPENDICES Appendix A - Photos Appendix B - Rating Curves Appendix C - License Holders Water Abstraction for Hydropower Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 18 APPENDIX A - PHOTOS Training Workshop Session in Progress at Tukuyu SMEC Office, December 2012 Water Level Station at Port Itungi and Some of the Visiting Team Members at Lake Nyasa beach Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 19 Gauging Station for Kiwira River in Kyela Met Station in Kyela Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 20 Gauging Station at Lufirio River Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 21 Bugema Micro Hydropower Plant at Busoka Village Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 22 Bugema Micro Hydropower Plant at Busoka Village Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 23 APPENDIX B - RATING CURVES Rumakali River is part of Lake Nyasa drainage basin and has two gauging stations i.e. 1RC11A at Mwakauta and 1RC 12 Nyituli tributary at Kidope. Data from 1RC11A represent inflows to Rumakali project since it is located at the proposed dam site. Nyituli tributary joins Rumakali downstream of the proposed site hence its data is not relevant unless a proposal to divert it. The 1996 to 2004 rating curve shown in this Appendix was used to generate 2006 inflows for the PSMP and it shows the river had discharges ranging from as low as 5 m3/s to as high as 45 m3/s during the period. It is potentially one of the lower cost hydro sites, and that is why preparation studies had commenced to review, update and further optimize the scheme. Figure Appendix B1 - Rumakali River rating Curve (Source: PSMP 2009) Masigira hydropower potential is located on Ruhuhu River, which forms part of Lake Nyasa drainage basin as well. A well-maintained and operated gauging station 1RB2 is strategically located close to the proposed intake pond. Data observed at this station represent inflows to the proposed plant. The rating curve shown in Figure 7 has been used to extend inflows to year 2006 and it shows that the river had discharges ranging from as low as 20m 3/s to as high as slightly above 100 m3/s during the said period of measurement. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 24 Figure Appendix B2 - Ruhuhu at Masigira Rating Curve (Source: PSMP 2009) Songwe River is part of Lake Nyasa drainage basin. Cascades of three hydropower potentials are located on this river. One gauging station exists close to lake but before the delta. This is station 1RD1 Songwe River at Kasumulu. The station has been rehabilitated but few rating programmes have been implemented. The last programme was in December 2008. Extensions of flow data for Songwe potentials have been derived from this station. The rating curve is as shown in Figure 9. Although recent rating seems to fit with previous data, the data should be used with great care since the river has the tendency to shift after every large flood. Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 25 Figure Appendix B3 - Songwe River at Kasumulu Rating Curve (Source: PSMP 2009) Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 26 APPENDIX C - MAP WITH LICENSED HYDROPOWER PLANTS AND PRIORITIZED PROJECTS (PSMP 2009) Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 27 APPENDIX D - LICENSE HOLDERS for HYDROPOWER License holder 1 St. Gertrude convent Immiliwaha 2 St. Gertrude convent Immiliwaha 3 4 5 6 7 8 9 10 11 Diocese of Njombe Nia Njema Need Foundation Mkonge energy systems co.Ltd Mkonge energy systems co.Ltd E A Power limited Kikundi cha mazingira Luswiswi Kisangani black smith and Ren. Tech Ushirika wa utumiaji umeme mlangali Makete power service limited 12 Makete power service limited 13 Owden Andalwisye Mwaikela 14 15 16 Mufindi Wood Plantation & Indutries Ltd SISTERS HOUSE MAGUU BENEDICTINE FATHERS 17 BENEDICTINE FATHERS 18 19 Wakulma Tea Co.Ltd Itete Hospital 20 Bulongwa Hospital (ELCT/SCD) 21 Consolata Hospital - Ikonda River Name Tel Lupali (d/s - 640kw), Boimanda Lupali (u/s - 183kW), Kitulila Madope/Luholomela Lilondo, Madaba Vill Kiwira, Ibililo Vill Kiwira , Lupepo Vill Kiwira, Kibwe Magereza Luswiswi Isigula, Mkiu-Kiyombo Likingo, Mlangali/Lupanga Idetele stream/ Usagatikwa & Iledevelo Idetele stream/ Usagatikwa & iledevelo 754239412 Capacity MW Date of Certificates Certificates Box 830 Njombe 0.64 25-Nov-10 LNBWB/NJO/0056 754239412 Box 830 Njombe 0.18 25-Nov-10 LNBWB/NJO/0057 26782033 765357070 Box 54 Njombe Box 113 Madaba Box 123 Tanga Box 123 Tanga Box DSM Box 543 Tukuyu Box 588 Njombe Ludewa P.O.BOX 20128 Makete P.O.BOX 20128 Makete 1.00 0.90 8.00 6.00 10.00 0.25 0.20 0.25 0.30 7-Sep-10 24-Sep-10 24-Sep-09 24-Sep-09 24-Sep-09 19-May-10 29-Jul-11 28-Jun-10 29-Sep-11 LNBWB/NJO/0061 LNBWB/SONGE/0088 LNBWB/RUNG/0089 LNBWB/RUNG/0090 LNBWB/RUNG/0091 LNBWB/ILE/0092 LNBWB/LUDE/0176 LNBWB/LUDE/0196 LNBWB/MAKE/0197 0.25 29-Sep-12 LNBWB/MAKE/0198 Mambwe , Mpanda Vlg/mwakaleli Rumakali, Rumakali village Tanga, Maguu Village Mkingazi, Mdunduwalo village Ruhila River/ Mdunduwalo village Suma , Busona village Kasyabone, Igembe rv)/ Kabembe village Rumakali River, Bulongwa village Ikonda river 784324624 P.O.BOX 68 Tukuyu 0.70 10-May-11 LNBWB/RUNG/0205 784772213 222 7-Nov-2011 LNBWB/MAKE/0207 756914438 252602162 P.O.BOX 215 Mafinga Box 76 Mbinga Box Peramiho 0.15 0.34 19-Dec-11 22-Dec-11 LNBWB/MBIN/0238 LNBWB/MBIN/0258 252602162 Box Peramiho 0.34 22-Dec-11 LNBWB/MBIN/0259 252552212 Box 700 Tukuyu Box 170 Tukuyu 0.65 0.25 7-Sep-10 10-Oct-10 LNBWB/RUNG/0004 LNBWB/RUNG/0018 784457884 Box 42 0.10 23-Nov-10 LNBWB/MAKE/0052 252411611 Box 700 Njombe 0.30 16-Jun-11 LNBWB/MAKE/0108 754458126 784358098 784358099 Postal Address Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 28 22 Consolata Hospital - Ikonda 23 Consolata Hospital - Ikonda 24 Tandala Diaconical center 25 Ludilu parish of the ELCT-SCD 26 Diocese/Njombe - Kissinga Mission 27 Makete power service limited 28 Makete power service limited 29 30 African Benedictines of Hanga William Daniel Kyanda 31 32 33 Archdiocese of Songea Archdiocese of Songea Catholic Diocese of Njombe 34 CATHOLIC DIOCESE OF NJOMBE 35 Ilundo Community Society 36 Ilundo Community Society 37 Ludewa Capacity Building Association 39 St.Alois Gonzaga 40 Bugema Micro Tandala river/ Ikonda Tandala Ibande river/ IkondaTandala Ijangala river/ Masisiwe village Salala river/ Ludilu village Siwe stream/ Kisinga village Idetele stream/ Usagatikwa and iledevelo Idetele stream/ Usagatikwa and iledevelo Hanga river Askofu River/ Paradiso vllage Lingatunda River 1 Lingatunda River 2 RUHUHU RIVER -1/ Mbugani village RUHUHU RIVER -2/ Mbugani village Nyelele River/ Ilundo Village Kipoke River/ Ilundo Village Lulange River/ Ludende Village Luwaita River/ Luwaita village Mbaka River/ Busoka Village 752411611 Box 700 Njombe 0.25 16-Jun-11 LNBWB/MAKE/0109 752411611 Box 700 Njombe 0.28 16-Jun-11 LNBWB/MAKE/0111 767680337 Box 35 Tandala 0.50 16-Jun-11 LNBWB/MAKE/0117 763811974 Box 112 Njombe 0.12 1-Jul-11 LNBWB/MAKE/0118 Box 54 Njombe 0.25 27-Jul-11 LNBWB/MAKE/0130 784358098 P.O.BOX 20128 Makete 0.28 29-Sep-11 LNBWB/MAKE/0197 784358099 P.O.BOX 20128 Makete 0.25 29-Sep-12 LNBWB/MAKE/0198 754565909 Box 217 Songea MBINGA 0.35 0.15 1-Oct-10 12-Mar-12 LNBWB/SONGE/0166 LNBWB/MBIN/0172 026-2782033 Box 150 Songea Box 150 Songea Box 54 Njombe 0.80 0.75 16.00 10-Dec-11 10-Dec-11 3-Apr-12 LNBWB/SONGE/0280 LNBWB/SONGE/0281 LNBWB/NJO/0282 026-2782033 Box 54 Njombe 16.00 3-Apr-12 LNBWB/NJO/0283 Box 480 Rungwe/77228 Dsm Box 480 Rungwe/77228 Dsm Box 126 Ludewa Njombe Box 74 Mbinga 0.25 24-Jul-12 LNBWB/RUNG/0 0.25 24-Jul-12 LNBWB/RUNG/0 0.25 24-Jul-12 LNBWB/LUDE/0 0.25 24-Sep-12 LNBWB/MBIN/0292 0.08 ??? 754295881 754295881 754054840 763874129 290 TOTAL Hydropower Report - Preparation of an Integrated Water Resources Management and Development Plan for the Lake Nyasa Basin (May 2013) Page 29