TANZANIA ELECTRIC SUPPLY COMPANY LIMITED ENVIRONMENTAL IMPACT STATEMENT FOR PROPOSED MALAGARASI STAGE III 44.8MW HYDROPOWER PLANT AT IGAMBA FALLS ON THE MALAGARASI RIVER IN KAZURAMIMBA WARD, KIGOMA REGION FINAL REPORT Non-Technical Summary – English Version PROJECT PROPONENT: Tanzania Electric Supply Company LTD P.O. Box 9024 Dar Es Salaam Phone : +255 22 2451131 – 9 Fax : +255 22 2451206 Email: [email protected] CONSULTANT: Dr. Flora Ismail Tibazarwa ESBI Engineering & Facility Management Ltd P.O. Box 105810 Dar Es Salaam Phone : +255 22 2451738/1744 Fax : +255 22 2451748 Email : [email protected] SUBMITTED TO : National Environmental Management Council (NEMC) P.O. Box 63154 Dar Es Salaam Phone : + 255 22 2127817 Fax : + 255 22 2134603 Email : [email protected] October 2012 Malagarasi ESIA Non-Technical Summary 1. Non-Technical Summary 1.1 Introduction TANESCO is proposing to develop a new hydropower plant at Igamba Falls on the Malagarasi River, to serve Kigoma-Ujiji Municipality and the surrounding towns of Kasulu and Uvinza with an affordable and reliable supply of electricity. Earlier feasibility studies have indicated that there are three potential hydropower projects that could be undertaken in the Igamba Falls area. This description is for Stage III of the potential three-stage Igamba Falls development which is the most downstream dam site and hydro-power station (Figure 2). The power generated from the project will be distributed to a number of communities in western Tanzania with approximately 1.3 million persons with increased access to electricity. Recently TANESCO has preceded with a number of interconnecting transmission lines and Kigoma should be linked to the national grid by 2015. TANESCO considers the Malagarasi hydropower scheme as important as the power at the end of the transmission line may be insufficient to service the power demand of the Kigoma area, thus reliance on the diesel generators may continue. Furthermore the MHPP would complement the other generation projects and reduce power loading problems by feeding excess power into the national grid. The future interconnector has been critical in shaping the hydropower plant design and associated works. It has allowed for full optimisation of the hydro resource as surplus energy will be distributed via the transmission line to other areas of Tanzania. The commitment of the Government to connecting Kigoma to the national/regional grid by 2015 has greatly increased the hydropower value of the Lower Malagarasi as surplus energy can, in the future, be used in other areas of the country while the grid will, in return, offers stable power in the case of low river flows. 1.2 Project Location The proposed project is located in western Tanzania about 100 km south of the town of Kigoma; some 27 km south of the main Uvinza-Kigoma road and railway (Figure 1). The main components of the project will include: • A dam and an intake pond below Igamba Falls. The power plant will produce up to 44.8MW and 5 MW during the late dry season. • An access road of about 27 km from the main Kigoma – Uvinza road south to the Malagarasi River. Page 1 ESBI International Malagarasi ESIA Non-Technical Summary Figure 1: Location of the proposed Hydropower Facility The hydropower scheme was initially conceived of as a three-step (Stages I, II and III) hydropower development layout. In the initial project studies the upper dam, Stage I was to be the reservoir with hydro power plants, while stages II and III were to be run-of-river ponds with hydropower plants. The Stage I reservoir would have been situated near the outlet of a gorge some two km upstream of the Igamba Falls, creating a 9 km-long narrow pond that would extend upstream into the gorge. New information on river flow and analyses of the optimum use of water resources and protection of the enviorment has resulted in the Selection of Stage III as the prefred development option. Page 2 ESBI International Malagarasi ESIA Non-Technical Summary Indicative road alignment Power House Stage III Stage III Dam Main Igamba Falls Upper rapids Stage I Dam Lower rapids Lower MalagarasiRiver Igamba Falls Stage II Dam Figure 2: Layout of the three cascade schemes (Stage I, II and III) 1.3 Description of the Project Environment The source of the Malagarasi River lies in the mountainous region, north of Kigoma and close to the Burundi border. From its headwaters, it flows in a north-easterly direction through the hilly and mountainous landscape, before it turns southwards into a flatter landscape. The gradient is gentle and the river flows in large meanders, before entering the Malagarasi swamps in the south-eastern part of the region. The Malagarasi swamps are a distinct hydrological feature of the basin, exerting a controlling influence on runoff. The wetlands can swell during the rainy season to hold about 10 % of the catchment that drains to them. A large portion of the entire catchment drains through the swamps. At this point, the Moyowosi River joins the Malagarasi. Some 50 km downstream the Ugalla River converges with the main river. The river then runs directly west, before breaking through the Masito Escarpment, to form rapids and waterfalls (Igamba) on its final run to Lake Tanganyika. The Igamba area is the location of the proposed project. As a result of its evolutionary history and geology a number of range-limited endemic species have evolved in the Igamba area. Of most interest to this project are the Igamba Snail which appears to favour the deep scour pools in the sandstone, and the Goby cichlid which is found throughout the falls area. The main habitat of these two species lies above the proposed Stage III scheme and will not be affected by the project. Page 3 ESBI International Malagarasi ESIA Non-Technical Summary 1.4 Major Impacts The purpose of an environmental and social impact assessment (ESIA) is to identify the major potential impacts of the proposed project and to provide a blueprint of how these impacts will be avoided, mitigated or minimized to acceptable levels. In summary the impacts are: Construction Phase: • The 27 km access road will result in some displacement of families along the alignment; • Highly disturbed area of the Direct Impact Zone approximately 184 ha; • A ponding dam of approximately 13.5 ha; • Construction period of 3 years 4 months with up to 550 workers on site during peak construction period; • Soil erosion and collapse of embankments; • Noise and dust on site and along the access route (trucking traffic will be high); • Loss of some aquatic habitat important to endemic species (Igamba snail and Goby cichlid); • Temporary reduced water quality; • Short term impact on wildlife and tourism; • Increase in illegal timber abstraction; • Social, health and safety impacts on local communities. Operation Phase: • The HPP is largely a run-of-river scheme. Downstream flows are not affected except during the late dry season when the dam is used as a reservoir for daily peaking. During peaking operations downstream river flows will vary daily from 10 – 33 m3/s. Although there are no identified significant social impacts from this there may some impact on river banks and fish populations. • The section of the river between the dam and the tailrace will be affected by reduced flows and an EFR of 10 m3/s is required to maintain biodiversity. • The existing community of Igamba will be affected through loss of arable lands, reduced access to natural resources, limited access to the river and, some loss of homes. • Loss of Labeo cf. coubie, a migratory fish from the reservoir area. • Reduce value of the area for tourism due to light and visual pollution. • Increase in illegal timber abstraction. Cumulative Impacts Should Other Stages of the Cascade be Developed • Loss of significant area of critical habitat for site specific endemic species. • Changes to downstream flows if Stage I (storage reservoir) is constructed. • Loss of the tourism value of the Igamba Falls and MUE area in general. Major Upstream Threats are: • Reduced dry season river flows due to changes in land use upstream and failure of the Malagarasi – Moyowosi Ramsar Site to successfully manage the upstream swamps. • Climate change impact on river flows. Page 4 ESBI International Malagarasi ESIA Non-Technical Summary 1.5 Alternatives Considered A number of alternatives including the no-project option were considered. In addition the three hydropower options (Stages I, II and III) were assessed within the Igamba Cascade. It was found that expansion of the existing thermal plant at Kigoma is an expensive and short term solution. There are no other viable hydropower alternatives and the renewable alternatives, although interesting, will not provide the base load required. The most significant alternative is connection to the national grid. This connection should be in place by 2015 and should be able to provide some power to Kigoma. TANESCO, though, feels that the power supply at the end of a long transmission line will be limited and possibly erratic. TANESCOs opinion is that the Malagarasi Hydropower scheme is important as it will serve to stabilise power in the interconnector and feed surplus power back into the national grid. The Stage III scheme was therefore assessed as the key mitigation for Stage II. Shifting the location from Stage II to Stage III mean that the new location (Stage III) would not flood critical snail habitat and would not dry out sections of the river where significant populations of snail were present, and therefore would be able to sustain the endemic Snail species. 1.6 Recommendations and plan for mitigation It is recommended that the Stage III hydropower scheme proceed with the proviso that key recommendations are included into the design.