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Environmental Impact Assessment Study of Kabeli ‘A’ Hydroelectric Project Executive Summary 1. Background The Kabeli A Hydroelectric Project (KAHEP) located in between the geographical coordinates, latitudes 27 o17'32"N to 27 o13’41"N and longitudes 87 o45'50"E to 87 o40'55"E in Pachthar and Taplejung district, Mechi zone of Eastern Development Region of Nepal, is based on the water resources of the Kabeli Khola, a natural border between the Panchtahar and Taplejiung districts in the Public Disclosure Authorized Middle Mountains of Eastern Nepal about 620 km east of Kathmandu. This project utilizes a 15 km long loop of Kabeli River formed with Tamor River (Figure 1). Figure 1: Location of the Key Project Structures in relation to the Project Districts and VDCs Namgkholyan VDC Taplejung District Thechambu VDC Taplejung District Public Disclosure Authorized Amarpur VDC Panchthar District Public Disclosure Authorized Panchami VDC Panchthar district Public Disclosure Authorized The KEL is the project proponent and has signed a Project Development Agreement (PDA) with the Department of Electricity Development (DoED) for the development of KAHEP. The Environment Protection Rule Schedule 1 classifies KAHEP as Initial Environmental Examination (IEE) category project. However, the project has been classified by the World Bank as a 'Category A' project and has to comply with the environmental and social safeguard policies of the Bank. This Environmental Assessment statement is prepared to meet the requirements of the government of Nepal and World Bank. i Environmental Impact Assessment Study of Kabeli ‘A’ Hydroelectric Project The access to the project area is through an all season 228 km long Mechi Highway connecting Charali at the East West national highway and Taplejung (Figure 2.3). The headwork site is about 2.4 km. from the Mechi Highway, while the Powerhouse is about 12.0 km away. 2. The Project The project is PRoR type with a proposed installed capacity of 34.70 MW with a design discharge 37.73m 3/s. The diversion dam with provisions for ponding will be constructed at 2.5 km upstream of Kabeli Bazaar at Dhuseni village of Amarpur VDC on the left bank and Khudurke Ban of Thechambu VDC on the right bank. The intake on the left bank will feed the underground settling basin and is diverted to the Powerhouse located at Tamor River bank close to Pinase village through a 4.322 km long headrace tunnel. A surface powerhouse will be constructed on the left bank of the Tamor River. The salient features of the project are presented in Table 1. Table 1: Salient Feature of the Project SN Items Description 1. Project Name Kabeli-A Hydroelectric Project Amarpur and Panchami VDCs of Panchthar District and 1.1 Location Thechambu and Nangkholyang of Taplejung District East 87° 45' 50" E West 87° 40' 55" E 1.2 Project Boundaries North 27° 17' 32" N South 27° 13' 41" N 1.3 Type of Development Peaking Run-of-the-river (PROR) 2 Hydrology at intake 2.1 Catchment area 864 km 2 3 2.2 100 year flood (Q 100 ) 1920 m /s 3 2.3 Probable maximum flood (Q 1000 ) 2750 m /s 2.4 Mean monthly flow 51.75 m 3/s 2.5 40 percentile flow 37.73 m 3/s 3 Headworks 3.1 Type/Length of weir Barrage with 6 radial gates including undersluice 3.2 Full supply level 575.3 m 3.3 Crest elevation 561.6m 3.4 Intake type Tunnel intake on left bank 4 Diversion during construction 4.1 Diversion flood (5 year dry season flow) 154 m 3/s 4.2 Diversion tunnel 360m long; 4.8m diameter D-shaped tunnel 80m at upstream side 4.3 Coffer Dams 90m long at downstream side 5 Approach Tunnel 5.1 Number 2 (1 each starting from either intake) 5.2 Type Inverted D shaped; Concrete lined 6 Settling basin 6.1 Type Underground settling basin 6.2 Number 2 basins with 2 hoppers in each 6.3 Total length including transition 113 m 6.4 Width 15.8 m each 6.5 Height 17 m 6.6 Flushing system S4 system 7 Waterways 7.1 Pair Tunnels (headrace) 7.1.1 Length 32 m 7.1.2 Type Inverted D shaped; Concrete lined 7.2 Headrace Tunnel ii Environmental Impact Assessment Study of Kabeli ‘A’ Hydroelectric Project SN Items Description 7.2.1 Length after pair tunnels 4322 m 7.2.2 Type Inverted D shaped; Concrete lined 7.2.3 Cross section Internal Finished Diameter 3.85 m 7.3 Surge Shaft 7.3.1 Type Underground and exposed to surface 7.3.2 Internal diameter 11 m 7.3.3 Height 60.5 m 7.4 Penstock 7.4.1 Material Mild steel 7.4.2 Length before bifurcation 218.6 m 7.4.3 Length after bifurcation 54.4 m 7.4.4 Internal Diameter 3.55 m 7.4.5 Shell Thickness 10-20 mm 8 Powerhouse 8.1 Powerhouse type Surface 8.2 Outer Dimension of PH 32m long and 16.9 m wide 9 Tailrace 9.1 Design tailwater level 458.5 masl 9.2 Length 93.1 m Longitudinal slope 1 in 1500 10 Turbine 10.1 Turbine type Vertical Axis Francis 10.2 Number of units 2 Numbers 11 Power and energy output 11.1 Gross head 116.8 m 11.2 Rated net head 107.22 m 11.3 Design discharge 37.73 m 3/s 11.4 Installed capacity 34.70 MW Annual estimated energy per excluding 6% 11.5 177.61 GWh outage 11.6 Firm energy excluding outage 132.86 GWh 11.7 Secondary energy excluding outage 44.75 GWh Other project facility requirements are the internal access roads; camps for engineers, contractors, and labours; quarry/burrow pits; construction powers, aggregate crushing, storage yards, Baching plants and mechanical yards; spoil disposal sites etc. All of these facilities will be located close to the headworkws and powerhouse sites. A total of of 47.718 ha of land will be required for the project. Of the total, 22.508 ha is permanent land required while 25.21 ha is temporarily required. A total of about 6 to 800 construction workforce is required on daily basis during construction period whereas the operation phase requirement is less than 50. The project is planned for construction within a period of four years. Estimated cost of the project is about 5 billion Nepali Rupees. The project districts are Pachthar and Taplejung whereas the projects VDCs to be impacted directly and indirectly are Amarpur, Panchami, Thechambu, and Namgkholyang. 3. Legislative and Regulatory Considerations A number of over arching and sectoral policies, legislations, and guidelines of the government of Nepal are attracted by the project. Similarly, the EA, forest, indigenous people, involuntary resettlement and cultural safeguard policies of the World Banks are attracted by the project. The policies, legislative mechanisms, guidelines and standards of the Government of Nepal to safeguard the environmental aspects (Environmental Assessment EA -0P 4.01, and Forestry - OP 4.36) of the proposed project are adequate and broadly conform to the World Bank’s natural iii Environmental Impact Assessment Study of Kabeli ‘A’ Hydroelectric Project environment safeguard policies. However, the provisions for the involuntary resettlement, cultural properties and indigenous people are not adequate to comply with the World Bank’s safeguard policies. 4. Baseline Environment 4.1 Physical Environment 4.1.1 The project area is located in the Mid-Mountain Physiographic Zone. Characteristic of the Mid-Mountain Physigraphic Zone is a ramification of the elevated mountaineous topgraphy (>1500m) with intervaining deeply entreched “V”shaped valleys (<700m). The steep mountain slopes, particularly the valley slopes and the upper middle hillslopes reflect the geomorphic dynamism of the area related to the mountain building tectonic activities. Most of the project structures and facilities are located at the valley section represented by active alluvial flood plains or on alluvial tars. 4.1.2 Geologically the area lies in the Lesser Himalayan Crystalline to Meta-sedimentary rock sequences representing Taplejung Window. The headworks area is comprised of dominantly granites. The settling basin, and headrace tunnel is made up of granite, gneisses, schists, phyllites and quartzites whereas the surge shaft and powerhouse areas consist of phyllite, schist, and quartzite. 4.1.3 Two distinct climatic zones sub-tropical and warm temperate to cool temperate climate at the immediate vicinity of the project. The monsoon has a greater influence on the precipitation of the area and also controls the summer season temperatures and wind pattern. The monsoon commences from June till September. Nearly 80 percent of the rainfall occurs during the monsoon season. 4.1.4 The Kabeli River is one of the tributaries of the Tamor River and has a total length of about 52.4 km at intake site. The catchment area of the Kabeli River is 864 km 2 at the barrage site. Tawa Khola, Phawa Khola and Inwa Khola are the major tributaries of the Kabeli River upstream intake. The river at intake has an average annual flow of 51.57m 3/s, minimum being in the month of March 8.11 m 3/s and maximum in the month of August 151.09 m 3/s. 4.1.5 About 40 to 50 landslides are seen within the catchments of Kabeli above Headworks. No recent active landslide features have been reported or noted close to the project development sites. The maximum recorded suspended sediment concentration is 13,616 ppm. The Monsoon is the period of high sediment load in the river, 4.1.6 Since the area is located in rural setting, the ambient air quality, water quality and noise levels are not been influenced by the industrial pollutions.