[ Karyir Riba ]
ROING, 12 Dec: The National Hydroelectric Power Corporation (NHPC) has commenced work to establish the largest hydropower project in India in Lower Dibang Valley (LDV) district.
As per reports, execution of the 2,880 MW Dibang Multipurpose Project (DMP) started in February 2023, and is anticipated to be completed by February 2032.
The Rs 31,876.39-crore project is being designed and engineered through an international consultant (RCC Dam), Studio Pietrangeli – SMEC JV, Rome, Italy, including construction planning and monitoring. Four experts from the design team had visited the site for seven days in August 2023. Another site visit was conducted by a team of geologists for 10 days in October 2023 for conducting geotechnical exploration of the site as well as of the construction materials.
The initial overall planning report (final) was submitted by the NHPC on 30 September this year, while the draft technical specification was submitted on 7 November, and the tender design report was submitted on 9 December.
In February, Larsen and Toubro Ltd was awarded the contract for construction of access roads to the dam project site, the left bank road network, the Dibang bridges, the road on the right bank of the dam site, and the temporary haulage road to Pathar Camp from ADC Morh, including all civil and HM works of the diversion tunnel.
Work for both access roads and diversion tunnel have started. Formation/pilot-cutting of the road from New Apali to MAT portal (PR-1), and from MAT portal to Dam Top (PR-3) are in progress. Survey and formation-cutting of the road from MAT portal to Adit to pressure shaft (PR-2) is in progress. Formation/pilot-cutting of road on the left bank, along Ashupani Nallah (PR-6) is also in progress.
Excavation work for catch drain is in progress, while excavation of DT works started on 4 December.
Construction for civil works for Lot 4, which includes head race tunnels, including intake, pressure shafts, penstocks, power house and transformer cavern, tail race tunnel, pothead yards and Adits, was awarded to Dibang Power Consortium in August. The first blast for the main access Tunnel-1 of the power house was successfully carried out on 7 December. Topographical survey work and mobilis-ation of human resource and machinery are in progress.
Notification of award for all electro-mechanical works was issued to Bharat Heavy Electricals Limited in August. The work is yet to start.
As for the main dam, including coffer dams, tender will be floated after finalisation of technical parameters by the design and engineering consultant (RCC Dam).
The DMP is a hydropower-cum-flood moderation scheme that envisages utilisation of a net operating head of 222.50 mtrs by construction of a 278-mtr high concrete dam across the Dibang river, with full reservoir level (FRL) at 530.30 mtrs and a power house of 2,880 MW (12 units of 240 MW each), at a location near Munli village in the district.
The total energy generation with an installed capacity of 2,880 MW works out to be 11,223 MU at bus bar for the 90 per cent dependable year.
The construction agency claims that the reservoir created behind the dam will provide flood moderation benefits in the downstream, for which the reservoir will be kept 40.10 mtrs below FRL in the monsoon period. The backwater in the reservoir will travel up to a length of 41 kms in the Dibang river and its tributaries. The flood moderation will save erosion of agricultural land and damage to crops, and further save crores of rupees being spent on flood control measures by the government, as per the construction company.
The government of India has extended a grant of Rs 6,715.55 crore towards the project, which includes Rs 6,159.40 crore for flood moderation and Rs 556.15 crore for enabling infrastructure such as roads and bridges.
