World Bank backs Vishnugad Pipalkoti hydro Jul 2011
Patrick Reynolds, Freelance Reporter
- The World Bank has approved a large funding commitment for construction of the 444 MW Vishnugad Pipalkoti hydro power project in Uttarakhand State, India.
Site of the dam with indication of rock conditions
- The project involves both excavation of significant caverns and excavation of TBM drives, which are still uncommon in Himalayan hydro works.
- Funding reviews have been in the pipeline for about four years but now the World Bank is to loan the full US$648 million towards the cost of the scheme, which is being developed by THDC India Ltd, a joint venture between the national and Uttar Pradesh State Governments. The low-interest loan has a six-year grace period and a maturity of 29 years, and is underwritten by the Indian Government.
- Vishnugad Pipalkoti is to be constructed on the Alaknanda River and comprises a 65m high diversion dam, a 490m long x 10m diameter diversion/spill tunnel; another 250m long spill tunnel; a 13.4km long x 8.8m wide headrace; an underground powerhouse (127m long x 20.3m wide x 50m high) and transformer hall (112m long x 16m wide x 24.5m high); a tailrace of almost 3.1km long and 8.8m wide; sedimentation chambers; and surge shafts.
Location of the powerhouse near Haat village
- Although the project's budget was based on use of drill+blast, most of the headrace and the tailrace tunnels are to be excavated by TBM. That decision was made by THDC, following favourable site investigation data along the alignment.
- Use of TBMs in the Himalayan region of India is relatively rare because of folded and tortured geology formations. Last year TunnelTalk reported how subcontractor SELI of Italy was building a 6.13m diameter double-shield TBM of upgraded capacity to excavate a 14.5km long section of the headrace tunnel for the Kishanganga hydro project.
- The project is to be undertaken through two engineering, procurement and construction (EPC) contracts for the civil and the electro-mechanical work.
- The debt to equity ratio for the project is the common 70:30 for hydro projects. Equity of US$274 million is committed equally by THDC and the national Government, with a share from Uttar Pradesh.
- Vishnugad Pipalkoti is expected to be completed by about 2016 and will feed into the country's northern grid which suffers severe power shortages at peak demand times. Vishnugad Pipalkoti is one of 20 large hydro schemes proposed for construction in the mountainous catchment of the Alaknanda.
Special TBM needed for Himalayan drive - TunnelTalk, March 2010
SELI set for tough drive on Kishanganga - TunnelTalk, May 2009
Current and planned tunnelling activity in India - TunnelTalk, July 2008
Add your comment
- Thank you for taking the time to share your thoughts and comments. You share in the wider tunnelling community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language professional.