Chanju-I hydroelectric update
The Chanju-I hydroelectric project is under construction on the Chanju River, in Himachal Pradesh, India. Entura has been involved with the development of this project since its inception. Entura has carried out the feasibility study, prepared the detailed project report and tender design, and the detailed design is currently being carried out by our office in India.
The Chanju-I hydroelectic project involves construction of a 16 m high barrage, 5 km long 3.2 m diameter D-shaped head race tunnel, two underground desilting chambers, 200 m long 2.3 m diameter surface penstock and a surface power house. A 500 m long construction adit is proposed to serve as a surge gallery during operation of the project.
The project is being delivered through item rate contracts for civil works and EPC contracts for electro-mechanical/hydro-mechanical works. Construction is in full swing and all the infrastructure works and access roads (about 10 km) have been completed. Three construction adits have been proposed for faster excavation of the head race tunnel.
By the end of February 2012, Adit 2 and Adit 3 had achieved a progress of 100 m and 140 m respectively with a daily progress of about 3 m per day per face on account of good rock encountered in the adits. The project area experienced unprecedented snow fall during the winter season and the work was stopped due to snow and extreme temperatures. Conditions have recently improved, and full scale construction is underway. River diversion has been completed at the barrage site and excavation is in progress.
Excavation is also in progress at the power house pit which involves about a 35 m cutting in over burden. The construction activities at this site are progressing slowly due to some challenges in slope stabilisation. The slope stabilisation is being carried out using soil nailing in over burden and the excavation will speed up after slope stabilisation is complete.