Under India-Bhutan Co-operation, Govt of India allotted Sankosh HEP for updation of DPR and Bunakha HEP (180 MW) for implementation. The river Sankosh, called Mo-chu in Bhutan traverses 214 km in Bhutan and further 107km in India. The total drainage area is 12061 sqkm. The river flow in steep gradient and narrow gorges upto the Indo-Bhutan Border making it an attractive potential for hydro power potential.
The Project is located on Sankosh river, near village Kerabari under Kalikhola Dzongkhang (Sub Division) of Sarpang Dzongkhang (District) in Southern Bhutan. The project is approachable by road diverting from the National Highway 31-C at Baribasa in West Bengal. The nearest rail head is Jorai (near Baribasa) on broad gauge line between New Jalpaiguri and Guwahati. The nearest airport is in Bagdogra near Siliguri (India) which is about 300 Km away from the Project Site. The distance between Baribasa and Kerabari village is 35 Km. The nearest sea port is Kolkata.
In 1995, CWC, New Delhi and RGoB in association with various other Government organizations, prepared the DPR of Sankosh Multipurpose Project (4060MW) with 265m high Rock fill dam.
In 2008, Govt. of India entrusted THDC with the work of updation of DPR of Sankosh Multi Purpose Project (4060 MW). Updation of DPR of Sankosh Project was completed in April’2009.
Subsequently, Ministry of Power, GoI, in a meeting held on 26.05.2009 at New Delhi directed THDC to conduct the feasibility study for adopting concrete dam option at Sankosh project due to better sediment management through concrete dam.
THDC conducted intensive field investigations, laboratory studies and desktop studies in order to conclude on the concrete dam feasibility. Following studies were conducted by THDCIL.
Ø Sedimentation Studies (submitted in October, 2010)
Ø Feasibility Studies for adopting concrete dam at Sankosh Project (submitted in February, 2011)
Ø Detailed Project Report for Sankosh HEP with concrete dam option (submitted in May, 2011)
From the financial analysis projected in DPR of Sankosh HEP with 4060MW installed capacity, it was observed that cost of the project and computed power tariff comes out to be very high compared to general norms prevailing in the country, thus, making the project less attractive in terms of economic viability. In order to improve the financial viability of Sankosh HEP, it was considered to reduce the height of Sankosh. The feasibility report on Sankosh-Punatsangchhu HEP III integrated complex was prepared and submitted to GOI in November, 2011. As per this study, the height of Sankosh Dam was optimized at 220m and type of Dam was RCC Dam.
This Feasibility Report was discussed and reviewed in CEA and CWC along with the representatives of RGoB in January, 2012. The power potential optimization has been done keeping in view of the water requirement for irrigation, minimal spillage from the dam, cost-benefit and other aspects. Project layout was also restructured. As per this discussion, the most economical height of RCC Dam was found to be 215m.
DPR of optimized Sankosh HEP(2560MW), Bhutan with 215m high RCC Dam has been prepared and submitted to GOI in August 2012. The levelised and 1st year tarrif as per this scheme has been found to be Rs 3.89 per Kwh and Rs 4. 78 per Kwh.
The Project is located on Sankosh river, near village Kerabari under Kalikhola Dzongkhang (Sub Division) of Sarpang Dzongkhang (District) in Southern Bhutan. The project is approachable by road diverting from the National Highway 31-C at Baribasa in West Bengal. The nearest rail head is Jorai (near Baribasa) on broad gauge line between New Jalpaiguri and Guwahati. The nearest airport is in Bagdogra near Siliguri (India) which is about 300 Km away from the Project Site. The distance between Baribasa and Kerabari village is 35 Km. The nearest sea port is Kolkata.
In 1995, CWC, New Delhi and RGoB in association with various other Government organizations, prepared the DPR of Sankosh Multipurpose Project (4060MW) with 265m high Rock fill dam.
In 2008, Govt. of India entrusted THDC with the work of updation of DPR of Sankosh Multi Purpose Project (4060 MW). Updation of DPR of Sankosh Project was completed in April’2009.
Subsequently, Ministry of Power, GoI, in a meeting held on 26.05.2009 at New Delhi directed THDC to conduct the feasibility study for adopting concrete dam option at Sankosh project due to better sediment management through concrete dam.
THDC conducted intensive field investigations, laboratory studies and desktop studies in order to conclude on the concrete dam feasibility. Following studies were conducted by THDCIL.
Ø Sedimentation Studies (submitted in October, 2010)
Ø Feasibility Studies for adopting concrete dam at Sankosh Project (submitted in February, 2011)
Ø Detailed Project Report for Sankosh HEP with concrete dam option (submitted in May, 2011)
From the financial analysis projected in DPR of Sankosh HEP with 4060MW installed capacity, it was observed that cost of the project and computed power tariff comes out to be very high compared to general norms prevailing in the country, thus, making the project less attractive in terms of economic viability. In order to improve the financial viability of Sankosh HEP, it was considered to reduce the height of Sankosh. The feasibility report on Sankosh-Punatsangchhu HEP III integrated complex was prepared and submitted to GOI in November, 2011. As per this study, the height of Sankosh Dam was optimized at 220m and type of Dam was RCC Dam.
This Feasibility Report was discussed and reviewed in CEA and CWC along with the representatives of RGoB in January, 2012. The power potential optimization has been done keeping in view of the water requirement for irrigation, minimal spillage from the dam, cost-benefit and other aspects. Project layout was also restructured. As per this discussion, the most economical height of RCC Dam was found to be 215m.
DPR of optimized Sankosh HEP(2560MW), Bhutan with 215m high RCC Dam has been prepared and submitted to GOI in August 2012. The levelised and 1st year tarrif as per this scheme has been found to be Rs 3.89 per Kwh and Rs 4. 78 per Kwh.