Rishikesh: 24th Sept, 2021 proved to be remarkable day in the history of Tehri Dam Project as Tehri reservoir has touched the level of 830m, its Full Reservoir Level, for the first time. Though the Project has been providing much needed 1000 MW peaking power and other benefits such as drinking and irrigation water, flood moderation, fishing, tourism etc. for the past 15 years, yet its full potential remained untapped. Tehri reservoir could not be raised to Full Reservoir Level (FRL), of EL 830m. However, with the active support of Ministry of Power, Govt. of India and Govt. of Uttarakhand, this mammoth task could be achieved after the pending rehabilitation issues of the Project were resolved by THDC with a very liberal view. Thereafter, Hon’ble Chief Minister of Uttarakhand, Sh. Pushkar Singh Dhami considered the larger interests of the public and permitted to raise Tehri reservoir level to EL 830m on 25th August, 2021. Prior to this permission, dam authorities were not allowed to raise Tehri reservoir to full level and full potential of the Project in respect of water and power was not getting fully utilized. Tehri Dam Project is a multipurpose hydro power scheme on river Bhagirathi and is the 3rd highest among earth fill dams and 10th highest among all dams of the World. The project consists of 260.5 M high Earth and Rock fill Dam, and 4 Machines of 250 MW each in an underground power house. Tehri dam project has a capacity to store about 2615 MCM of surplus flood water during monsoon. Post monsoon, the stored water provides irrigation support to 8.74 Lac hectares land in the Gangetic plains of Uttar Pradesh; and also provides around 300 cusecs of drinking water to New Delhi for about 40 Lacs population and 200 cusecs to UP for about 30 Lacs population. Tehri project in fact has quenched the thirst of Delhi and Agra in real sense. Project has also enabled the farmers of Tehri command area to take even upto 3 crops in a year. It ensures sufficient discharge by releasing additional water in river Ganges during lean period for different “holy Snans” and “Parvas” at Haridwar and Prayagraj. It also ensures sufficient water discharges in rives Ganges by additional releases during “Kumbh Mela” for whole season on the demand of Govt. of Uttarakhand and Govt. of UP. Tehri power plant provides 1000MW of peaking power and more than 3000Million Units of energy annually to the northern grid, of which 12% goes to Uttarakhand state free of cost. Thus, Tehri project has been a boon for the people of society and these benefits are now likely to increase further with the Hon’ble Chief Minister’s decision to raise Tehri reservoir to full level. Tehri dam project was conceived in the year 1949 and it was cleared by the Govt. of India in the year 1986 as a Joint Venture Company of Govt. of India and Govt. of Uttar Pradesh. A bilateral techno-economic agreement between India and Russia was signed in 1986. THDC India Ltd. (formerly Tehri Hydro Development Corporation) was incorporated to implement the scheme in 1988. Safety of the dam and its impact on quality of water and environment had also been contentious issues. Several government departments and panels of eminent scientists and experts were constituted to deliberate these issues and after their recommendations, construction of main dam started in 1990 with raising of the upstream coffer dam. Seismic safety of the dam was again reviewed by the Indian and Russian experts. Govt. of India approved the implementation of the project in 1994 and actual construction of dam works started in 1995. The construction of project structures continued with intermittent protests and could finally be completed in 2005. The commissioning of the project could start in Oct’ 2005 when the Honorable High Court of Uttarakhand allowed the closure of the last diversion tunnel (T-2) to start filling of the Tehri reservoir. Subsequent to the commencement of the initial filling of the reservoir in Oct’ 2005, the commissioning of the 4 units of the power house also started, one by one, and the project was fully commissioned in July 2007. The initial filling of the Tehri reservoir was a challenge as Tehri dam was the 1st earth and rock fill dam of such a height in India. THDCIL took every precaution, reviewed available literature about the initial filling of high dams worldwide and consulted eminent hydro project experts to frame the dam filling program along with the program of regular monitoring of the structures through instruments installed and geodetic observations. After the closure of the last Tunnel T-2 in Oct 2005, the reservoir was gradually filled above EL (+) 638m up to EL (+) 785m by Oct 2006 i.e. till the completion of the 1st filling season. Thereafter, from Nov’ 2006 to June 2007, the reservoir depleted back to EL 740m. Till the year 2020, the reservoir was filled up to EL 828m, as GoUK permitted THDCIL to raise the reservoir level up to 828m only. Permission for filling up to EL 830m was granted by the State Government this year in Aug 2021. The reservoir touched EL 828m on 11th Sep’ and thereafter filling was done @ 0.30m in 48 hrs to reach EL (+) 830 m on 24th Sep 2021. 24th Sep’ 2021 has become a historical date in the history of the Tehri dam project being the date of achieving the full potential of the project in all respects which was conceived many years back. 24th Sep 2021 shall be remembered as the beginning of a new era in the history of the Tehri dam project from where it started delivering the maximum intended benefits to society fully. Most of the credit to this feat goes to the current political leadership of the state under the guidance of Hon’ble Chief Minister, Shri Pushkar Singh Dhami and Irrigation Minister, Shri Satpal Maharaj, who acknowledged the situation of wastage of national resources in view of the restricted impoundment of the reservoir and grated the permission to fill the reservoir to its full capacity. The strong pursuit of the Ministry of Power, Government of India has been another push to achieve this historical milestone. Management of THDCIL led by its CMD, Mr. R.K. Vishnoi has thanked the state leadership and congratulated the people of the state on achieving this much-awaited goal. He further mentioned the commitments made by THDC to Hon’ble CM and Sh. Satpal Maharaj, Hon’ble Minister of Irrigation, GoUK regarding project affected people shall be fulfilled instantly after reviewing the verified list of beneficiaries from Distt. Administration.
