Tarbela Dam is located in Pakistan and is the world’s largest fill-type dam. It is built over the River Indus near the small city of Tarbela within the Haripur District of the KPK. It is also the second biggest dam in the international in terms of reservoir potential, that's 11.Sixty-two million acre-ft (14.3 billion cubic meters).
Construction at the primary factors of the project turned into began in 1968 and initial operations of the dam began in 1978. The project turned into fully completed in 1984, at a price of $1.49bn.
The mission became achieved with the aid of the Water and Power Development Authority (WAPDA) on behalf of the Government of Pakistan. Construction was done under a single civil works contract.
Major monetary contributions for the mission got here from the World Bank in the shape of a financial institution loan and two International Development Association (IDA) credits. The financial institution mortgage was approved in 1968 and the two IDA credits have been approved by using 1978. The mortgage and credit had been fully paid out by way of September 1981.
Pakistan is presently building the Diamer-Bhasha dam at the River Indus, so as to boom the life of the Tarbela dam by 35 years. The new dam challenge is partially financed by means of the US.
Purpose and want for Pakistan’s dam task :
“The challenge becomes constructed via Tarbela Dam Joint Venture, which was led by Italian contractor Impregilo.”
Pakistan changed into totally depending on unregulated flows of the Indus River and her tributaries even after two decades of her independence. The agricultural yield turned on the lower side because of a deficiency of water for the duration of the vital developing season. The important motive in the back of this trouble was the seasonal variations within the river glide. Additionally, there had been no storage reservoirs to preserve surplus flows.
In order to bolster the irrigation gadget, the Pakistani Government, with help from the World Bank, launched the Indus Basin Project, which was made out of big dams. The first dam built below this water manipulation challenge turned into the Mangla Dam on the Jhelum River, even as the other was Tarbela at the Indus River.
The number one purpose of the Tarbela Dam Project became to modify the flows of the Indus River for irrigation use. Other objectives have been to gain big technology in hydroelectric power and flood management by keeping snow melt and monsoon flows of the Indus River.
Components of the arena’s biggest fill-kind dam
The Tarbela Dam Project worried about the development of an earth and rock-fill dam at the River Indus and an electricity plant. The maximum height of the primary embankment from the bottom foundation point is 470ft and the length is 9,000ft at its crest. The dam required 138 million cubic yards of fill.
“The task became done with the aid of the Water and Power Development Authority (WAPDA) on behalf of the Government of Pakistan.”
The predominant embankment is flanked via auxiliary embankments on the left bank. The most top of one of the auxiliary embankments is 345ft, whilst that of the alternative is 220ft. The lengths at crest are 2,340ft and 960ft respectively.
The two auxiliary embankments bring spillways, the carrier spillway, and the auxiliary spillway. The service spillway is geared up with seven gates and has a discharge capacity of 650,000 cusecs. The auxiliary spillway with its 9 gates can discharge 850,000cusec.
The valley wall at the right financial institution, at the upstream cease, changed into reduced thru to construct a group of 4 tunnels. Three of those tunnels were meant for the hydroelectricity era, even as the fourth tunnel is used for irrigation releases. A fifth tunnel became constructed on the left bank of the river. It became operational in 1976 and is largely used for irrigation purposes.
Catchment place of the Tarbela Dam reservoir in Haripur District
The catchment region of the reservoir created via the dam is 169, six hundred rectangular kilometers. The reservoir, with the most depth of more than 450ft, can impound as much as eleven.62 million acre-feet (MAF) of water at the most lake elevation of 1,550ft. The net usable potential of the reservoir is nine.68MAF.
The water is stocked during the months of June, July, and August, while the river flow is at its most.
Tarbela hydropower plant near the River Indus
The Tarbela hydro energy plant is built on the proper aspect of the primary embankment. It is set up with 14 energy-generating gadgets and the water is fed from outlet tunnels one, and 3. The plant has a total mounted ability of 3,478MW.
Four turbines of 175MW every on tunnel one were placed into manufacturing in 1977. There are six 175MW mills on the tunnel, 4 of which have been commissioned in 1982 and the last two in 1985. Four turbines of 432MW each had been established in tunnel 4 in 1992.
Key players worried
The task was built by using Tarbela Dam Joint Venture, which became led by using Italian contractor Impregilo. The joint mission became a consortium of three Italian and three French heavy civil engineering contractors. Five German and Swiss agencies joined the consortium in 1969.
Members of the joint project led by Impregilo blanketed Costruzioni Generali Farsura, Impresa Astaldi Estero, Compagnie de Constructions Internationales, Compagnie Francaise d’Entreprises, Societe de Construction de Batignolles, Hochtief, Philipp Holzmann, Strabag Bau, Ed Zueblin, C. Baresel, Conrad Zschokke, and Losinger.
