Tarbela Dam
The Tarbela Dam or the Tarbela Reservoir ( in the national language Urdu: تربیلا بند ) is a dam or a dam on the Indus in Pakistan ( Asia). The English name is " Tarbela Dam" or " National Dam".
Dam
The dam is located about 50 kilometers northwest of Islamabad in Haripur district and covers a significant part of Pakistan's demand for electricity from hydropower. The Tarbela Dam is part of the " Indus Basin Project ", which has been decided in a treaty between India and Pakistan in 1960. The contract assures Pakistan of water inflows independently of India's control over the river headwaters. The dam balances the outflow of the Indus during the different seasons.
Dam
The built 1968-1977 from soil and rock masses at Haripur in the Peshawar valley dam - the Tarbela Dam - has a dam volume of 106 million cubic meters ( according to other sources, there are 121.720, 127.908, or 129.2 million cubic meters ), is about the maximum foundation level 143.26 m and 2743.20 m long. He is so after building one of the largest volume Erdschüttdämme the world. The dam has already caused considerable costs for maintenance, monitoring and repairs due to large structural engineering problems. Instead of the 1968 estimated cost of $ 800 million, he is said to have Pakistan to 1986 cost about 1.5 billion dollars.
Reservoir
The storage space of the Tarbela Reservoir, which has a two-tier catchment area of 158,000 or 10,360 km ² area is 13.69 km ³ in size. The water surface is 240 or 254 km ² according to two different information.
120 villages with 96,000 residents had to be relocated for the construction of the dam.
Power station
The attached at the dam power plant serves the power generation and irrigation. There, 28 % of Pakistan's electricity needs are generated. The power plant capacity is 3,478 MW in 14 turbines. (Another source indicates 4,678 MW. ) A new smaller hydroelectric power plant, the Ghazi Barotha Hydel Power Project, was built approximately 8 km below the Tarbela Dam. It serves only to generate electricity.
Claims
In July 1974 there was a damage case in which it would be almost come to disaster. The first filling of the reservoir, the sample storage, had two of the four tunnels that were used to discharge, be taken out of service because they were damaged. A week later broke one of the two remaining tunnels together. Half a million cubic meters of embankment material and rock collapsed and were washed away. This threatened the stability of the dam and so the water level had to be lowered. For this, the single undamaged and the two lower broken tunnel was used. Only the undamaged tunnel had been built by the New Austrian Tunnelling Method (NATM ). After the successful emergency lowering, it was discovered that the seal carpet in the storage space before the dam was destroyed in many places and had meter deep holes ( sink-holes ).
1976 were large settlements on the water-side slope.
Between 1975 and 1978 the holes with large loads of soil material were filled.
Normal operation was not until 1978 included.
Environment
The dam has indeed fulfilled its purpose, to store water for agriculture. But there has been some negative consequences for the environment in the Indus Delta. The reduction in runoff has reduced the mangrove stock in the Delta and some fish species have disappeared.