Project specifications
Considering that the construction of the Mollasadra Dam and Power Plant has reached its final stage and the dam will become operational in the near future, we have decided to introduce the specifications of the dam in this issue.

Generalities
The site of the Mollasadra Dam and Power Plant is situated in the north of Fars Province in Eqlid on the Tang-e Boraq River, one of the Kor River’s main branches. This dam is being constructed 60 km further up from the Dorudzan Dam and its construction work is near completion. During a tender in 1999, the client, Fars Province’s Regional Water Company, signed a contract for the implementation of the project with National Building Kitech Consortium from Iran and China. The contract for the construction of the Mollasadra Dam and Power Plant was officially signed on 16 February 1999. The duration of the project was 50 months and the Frankfurt branch of the Iranian Saderat Bank and the Chinese Ekrim Bank have been providing the necessary funds. The initial cost of the agreement was 75,700,000 US dollars, 35 million dollars of which was allocated to the construction of the dam and the remaining 40,700,000 dollars was allocated to the construction of the power plant and the water transfer tunnel. Considering that the contract was inclusive of the project finances, it wasn’t possible to begin the implementation of the project until 2002 because the finalization of the finance and financial agreements had to go through various administrative stages. Finally, following the finalization of the agreements, necessary contracts and guarantees, the activation of the credit lines and the payment of prepayments, the official start of work on the project was announced to the contractor on 6 August 2002. Most of the contract’s executive work was completed by the beginning of 2007.
The Mollasadra Dam’s reservoir was filled on schedule in January 2006 so that with the storage of water produced by wintry and spring showers it would be possible to transfer was to the dam for trial runs and the subsequent operation in 2006.

Project objectives
The main objectives of the Mollasadra Dam and power Plant project are as follows:
• The supply of water for the better exploitation of the lands between the Mollasadra and Durudzan dams.
• To control the overflow of the Kor River and to lessen the danger of the overflowing of Dorudzan Dam, which causes a lot of damage to the irrigation networks of the lands beneath Dorudzan.
• Overcoming the shortage of water flows to the vast agricultural networks of the lands beneath the Dorudzan Dam by the joint operation of the Dorudzan and Mollasadra dams.
• The annual production of 170 million KW/h of electricity with a capacity of 100 MW.
• Joint operation with the Dorudzan Dam and improving water supplies from the Dorudzan Dam consisting of Drinking water to the city of Shiraz and industrial consumption (Shiraz petrochemicals Company).
• To store the surplus output of the Kor River and release it during droughts by constructing the Mollasadra Dam and its joint operation with the Dorudzan Dam. Environmentally, this stops a drop or increase in the amount of water entering dry lakes. The expansion rate of lakes improves and the lands around these lakes which are one of the country’s main environmental resources and a place for migrant birds will be saved from the flooding they experience during high water years.

Project’s Technical Aspects
The Mollasadra Dam is a rockfill dam with a JC core and its height from the river bed is 72 metres (m). The dam’s crest at its maximum height is 2122 m by 630 m and its width is 10 m . The dam reservoir’s balanced height is 2115 m and the total volume of the reservoir at this level reaches 440 million cubic metres and this dam regulates 350 million cubic metres of water per annum.
Mollasadra Dam’s water diversion system is a concrete gallery and consists of two facing cells which have been embedded into the stone and have been constructed on the dam’s right wing. This gallery is 222 m long and its cross section is five metres high. This system is capable of discharging flood waters for 50 years at a rate of 219 cubic metres per second. The dam’s lower discharge system is a water diversion tunnel which has a service and emergency chamber and has a discharge rate of 140 cubic metres per second. This dam’s spillway is free chute which has a capacity to discharge 2800 cubic metres of water per second. The width of this spillway at its plummeting point is 88 m and its height and length are 10 m and 500 m respectively. Its energy maintenance system is a cup-shaped pendulum.
The water transfer tunnel to the power plant is 3286 m long and has a circular cross-section with a 4.5 m diameter. The height of the chamber’s shaft is 63.64 metres. This tunnel has a service chamber with a 78.72 m high shaft and a diameter of 10 m. At the end of the tunnel, water in transferred to the power plant via a 300 m steel pipe with an inside diameter of three metres. It has been designed to with stand water with a pressure of 210 mwc and its average horizontal inclination is 60 %.
The Mollasadra Hydroelectric Power Plant has a capacity of 100 (2x50) MW. It has two francis Turbines with a vertical axis which is capable of producing 180 million KW/h of electricity per annum at peak energy times. The maximum water level of this power plant at the reservoir’s normal operational level is 235 m and at its minimum operational level it is 200 m.

The history of the implementation of the project

The contract for the construction of the dam was officially announced to the contractor on 6 August 2002. However, due to the necessity to equip the workshops during the initial months of the start of the project, and also due to the fact that the region was snowed in and prone to various wintry showers at the beginning of 2003, it was impossible to start any major work on the project. As a result, the execution of the project began in mid 2003.
At that time in order to overcome the performance problems faced by the Kitech Company, the client and project supervisors took various measures. It was agreed that the Kitech Company would carry out the main activities through the use of the Chinese Crowbar (CGGC) Company. This company was one of the main contractors of China’s big three gorges project and has bigger executive and operations potential. After 15 months since the start of the implementation of the project, the Mollasadra Dam’s water diversion system was inaugurated on 1 June 2004. After that, new work began. Excavation work on the 3286 m water transfer tunnel finished two months ahead of schedule on 9 April 2005, nine months after the water diversion system.

Reporter : mehdi akbarsefat

َApproved by : Story Id 28

Create date : 26 Apr 2008 14:21

Id : 3134

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