Siah Bishe Pumped Storage Project Upper & Lower Dams

Project Outline

Pumped storage hydroelectricity is one of the most efficient methods for providing balance in power grid to supply high peak demands. The Siah Bishe Pumped-storage Hydroelectric Power Project and its dams are located in Mazandaran Province, over Chaloos River, 125 km north of Tehran. It is also adjacent to Chaloos Road, 10 km north of Kandovan Tunnel (75 km from Chaloos City). It has an installed capacity of 1000 MW. In comparison to country’s other projects, which are in the primary stages or under construction, this project is unique on behalf of operation of pumped storage and type of dams. This project consists of building the first pumped storage plant and the first Concrete Face Rockfill Dam (CFRD) in the country. The project is basically intended to supply electricity at times of peak demand and create a safe consumer for the entire Iran power grid during the hours of low electrical demand.

Decline in the annual costs of depreciation of thermal power plants up to $19 M, creation of an entertaining and touristic environment for foreign and domestic tourists and employment in the project area during the period of its execution and operation are some of the other objectives of the present project.

In a tender held on 2003, the Siah Bishe Project was awarded to selected contractors, within the framework of two design-build contracts. On Aug. 3, 2003, Beta, Soils Engineering Services (SES) and Kayson Company entered into a joint venture agreement, with the last-named party as the leader of the consortium, to carry out contract A which includes designing and building of the body of two concrete-face dams as well as the main parts of the headrace tunnels and related installations. In June 2010, construction of the complementary operations of the two dams was notified to the parties.
The design of CFRD dams and the related structures was done by a team of Iranian designers and the Swedish Pöyry company (Electrowatt).

Scope of Work

The second phase of the project and the joint venture’s sphere of work involve detailed design, construction of two Concrete Face Rockfill Dams (CFRD), the concrete-face upper and lower dams, and completion of headrace tunnels. The power plant’s up and down pumped-storage reservoirs respectively have a storage volume of 4.3 and 6.9 million cubic meters, stand 82.5 & 102 meters high and 436 & 332 meters across the crest.

Each of the two headrace tunnels which link up the two dams is 2000 meters long, with approximate excavation diameter of 7m and final diameter of 5.7m. The tunnels will have a 40 cm thick concrete lining.