Siah Bishe Pumped Storage Project Upper & Lower Dams

Project Overview

Pumped-storage power plants have emerged as one of the most effective solutions for regulating electricity grid loads. The Siah Bishe Dam and Hydropower Plant project is located on the Chalus River, 125 kilometers north of Tehran, adjacent to the Chalus Road and 10 kilometers north of the Kandovan Tunnel (75 kilometers from the city of Chalus), in Mazandaran Province. The -1,000megawatt Siah Bishe Dam and Hydropower Plant Complex is distinct from other projects currently under study or construction in the country due to its pump-storage operation and the type of dams used. This project is the country’s first pump-storage facility and also the first concrete-faced rockfill dam (CFRD) in Iran.

The primary objective of this project is to supply electricity during peak demand periods and ensure reliable power for the national electricity grid during off-peak times. Additional objectives include reducing annual depreciation costs of thermal power plants by $19 million, creating a recreational and tourism destination for both domestic and international visitors, and generating employment in the region during both the construction and operational phases of the project.

The Siah Bishe project was awarded in 2003 through a tender process and structured under two Design and Build contracts. Contract A, which included the design and construction of two concrete-faced rockfill dams (CFRDs), primary water supply tunnels, and associated structures, was awarded to a joint venture led by Kayson Company, with Beta and Soil Mechanical Engineering Services as partners. Additionally, in June 2010, a separate contract for supplementary works related to the Siah Bishe dams was awarded to the same joint venture.

The design of the CFRD dams and associated structures was carried out by a team composed of Iranian engineers in collaboration with the Swiss company Electrowatt. The Upper and Lower Dams of the Siah Bishe Pumped Storage Power Plant Project received the Crystal Prize in the National Award for the Best Iranian Project for the years 2011–2012.

scope of Work

Phase 2 involved the design and preparation of detailed drawings for the construction of two concrete-faced rockfill dams (CFRDs). The upper dam was constructed with a height of 82.5 meters, a crest length of 436 meters, and a reservoir capacity of 4.9 million cubic meters. The lower dam was built 102 meters high, 332 meters long at the crest, and had a reservoir capacity of 6.9 million cubic meters. Associated structures were also completed as part of this phase.

A key component of the contract included the construction of two connecting water supply tunnels between the dams. Each tunnel was approximately 2,000 meters long, with an excavation diameter of about 7 meters and a finished diameter of 5.7 meters, and featured a -40centimeter-thick concrete lining.

Project statistics