Upper Beyhan Dam and HEPP

The Beyhan I Dam, with its hydroelectric power plant, is located on the Murat River, a tributary of the Euphrates in Bingöl province, Türkiye.

The primary scope of the civil engineering work was the erection of Upper Beyhan, a roller-compacted-concrete (RCC) gravity dam with a 582.10 MW hydroelectric power plant. It provides an ogee spillway, which has a discharge capacity of 10,500 m³/s. The dam is 97-meter tall from the foundation and has a crest length of 521 meters.

The river diversion works comprised three (3) tunnels measuring 535 meters, 572 meters, and 582 meters long. Each tunnel was driven through the left abutment of the canyon wall to a diameter of 11.5 meters, and a total of 168,000 m³ of tunnel excavation was carried out for them. They were all lined with reinforced concrete to an eventual diameter of 9.5 meters respectively.

Nearly 1,650,000 m³ of soil was excavated to ensure an adequate foundation for the dam, and abutments. Furthermore, approximately 1,350,000 m³ of RCC was poured from start to finish to build the retaining wall. The power intake, which is integrated into the RCC dam, required 101,500 m³ of conventional vibrated concrete (CVC) as well.

Almost 3,400,000 m³ of rock and earth were removed for the spillway excavation on the left abutment, and a quantity of 214,000 m³ of conventional vibrated concrete (CVC) was used in the construction of a separate 3-bay spillway furnished with four (4) tainter gates. About 400,000 m³ of material was excavated for the powerhouse, and 228,000 m³ of (CVC) concrete was placed to build it.

The contract deliverables also covered the installation of four (4) vertical axis, Francis-style turbine-generator units and auxiliary equipments, as well as installing a 400 kV switch-yard. While three (3) units are equally rated at 183.5 MW each, one small unit rated at 31.6 MW. In unison these four units reach a power capacity of 582.10 MW.