Özlüce Dam and HEPP

The Özlüce Dam and Hydro Electric Power Plant (HEPP) are located on the river Peri, a tributary of the Euphrates in Elazığ province in eastern Türkiye.

The project involved the construction of a 15 million m³ central clay core rock-fill embankment dam, which is 164 meters tall from the foundation and has a crest length of 476 meters, including an overflow separated spillway with a discharge capacity of 4,750 m³/s and regulated by 4 radial gates. The installation of a triple-line grout curtain was carried out with a vertical depth length of 180 meters along the cut-and-cover gallery at the dam foundation, which was further supported with contact and consolidation grouting with two levels of grouting galleries at each abutment.

As part of the construction scope, two diversion tunnels measuring 865 meters and 900 meters, were each excavated to attain an initial diameter of 9 meters, and were lined with reinforced concrete to an operating diameter of 7.5 meters respectively. As an integral part of the project, a 570-meter long power tunnel which leads to the powerhouse was excavated to reach a diameter not less than 9 meters, and was lined with reinforced concrete resulting in an eventual diameter of 7.5 meters. The Power plant houses two (2) vertical-shaft turbine-generator units, each rated at 100 MW, with a total installed power of 200 MW. The project also included the construction of a 400 kV and 170 kV switchyards to transmit electricity to a 400 kV grid and to another 170 kV grid through two coupling transformers.

The construction of the dam and HEPP commenced in 2000, and the site was completed and fully commissioning in 2005 with commercial production operation in the same year. The Özlüce Dam and HEPP are owned and operated by the state-owned company General Directorate of State Hydraulic Works (DSİ).