The Ilısu Dam () is a concrete-face rock-fill dam on the Tigris near the village of Ilısu and along the border of Mardin and Şırnak Provinces in Turkey. It is one of the 22 dams of the Southeastern Anatolia Project and its purpose is hydroelectric power production, flood control and water storage. When operational, the dam will support a 1,200 MW power station and will form a 10.4 billion m3 reservoir. Construction of the dam began in 2006 and was originally expected to be completed by 2016. As part of the project, the much smaller Cizre Dam is to be constructed downstream for irrigation and power. The dam has drawn international controversy, because it will flood portions of ancient Hasankeyf and necessitate the relocation of people living in the region. Because of this, the dam lost international funding in 2008. Most historical structures in Hasankeyf were moved to the new Hasankeyf prior to the filling of the dam. The dam began to fill its reservoir in late July 2019. Due to rainfall, the dam has achieved water levels up to 100m above the river bed and stored 5 billion cubic meters of water. The water level had reached an elevation of 498.2m on 1 April 2020.
DSI has started testing 2 turbines for energy production after completing the spillway testing. The dam reservoir has attained a water volume of 7.6 billion cubic meters. Water storage crest level was 513m on 19 April 2020. It would need 12m rise to achieve the maximum storage level.
The first of six generators was commissioned on 19 May 2020, while its power plant is scheduled to reach full capacity by the end of 2020. Three hydro-turbines have been commissioned since 19 June 2020 and the remaining three are being tested. So far the dam has contributed 51M$ energy towards economy.
Design
The Ilısu Dam will be a high and wide rock-fill embankment dam with a structural volume of . It will be wide at its crest and wide at its base. The dam will have an overflow spillway on its right bank which will be controlled by eight radial gates which will pour into four chutes before the water reaches a plunge pool. Its power station will be above ground and will contain 6 x 200 MW Francis turbine-generators with an expected annual generation of 3,833 GWh and gross hydraulic head of . The dam's reservoir will have a capacity of , of which will be active (or live, useful) storage and will be inactive (dead) storage. At a normal elevation of above sea level, the reservoir surface area will cover .
Background
Beginning in 1954 the Turkish government surveyed of the Tigris river downstream of Diyarbakır with the aim of identifying suitable locations for a hydroelectric power plant at an elevation below . Turkey's Electric Power Resources Survey and Development Administration (EIE) included 10 potential sites in its 1971 Tigris River Pre-Investigation Report. By 1975, the EIE had completed a technical and economic evaluation of the sites. Ilısu was selected as the preferred site for geological reasons. A feasibility study and final design by international consultants (1980–82) resulted in a recommendation to construct both the Ilısu Dam and the Cizre Dam downstream.
There was little movement on the project for more than 15 years until the dam was added to the State Hydraulic Works' formal construction program in 1997 or 1998.
On 5 August 2006, the foundation stone for the dam was laid and initial construction began.