Lake Tharthar, Artificial lake between Tigris and Euphrates rivers in Al Anbar Governorate, Iraq.

Lake Tharthar is an artificial reservoir created between the Tigris and Euphrates rivers in northern Iraq's Al Anbar Governorate. The water body serves as a vast storage basin connected to both rivers through a network of channels and control structures.

The lake came into being in 1956 following the construction of canals and dams designed to control water movement between the two rivers. This infrastructure allowed the region to manage flooding and improve water distribution across the landscape.

The lake's name comes from the Tharthar depression, which formed in the Holocene when gypsum in the Fatha Formation dissolved. Water reaches the lake through the Tharthar Canal from the Samarra Barrage, whose 17 gates were built in 1956. The Taksim Tharthar Canal carries water 37.5 km to the Euphrates near Fallujah, opened on 10 October 1976.

The lake lies about 100 km northwest of Baghdad, reached from the Samarra Barrage, where the Tharthar Canal diverts Tigris floodwater through a regulator with 17 gates. The main outlet canal runs 37.5 km south to the Euphrates near Fallujah, and the Dhira'a Dijla branch continues 65 km east to the Tigris at Taji. The surrounding ground is desert shrub and marsh edge, so plan for heat and distance.

The water body hosts more than 50 bird species and has been designated as an Important Bird Area for Iraq. Several species found here are endangered, using the lake as a stopover during their seasonal migrations.