In 1956, the southern part of the Tharthar depression was turned into an artificial reservoir to collect floodwaters of the Tigris River. The water flows via an artificial inlet canal, named Tharthar Canal. The canal diverts the excess water, by means of a regulator Samarra Barrage. It merges with the lake in its southeastern bank. The lake has an artificial outlet called Taksim Tharthar Canal, which drains to the Euphrates River directly. The canal, after 28 km from its outlet, bifurcates to another canal called "Dhira'a Dijla" that returns water back to the Tigris River. Lake Tharthar was the site of a raid in 2005 against an insurgent training base in the region.
Description
The Tharthar depression formed During Holocene age, mainly by karstification, due to dissolving of gypsum rocks of the Fatha Formation. Tharthar covers roughly, flows from the central and eastern parts of Sinjar Mountains and adjacent hills, with a floor of – 3 m, above the sea level. The maximum length and width of the depression are 120 and 48 km, respectively. The eastern rim of the depression is higher than the western one, the heights of both rims are and, respectively. The main purpose of the Tharthar Lake is to collect excess water of the Tigris River during flood seasons and to recharge water to the Tigris and Euphrates Rivers during dry seasons, when there is shortage of water in both rivers. Moreover, it aims in washing out the salts from the stored water, in the lake by means of natural continuous draining of the stored water.
Flora and fauna
Tharthar lake and the surrounding areas are considered one of the most important grazing areas in Iraq, including the wide wheat and corn fields covering the area. The area harbors many species of animals and vegetation.
Ten fish species have been found in the lake including: Aspius vorax, yellowfin barbel, B. luteus, B. sharpeyi, goldfish, Cyprnion kais, common carp, Silurus triostegus, Chondrostoma regium, and Liza abu.
Plants
Tharthar lake and the surrounding area contains about 38 species of plants. Four main habitat types observed within the Al-Tharthar Lake and Al Dhebaeji Field area:
Inland standing water: aquatic communities – rooted submerged vegetation, characterized by Vallisneria spiralis, Potamogeton crispus and Potamogeton perfoliatus.
Flooded communities: periodically or occasionally flooded land dominated by Cyperus sp., Rumex dentatus, Polygonum argyrocoleon, Polygonum sp. and Bacopa monnieri.
Marsh vegetation: helophytic vegetation - reedbeds, characterized by Phragmites australis.
Terrestrial vegetation: desert shrub characterized by Tamarix sp., Alhagi maurorum, Atraplex leucoclada and Cornulaca aucheri.
