Tartar River originates from the slopes of the northern ranges of Artsakh and the southern ranges of Mravsar, at an altitude of 3158m. It flows through the Mardakert and Karvatchar districts.
The length of river is 200km, basin-2653km². It feeds by underground (71%) and melt waters. Water level average difference is 15.5m on 1km, near the village Madaghis - 7.5m on 1km, the flow velocity is about 4m/sec. The average annual water consumption is 21.9m³/sec. The river is mountainous, most part of which passes through the canyon-shaped, deep gorge. River overflows in spring.
Tartar has a great energy and irrigation value. Sarsang reservoir, with capacity of 600 million cubic meters, was built in order to streamline the regime of the river and more efficient use of water. Madaghis hydro power is also on the river Tartar. Hydro power of the same name near the reservoir is constructed.
Forests and cliffs, along the whole length of Tartar, cover the banks. Not far from the river, Dadivank is situated. Rafting is possible on catamarans in the full-flowing periods.