Lake Urmia was once one of the biggest saltwater lakes in the world

The governing factor of Lake Urmia’s hydrography is its lack of an outlet. It forms the dead end of a large drainage system that covers an area of about 20,000 square miles (52,000 square km) and is subject to great seasonal variation. The main affluents are the Talkheh (Ājī) River in the northeast, which gathers the melted snows from the Sabalān and Sahand massifs, and the twin rivers Zarīneh (Jagātu) and Sīmīneh (Tatavi) in the south.