From there, it flows westwards, marking part of the border of Afghanistan and Tajikistan.After passing the city of Khorugh, capital of the Gorno-Badakhshan Autonomous Region of Tajikistan it receives water from one of its main tributaries, the Bartang River.A water treaty between the Soviet Union and Afghanistan, signed in 1946, allows Afghanistan to draw 9 million cubic metres of water a year from the Panj.According to the Panj River Basin Project, environmental damage could be expected if Afghanistan drew the entire amount of allocated water from the river under the treaty.The Aga Khan Development Network has been engaged in a project to build a series of three bridges across the Panj River between Tajikistan and Afghanistan.