Afghanistan is a country in Central Asia bordering the northern and western regions of Pakistan and eastern regions of Iran. The country borders six countries: China, Iran, Pakistan, Tajikistan, Turkmenistan, and Uzbekistan.
The Amu Darya is the longest river to pass through Afghanistan, while the Helmand is the longest river wholly flowing within the country. The Amu Darya also flows through Tajikistan, Uzbekistan, and Turkmenistan. The hot weather of Afghanistan dries up the rivers in the dry season. The highlands of the country and mountain streams support the rivers. During winter the river flow is continuous due to the melting ice. The rivers drain in different places depending on the course followed. The shared rivers have also led to territorial disputes and water treaty signed by individual countries has resolved the disputes. Below are the longest rivers in Afghanistan.
The Amu Darya River is 879 miles long. The river is sourced from Qal’eh’ye Panjeh in Afghanistan at the junction of the Vakhsg and Panj rivers. It then flows north-westwards to drain the remains to the Aral Sea or disappear in the deserts. The river has a basin area of 534,739 square kilometers. The high mountains provide the needed precipitation to maintain the flow since downstream increased evaporation reduces the river water. The river provides water for irrigation. In the 5th Century, people settling along the river course used its waters for irrigation and establishment of towns and cities. In the past, the river provided the territorial boundary of Greater Iran from Turan. Before 1970, the river used to branch into many tributaries to form a delta before draining into the Aral Sea. In the 1950s the Soviet Union started to divert massive amounts of water that had been set up to irrigate cotton and other plantations in the lowland region of the river. By 1960, the Karakum Canal was completed to carry water from the Turkmenistan side westward to Mary and Ashgabat. This diversion resulted to decreased amount of river water flowing into the sea. As irrigation increased on the hot, dry floodplains, salinity in the river and the soils became infertile. By the 21st Century, the river no longer drained in the Aral Sea. Poplars, Jupiters, and blackberries grow in the mountain edge of the river. In the lower region willows, buckthorn, and oleasters dominate in the lower regions. Salt and drought resistant trees grow on the lowest reaches. The river is devoid of fish and birds.
Flowing for 715 miles, the Helmand River runs entirely within the borders of Afghanistan. The river rises in the Baba Range, East-Central Afghanistan, flows southwestward into the country, changes course to a short northward flow, and empties in the Helmand swamps in the southwest boundary of the state and Eastern Iran. The river has many tributaries, including the Tarnak and Arghandab. Along the river course, a reservoir was built at Kajak to provide water for irrigation schemes and control floods. Another dam diverts the water to a canal. The river provides the perfect environment for a large group of migratory birds. The primary threat facing the river is Afghanistan pursuit concerning water resource development projects. The construction of Kamal Khan Dam on the lower reaches of the river and the renovating of Kajaki dam are destroying the river's natural flow and polluting it too.
The Hari River is sourced from the western slopes of the Selseleh-ye Kuh-e Baba Range, which are outliers of the Hindu Kush Mountains in Central Afghanistan. The river then flows west past the Chaghcharan and Herat, an ancient city, then north where it crosses into Turkmenistan and disappear in the Karakum Desert. The Jam River meets the Hari River in the Minaret of Jam, some 120 miles upstream from the ancient town of Herat. With a length of 684 miles, the Hari River provides water for irrigation some of Afghanistan productive lands. The Afghan-India Friendship Dam is a dam constructed in Heat Province for hydroelectric and irrigation purposes. History references the river as River Sarayu which provided a religious site where Buddhists monks lived and worshiped.
The Panj River, a tributary of the Amu Darya River, runs for 572 miles. The river rises from the confluence of River Pamir and River Wakhan in the village of Qila-e Panja. From the confluence, it flows westwards to form the Tajikistan and Afghanistan border. Past the city of Khorog in Tajikistan, the river meets its tributary, River Bartang, and the joined River flows southwest to accede to the river Vakhsh forming the Amudarya River. In the late 20th Century the river strategic location played a significant role in the Soviet rule and the Soviet military operations in Afghanistan. The water treaty between the country and the Soviet Union allows Afghanistan to draw nine cubic meters, but the country only draws 2 million as drawing all the water as per the treaty the process could damage the natural flow of the river.
Afghanistan and Iran have for many generations quarreled over the rights to the waters of the Helmand River. Iran argues that it has a claim over some of the river water and also protests over Afghanistan activities that dry up the Helmand River during the dry season. The disputes continue despite water treaties and commissioners from both countries trying to discuss boundary and operations that will mitigate the existing conflicts.
All of the major rivers in Afghanistan are prone to degradation and pollution from human activities such as damming and the creation of canals, which are used to divert river water to irrigate farmlands and to produce hydroelectricity. The longest river in the country had a delta in its mouth but today hardly any water drains into the sea.