The Indus River (pronounced /ˈɪndəs/ IN-dəs) is a river that flows through multiple countries in Asia, including parts of South and Central Asia. It is 3,180 kilometers (1,980 miles) long and begins in the Tibet Autonomous Region of China, where it is called Sengge Zangbo. The river flows northwest through the disputed Kashmir region, first through the Indian-administered Ladakh and then the Pakistani-administered Gilgit-Baltistan. After passing near the Nanga Parbat mountain range, it turns sharply to the left and flows south-by-southwest through Pakistan’s Sindh province. It splits into two branches before emptying into the Arabian Sea, near the port city of Karachi.
The Indus River drains an area of about 1,120,000 square kilometers (430,000 square miles). It carries approximately 175 cubic kilometers of water each year, making it one of the 50 largest rivers in the world by average annual flow. On its left bank in Ladakh, the Zanskar River joins the Indus. In the plains, the Panjnad River, formed by the merging of five rivers—Chenab, Jhelum, Ravi, Beas, and Sutlej—also flows into the Indus. Other major tributaries include the Shyok, Gilgit, Kabul, Kurram, and Gomal rivers. The river begins in mountain springs and is fed by glaciers and rivers in the Himalaya, Karakoram, and Hindu Kush mountain ranges. It supports ecosystems in temperate forests, plains, and dry areas.
Geologically, the Indus River’s headwaters and those of the Yarlung Tsangpo (later called the Brahmaputra) flow along the Indus-Yarlung suture zone. This zone marks where the Indian and Eurasian tectonic plates collided about 50 million years ago. These rivers, diverted by the rising Himalayas, outline the western and eastern edges of the mountain range. After leaving its narrow Himalayan valley, the Indus River, along with its tributaries, forms the Punjab region of South Asia. Its lower course ends in a large delta in Pakistan’s Sindh province.
Historically, the Indus River was vital to many cultures. Around 3000 BCE, the Indus Valley Civilization, a major Bronze Age society, flourished in the region. By 2000 BCE, the Punjab area was referred to as "Sapta Sindhu" in the Rigveda and "Hapta Həndu" in the Avesta, both meaning "seven rivers." Ancient kingdoms like Gandhāra and Sindhu-Sauvīra also emerged in the Indus Valley. The river became known to the Western world during the classical period when King Darius of Persia sent his Greek subject, Scylax of Caryanda, to explore it around 515 BCE.
Etymology and names
The word "Indus" in the English language comes from Late Latin "Indus" (used in 1598). This Latin word was based on the classical Latin "Indus," which meant "inhabitant of India" or "Indian." The term originated from ancient Greek "Ἰνδός," meaning "inhabitant of India," "Indian," or "the River Indus." This Greek word came from Old Persian "hindu," which referred to an eastern area of the Achaemenid Empire (known as "hind India" or "Hindush"). It also connects to Avestan "hiṇdu" or "həṇdu," meaning "river." These words share the same root as the Sanskrit word "sindhu," which means "river." This root also gives the name to the region of the Indus. In ancient Greek, the river was called "Σίνθος," meaning "the River Indus." In Sanskrit, the word "Sindhu" can mean "stream," "river," "flood," "sea or ocean," "region or country near the Indus," or "people of Sindh."
Today, the river is called "Sindh" or "Daryā-i-Sindh" (meaning "the River Sindh") in Urdu. This name is different from the name of the Province of Sindh ("Sūba-i-Sindh" in Urdu). In Ladakhi and Tibetan languages, the river is known as "Senge Tsangpo." The Balti people call it "Gemtsuh" or "Tsuh-Fo." Pashtuns refer to it as "Nilab," "Sher Darya," or "Abbasin." Sindhis call it "Sindhu," "Mehran," "Purali," or "Samundar."
Description
The Indus River is an important source of water for Pakistan’s economy, especially in Punjab province, which is a major area for farming in the country. The name Punjab means “land of five rivers,” and these rivers are the Jhelum, Chenab, Ravi, Beas, and Sutlej. All of these rivers eventually flow into the Indus. The Indus also supports many large industries and provides most of Pakistan’s drinking water.
The length of the Indus River varies depending on the source. This article uses a length of 3,180 kilometers (1,980 miles), as reported by the Himalayan Climate and Water Atlas in 2015. Earlier sources, such as The Imperial Gazetteer of India from 1909, listed the length as “just over 1,800 miles.” Modern sources often use either 2,880 kilometers (1,790 miles) or 3,180 kilometers (1,980 miles). The Encyclopedia Britannica originally listed the shorter measurement in 1999 but updated it to the longer measurement in 2015. Both lengths are still commonly used in modern writings. In 2011, a Chinese research group suggested the river might be about 3,600 kilometers (2,200 miles) long, based on satellite images and fieldwork, but this measurement has not been fully analyzed yet.
The Indus River begins in Tibet, though there is some debate about its exact starting point. Traditionally, the source is considered to be the Sênggê Kanbab, also called the “Lion’s Mouth,” a spring near Mount Kailash. This spring is marked by a line of stone monuments. Nearby, other rivers may form a longer stream than the Sênggê Kanbab, but these depend on snowmelt. The Zanskar River, which joins the Indus in Ladakh, carries more water than the Indus itself before that point. Another possible starting point is where the Sênggê Zangbo and Gar Tsangpo rivers meet, near the Gangdise Shan and Nganglong Kangri mountain ranges. A 2011 study suggested the source might be a lake northeast of Mount Kailash, rather than the two previously mentioned locations.
The Indus flows northwest through Ladakh (part of Indian-administered Kashmir) and Baltistan and Gilgit (part of Pakistan-administered Kashmir), just south of the Karakoram range. The Shyok, Shigar, and Gilgit rivers bring glacial water into the Indus. The river then turns south and flows into the Punjab plains near Kalabagh, Pakistan. It passes through deep gorges near the Nanga Parbat mountain range, which are 4,500 to 5,200 meters (15,000 to 17,000 feet) deep. The river moves quickly across the Hazara region and is dammed at the Tarbela Reservoir. The Kabul River joins the Indus near Attock. After this, the Indus flows through the flat areas of Punjab and Sindh provinces, where its movement slows and the river becomes braided. The Panjnad River joins the Indus at Mithankot. Beyond this point, the river was once called the Satnad River, meaning “seven rivers,” because it carried water from the Kabul River, the Indus River, and the five rivers of Punjab. The river ends in a large delta near Thatta in Sindh province.
The Indus River is one of the few rivers in the world that has a tidal bore, which is a wave that moves upstream during high tide. The Indus is mainly fed by snow and glaciers in the Himalayas, Karakoram, and Hindu Kush mountain ranges. The river’s flow changes with the seasons, decreasing in winter and increasing during the monsoon months of July to September. Evidence also shows the river has gradually changed its course over time. After an earthquake in 1816, the Indus shifted westward, no longer flowing into the Rann of Kutch and Banni grasslands. By 2011, floodwaters from the Indus occasionally reached the Rann of Kutch during heavy rains.
History
The major cities of the Indus Valley Civilization, such as Harappa and Mohenjo-daro, were built around 3300 BC. These cities were among the largest human settlements of the ancient world. The Indus Valley Civilization covered a large area from northeast Afghanistan to Pakistan and northwest India. It stretched from east of the Jhelum River to Ropar on the upper Sutlej. Coastal settlements were found from Sutkagan Dor near the Pakistan-Iran border to Kutch in modern Gujarat, India. An Indus site was discovered at Shortughai on the Amu Darya in northern Afghanistan, and another site, Alamgirpur, is located 28 kilometers from Delhi. To date, over 1,052 cities and settlements have been found, mostly near the Ghaggar-Hakra River and its tributaries. Major cities included Harappa, Mohenjo-daro, Lothal, Dholavira, Ganeriwala, and Rakhigarhi. Only 40 Indus Valley sites were found along the Indus River and its tributaries. However, most of the Indus script seals and inscribed objects discovered were found along the Indus River.
Some scholars believe that the Gandhara grave culture, associated with early Indo-Aryans, existed in Gandhara from 1700 BC to 600 BC. By this time, Harappa and Mohenjo-daro had already been abandoned.
The Rigveda mentions several rivers, including one called "Sindhu." This name is believed to refer to the modern Indus River. The word "Sindhu" appears 176 times in the Rigveda, 94 times in the plural form. It was often used to describe any river, but later it specifically referred to the Indus River. In the Rigveda, most rivers were given a feminine form, except the Brahmaputra.
The word "India" comes from the Indus River. In ancient times, "India" referred to the areas near the east bank of the Indus, such as Punjab and Sindh. By 300 BC, Greek writers like Herodotus and Megasthenes used the term to describe the entire Indian subcontinent, which includes regions much farther east.
The lower part of the Indus River forms a natural boundary between the Iranian Plateau and the Indian subcontinent. This area includes parts of Balochistan, Khyber Pakhtunkhwa, Punjab, and Sindh in Pakistan, as well as Afghanistan and India. The first West Eurasian empire to control the Indus Valley was the Persian Empire during the rule of Darius the Great. During his time, the Greek explorer Scylax of Caryanda was asked to explore the Indus River. Later, Alexander the Great's armies crossed the river, but after conquering the western bank, they chose to retreat along the southern part of the river, ending Alexander's campaign in Asia. Alexander's admiral, Nearchus, traveled from the Indus Delta to explore the Persian Gulf until reaching the Tigris River. Over time, the Indus Valley was ruled by the Mauryan and Kushan Empires, Indo-Greek Kingdoms, Indo-Scythians, and Hepthalites. Later, Muslim armies led by figures like Muhammad ibn al-Qasim, Mahmud of Ghazni, Muhammad of Ghor, Timur, and Babur crossed the Indus River to invade Sindh and Punjab, creating a gateway to the Indian subcontinent.
Geology
The Indus River is an antecedent river, meaning it existed before the Himalayas formed and carved through the rising mountains.
The Indus River supplies the Indus submarine fan, which is the second largest sediment deposit on Earth. This fan contains about 5 million cubic kilometers of material eroded from nearby mountains. Studies of the river’s current sediment show that the Karakoram Mountains in northern Pakistan and India are the main source of material, with the Himalayas contributing the next largest amount, mostly through major rivers in the Punjab region (Jhelum, Ravi, Chenab, Beas, and Sutlej). Analysis of sediment in the Arabian Sea shows that five million years ago, the Indus River was not connected to these Punjab rivers, which instead flowed east into the Ganga. These rivers were later captured by the Indus. Earlier research found that sand and silt from western Tibet reached the Arabian Sea 45 million years ago, suggesting an ancient Indus River existed by that time. The delta of this early Indus River has been discovered in the Katawaz Basin, located on the border between Afghanistan and Pakistan.
In the Nanga Parbat region, the large erosion caused by the Indus River after it was redirected through the area is believed to expose rocks from the middle and lower parts of Earth’s crust.
In November 2011, satellite images showed the Indus River had returned to India, flowing into the Great Rann of Kutch, Little Rann of Kutch, and a lake near Ahmedabad called Nal Sarovar. Heavy rains had caused flooding in the river basin and in lakes such as Manchar, Hemal, and Kalri (all in modern-day Pakistan). This event occurred two centuries after the Indus River changed its course westward following the 1819 Rann of Kutch earthquake.
The Induan Age, which marks the beginning of the Triassic Period in geological history, is named after the Indus region.
Wildlife
Accounts from the time of Alexander’s campaign show that the Indus Valley had many forests. The Mughal Emperor Babur wrote in his memoirs, the Baburnama, that he saw rhinoceroses near the river. However, deforestation and human activities have caused the vegetation in the Shivalik Hills to decline. The Indus Valley is now dry with little plant life. Farming in the region depends mostly on irrigation systems. The Indus River and its area have many types of plants and animals. Around 25 species of amphibians live there.
The Indus River dolphin (Platanista indicus minor) is found only in the Indus River. It is a type of South Asian river dolphin. In the past, these dolphins lived in the river’s tributaries. According to the World Wildlife Fund, this dolphin is one of the most endangered aquatic mammals, with about 1,816 remaining. Threats include habitat damage from dams and canals, getting caught in fishing nets, and water pollution from industries.
Two otter species live in the Indus River basin: the Eurasian otter in the northeastern highlands and the smooth-coated otter in other areas. The smooth-coated otters in the Indus River are a type found only there, called the Sindh otter (Lutrogale perspicillata sindica).
The Indus River basin has high biodiversity, home to more than 180 freshwater fish species, 22 of which are found nowhere else. Fish were important in ancient cultures, like the Indus Valley Civilization, where fish were often shown in art. The Indus script includes a symbol that may have meant "fish" or referred to stars or gods.
In the highest parts of the Indus River basin, only a few fish species live, such as Diptychus, Ptychobarbus, Schizopyge, Schizopygopsis, Schizothorax snowtrout, Triplophysa loaches, and the catfish Glyptosternon reticulatum. As the river flows downstream, more species appear, including the golden mahseer (Tor putitora) and Schistura loaches. Near Thakot, Tarbela, the Kabul-Indus confluence, Attock Khurd, and Peshawar, the number of fish species increases, including many types of carp, loaches, catfish, and other fish. As the river moves through the Punjab Plain, it becomes slower, and major carp species become common. In some lakes and tributaries of the Punjab region, snow trout and mahseer are still found, but these species are rare in the lower parts of the river. Many fish species from the middle sections of the river are also found in the lower areas. Examples include the Aphanius pupfish, Aplocheilus killifish, palla fish (Tenualosa ilisha), catla (Labeo catla), rohu (Labeo rohita), and Cirrhinus mrigala. The lowest part of the river and its delta include freshwater, brackish, and marine fish species, such as pomfret and prawns. Conservationists consider the delta an important ecological area because the river splits into marshes, streams, and creeks before meeting the sea.
The palla fish (Tenualosa ilisha) is a favorite food for people living along the river. Fish populations are moderately high, with Sukkur, Thatta, and Kotri being major fishing areas in the lower Sindh region. Because of damming and irrigation, fish farming has become an important economic activity.
Economy
The Indus River is the main source of water for the Punjab and Sindh plains in Pakistan. It supports farming and food production because rainfall is low in the lower Indus valley. Irrigation canals were first built by the people of the Indus Valley Civilization, later by engineers from the Kushan and Mughal Empires. The British East India Company introduced modern irrigation in 1850, building new canals while repairing older ones. The British oversaw the creation of one of the world’s most complex irrigation systems. The Guddu Barrage is 1,350 meters long and provides water to Sukkur, Jacobabad, Larkana, and Kalat. The Sukkur Barrage serves an area covering 20,000 square kilometers.
After Pakistan became independent, a 1960 treaty between India and Pakistan ensured Pakistan would receive water from the Indus River and its tributaries, the Jhelum and Chenab rivers, without interference from India. The Indus Basin Project included building two major dams: the Mangla Dam on the Jhelum River and the Tarbela Dam on the Indus River, along with smaller dams. The Pakistan Water and Power Development Authority built the Chashma-Jhelum link canal, connecting the Indus and Jhelum rivers to supply water to Bahawalpur and Multan. The Tarbela Dam, located near Rawalpindi, is 2,743 meters long and 143 meters high, with a reservoir 80 kilometers long. It supports the Chashma Barrage for irrigation and flood control and the Taunsa Barrage, which also generates 100,000 kilowatts of electricity. The Kotri Barrage near Hyderabad is 915 meters long and provides water to Karachi. Linking tributaries to the Indus has expanded water access to the Peshawar valley in Khyber Pakhtunkhwa. These irrigation and dam projects enable Pakistan to grow large amounts of crops like cotton, sugarcane, and wheat. The dams also produce electricity for industries and cities.
People
The Indus River is sacred to Hindus. The Sindhu Darshan Festival is held every year on Guru Purnima along the Indus River.
People from the Indus Valley region in Pakistan and Northwest India have a greater mix of ANI (or West Eurasian) genetic traits compared to other South Asians. This includes contributions from Western Steppe Herders, with evidence showing that there were many migrations from the west over a long time.
Modern issues
The Indus Waters Treaty (IWT) is a water-sharing agreement between India and Pakistan that divides the water from the Indus River system. Under the treaty, India received about 33 million acre-feet (41 billion cubic meters) of water (16%), while Pakistan received about 177 million acre-feet (218 billion cubic meters) of water (84%). On April 23, 2025, India suspended the treaty after a terrorist attack near Pahalgam in Kashmir, citing national security concerns. India then stopped the flow of water from the Chenab River at the Baglihar Dam as a "short-term punitive action." India also performed reservoir flushing to increase the storage capacity of the Salal and Baglihar projects. These actions were taken outside of the normal season and without informing Pakistan. Pakistan warned that disrupting water flow from shared rivers could be considered an act of war and that it might use nuclear weapons.
The IWT gives India a military advantage because it only covers the Indus River system in India and parts of Pakistan, as outlined in Articles II (1 to 4) and III (2 to 3). According to the treaty, Pakistan cannot attack or destroy dams, power stations, or other infrastructure in the Indian part of the Indus system, as this would violate the treaty and could lead to its cancellation.
The Indus River once carried nearly all of its water and 400 million tonnes of silt to its delta. Since the 1940s, dams, irrigation systems, and other structures have been built on the river. The Indus Basin Irrigation System is the largest continuous irrigation system in the world, developed over 140 years. These structures have reduced the river’s flow and silt. By 2018, the average annual water flow below the Kotri barrage was 33 billion cubic meters, and silt discharge was about 100 million tonnes. The 2010 Pakistan floods were seen as beneficial for the delta’s ecosystem and people because they brought fresh water. Further use of the river’s water is no longer economically practical.
Reduced water flow, deforestation, pollution, and global warming threaten the Indus delta’s plants and animals. Dams have also separated the delta’s population of Indus River dolphins from those upstream. Large-scale water diversion for irrigation has caused problems, including sediment buildup in canals, which harms agriculture and vegetation. Irrigation has also increased soil salinity, lowering crop yields and making some farmland unusable.
The Tibetan Plateau holds the world’s third-largest ice reserve. Qin Dahe, a former leader of China’s Meteorological Administration, warned that faster glacier melting and rising temperatures could benefit agriculture and tourism in the short term but would cause long-term problems. Glaciers are critical for the Indus River’s water supply. If they disappear, Pakistan’s water supply could be at risk.
David Grey, a World Bank water advisor, said there is not enough data to predict how climate change will affect the Indus River’s flow. However, he warned that glacier melt could reduce the river’s flow by up to 50%, which would severely impact people living in desert regions who depend on the river for survival.
U.S. diplomat Richard Holbrooke once said that falling water levels in the Indus River "could very well precipitate World War III."
Factories along the Indus River have increased water and air pollution, harming the endangered Indus River dolphin. The Sindh Environmental Protection Agency has ordered polluting factories to close under the Pakistan Environmental Protection Act, 1997. Fishermen using poison to kill fish has also contributed to dolphin deaths, leading the government to ban fishing near the Guddu Barrage to Sukkur.
The Indus River is the second-largest contributor of plastic to the oceans, after the Yangtze River.
The Indus River frequently experiences moderate to severe flooding. In July 2010, heavy monsoon rains caused the river to flood, devastating parts of Pakistan. Over 2,000 people died, and more than a million homes were destroyed. In 2011, heavy monsoon rains caused floods in Sindh, eastern Balochistan, and southern Punjab, killing 434 people and affecting 5.3 million people and 1.5 million homes. The floods damaged 1.7 million acres of farmland, worsening the region’s already difficult situation after the 2010 floods.
Barrages, bridges, levees and dams
The upper Indus River in Tibet, known as the Senge Zangbu, is a small stream until it flows into the deep valleys of the Himalayas and Karakoram mountains. In Tibet, the Indus River relies mostly on water from melting snow and glaciers in the Karakoram and Hindu Kush mountain ranges, rather than from the Tibetan plateau or rain. The Indus River gains most of its water as it flows through the Ladakh and Gilgit-Baltistan regions, where major rivers like the Zanskar, Shyok, and Gilgit join the main Indus River. Because of this, the Indus River has few large projects. One example is the Shiquanhe Hydropower Station, a small run-of-the-river project near Shiquanhe with a capacity of about 6 megawatts. Another is the Zanda Hydropower Project, a small run-of-the-river project on the Sutlej River, a major tributary of the Indus, located in Zanda County with a capacity of 0.8 megawatts.
In India, along the main Indus River, there are two major combined barrage and hydroelectric projects. The first is the Stakna Hydroelectric Project near Leh, a run-of-the-river project with a capacity of 4 megawatts. The second is the Nimoo-Bazgo Dam near Alchi village, a concrete gravity dam 57 meters tall with a gross capacity of 52.82 million cubic meters and a live capacity of 1.12 million cubic meters, generating 45 megawatts of electricity.
In Pakistan, there are currently six barrages on the Indus River: Guddu Barrage, Sukkur Barrage, Kotri Barrage (also called Ghulam Muhammad Barrage), Taunsa Barrage, Chashma Barrage, and Jinnah Barrage. A new barrage called the Sindh Barrage is planned as a terminal structure on the Indus River. Several bridges cross the Indus River, including the Dadu Moro Bridge, Larkana Khairpur Indus River Bridge, Thatta-Sujawal Bridge, Jhirk-Mula Katiar Bridge, and a recently planned Kandhkot-Ghotki Bridge.
The entire left bank of the Indus River in Sindh province is protected from flooding by a system of levees that stretch about 600 kilometers. The right bank is also protected by levees from the Guddu Barrage to Lake Manchar. However, the construction of these levees has caused the river to build up sediment rapidly over the past 20 years, leading to breaches upstream of barrages and flooding in large areas.
In Pakistan, the Tarbela Dam is built on the Indus River. A controversial proposal for the Kalabagh Dam has also been made on the Indus River. Additionally, Pakistan is constructing the Munda Dam on the Swat River.
Tourism
Many Buddhist monasteries in Ladakh, ancient sites from the Indus-Sarasvati Valley Civilization along the Indus and Sarasvati (Ghaggar-Hakra) rivers, and areas like the Indus Sagar Doab and Indus River Delta offer tourism opportunities. These include places such as the Baglihar Dam, the annual Sindhu Darshan Festival in Leh, and the Sindhu Pushkaram Festival, which happens every 12 years at the meeting point of the Indus and Zanskar rivers near Nimoo. The Sindhu Pushkaram Festival lasts 12 days and begins when the planet Jupiter enters the Aquarius constellation.
The Sindhu Darshan Festival is a 3-day event held in June at Sindhu Ghat, located 9 kilometers southeast of Leh city near Shey. It celebrates the Sindhu (Indus) River, which is an important historical symbol in India and has been honored since ancient times. The Bollywood movie Dil Se was filmed during the first Sindhu Darshan Festival in October 1997.