The correct answer is Satluj River. Explanation & Key Takeaways: Satluj River • The Satluj originates in the Raksas Tal near Mansarovar at an altitude of 4,555 m in Tibet. • it is known as Langchen Khambab in Tibet. • It flows almost parallel to the Indus for about 400 km before entering India and comes out of a gorge at Rupar. • It passes through the Shipki La on the Himalayan ranges and enters the Punjab plains. • It is an antecedent river. • It is a very important tributary as it feeds the canal system of the Bhakra Nangal project. Hence option 2 is correct Related Concepts: Beas River • The Beas is an important tributary of the Indus, originating from the Beas Kund near the Rohtang Pass at an elevation of 4,000 m above the mean sea level. • The river flows through the Kullu valley and forms gorges at Kati and Largi in the Dhaoladhar range. • It enters the Punjab plains where it meets the Satluj near Harike. Ravi River • The Ravi is an important tributary of the Indus. • It rises west of the Rohtang pass in the Kullu hills of Himachal Pradesh and flows through the Chamba valley of the state. • Before entering Pakistan and joining the Chenab near Sarai Sidhu, it drains the area lying between the southeastern part of the Pir Panjal and the Dhauladhar ranges. Chenab River • The Chenab is the largest tributary of the Indus. • It is formed by two streams, the Chandra and the Bhaga, which join at Tandi near Keylong in Himachal Pradesh. Hence, it is also known as Chandrabhaga. • The river flows for 1,180 km before entering into Pakistan. Jhelum River • The Jhelum, an important tributary of the Indus, rises from a spring at Verinag situated at the foot of the Pir Panjal in the southeastern part of the valley of Kashmir. • It flows through Srinagar and the Wular lake before entering Pakistan through a deep narrow gorge. • It joins the Chenab near Jhang in Pakistan. Indus River System • It is one of the largest river basins in the world, covering an area of 11,65,000 sq. km (in India it is 321,289 sq. km and a total length of 2,880 km (in India 1,114 km). • The Indus also known as the Sindhu, is the westernmost of the Himalayan rivers in India. • It originates from a glacier near Bokhar Chu (31°15' N latitude and 81°40' E longitude) in the Tibetan region at an altitude of 4,164 m in the Kailash Mountain range. • In Tibet, it is known as ‘Singi Khamban; or Lion’s mouth. • After flowing in the northwest direction between the Ladakh and Zaskar ranges, it passes through Ladakh and Baltistan. • It cuts across the Ladakh range, forming a spectacular gorge near Gilgit in Jammu and Kashmir. It enters into Pakistan near Chilas in the Dardistan region. • Left Bank Tributaries: Zanskar River, Suru River, Soan River, Jhelum River, Chenab River, Ravi River, Beas River, Sutlej River, Panjnad River, Ghaggar- Hakra River, Luni River. • Right Bank Tributaries: Shyok River, Hunza River, Gilgit River, Swat River, Kunar River, Kabul River, Kurram River, Gomal River, Zhob River. • The river flows southward and receives ‘Panjnad’ a little above Mithankot. • The Panjnad is the name given to the five rivers of Punjab, namely the Satluj, the Beas, the Ravi, the Chenab and the Jhelum. • It finally discharges into the Arabian Sea, east of Karachi. • The Indus flows in India only through Jammu and Kashmir. Indus Water Treaty • The Indus water treaty is the water distribution treaty signed between India and Pakistan in 1960. • It was brokered by the World Bank. • The Indus water treaty deals with the river Indus and five tributaries, which are classified into 2 categories. • Eastern rivers: • Sutlej • Beas • Ravi • Western rivers: • Indus • Jhelum • Chenab • As per the treaty, all the water of the eastern rivers shall be available for unrestricted use in India. • India should let the unrestricted flow of water from western rivers to Pakistan. It doesn’t mean that India cannot use western rivers. • As per the treaty, India can use the western rivers' waters for non-consumptive needs, like irrigation, storage and electricity production. • The treaty allocates 80% of the water from the six rivers to Pakistan. • A permanent Indus commission was set up as a bilateral commission to implement and manage the treaty. • Even though Indus originates from Tibet, china has been kept out of the IWT. • The mainstream of Indus flows only through the Union Territory of Ladakh. • Approximately a third of the Indus basin is located in India Ladakh, Jammu and Kashmir, Himachal Pradesh and Punjab and the rest is in Pakistan.