The Ravi River () is a transboundary river crossing northwestern India and eastern Pakistan. It is one of five rivers associated with the Punjab region. Under the Indus Waters Treaty of 1960, the waters of the Ravi and two other rivers were allocated to India. Subsequently, the Indus Basin Project was developed in Pakistan, which transfers waters from western rivers of the Indus system to replenish the portion of the Ravi River lying in that country. Many inter-basin water transfers, irrigation, hydropower and multipurpose projects have been built in India. History According to ancient history traced to Vedas, the Ravi River was known as (). The Ravi was known as Purushni or Irawati to Indians in Vedic times and as Hydraotes () to the Ancient Greeks. Part of the Battle of the Ten Kings was fought on a river, which according to Yaska (Nirukta 9.26) refers to the Iravati River (Raavi River) in the Punjab. Geography The Ravi River, a transboundary river of India and Pakistan, is an integral part of the Indus River Basin and forms the headwaters of the Indus basin. The waters of the Ravi River drain into the Arabian Sea (Indian Ocean) through the Indus River in Pakistan. The river rises in the Bara Bhangal, Kangra District in Himachal Pradesh, India. The river drains a total catchment area of in India after flowing for a length of . Flowing westward, it is hemmed by the Pir Panjal and Dhauladhar ranges, forming a triangular zone. River course Source reach The Ravi River originates in the Himalayas in the Multhan tehsil of Kangra district of Himachal Pradesh, India. It follows a north-westerly course and is a perennial river. It is the smallest of the five Punjab rivers that rise from glacier fields at an elevation of , on the southern side of the Mid Himalayas. It flows through Barabhangal, Bara Bansu, and Chamba districts. It flows in rapids in its initial reaches with boulders seen scattered in the bed of the river. The Ravi River in this reach flows in a gorge with a river bed slope of and is mostly fed by snowmelt, as this region lies in a rain shadow. Two of its major tributaries, the Budhil and Nai or Dhona join downstream from its source. The Budhil River rises in Lahul range of hills and is sourced from the Manimahesh Kailash Peak and the Manimahesh