Rivers in Himachal Pradesh
Himachal Pradesh provides water to both the Indus and Ganges basins. The drainage systems of the region are the Chenab, the Ravi, the Beas, the Sutlej and the Yamuna. These rivers are perennial and are fed by snow and rainfall. They are protected by an extensive cover of natural vegetation. The Beas rises in the "Pir Panjal" range near the Rohtang Pass and flows about in Himachal Pradesh. The river is joined by a number of tributaries; the major tributaries are the "Parbati", the "Hurla", the "Sainj", the "Uhl", the "Suheti", the "Luni", the "Banganga" and  the "Chaki". The northern and eastern tributaries of the river are snow fed and perennial, while the southern ones are seasonal. During the month of August, increase in the inflow sometimes results in floods. The Chenab River (Vedic name Askni), the largest river (in terms of volume of water) is formed after the meeting of two streams namely, Chandra and Bhaga at Tandi, in Lahaul. It flows and covers an area of in Himachal Pradesh, before entering Jammu and Kashmir. The Chandra passes through the barren tribal land. The Ravi is born in Bara Banghal, Kangra district as a joint  stream formed by the glacier fead "Bhadal" and "Tantgari". The river is about long and has a catchment area of nearly . Chamba lies on its right bank. The Sutlej originates in distant Tibet. The river cuts through both the great Himalayan and the Zaskar ranges and crosses the Indo-Tibetan border (near Shipkila). Then the river Spiti joins Sutlej from the north, the Baspa joins it from the south. Passing through gorges it emerges from the mountains at Bhakra. The catchment area of Sutlej in Himachal Pradesh is about . The Yamuna has its origin in Yamunotri in Uttarkashi district, Uttarakhand . Its total catchment area in Himachal Pradesh is . Its tributaries are the "Tons", the "Giri" and the "Bata". Of these, Giri and Pabbar (a tributary of Tons) originate and flow in Himachal Pradesh. The Ghaggar river originates near the village of Dagshai in the Shivalik Hills of Himachal Pradesh at an elevation of above mean sea level and flows through Punjab and Haryana states into Rajasthan; just southwest of Sirsa, Haryana and by the side of Talwara Lake in Rajasthan.