The Yamuna River is the biggest tributary of the Ganga River. It is also considered as a sacred river in India. The Yamuna River originates from the Yamunotri Glacier near Banderpoonch peaks (38°59′ N 78°27′ E) in the Mussourie range of the lower Himalayas at an elevation of about 6,387 meters above the mean sea level in district Uttarkashi (Uttarakhand).
A hot water pool is present at Yamunotri and the water is so hot that people cook rice and potato by putting them in cloth bags and dipping the bag in the hot water. Arising from the source, the Yamuna River flows through a series of valleys for about 200 km in lower Himalayas and then emerges into Indo-Gangetic plains. In the upper reaches, the main valley is overlooked by numerous hanging valleys, carved by glaciers. The gradient of the river is steep here and the entire geomorphology of the valley has been carved by the erosive action of the river water. In the headwater reach of 200 km, Yamuna draws water from several major streams. The combined stream flows through the Shivalik range of hills of Himachal Pradesh and Uttarakhand states of India and enters into plains at Dak Pathar in Uttarakhand where the river water is regulated by a weir and is diverted into a canal for power generation. On the right side of the Yamuna basin is the Mussourie spur-along which lies the sprawled hill station of Mussourie (also known as the Queen of Himalayas).
From Dak Pathar, the Yamuna flows through the famous Sikh religious shrine of Poanta Sahib. Figure 9 shows the bed of Yamuna River near Dak Pathar. Flowing through Poanta Sahib, it emerges from the foothills of Kalesan, north of Tajewala. It reaches Hathnikund/Tajewala in the Yamuna Nagar district of Haryana state, where the river water is diverted into Western Yamuna canal and Eastern Yamuna canal for irrigation. During dry season, practically no water flows in the river downstream of Tajewala barrage and the river remains dry in several stretches between Tajewala and Delhi. Ground water accrual and contributions from seasonal streams again regenerate the river. Yamuna River enters Delhi near Palla village after traversing for about 224 km.
A canal known as the Satluj Yamuna link (SYL) canal joining Satluj with Yamuna is under construction here. This canal was to transfer Haryana’s share of 3.5 MAF of water from the Indus basin. The state of Haryana has completed its portion of the canal but Punjab is yet to complete its portion. Punjab Government is not in favour of construction of this canal. Recently, the Punjab legislature passed an act known as the Punjab Termination of Agreement Act 2004 whereby the earlier agreements have been declared as null and void.
Further downstream, there is a barrage at Wazirabad which supplies drinking water to the city of Delhi. Generally, the flow in the river downstream of the Wazirabad barrage is almost nil in dry season because the available water is not adequate to meet the demand of Delhi. Yamuna River flow downstream of the Wazirabad barrage largely consists of untreated or partially treated domestic and industrial wastewater contributed by numerous drains along with the water transported by Haryana Irrigation Department from the Western Yamuna Canal (WYC) to the Agra Canal via the Nazafgarh Drain and the Yamuna. About 22 km downstream of the Wazirabad barrage, the Yamuna water is diverted into the Agra Canal for irrigation through the Okhla barrage. Generally, water flow through the barrage during the dry season is nil. Whatever water flows in the river beyond the Okhla barrage is contributed through domestic and industrial wastewaters generated by East Delhi, Noida and Sahibabad and joins the river through the Shahdara drain