Yamuna
Current channel

The river flows southwards for about 200 kilometres (120 mi), through the Lower Himalayas and the Shivalik Hills Range. Morainic deposits are found along the steep Upper Yamuna, highlighted with geomorphic features such as interlocking spurs, steep rock benches, gorges and stream terraces. Large terraces formed over a long period of time can be seen in the lower course of the river, such as those near Naugoan. An important part of its early catchment area, totalling 2,320 square kilometres (900 sq mi), lies in Himachal Pradesh. The Tons, Yamuna's largest tributary, drains a large portion of the upper catchment area and holds more water than the main stream. It rises from the Hari-ki-dun valley and merges after Kalsi near Dehradun. The drainage system of the river stretches between Giri- Sutlej catchment in Himachal and Yamuna- Bhilangna catchment in Garhwal, also draining the ridge of Shimla. Kalanag (6,387 metres) is the highest point of the Yamuna basin. Other tributaries in the region are the Giri, Rishi Ganga Kunta, Hanuman Ganga and Bata, which drain the upper catchment area of the Yamuna basin.

From the upper catchment area, the river descends onto the plains of Doon Valley, at Dak Pathar near Dehradun. Flowing through the Dakpathar Barrage, the water is diverted into a canal for power generation. Further downstream, the Assan River joins the Yamuna at the Asan Barrage, which hosts a bird sanctuary. After passing the Sikh pilgrimage town of Paonta Sahib, the Yamuna reaches Tajewala in Yamuna Nagar district (named after the river) of Haryana. A dam built here in 1873 is the origin of two important canals, the Western and Eastern Yamuna Canals, which irrigate the states of Haryana and Uttar Pradesh. The Western Yamuna Canal (WYC) crosses Yamuna Nagar, Karnal, Panipat and Sonipat before reaching the Haiderpur treatment plant, which contributes to Delhi 's municipal water supply. The Yamuna receives wastewater from Yamuna Nagar and Panipat cities; beyond this it is replenished by seasonal streams and groundwater accrual. During the dry season, the Yamuna remains dry in many stretches between the Tajewala dam and Delhi, where it enters near the Palla barrage after traversing 224 kilometres (139 mi).

The Yamuna defines the state borders between Himachal Pradesh and Uttarakhand, and between Haryana, Delhi and Uttar Pradesh. When the Yamuna reaches the Indo-Gangetic plain, it runs almost parallel to the Ganges, the two rivers creating the Ganges-Yamuna Doab region. Spread across 69,000 square kilometres (27,000 sq mi), one-third of the alluvial plain, the region is known for its agricultural output, particularly for the cultivation of basmati rice. The plain's agriculture supports one-third of India's population.

Subsequently, the Yamuna flows through the states of Delhi, Haryana and Uttar Pradesh before merging with the Ganges at a sacred spot known as Triveni Sangam in Prayagraj. Pilgrims travel by boats to platforms erected in midstream to offer prayers. During the Kumbh Mela, held every 12 years, large congregations of people immerse themselves in the sacred waters of the confluence. The cities of Baghpat, Delhi, Noida, Mathura, Agra, Firozabad, Etawah, Kalpi, Hamirpur, and Prayagraj lie on its banks. At Etawah, it meets it another important tributary, Chambal, followed by a host of tributaries further down, including, Sindh, the Betwa, and Ken.
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