<P> Other tributaries in the region are the Giri, Rishi Ganga, Kunta, Hanuman Ganga and Bata tributaries, which drain the Upper Catchment Area of the vast Yamuna basin . Thereafter the river descends on to the plains of Doon Valley, at Dak Pathar near Dehradun . Here through the Dakpathar Barrage, the water is diverted into a canal for power generation, little further down where Yamuna is met by the Assan River, lies the Asan Barrage, which hosts a Bird Sanctuary as well . After passing the Sikh pilgrimage town of Paonta Sahib, it reaches Tajewala in Yamuna Nagar district (named after the river itself), of Haryana, where a dam built in 1873, is the originating place of two important canals, the Western Yamuna Canal and Eastern Yamuna Canal, which irrigate the states of Haryana and Uttar Pradesh . The Western Yamuna Canal (WYC) crosses Yamuna Nagar, Karnal and Panipat before reaching the Haiderpur treatment plant, which supplies part of municipal water supply to Delhi, further it also receives waste water from Yamuna Nagar and Panipat cities . Yamuna is replenished again after this by seasonal streams and groundwater accrual, in fact during the dry season, it remains dry in many stretches from Tajewala till Delhi, where it enters near Palla village after traversing 224 kilometres (139 mi). </P> <P> The Yamuna also creates natural state borders between the Himachal Pradesh and Uttarakhand states, and further down between the state of Haryana, Delhi and Uttar Pradesh . Along with the Ganges to which run almost parallel after it touches the Indo - Gangetic plain, the largest alluvial fertile plain in the world, it creates the Ganges - Yamuna Doab region spread across 69,000 square kilometres (27,000 sq mi), one - third of the entire plain, and today known for its agricultural outputs, prominent among them is the cultivation of Basmati Rice . The plain itself supports one - third of India's population through its farming . </P> <Table> <Tr> <Th> State </Th> <Th> Catchment area (km) </Th> <Th>% of catchment area </Th> </Tr> <Tr> <Td> Uttar Pradesh and Uttarakhand </Td> <Td> 74,208 </Td> <Td> 21.5% </Td> </Tr> <Tr> <Td> Himachal Pradesh </Td> <Td> 5,799 </Td> <Td> 1.6 </Td> </Tr> <Tr> <Td> Haryana </Td> <Td> 21,265 </Td> <Td> 6.5 </Td> </Tr> <Tr> <Td> Rajasthan </Td> <Td> 102,883 </Td> <Td> 29.8 </Td> </Tr> <Tr> <Td> Madhya Pradesh </Td> <Td> 14,023 </Td> <Td> 40.6 </Td> </Tr> <Tr> <Td> Delhi </Td> <Td> 1,485 </Td> <Td> 0.4 </Td> </Tr> </Table> <Tr> <Th> State </Th> <Th> Catchment area (km) </Th> <Th>% of catchment area </Th> </Tr>

Write the factors that have polluted the yamuna