of Bengal near Sagar Island in the South 24 Parganas district. Numerous rivers flow eastwards through West Bengal and join the Bhagirathi on the right bank. These include: The Mayurakshi River—which is fed by the Brahmani, Dwarka, Bakreshwar, and Kopai—joins the Bhagirathi near Kandi, Murshidabad. The Ajay River, which rises in the hills of Bihar and is joined by the Kunur, flows down the plateau fringe, marking the boundary between Bardhaman and Birbhum districts and joining the Bhagirathi near Katwa. The Damodar River joins the Bhagirathi near Uluberia. The river is also known as "the sorrow of Bengal", and controlled by the Damodar Valley Project. The Dwarakeswar and Shilabati rivers join to form the Rupnarayan River. The Kangsabati and Keleghai rivers join to form the Haldi River. The Rupnarayan and Haldi then join the Bhagirathi in the East Midnapur district. The Subarnarekha River, after flowing for a short distance in West Bengal, re-enters into Orissa. Similarly, several rivers flow westwards into West Bengal and join the Bhagirathi on its left bank. These include: The Bhairab River and the Jalangi River, which join together (then known as Jalangi) before joining the Bhagirathi. The Mathabhanga River, which divides into two branches: the Churni and Ichhamati. The Churni meets the Bhagirathi, while the Ichhamati flows southwards and joins the Kalindi River. These rivers carry with them plenty of water, keeping the Bhagirathi River submerged with water throughout the year. The rivers also carry silt and sand eroded from the western plateaus and deposit them in the Bhagirathi. This silting causes trouble for the Kolkata Port and often causes flooding during years of heavy rain. The Sunderbans region is covered by numerous estuaries and streams, mainly distributaries of main rivers. The rivers are interconnected and are fed by tidal waters. The major rivers of the area are the Hooghly, Matla, Gosaba, Saptamukhi, Haribhanga, Piyali, Thakuran (or Jamira), Raimangal, Kalindi, and Ichhamati. The Teesta River cuts deep gorges from north to south in the mountainous Darjeeling district. It then enters the plains at Sevoke and flows in a mighty stream in a straight line towards the southeast, until it pours into the Brahmaputra River in Bangladesh. The Torsa, Jaldhaka, Kaljani, Raidak, Sankosh, and Mahananda rivers originate in the northern hilly region which rise in the Himalayas and flow in a southerly direction through the districts of Darjeeling, Alipurduar, Jalpaiguri, Cooch Behar and North and South