Patna, June 6 : Collapse of Khagaria-Bhagalpur bridge over the Ganga river will have a long-lasting effect on the water biodiversity of the region, as per environmental experts. Ashok Ghosh, the professor of Mahavir Cancer Institute and former chairman of Bihar state pollution control board told IANS: "Such a big chunk of concrete structure falling into the Ganga will have a big environmental effect for a long time. It will deeply hurt the water biodiversity of the river in this region. The water-borne animals will be adversely affected by it." "Unlike silt, the concrete structures used in the making bridges are non biodegradable materials. Hence, there is no question of the concrete structures dissolving in water. The iron rods may turn into rust after coming in contact with water but it is a slow process which takes years. Also, the ongoing projects of cleaning the river will also suffer a big jolt due to the bridge collapse," Ghosh said. The concrete structures of such a massive amount change the flow of the river as well. It makes the river more shallow in the region which leads to flooding. Khagaria in particular is affected by floods in the monsoon sessions. The fresh structural disaster would create more trouble for people living in the region," Ghosh said. Bihar is located in the low lying area of Himalayan range. As a result, a large number of rivers like Kosi, Kamla Balan, Gandak, Parman, originate from Himalaya and its water cross various North Bihar districts to finally fall in Ganga river. The biggest challenge of the state government is the silt carried by these rivers and its accumulation in the low-lying areas of North Bihar and in the Ganga river. It makes the rivers more shallow by disturbing the natural drains. It turned worse after the drainage system of various districts were developed in an unplanned manner. The water comes from the Himalayan range but does not return or exit to other sides due the ill drainage system. /IANS