NEW DELHI: Large-scale illegal sand mining could be changing the face of Noida in many ways. Experts say it is likely to deplete and pollute groundwater, ruin river bank ecology and alter the course of the river. Some of these effects are already being felt.
Scientists are particularly worried about groundwater in Noida. "While the construction sector cannot do without sand, we have to understand that sand acts as a filter," says Saumitra Mukherjee (geology and remote sensing expert), School of Environmental Sciences, Jawaharlal Nehru University. "It's a permeable layer that holds water and facilitates groundwater recharge. It also filters the pollutants from the river water. If the layer of sand is missing, our groundwater can be highly polluted. It would become a saline patch if the water is not able to percolate through and that will affect agriculture as well." He recommends regulated mining in places where the sand deposition is more and leaving the present mining areas to recover.
The UP ground water department's data shows Noida's water table is going down at a rate of 70cm per year, while in Greater Noida the rate is 20cm per year. After conducting a study, the Jamia Millia University wrote to the Noida Authority in 2011 about the falling groundwater levels. The letter states that the water level was in the range of 10-19 feet when Noida was commissioned but has gone down to 70-123 feet.
Sand mining has also affected the ecology of the river bed, which is home to many small organisms and plants. "Mining immediately destroys the habitat of these small organisms which are crucial for maintaining a healthy river ecology," says Chandra Bhushan, deputy director general, Centre for Science and Environment (CSE). Unchecked mining also weakens infrastructure like flyovers and bridges as they remain exposed due to erosion, he says.
"Sand is an integral substance for river ecology. It has a structural functioning of maintaining boundaries. So large-scale extraction weakens the boundary and destabilizes life in a river... In Chambal and Ganges rivers, gharials and turtles need sand for basking and nesting sites," says Asghar Nawab, Project Coordinator (River Basin) Freshwater & Wetlands Programme, WWF. He fears that turtles that nest along the Hindon may be very badly affected. "The Hindon has a good habitat for turtles but a lot may have been destroyed".
