Groundwater leakage worries BMC

Water is leaking out from the ground in Azad Maidan near CST and Marine Lines. The Brihanmumbai Municipal Corporation (BMC), which took note of the surface run-off recently, has now asked a consultant geologist to look into what might be causing the phenomenon.

SK Gupta, a consultant geologist who has already inspected the area along with BMC’S hydraulic department officials, said that the surface run-off is the result of saturation of the groundwater aquifer, an underground layer that holds water within soil, porous rock, or similar material.

“This phenomenon is termed rejected recharge. The water table in south Mumbai is shallow. A rainfall above 500mm is sufficient to fill it to capacity,” Gupta said.

The area has already seen rainfall in excess of 2,200mm. “The additional water received in the form of rain is being rejected by the ground. This is causing the run-off,” Gupta added.

A former deputy director of the Groundwater Surveys and Development Agency (GSDA), Gupta said that a report will be submitted to the BMC in the next few days.

The hydraulic department, meanwhile, has begun planning ways to stem the surface run-off. “We will have to ensure that the ground water table declines,” a senior engineer said.

One of the measures being discussed is digging an open well near Metro Cinema. “This will help extract 50,000 litres of groundwater daily. As the water table decreases, the aquifer will begin accepting rainwater again,” the engineer said.

The water drawn from the well could be diverted to the railways to reduce their dependence on drinking water supplies for secondary purposes, the engineer added.