If you see Corporation workers laying a structure made up of precast concrete rings on your street, close to a vacant land or at a park, count yourself lucky. The civic body has identified 74 areas in Chennai for laying these structures, called “baby wells”, and yours is clearly one of them.
This exercise is being carried out by the Greater Chennai Corporation (GCC) over two years under its Integrated Stormwater Management Planning. These baby wells benefit residents in two ways — preventing inundation and recharging the groundwater table.
Localities with a higher rate of rainwater percolation have been chosen for this project. “We have completed work at 23 localities in the city; work on the remaining areas is under way,” says a Corporation official.
What’s a baby well?
A baby well is nothing but a recharge well. It is usually a precast cement ring-lined structure, with a minimum diameter of three feet and depth of 10 feet. It takes water from the driveway/ road, filters and sends it underground, thereby replenishing the groundwater table.
Sekhar Raghavan, Director of Rain Centre, says these structures should not be confused with recharge pits, which have not been very effective. “Recharge wells are empty baby wells. These wells are better installed at street corners, the risk of damage due to movement of vehicles is low here,” he says.
“We are linking the recharge wells to the stormwater drains,” said the official.
According to experts, when soil profile is extremely favourable, a well-designed recharge well can send million litres of water into the ground, annually.
Accumulation of silt and muck is among the challenges faced while maintaining these structures.
“Well-maintained structures can sometimes be 90% effective during monsoon,” says Raghavan, adding that they should be cleaned periodically, especially before the onset of monsoon.