Build Recharge wells to prevent waterlog: Expert

For a city that lacks a permanent solution to prevent waterlog during rains while people struggle to wade through stagnated water, experts suggest that well-maintained rainwater recharge wells may be a perfect solution to check flooding and recharge the groundwater as well.

Every year, during the Northeast monsoon, Chennaiites, especially those who live in low-lying areas have to live in knee-deep rainwater. To help them, officials from the Greater Chennai Corporation come with generators and motor pumps to force the water out. While this solution means well, it has little scientific approach in preventing inundation.

“Our locality gets flooded every monsoon and destroys our normal lives. Despite storm water drains in the area, water continues to stagnate. Since this has been happening over years, it’s high time that the corporation come up with a diversified solution,” said M Sivakumar, a resident of Kaliamman Koil Street near Koyambedu.

The officials from the civic body, however, has been sticking to only to construction storm water drains as the only solution, which has failed to provide relief in several areas.

“The drains are yet to be constructed in some parts of the city such as in Kosasthailyar and Kovalam basins, while there are some that need to be completed,” a sen ior official said.

Meanwhile, Sekhar Raghavan the director of Rain Centre, suggested that the groundwater recharge wells in the low-lying areas could reduce, if not prevent flooding. “Recharge wells have the ability to prevent waterlog if they are built on roads, especially in the flood-prone areas,” he said.

Raghavan added that the Rain Centre, with Mylapore MLA R Natraj and resident welfare association, has built nearly 40 recharge wells on the roads of Raja Annamalaipuram. “We cannot depend on engineering solutions only. The Chennai Corporation has been focussing only on building storm water drains and discharging the rainwater into the sea. These structures may lessen the impact, but cannot provide a permanent solution,” Raghavan said.

Meanwhile, a senior official said that Chennai in average is 2.5 metres above the sea level and low-lying areas such as Velachery, Kargil Nagar and others are located below the sea level and so they get flooded easily. “Once the soil gets saturated, rainwater does not enter the ground. In such a case, we must use motor pumps to force the water away,” the official added.

When asked about the possibility of building recharge wells, the official said that “letting stagnated water into the water table will pollute the groundwater”.

According to data obtained from the civic body, there are 205 spots in the city that are vulnerable to inundation. “We had 306 vulnerable spots last year and we have reduced the numbers by constructing storm water drains. Now, we have taken steps to post our staff in 22 subways round the clock to monitor the water level and to operate the pumps,” the official said.

While the Chennai Corporation spends hundreds of crores to build storm water drains, the Rain Centre has been building recharge wells at only Rs 19,500 per well. “Usually, our recharge wells are 15 feet deep with 3 feet diameter and it would cost not more than Rs 19,500,” Sekhar Raghavan, the director of the organisation, said. Explaining the structure of recharge wells, Raghavan said that the wells are left empty without sand or gravel. “If the officials make arrangements to let the rainwater to enter the recharge wells, there will be no inundation,” he said. Apart from recharge wells, Raghavan also suggested leaving gaps on both sides of roads in the areas like Besant Nagar, Choolaimedu and others, where the soil is sandy, so that the water can percolate easily.

Civic body started constructing missing link storm water drains at Rs 440 crore