Chembarambakkam reservoir gets infrastructure overhaul ahead of Northeast monsoon

In a move to prepare Chembarambakkam reservoir for peak inflow during the ensuing Northeast monsoon, the Water Resources Department has fast-tracked restoration efforts of reservoir infrastructure and ensure stability.

One of the five major reservoirs feeding Chennai’s drinking water needs, the water body is spread over 25.51 sq.km. and now has 41.15% of its storage capacity of 3,645 million cubic feet.

Officials of the WRD said efforts to step up the reservoir storage by transferring water from other lakes have been suspended to facilitate work on strengthening the reservoir’s damaged infrastructure. The project would be over before the onset of the NE monsoon.

With the largest storage capacity among the city’s drinking water reservoirs, the water body has endured the onslaught of extreme weather events over the past decade.

“We have carried out temporary works to fix the damage caused by heavy rainfall episodes. But the Rs.22.95 crore project aims at providing permanent restoration of the flood-damaged infrastructure,” said an official.

Nearly 266 million litres a day (mld) of water is being pumped and treated at the Chembarambakkam water treatment plant for city water distribution. A marginal amount of water is discharged for irrigation.

Residents noted that the reservoir was a major source of groundwater recharge and still fed agricultural needs. Improving its infrastructure was essential to stave off the threat of flooding in areas along the Adyar river.

M.Elango, a resident of Chembarambakkam, said the maintenance work of the reservoir must be carried out periodically without such long breaks to withstand the impact of extreme weather events. The authorities must also take measures to arrest sewage inflow into the reservoir from neighbouring localities and Irungattukottai.

Residents also wanted inlet channels bringing water from catchment areas to be improved.

The WRD is now carrying out work to repair the damaged parapet wall on the top layer of the bund. Work is in progress to strengthen the foreshore bund. “We will also start work in a few days to replace the stone pitching in the interior portion of the bund slope. The slope protection work will be carried out near the shutters as it was heavily affected by intense wave action during the NE monsoon during the past two years,” said an official.

The department would also construct a skin wall, an additional concrete outer layer, over the existing surplus weir structure to prevent seepage loss. Flood protection wall for a length of 120 metre near the vents would be constructed. Desilting exercise has been put off till next summer.