Cholavaram reservoir, one of Chennai’s drinking water resources that was heavily impacted by cyclones and extreme weather events in the past, will be completely rejuvenated by this year end.

The Water Resources Department has sought funds to execute the second phase of work to strengthen the bund of the reservoir and reduce flood risk in the downstream areas. With the prime of the Northeast monsoon over and withdrawal likely in a few days, the department has accelerated the first phase of the project in the water body that suffered severe damage post cyclone Michaung in 2023.

Spread over 5.42 sq.km., the Cholavaram reservoir functions as a balancing reservoir between Tamaraipakkam anicut and Red Hills reservoir. It continues to receive a portion of the surplus water being released from Poondi reservoir located upstream. The reservoir got an inflow of 230 cubic feet per second (cusecs) through the upper supply channel on Monday.

The department plans to fill up to 50%-60% of the reservoir’s storage capacity of 1,081 million cubic feet.

Officials of the WRD said nearly 50% of the work, which is being executed at a cost of Rs. 40 crore, has been completed so far to improve critical portions of the bund and prevent leaks, erosion and ensure dam stability.

It may be recalled that the bund and parapet wall were affected for a length of nearly 1.2 km when the water body was filled to its brim. There have been several occasions in the past when portion of bund running for 200 metre had often developed cracks or slipped, including in 2014, 2015 and 2017.

Of the total bund length of 3.57 km, the department started work to improve nearly 1,050 metre last year. Building a diaphragm wall, which is a concrete wall built for a depth of six metre near the bund, is one of the major techniques being used to reinforce the bund and prevent seepage. This wall would help retain the lake bund’s stability even during extreme weather events.

Officials said the measures were being carried out to protect the bund against erosion due to wave action and withstand the hydraulic pressure. “We have sought an additional Rs.40 crore to start the second phase of the project as well and repair the remaining portion of the bund with a similar technique,” said an official. The reservoir would have the ability to store water to its capacity by this year-end.