The WRD has carried out work on the Red Hills reservoir after nearly two decades

The one-year-long project to strengthen the Red Hills reservoir, one of Chennai’s major sources for drinking water, is almost over. The work, which included plugging of holes in two masonry weirs and the strengthening and widening of the bund, was executed at a cost of Rs. 10.56 crore and is expected to be completed in two to three months.

It is after two decades that a major project was initiated by the Water Resources Department to strengthen the reservoir created in 1876. The reservoir that stretches over 20.86 square miles was originally a small tank with a capacity of 500 million cubic feet (mcft). In late 1990s, the storage was increased to 3,300 mcft to store Krishna water received from Andhra Pradesh.

The weirs, which were earlier used to release excess water, were replaced with two shutters a few decades ago. The two weirs on either side of the floodgates currently function as water retaining structures. While one of them has been repaired, work is on to strengthen the other one that has turned porous over the years.

“We are also strengthening the main bund along GNT Road for a stretch of three km to prevent seepage. Whenever the water body reaches its full capacity, it loses one mcft every two or three days,” said an official.

Filter arrangements on the earthen bund are being provided to collect the seeping water and dispose it. The seepage would otherwise affect the structure. “We are also de-weeding some parts of the dry lake bed. Work is in progress to widen the bund from the existing five metres to 7.5 metres to make it more stable,” the official added.

The department is also installing gates near shutters and treatment plants to prevent people from entering the premises. Its boundary would be demarcated in vulnerable areas.

The reservoir is surrounded by encroachments into the waterspread area, including Bhanu Nagar in Ambattur, Thendral Nagar, Tirumullaivoyal, Kannapaswamy Nagar, Puzhal and Naravarikuppam. There are plans to survey encroachments in the neighbouring areas of the lake.

The department also proposes to fence off or construct a 20-km-long compound wall to protect vulnerable open waterspread areas. Inlets would be provided for water to flow from catchment areas.