Storage in city lakes to improve after desilting

5.39 crore cubic metres of silt is expected to be cleared from the reservoirs

CHENNAI,TAMIL NADU, 15/12/2018: The sprawling waterbody in Chembarambakkam, which was brimming over with water after the deluge of 2015, is now a large patch of dry land and a grazing ground for cattle as it has hardly 7% of its total capacity in Chennai on December 15, 2018. Photo: B. Velankanni Raj

The three major lakes that supply drinking water to the city would soon have better storage capacity. After many deadlines, the long-pending project to desilt the waterbodies and carry out improvement work is set to begin in two months.

Following a recent government order, bids would be called next week for executing civil works in the lakes, including strengthening of the lake bund and improving channels that bring inflow to the waterbodies.

Work on in Cholavaram

The Water Resources Department has already started similar work in Cholavaram lake.

The lakes in Red Hills, Poondi and Chembarambakkam would be desilted perhaps for the first time in many decades.

Though the four water bodies are said to have a combined capacity of 11, 257 million cubic feet (mcft), they are able to store only 80% of water due to siltation during monsoon, said sources in the WRD.

Chembarambakkam reservoir, spread over 2,551 hectares, has been able to store 20% less than its original capacity due to silt deposits.

Besides loss of the precious resource that would ensure drinking water supply for one or two additional months, a shallow reservoir also leads to inundation of surrounding areas.

Officials of the WRD said two supply channels — Bangaru channel bringing water from Kosasthalaiyar and Cooum rivers and eight-km- long Chowdrikal channel would be desilted by May.

The vulnerable portions of these channels would be repaired.

The State government has sanctioned ₹4 crore towards the project.

Similarly, supply channels of Poondi reservoir from Nandhi and Nagari arms and Kesavaram anicut would also be improved apart from laying approach roads at a cost of ₹11 crore.

The department plans to execute a revenue generation model wherein the contractor would be allowed to sell silt removed from the four lakes.

Revenue to go up

The project to be implemented over a period of four years is expected to generate about ₹700 crore. Of this, silt cleared from Chembarambakkam reservoir would generate a revenue of ₹180 crore.

According to an earlier estimate, silt up to seven feet, or 5.39 crore cubic metres, is expected to be cleared from the reservoirs.

Meanwhile, residents of Red Hills demand that measures must be taken to arrest release of sewage from places, including West Balaji Nagar, Ambattur.