Corporation scrapes Cauvery bed for summer water supply

Five borewells being drilled near Kambarasampettai Head Works

Mayor A. Jaya, right, inspecting the digging of borewell on the dry Cauvery river bed at Kambarasampettai pumping station, Tiruchi, on Wednesday. Photo: M. Moorthy

The Cauvery river bed has turned bone dry and the water table in the city has slumped already. With a long summer ahead, the Tiruchirapalli City Corporation is gearing up to meet the city’s drinking water requirements over the next three or four months by sinking five additional deep borewells on the riverbed to maintain the current level of supply.

The giant borewells are being sunk around the Kambarasampettai Head Works, one of the city’s main drinking water sources, at an expenditure of Rs. 55 lakh. The borewells are expected to yield about 10,000 litres per minute (LPM) and help the civic body see through the summer.

Down the years, the corporation had sunk a series of borewells around the collector wells of the water schemes feeding the city from the Cauvery river.

Twenty one borewells have been sunk around the Kambarasampettai Headworks to supplement the yield from the main collector well. The borewells have been contributing up to 30 million litres of water a day. But at least four of them, sunk in the late 1990s, have dried up.

The additional borewells are being sunk now in view of the possibility of the water table going down further at the height of the summer. The corporation is digging deeper this time.

The five new borewells are being sunk for a depth of 60 feet. In normal times, water will be available on the riverbed at a depth of just 10 feet. But with the river going dry since December, after the storage level at the Mettur reservoir depleted, water is now available only at a depth of 20 feet.

Currently, the city gets about 90 million litres a day (MLD), mostly from the Cauvery bed.

The Rs. 221.42-crore new drinking water augmentation scheme, with its source at Coleroon river, is expected to become operational at least by next month and ensure a comfortable position by providing an additional 60 MLD of water to the city.

On Thursday, Mayor A. Jaya, accompanied by Executive Engineer R. Chandran, took stock of the situation and inspected the work on sinking borewells at Kambarasampettai.

Later, she said that the work was under way on sinking 50 borewells, all fitted with hand pumps, in areas facing short supply in the city at a cost of Rs. 40,000 each. Ten others with power pumps were coming up.

Arrangements are on to supply water through tankers to fill an additional 50 PVC tanks.

Five new generators are to be acquired, at an investment of Rs. 1.18 crore, to keep the corporation’s water pumping stations and sumps running at times of load-shedding. All these works are to be executed at a cost of Rs. 3.59 crore, which includes a grant of Rs. 3.44 crore sanctioned by the State government for drought relief work. All the works to augment water supply are to be completed by this month end.