Groundwater table has dipped in several places across the city over the past year.

The water level is now at an average of 4.70 metre, which is 0.5 metre lower than last year, according to a study conducted by Metrowater. The prolonged dry weather and inadequate rains have led to the drop in the water table.

Residents of several years are heavily dependant on tanker lorry supply as the water level in their wells has dipped and also turned saline in some pockets such as Okkiyam Thoraippakam and Ambattur. Residents of Ambattur said borewells were being dug deeper to cope with the shortage.

According to a Metrowater official, the water table in some areas such as Valrasaravakkam, Ambattur and Perungudi has seen the worst dip this May. The ground in these areas is composed of hard rock and clay that make percolation of water difficult.

The water levels vary depending on the soil condition and density of population.

The quality of groundwater too has deteriorated. The total dissolved solids in the water ranged between 900 and 1,900 parts per million (ppm) — 200 ppm more than last year — in various localities. The desired limit for drinking water is 500 ppm. (Metrowater collates data collected from 145 observation wells for its monthly study.)

As part of its effort to improve groundwater table levels, Metrowater has started a campaign to encourage residents to harness rainwater. Officials of Metrowater said pamphlets on the importance of maintaining rainwater harvesting structures are being distributed.

“We plan to cover 7.40 lakh buildings during the campaign. Rallies and meetings will also be organised to create awareness about RWH,” said an official. A team of officials also plans to inspect rainwater harvesting structures in residential and commercial buildings.

Release of Krishna water

Residents concerned with dipping groundwater levels and dwindling storage in reservoirs may enjoy some respite soon. Krishna water from Kandaleru reservoir in Andhra Pradesh will be released on June 30 and reach the city by July 2 or 3.

R. Emaraj, chief engineer, Water Resources Department (Chennai region), who inspected the Kandaleru-Poondi canal on Friday, said the work to provide a temporary channel to ensure the free flow of Krishna water is nearing completion. Water would be diverted through this channel until the damaged portion of the canal in Ubbalamadugu, Andhra Pradesh, is repaired.

About 500 cubic feet of water per second (cusecs) would be released to the city. That amounts to 1,200 million litres of water a day and will the supply of drinking water in the city.

A team comprising the secretary of municipal administration and water supply, Phanindra Reddy, and managing director of Metrowater, B. Chandramohan, inspected the repair work on the canal, said Mr. Emaraj.

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