In less than a fortnight, water supply from the four city reservoirs will stop, as storage has hit rock bottom. Chennai Metrowater has started tapping water from private agricultural wells in Tiruvallur district to offset the widening gap between demand and supply.
From June, the city has to brace for a decrease in the volume of drinking water supply by 50 million litres a day (mld) after the drawal from reservoirs is stopped. Chennai Metrowater now supplies 550 mld per day through pipelines and tankers. Water drawal from the Cholavaram reservoir through the giant pipeline stopped recently as the waterbody went bone dry.
The four reservoirs have a combined storage of 306 million cubic feet as on Friday. This is one of the worst scenarios in recent years. Metrowater officials recalled that the storage position in reservoirs was better with 729 mcft even on May 3, 2017, the year when the city experienced one of its worst droughts in 140 years.
In a bid to tackle the worsening water crisis in Chennai, Metrowater has started tapping water from private agricultural wells in Tamaraipakkam and Minjur regions. The water agency has identified nearly 300 wells from where up to 90 mld would be drawn for city supply. For now, about 50 mld is being extracted from agricultural wells, apart from 40 mld supplied from Metrowater-owned wells.
Metrowater is also preparing to draw from agricultural wells near Poondi, at the rate of nearly ₹3 per kilolitre, later this month. Water extracted from Tamaraipakkam and Poondi would be sent through a pipeline to Red Hills for treatment and distribution, said an official.
Quarries in Erumaiyur
One more source would be added soon, as work to pump 10 mld of water collected in abandoned quarries in Erumaiyur near Tambaram started on Friday. Officials said nearly 10 mld would be supplied from the five quarries here from June. Water from here too would be transported to Chembarambakkam treatment plant for supply. “We have tested the quality of raw water that has a total dissolved solid level of less than 100 mg/1. It is considered excellent for drinking,” said an official.
With other sources, such as desalination plants, Veeranam tank and borewells in Paravanar basin, Metrowater plans to sustain the drinking water supply at 500 mld till November.