The Chennai Metro Water Supply and Sewerage Board (CMWSSB) on Monday told the Madras High Court that though it supplies 830 million litres of water a day in the city during a normal season, it reduced the quantum to 525 MLD since June 1 due to severe shortage of rainfall.
Justices S. Manikumar and Subramonium Prasad were told that the water supply was maintained at 550 Millions of Litres per Day (MLD) between January 1 and May 31 and had to be reduced since June 1. Deficit rainfall from 2017 and consequent depletion in storage capacity of reservoirs were cited as reasons for reduction in water supply.
The judges had last week directed Additional Government Pleader E. Manoharan to obtain these details during the hearing of a random case related to alleged mixing of sewage in a water channel in Vellore district. They wanted to know how was the CMWSSB exactly managing the acute water crisis in the city.
Filing a detailed affidavit in compliance of the court order, CMWSSB Chief Engineer S. Arumugam said the board had been entrusted with the responsibility of providing safe drinking water and ensuring safe disposal of sewage generated within the Corporation area spread over 426 square km and covering a population of 74.38 lakh.
The services were offered through 200 depot offices of the board. The CMWSSB was operating water treatment plants at Kilpauk, Redhills, Chembarambakkam, Surapattu and Vadakuthu. It also had two desalination plants at Minjur and Nemmeli. Together, all of them could totally handle 1,494 MLD.
Pitiable storage level
However, highlighting the pitiable storage level of the reservoirs around Chennai, the board said the Poondi reservoir now had just 26 mcft of water as against its capacity of 3,231 and the Cholavaram and Redhills reservoirs had absolutely no water at all as against their storage capacity of 1,081 and 3,300 mcft respectively.
The storage capacity of Chembarambakkam too was a negligible 1 mcft through its storage capacity was 3,645 mcft. On the whole, the four major reservoirs situated around the city had just 27 mcft of water as on Sunday (June 16, 2019) though their total storage capacity was as high as 11,257 mcft.
The Veeranam lake in Cuddalore district was the only promising source as it had 569 mcft of water as against its capacity of 1,465 mcft. Out of the supply of about 500 MLD maintained by CMWSSB at present, 180 MLD was met with water from Veeranam as well as the Neyveli Lignite Corporation aquifer.
Another 180 MLD was met by the two desalination plants in operation at Minjur and Nemmeli. The board was also drawing 95 MLD from Tamaraipakkam, Poondi and Minjur agricultural wells; 10 MLD from Rettai Eri in Kolathur and 35 MLD from the borewells dug by it at various places in the city, the Chief Engineer said.
Listing the short-term emergency drought mitigation measures taken by it, the board told the court that various works such as erection and rehabilitation of pumps, provision of High Density Polypropylene (HDPE) tanks, rehabilitation of public fountains and erection of new borewells had been undertaken at a cost of ₹212.22 crore.
“By hiring 900 water lorries, 9,400 lorry trips a day are being made in Chennai city and it is the highest in the history of CMWSSB. Further, 2,000 and 3,000 litre tanker mini lorries were introduced for the first time during 2019 to supply water to narrow streets... totally, 12,129 HDPE tanks are functional in the city and it is also the highest,” the affidavit read. In so far as intermediate measures were concerned, the CMWSSB told the court that it had undertaken a feasibility study to establish modular desalination plants of 1 MLD to 5 MLD capacity at various locations in the city. In the long-term, steps had been taken to establish two more regular desalination plants for the city.
One of the two plants with a capacity of 150 MLD was expected to be commissioned by 2021 at Nemmeli and another with a capacity of 400 MLD was expected to come up at Perur by 2024, the court was informed. The CMWSSB also said that steps were under way to rejuvenate as many as 210 waterbodies in the city.
After perusing the affidavit, the judges directed the AGP to obtain instructions by Tuesday on the capacity of the existing desalination plants and the quantum of water that was actually getting desalinated over there on a daily basis.