Desperate times call for desperate measures.
The Brihanmumbai Municipal Corporation (BMC) has decided to desilt the Tansa lake, for the first time in 118 years, hoping it will increase the lake’s holding capacity by around 10 per cent.
The lake has not been desilted since it was constructed in 1892. The BMC is now said to be acting on a recent report by the Maharashtra Engineering Research Institute (MERI), which says the lake has accumulated 9.88 per cent silt at its base, which needs to be removed to enhance its holding capacity.
Prakash Limaye, assistant engineer (civic water department) said: “We will try to desilt the lake before the monsoon begins, since that kind of work will be much easier when the lake level is low.”
“If the desilting happens before the monsoon, the lake’s holding capacity will be augmented by 18,230 million litres, meaning it can supply an additional 35-36 days worth of water to the city in the next year,” Limaye said. Currently, the Tansa supplies the city 455 million litres daily (MLD), out of Mumbai’s supply of 2,900 MLD.
The water department is preparing a proposal for the desilting, which it will table before the civic standing committee soon. Rahul Shewale, chairman of the standing committee, said: “I will pursue the matter with the water department, so we can finish the work before the monsoon.”
R C Malviya, BMC executive engineer, said: “We did try in 1998, to desilt the lake but we didn’t succeeded. After the Tansa, the BMC will repeat the process in the Modak Sagar, which has around 11 per cent of accumulated silt.”
The city gets about 1,350 MLD from the Tansa and the Modak Sagar. Apart from the Tansa, the BMC has also carried out a survey of the Vihar and Tulsi lakes. Shewale, along with some standing committee members and top civic officials visited the Tansa and Modak Sagar sites on Wednesday in view of the grim outlook for water for the year ahead.