Its plans of a desalination plant to convert sea water for potable use and a greywater recycling plant are yet to take off,the BMC has mooted a new proposal but this time to slow down evaporation from lakes.
The BMC is looking at a method adopted by Singapore,known for its water supply and conservation practices,which would involve spreading of a thin film of a potable,oil-based liquid over the surface of the six lakes that supply water to Mumbai.
This would reduce penetration of sunrays into the lakes to 5-10 feet,from 20 feet. An official from BMC’s Bhandup water treatment complex said this could reduce evaporation by at least 20 per cent.
The liquid is potable and can be consumed without any harm. It also does not cause any harm to aquatic life. The film of oil is extremely thin and does not affect quality of water at all,” said the official.
The proposal was placed before the civic administration by Mayor Shradhha Jadhav and BMC political group leaders who recently visited Singapore to study the functioning of its Public Utilities Board that manages water supply. They also visited the desalination plant there.
The proposal is being studied for feasibility by the hydraulic engineering department. “While it is a useful technology for the city,considering much water is lost due to evaporation,it is also technically challenging to implement here. The catchment areas of our lakes are spread over a large area. We are therefore studying the technical and financial viability of the same,” said hydraulic engineer Vinay Deshpande. Over 10 per cent of the water in lakes is lost to evaporation.