Lake tapping, advance technology reduce water cuts in Mumbai

The city of Mumbai despite the depleting water levels of reservoirs is facing only a ten per cent water cut.

While many believe that this is due to the ongoing elections to avoid voter's wrath over water the engineers in the municipal corporation believe that it is 'water tapping' and new technology at water treatment plants that have done the trick.

Increased lake tapping at water treatment plants in addition to better technology has increased water availability by 6 to 7 per cent.

Now the lakes supplying water to Mumbai have only 15 per cent of water stock and Brihanmumbai Municipal Corporation (BMC) is waiting for the official nod from the state to use water from the reserved stock.

There are seven lakes which have 14.47 lakh million litres storage capacity through which the city gets around 3800 million litres water every day.

Last year, there was only 90 per cent water stock at the end of monsoon, so BMC had to declare 10 per cent water cut in November. As on date, the city has only 2.23 lakh litres of (15 per cent) water stock. In 2015-16 city imposed 20 per cent water cut with a similar stock of water.

However, lake tapping technology has helped the city this time.

"Two years back, BMC had to release 120 million litres water lying unused from the water treatment plants in Bhandup and Panjrapole every day. Now with upgraded technology we can recycle water and supply it to the city," said Ashok Tawadia, Chief Engineer, Hydraulic Department.

Bhandup treatment plant processed 2810 MLD and Panjrapole processed around1365 MLD water.

Hence, technology has bettered the supply.

"BMC had done lake tapping in the Modak Sagar lake in 2015. Earlier the lowered drawable limit was 143 meter but now BMC can draw the water till 139-meter mark. It increased water availability by 30,000 million litres. In other words, the city gets around 100 million litres extra water every day," said another officer from the civic body.

Together it helps to increase around 220 MLD or 6 per cent more water to the city as per BMC and helps reduce the water cuts.

BMC has also written a letter to the state government seeking permission to release 70,000 million litres water from upper Vaitarna river and 1 lakh million litres water from Bhatsa from the reserve stock.

Key Insights

• Increased lake tapping at water treatment plants in addition to better technology has increased water availability by 6 to 7 per cent
• Now the lakes supplying water to Mumbai have only 15 per cent of water stock and BMC is waiting for the official nod from the state to use water from the reserved stock 
• A lake tapping is a process to make tunnel at the bottom of the lake by blasting dynamite explosives