Mumbai’s 100km liquid delve scheme to be world’s maximal in 6 eld | city News – Information Important Internet

MUMBAI: July 2024 module go downbound as the period when municipality got its ‘underground’. Any period now, a conception of the city’s Metro Line 3, which is nearly all underground, module begin operations. metropolis has a 20-year lead, but not whatever undergo that municipality started antiquity bounteous tunnels and using delve dull machines (TBMs) such before the Capital. It’s meet that Mumbai’s tunnels until today were meant for agitated water, not people.

Quietly, without media frenzy, the city’s liquid delve meshwork decussate the 100km mark on June 21, with the termination of a 9.7km underwater delve from Ghatkopar to Parel via Wadala. Although China, Nihon and whatever another countries ingest liquid tunnels in cities, exclusive New royalty City with a 111km liquid delve meshwork is aweigh of municipality now.

WHY DIG SO DEEP?

Mumbai’s liquid tunnels separate 100-110m beneath the opencast – assorted pipelines that are at a depth of 3-5m – and outlay nearly Rs 100 crore per km to build. For instance, the 9.7km Ghatkopar-Parel delve outlay Rs 943 crore. Wouldn’t it be cheaper to follow to pipelines then? Maybe, if you could encounter the expanse to place more of them. But added municipal commissioner Abhijit Bangar said tunnels hit individual advantages.

Bangar, who holds calculate of Brihanmumbai Municipal Corporation’s (BMC) liquid cater projects department, said, “Because the tunnels are deeper, the chances of dirtying and thieving are significantly reduced. Currently, municipality loses near to 35% of its liquid cod to whatever of these issues. Tunnels crapper support turn this expiration marginally.”



There’s also a strategic think for actuation the liquid meshwork unfathomable underground: “As an planetary city, municipality faces the venture of sabotage. But it is such more hard for anyone with such intentions to manipulate with stock 100m underground.”

It’s also eco-friendly in a artefact because when liquid from lakes and streams drops 100m to move the tunnels, “gravity facilitates easier and more economical liquid supply”.

DECADES OF TUNNELING

The prototypal delve to circularize liquid to municipality was shapely right the municipality in 1955. It was 6.7km daylong and transferred liquid from the Modak Sagar lake to Bel Nullah in Thane district.

In 1963, the prototypal underwater delve was shapely within the municipality using the then subverter newborn European tunnelling method (NATM) that requires dominated blasting. This 5.8km delve ran from Mulund in the easterly to Kandivli in the westerly and had a diam of 2.5m (8.2 ft).

By 1983, a delve dull organisation (TBM) had arrived in the municipality to physique the 3.8km delve from Mahalaxmi Racecourse to Malabar Hill. “It was the prototypal happening in the whole land that a TBM was used,” says a BMC official.

The municipality region’s liquid delve meshwork kept growing. During 1983-91, a delve was shapely low Kasheli watercourse in Bhiwandi. Between 1995 and 2000, a 4.9km liquid delve was shapely between Ruparel and Mahalaxmi Racecourse.

The terminal field delve before the Ghatkopar-Parel unification was shapely in 2018 between Powai and Vervalli, a indifference of 2.2km.

A MEGA-PROJECT

The Ghatkopar-Parel liquid delve complete terminal period is on a assorted scale, though. It was shapely in digit phases. Boring of the Ghatkopar-Wadala debase was ended by Sept 2022, and the 5.3km Wadala-Parel debase was started a period later. An authorised said impact on this send went on during the pandemic.

The TBM utilised to take this delve was collective in China and down into the connector at Ghatkopar’s Hedgewar Garden. Since then, impact has been carried on in threesome regular shifts. “Alignment is of limit grandness in a send aforementioned this,” said an official, adding, “We requirement to secure that the delve is brought discover at the expected place at the aforementioned depth. So, over 100 labourers are at impact at some saucer of happening crossways the threesome shifts.”

While the dull has been finished, the Ghatkopar-Parel delve module move transporting liquid exclusive by Apr 2026

ONGOING WORKS

Other delve entireness are on meanwhile. There’s the Rs 618-crore Ghatkopar-Trombay liquid delve which measures 5.5km. Another delve activity 3.2km is existence shapely between Powai and Ghatkopar. Once commissioned, these module circularize aerated liquid to different parts of Mumbai.

Two another daylong tunnels are on BMC’s art board. There’s a organisation to physique a 7.1km delve from Kasheli right the municipality limits to Mulund Octroi Naka. Another delve activity 14.1km module bring liquid from Yewai Master Balancing Reservoir in Thane regularise to Kasheli.

MANY CHALLENGES

Building some tunnel, modify with a TBM, is not easy. Sometimes, you separate into anaemic rocks or cavities that requirement to be filled up first. “A TBM cannot near by itself. It staleness intend a concern appendage around it. So, if there’s a cavity, we modify it up to permit the TBM intend traction,” an authorised explained.

Falling rocks and flow bear another risks to the organisation and its crew. In the Ghatkopar-Parel tunnel, for instance, such happening module be spent on covering the walls with objective to preclude seepage.

But the large contest today comes from grouping take unfathomable eager wells within the city. “Nobody should take a eager substantially in the municipality without BMC’s permission. Maps of liquid tunnels are acquirable in apiece administrative ward and permissions for eager wells are acknowledged exclusive after confirming that the place does not untruth above a tunnel,” an authorised said. “Still, there hit been instances of grouping take unfathomable and high our tunnels.”