How did Mumbai civic body lose this drain of thought?

The condition of Everard nullah in Chunabhatti stands as one of the examples of the Brihanmumbai Municipal Corporation’s (BMC) claims that it has completed 104% of the pre-monsoon desilting work on nullahs across the city, said the panel of experts who participated in HT’s annual audit for monsoon preparedness earlier this week. Desilted, cleaned and widened with a free flow of stormwater, Everard nullah has got the maximum marks by HT’s experts’ panel.

However, just 100 metres downstream, where a private nullah that runs through the premises of Somaiya Institute and merges with Everard nullah, the site breaks all illusions of Mumbai being ready to handle this year’s monsoon and preventing waterlogging. Clogged with garbage and hardened silt, this private nullah hardly has any flow of water.

However, BMC’s explanation for its unkempt state is that this nullah runs through private premises, and hence, is the responsibility of the party concerned to desilt it every monsoon. Authorities claimed that they send the responsible party frequent reminders every monsoon to clean the nullah as well as to widen it, but to no avail. As the nullah caters to the areas of Kurla and Chunabhatti, its impact on waterlogging in these areas is high, according to HT’s panel of experts.

A senior civic official from the stormwater drains department, said, “BMC has completed 100% of pre-monsoon desilting and cleaning work at Everard nullah. The other nullah is a private nullah, and the respective property [owner] has not done any work.”

As part of HT’s monsoon audit that was conducted on Wednesday, a panel of three experts inspected two nullahs in the eastern suburbs as well as two chronic waterlogging spots – Gandhi Market and Hindmata Junction on Babasaheb Ambedkar Road – in the Island city and graded these spots an average of 1.7 marks out of 5.

The experts graded Everard nullah the highest score, averaging 3.83 out of 5, followed by Hindamata junction (1.33).

The private nullah got 1 mark out of the total 5, while Gandhi Market was given 0.5 rating.

One of the experts on the panel, DK Pathak – who retired in 2009 as deputy engineer of BMC’s stormwater drains department after 33 years of service –said, “The intersection where the private nullah meets Everard nullah is a T junction. Hence the flow of water from the private nullah gets interrupted due to the smooth flow of Everard’s nullah at the 90° angle. If this was a Y junction, the flow from the private nullah would have been smoother.”

After multiple projects over the years – since the 2005 deluge –have failed to mitigate waterlogging at Hindamata, BMC is now constructing two underground water-holding silos at the junction, and one at Gandhi Market to deal with the chronic problem.

However, according to experts, this is unlikely to put an end to waterlogging at these two chronic flooding spots.

Udaykumar Shiroorkar, a retired assistant engineer of BMC, who was a part of HT’s panel of experts, said, “The expenditure is unnecessary, and the civic body needs to weigh its usefulness against its cost. At the most, this will reduce the water receding time by a few hours.”

According to Pathak, the storage capacity of tanks at both these places is meagre in comparison to the quantity of water accumulated after a heavy downpour.

“Topographically, Hindmata is saucer shaped, and hence, prone to waterlogging. The water receding time from Gandhi Market entirely depends on the cleaning and widening of the successive drains and culverts,” said Pathak.

While each of the silos at Hindamata will have a capacity to hold 1,000 cubic metres (1 million litres) of water, the one at Gandhi Market will be able to hold 1,200 cubic metres of water.

Water from these silos will be channelled from underground pipes to two other bigger underground silos — one at Pramod Mahajan Udyan on Senapati Bapat Road near Elphinstone station, and one under St Xavier’s ground in Parel.

As part of phase 1, construction of these silos and the underground water dispensing system will cost the civic body ₹60 crore.

The entire project of construction of five water silos to provide relief from waterlogging, is likely to cost around ₹130 crore.