According to data from the India Meteorological Department, Maximum City’s highest ever 24-hour rainfall was recorded on July 5, 1974, in Colaba, at 575.6 mm. At the IMD’s Santacruz station, representing the city’s suburban area, the biggest extreme rainfall day was July 26, 2005, when a cloudburst belted down 944 mm rain in a single day. The second highest ever rainfall received in the suburbs, where much of Mumbai lives, was recorded on June 10, 1991, at 399 mm. The downpour in the wee hours of Tuesday averaged 375.2 mm in the suburbs, but the Met department and the Brihanmumbai Municipal Corporation both now adopt a decentralised system of measuring precipitation, and multiple suburban localities received well over that average — Dindoshi recorded 479.56 mm rain in 24 hours, Kandivali recorded 455.91 mm, Malad recorded 451.32 mm, Chincholi recorded 447.54 mm, Goregaon recorded 412.25 mm, Vikhroli recorded 403.55 mm and Kurla recorded 399.49 mm.
In sum, for large parts of suburban Mumbai, Monday night’s rainfall is the second highest ever recorded, almost half the quantum of average rain received on the day of the 2005 deluge. But while Tuesday’s flood waters may have triggered memories of the July 26, 2005 tragedy, nobody disputes that Mumbai’s response to disasters has come a long way since.
The state and civic agencies undertook a series of projects in the aftermath of the 944-mm deluge, key among them being the decision to finally implement the Brimstowad (Brihanmumbai Storm Water Drainage) project, whose cost had grown manifold since being proposed in the 1990s. According to officials, the BMC has spent at least Rs 650 crore on the widening and deepening of the Mithi river, Mumbai’s ‘mother drain’, with 95 per cent of proposed works for the Mithi completed.
All Mumbai agencies from the police to the municipality have clearly drafted standard operation protocol for disaster management, better-equipped disaster cells and control rooms, etc. Mumbai’s Doppler radar-based weather forecasting system, recommended and installed after the 2005 deluge, made accurate rain pattern predictions for the week starting July 1, “very heavy, localised rainfall”. An extensive CCTV camera network, proposed after the Mumbai terror attack of 2008 and installed in 2017 at a cost of Rs 949 crore, now monitors traffic congestion as well as rising flood waters, helping along the conversation on hotlines between the BMC, other infrastructure building agencies, the Fire Brigade, the police and the IMD.
The depth and reach of social media have made Twitter, Facebook and WhatsApp critical tools for dissemination of advisories and real-time situation updates. “I had just landed in Mumbai from an international flight on Monday night. I saw the rain, switched on my phone and scrolled through WhatsApp messages on different groups. In 10 minutes I knew — at midnight — which areas were flooded. Google Maps gave a fair and remarkably accurate update on traffic conditions. Even the much maligned municipality was active and responsive on Twitter,” says entrepreneur Kapil Chandni. According to him and thousands of others, the convergence of alert Mumbaikars, social media and technology has had a profound change on how Mumbai responds to its monsoon.
In a first, advisories to stay indoors came in respectable time. Commissioner of Mumbai Police Sanjay Barve tweeted at 6.30 pm: “Heavy to Very Heavy rains expected in Mumbai & MMR in the next 3 days as per intimation received from IMD. I request Mumbaikars to check weather updates & plan the day accordingly.” This was after the IMD and private weather forecasters had both put out clear statements on what to expect over the next two-three days, information updated through a ‘nowcast’ around midnight by the IMD and further tweets and Facebook posts from private forecasters.
The crisis messaging systems that were conspicuously absent were the Railways’ and the airlines’. “We sat in the train for well over two hours between 11.30 pm and 1.30 am, as more and more trains seemed to be stranded between Kurla and Vidyavihar stations on Central Railway. There was no information on what to expect and if service would resume,” said V Singh, a media professional. At 12,40 am, CR tweeted that “nature’s fury” had led to the suspension of services on the Kurla-Thane section, where lakhs of daily commuters live. Thousands jumped off and walked on the flooded tracks to get home. Those on the harbour line made it home once the trains traversed the section of Chembur-Tilaknagar tracks that were submerged, while others stranded in trains at Kurla and Vidyavihar had to be rescued by RPF teams — while CR tweeted later that RPF and GRP teams were conducting the rescue, commuters were at no point told what to expect.
Fifteen years ago, much of the destruction in the suburbs was caused by the Mithi river in spate. On Monday night, the early warning system for slums along the Mithi worked effectively, said Additional Municipal Commissioner Ashvini Joshi. “The Mithi river reached the danger mark of 3.25 metres and about 1,600 people from the Kranti Nagar slum were evacuated. As the Mithi river level rose, we stopped discharging flood water from LBS Road into the Mithi.” This kept Kranti Nagar and Sandesh Nagar safe, but caused flooding on the railway tracks at Kurla and Sion, where railway commuters had no information on what was happening outside.
Also, automobile and motor insurance companies now send out multiple alerts to users on what not to do in rains. While multiple incidents of deaths inside closed and locked cars stranded in flood waters were reported in 2005, Monday night saw a single such tragic case.
River floods are different from floods caused by undue, sudden pressure on local drainage networks. In Mumbai, the 18-km Mithi, the 12-km Dahisar river, the 7-km Poisar river and the 7-km Oshiwara rivers have been turned into suburban nullahs, with encroachments along their banks reducing their width choking them entirely at places. Among the major recommendations of an extensive report by a fact-finding committee after the July 26, 2005 deluge was the restoration of the degraded rivers and river-banks, to probe pollution and encroachment problems for each river, identify specific boundaries for each river, establish buffer zones, etc. While a grand plan for the rejuvenation of the Mithi was initiated, no long-term revival of these rivers has been undertaken.
While July 2 differs from July 26 starkly in the repeated allusions to climate change, among others by Municipal Commissioner Praveen Pardeshi and Sena youth leader Aaditya Thackeray, climate science is yet to inform urban planning or municipal budgeting in any concrete way.
Incredibly, recommendations to protect the Sanjay Gandhi National Park — a rare national park within a megacity — and its fringes, as well as the salt pans and mangrove stretches, are all set to be jettisoned in coming months and years. Construction inside the Aarey Colony and the anticipated felling of 54,000 mangrove trees for the proposed bullet train are only the most recent subjects yielding protests by environmental activists. An initiative to prepare contour-maps of the city, for a flood modelling system, remains incomplete — civic officials confirm that contour maps for drains were prepared, not for the rest of the city. (This means in heavy rain, municipal engineers know which drains’ contours will allow for retention of water longer, but no scientific information exists, for example, on which direction the Mithi river’s flood waters will rush out.) Other recommendations to empower the Maharashtra Pollution Control Board to ensure compliance of environmental regulations by municipalities, a Mumbai Watershed Council to advise all agencies on planning for days like Tuesday, etc were never undertaken