Incessant rain in Mumbai over the last two days has brought back memories of the record-breaking July 26, 2005, downpour that had paralysed the city. Tuesday’s rain was not, however, triggered by any unusual event, nor was the amount of rainfall anywhere near the July 2005 mark. The Santacruz observatory recorded 315.8 mm of rainfall between 8:30 am and 8:30 pm Tuesday, which was a third of the 944 mm that some parts of the city had received on that 2005 day. Colaba and Thane stations recorded less rainfall than Santacruz.
“Parts of Mumbai get inundated with even 50 mm of rainfall. And in the last two days the city has received over 350 mm rains. These rains were forecast well in advance. No special event has triggered it. And it is not very unusual for Mumbai. It has received more rains in the past. Tuesday’s rainfall in Santacruz, however, was the highest single-day rainfall recorded in August this monsoon season,” said Mrutyunjay Mohapatra, head of services at the India Meteorological Department.
“What has been crucial in this spell is the timing of the rains. Had the same amount of rainfall happened in May or June, the situation would not have been so bad. But Mumbai already has had about 2,000 mm of rainfall this monsoon season (since June) which is more than normal. The soil is already saturated with moisture. Its ability to absorb water is diminished. So we are seeing a much larger impact of the rains on city life,” Mohapatra said.
Meteorological officials have been pointing to a strong low-pressure area that had developed over southern Madhya Pradesh, one of the several that form during the monsoon season and lead to rains all over the country. The meteorological department has predicted more parts of Maharashtra and Gujarat over the next couple of days. For Mumbai, it could mean nearly 500 mm over three to four days.
Mumbai, however, is just the latest in a long list of towns and cities that have experienced flooding this year. A couple of weeks ago, Bengaluru had received massive rains, about 180 mm in a single day, and was faced with similar flooding and resultant chaos. Before this, large parts of Assam, Bihar, Uttar Pradesh, Gujarat, Nagaland, Arunachal Pradesh, Chhattisgarh, and Odisha have also experienced floods this season. As many as 280 districts in 23 states have been affected by flood-like situations this year.
Part of the reason is the good rainfall that has taken place so far this year. More importantly, the regional distribution of monsoon rainfall has been quite even. Most areas in the country have had one or more good spells of rainfall. Of the 36 meteorological subdivisions in the country, 30 have received either normal or excess rainfall so far, though the country as a whole has received 4% less than normal rains. Only Kerala, south-interior Karnataka, Vidarbha, eastern Madhya Pradesh, western Uttar Pradesh, Haryana and Delhi, and Punjab have had deficient rainfall this season. “The result has been that nearly all the flood-prone areas in the country have experienced flooding at some point this season,” Mohapatra said.