It is only when the rain brings Mumbai to a standstill every year that the country wakes up to the reality, intensity and the joy and sadness of monsoons. In the last three days, the city has received more than its July average of 500 mm rain, grossing about 350 mm on just one day. Such heavy downfall is enough to bring any city in the world to a standstill, more so to Mumbai, which is densely concretised, over populated and terribly maintained.
Luckily, Mumbai is a coastal town where water flows out to the sea. But had the same water fallen on the capital New Delhi, hundreds would have died as Yamuna would have overflown.
The water that has fallen on Mumbai, if collected fully, would have solved the drinking water problem that the country is facing.
About 70 to 100 mm of rain in 24 hours is the maximum any non-coastal city or big town in India can take before it is flooded and its roads and houses drowned out. In any case, no Indian city or town is planned to take such a deluge and in case almost all water bodies or rivers have been dried out due to terrible planning and excess damming.
Fortunately, inland towns do not get that much rainfall or the country would have been left with destroyed towns after the monsoon season. Even Kerala, where more than 500 people died during the floods last year, most districts got 500 mm rain — more than average during the entire season. Wayanad, for example, got 2,676 mm rain from June to July.
So Mumbai’s downpour in the last three days is humungous by any standards. Despite such rains every year, the administration does not have the equipment to handle the calamity, often summoning the Indian Navy for inflatable boats for rescue operations. Ironically, over the last few years, the navy has done more crisis handling inside the metropolis than in the high seas off Mumbai.
But far away from the financial capital, Cherrapunji in Meghalaya received 1,565 mm rain in a single day on June 15, 1995. It is a world record for 24 hours of rain. But such a cloud burst would have destroyed Mumbai. In June 1995, “for 40 days it rained non-stop,” MET observer Mondal had told this reporter.
If Cherrapunji had not been a plateau, perched atop a cliff, such a rain would have washed out the entire village, almost 100 years (1897) after the entire region had been devastated by the world’s worst earthquake of 8.6 on the richter scale. The place certainly attracts world records.
Rainfall figures are taken thrice a day in the meteorological departments throughout the country. On June 15 that year, during the first reading between 8.30 am and 11.30 am, it rained 175.0 mm. That itself would have given indication of what was to follow. Any weather man would have wondered if he was hallucinating after seeing so much water in the glass barrel placed inside the housing unit into which rain water drips in.
When Mondal went in for the next reading of the rainfall, it had become 440 mm from 11.30 am to 5.30 pm. This amount of rainfall has not been witnessed in any other place in the world in five hours. The highest rainfall recorded in Delhi was in 1,958, 121 mm. That night, it rained 110.mm between 5.30pm and 8.30 pm. And when the small village slept in fear with the rat-a-tat of the never-ending rain on their tin roofs, it rained 680 mm by 5.30 am. For the next three hours till 8.30am on that gloomy, wet morning, another 158.0 mm fell, taking the total rainfall to 1,563mm, a deluge that finds no explanation anywhere.
The Brahmaputra river, which would take some of the water falling down in silvery cascades from Cherrapunji, was in spate and the levels were rising dangerously in Dibrugarh and Neamati Ghat. But no major causalities were reported apart from a small bridge that washed away nearby. The reason is that the rains remained concentrated on one small village — the rain-blessed Cherrapunji praised by poets and studied by scientists.
Such intense rains, like the one being witnessed in Mumbai now, are caused by low pressure systems of falling pressure with counter clockwise winds around them. They do not have the intensity or the dimension of a proper depression, yet the rainfall generated by these system is high according to experts.
(The author is a senior journalist and author. Details for this article have been taken from his book, ‘Under a Cloud: Life in Cherrapunji, the Wettest Place on Earth’.)