49% of entire monthly rainfall recorded in Mumbai within 48 hours

Of the total quantum of rain recorded during the 48-hour period, 268mm was recorded between July 7 and 8 while 154mm was recorded between July 8 and 9.

Last year too, Mumbai surpassed the halfway mark of its monthly quota of rain within nine days of July as it had recorded 494mm or 57% of its monthly quota of rain.

However, this year, Mumbai recorded 35% less rain during the month of June, despite an early onset of monsoon.
IMD officials have maintained that owing to an offshore trough above Mumbai, rainfall activity intensified in the past two days.

“The sudden intense rainfall was the result of an offshore trough that intensified post 12.30am (July 8), leading to very heavy rainfall within a very short span. Also, a cloud patch emerged towards the northern side which acted as another contributing factor,” said an IMD official.

The IMD had issued a red alert for Mumbai on Tuesday. However, with the rainfall losing intensity, the warning was downgraded to a yellow alert later in the day. An IMD official said during the next 24 hours, rainfall activity in Mumbai will get subdued. “The rainfall activity will become comparatively less on Wednesday (July 10). However, starting Thursday (July 11), rains may pick up gradually,” the official added.

In its five day forecast issued on Tuesday afternoon, the weather bureau issued a yellow alert in Mumbai between July 11 and 13. Meanwhile, an orange alert has been issued for Raigad, Ratnagiri and Sindhudurg districts between July 12 and 13.

On Tuesday morning, Mumbai woke up to very heavy showers with 167.5mm rainfall recorded in Matunga, 158.5mm in Sion, 124mm in Vikhroli and 113mm in Dahisar.

According to IMD, very heavy rainfall is identified when 115.6mm – 204.4 mm rainfall is recorded within a 24-hour period.

Water stock in lakes rise by 1.25%

The average overall water stock in all the seven lakes that supply water to Mumbai stood at 20.48% on Tuesday morning–an increase of 1.25 percentage points from 18.75% on Monday. The highest rainfall of 214mm and 196mm were recorded in the catchment areas of Tulsi and Vihar lakes, which are located in suburban Mumbai.

Mumbai draws its water from seven different lakes – Tulsi, Vihar, Bhatsa, Modak Sagar, Tansa Upper Vaitarna and Middle Vaitarna. The catchment areas of these lakes get filled during monsoon, following which the water is supplied through pipelines. The catchment areas of all the lakes, besides Tulsi and Vihar are located in Palghar, Thane and Nashik districts.

According to BMC’s water level chart, last year, the average water stock in all the seven lakes stood at 23.11% on July 9, while in 2022 it was 28.89%.