Is Mumbai Ready for Rainfall Exceeding 100 mm Per Hour?

Mumbai, June 26 (NationPress) The Guardian Minister for Mumbai Suburbs, Ashish Shelar, announced on Thursday that the city's existing stormwater drainage system is only capable of managing rainfall up to 55 mm per hour.

Given the rising frequency and intensity of rainfall events, he emphasized the necessity of developing a new, dedicated master plan to effectively handle precipitation levels surpassing 100 mm per hour.

The Minister mentioned that the National Disaster Management Authority (NDMA), operating under the Union Ministry of Home Affairs (MHA), will allocate additional funds to back this initiative.

He highlighted that the NDMA, recognized the ongoing flood challenges faced by Mumbai.

"In the initial phase, Rs 500 crore has been earmarked by Prime Minister Narendra Modi's administration for the Brihanmumbai Municipal Corporation (BMC) to execute immediate flood-control measures. The NDMA has also mandated the BMC to devise a comprehensive action plan based on real-time evaluations of the city's flood-prone zones. The preliminary plan drafted by the BMC is presently under scrutiny by an expert panel from the IIT," stated the Minister.

"Identifying flood-affected areas is crucial, as we will enhance drainage infrastructure in those spots to accommodate over 100 mm of rainfall per hour. A thorough report will be generated with support from the IIT, with initial project estimates around Rs 5,000 crore. The NDMA is anticipated to contribute a significant share of the funding for this vital infrastructure improvement," he added.

During his discussions with Maharashtra Chief Minister Devendra Fadnavis, Minister Shelar revealed plans to incorporate Japanese drainage technologies in Mumbai.

"Consequently, the BMC is weaving these advancements into the new master plan," the Minister noted.

He urged officials to collaborate with entities such as the Railways, Metro, and the Mumbai Metropolitan Region Development Authority (MMRDA) to formulate this extensive plan.

He directed that the final report should be ready within the next month.

"In 2017, Mumbai witnessed 26 days of rainfall and 21 days in 2024. According to BMC research, the city experiences substantial rainfall averaging 16 to 20 days annually, with several instances exceeding 100 mm per hour. From 2014 to 2019, rainfall peaked at 131 mm/hour, and on May 19, it soared to 182 mm/hour. On July 26, 2005, the city received nearly 1,000 mm of rain within 16 hours — averaging 139 mm/hour — resulting in severe flooding due to a high tide. Recently, heavy rainfall over 100 mm per hour has become increasingly common. When such intense rain coincides with high tide, effective drainage is nearly impossible, leading Mumbai to confront flood-like conditions," stated the Minister's office.

Minister Shelar pointed out that prior to the devastating deluge on July 26, 2005, Mumbai's stormwater drains could only handle 25 mm/hour.

"After the Chitale Committee's recommendations, this was upgraded to 55 mm/hour. Nevertheless, with rainfall routinely exceeding 100 mm/hour, further capacity enhancements are imperative," he asserted.

The BMC is also planning to construct four new pumping stations, both large and small, as part of these efforts, the Minister added.

"Currently, there are nine small pumping stations in Mumbai. Two more are to be established at Maharashtra Nagar and Dharavi T-Junction. Additionally, there are six large pumping stations, and two more will be built at Mogra and Mahul. These new facilities will facilitate the drainage of water from flood-prone areas including Kurla and Andheri," he concluded.