Ahead of monsoon, Mumbai gets state-of-art flood warning system (Lead)

After Chennai, Mumbai on Friday got India’s second state-of-the-art Integrated Flood Warning System (IFWS) which will make it possible to predict floods at least three days in advance, enabling more lives to be saved.

The system was jointly inaugurated by Union Earth Sciences Minister Harsh Vardhan and Maharashtra Chief Minister Uddhav Thackeray in the presence of top officials from both sides, via video-conferencing.

Harsh Vardhan said that with this, the scientists of the Earth Sciences Ministry – who developed the IFWS – have proved that India is not less than anyone in the world in science.

“Mumbai floods, especially in 2005 and 2017, are etched in everyone’s memory. This highly advanced IFWS will help the people of the city in a big way,” he said.

Terming it as a ‘gift to the people of Mumbai,’ Thackeray said: “The IFWS is a blessing for Mumbai in a situation where monsoon has become more difficult to predict. If the IMD had not given early warning of the Nisarga Cyclone, the effect would have been disastrous. It is necessary to do flood management as Mumbai has some areas which are lower than the sea level, making it difficult for water to drain out.”

The IFWS will help Mumbai become more resilient by providing early – at least 72 hours before, along with 3-6 hours Nowcast or immediate weather updates – flood warnings, especially during high rain and cyclones.

This would help evacuate people from low-lying areas as the forecast would be available in advance before a particular spot may get flooded, besides forecasting the amount of rainfall for each pocket.

Earth Sciences Secretary Dr. M. Rajeevan said that more than 160 observatories and four more radars (by 2021 season) have been ordered for Mumbai to enable forecasting rainfall with a precision of 500 metres and every 15 minutes.

BrihanMumbai Municipal Commissioner I.S. Chahal said IFWS can be a model for the rest of India and expressed gratitude to the Centre for launching it well before the onset of monsoon 2020 in Mumbai.

IMD Mumbai’s DDGM K.S. Hosalikar said that four Doppler Radars for Mumbai will be installed by monsoon 2021 to make Mumbai, Maharashtra and the country more weather resilient.

Coastal Mumbai island has been experiencing floods, including the ones on August 29, 2017 which paralysed the city, preceded by the great flooding of July 26, 2005 when the city received 94 cms rainfall in a day – a 100-year old record.

With a view to be flood-ready, in July 2019 the BMC and state government had approached Earth Sciences Ministry to develop the iFlowsMumbai to enhance the city’s resilience with early warning of flooding during heavy rains or cyclones, officials said.

The system is built on a seven-modules structure – Data Assimilation, Flood, Inundation, Vulnerability, Risk, Dissemination Module and Decision Support System, incorporating the best from IMD, NCMRWF, IITM, BMC, etc.

The system has provisions to capture the urban drainage in Mumbai to predict the areas of flooding, along with data on river bathymetry from Mithi River and its branches in Dahisar, Oshiwara, Poisar, Ulhas River in Thane, the lakes and creeks.

A web GIS-based decision supports system is built to calculate the vulnerability and risk of elements exposed to flood.