Every monsoon, the city is just a step away from any disaster. A Development Plan that takes this into consideration is very crucial. Mumbai’s monsoon problems — potholes, overflowing drains, flooding — are demonstrations of a larger fundamental planning issue. For nearly five decades, Mumbai has practiced planning for regulating development. Its key function is to adapt to the city’s present condition with enough vigilance to guide development, safety and improvement for the next 20-year period.
Let us look at the annual challenges the monsoon throws up.
Drainage: Mumbai’s drainage system capacity can take about 25 mm of rain per hour. In the suburbs of Greater Mumbai (including its existing No-Development Zones and natural areas), drainage capacity is expected to double up to 50 mm in the coming decade through implementation of Brimstowad (Brihanmumbai Storm Water Disposal system) projects. However, every year we record heavy rainfall exceeding 65 mm per hour, which means several days of floods. Even the enhanced drainage capacity in the suburbs cannot deal with this. The BMC and its contractors do not conduct desilting operations. What we need is better inter-agency coordination to see to it that the silt is not just removed but disposed off too. Mumbai also needs more pumping stations, to push the water out to the sea. The Storm Water Drain department’s topographic contours map, created using aerial photography and photogrammetric mapping, must be studied while planning. Development without considering natural water flows and drains can collapse the city’s defences against the monsoon’s incursion.
Transport: Over 90% of Mumbai is made up of pedestrians. During peak hours, the suburban local trains transport over 22 lakh passengers. And every year due to rains, locomotives succumb to waterlogging and electrical failures, pushing commuters onto the roads. What the Development Plan needs to do is pay more attention to upgrading existing pedestrian networks and public transport. Also strengthen the norms and pricing policies for parking as vehicles are also seen parked on both sides of the roads.
Open spaces: Natural green spaces are not just good for the soul but they also play a very important role in the absorption of rain water. They raise groundwater percolation, and also act like holding ponds, increasing the rainfall’s ‘time of retention’ on city surfaces. The BMC must pay heed to the Bombay HC’s criticism of the zeal to destroy mangroves “under the garb of development”. The mangroves help to cushion the land against the waves and prevent soil erosion. What the DP needs to do is protect existing green spaces or the natural buffers and create more of them, ensuring that they are accessible and distributed.
Disaster preparedness: Disaster management without a plan is a Digital Mumbai without internet connectivity. Recently, in Uttarakhand in 2013 and 2016, and in Chennai in 2015, unregulated construction on natural drains and riverbeds precipitated devastating floods. But the BMC seems to be unwilling learn from these mistakes. The DP must incorporate the Chitale Committee (committee of experts) recommendations on preparedness, mitigation, rescue and relief. But those recommendations barely find mention in the RDDP (revised draft development plan). In doing so, the RDDP should also adhere to the national standards for social and welfare amenities per citizen, for health, education and open spaces.