The BMC is set to take up remodelling of old drains and widening of the existing ones in view of the unusual flooding witnessed by Mumbai this monsoon. It will also look into collapsed drains and divert storm water drain lines in case of emergency.
This year, the city had witnessed unusual flooding in many parts, especially in south and central Mumbai. Areas like Girgaon Chowpatty, Marine Drive, Churchgate, Walkeshwar, Breach Candy and Chinchpokali had witnessed unusual waterlogging. Also, areas like Grant Road, Mumbai Central, Hindmata and Parel saw long hours of waterlogging.
While BMC officials had blamed extremely heavy rainfall for these unusual occurrences, at some locations, more than a century old drains were found to be one of the contributing factors behind the waterlogging.
On August 5 and September 23, Mumbai had recorded the highest rainfall of 331.2 mm and 267.62 mm rainfall, respectively, in 24 hours.
A senior official from BMC’s storm water drain department said that the contractor that will be appointed will remodel old drains, convert old arch and dhapa drains into new pipe drains, reconstruct collapsed nullah walls and old drains as well as divert drains in case of emergency.
“The work will be completed in the next one or two years. Island city has the oldest drain networks. In many cases, the drain capacity has further reduced either due to collapse or cavity has been formed. Widening and reconstruction of these drains will help abate waterlogging,” said the official. These works will cost the civic body around Rs 50 crore. According to BMC data, the island city has a drain network of over 550 km.
On August 5 and 6, BMC officials had found that an old drain near Walkeshwar had collapsed – one of the reasons leading to the uncommon flooding in Chowpatty. Officials had also found missing drain links. Similarly, in Mumbai Central, BMC drains were damaged due to the Metro 3 corridor construction work. While BMC has claimed that rainwater receding capacity of the drains is 50 mm per hour, in the island city, it is less as the drains are old.
Further, the civic body will remove trees whose roots are damaging or blocking drains. Officials said that in some cases, tree roots have gone below the drains and such trees need to be removed with permission from the Tree Authority. Also, BMC will lay new RCC (reinforced cement concrete) pipes drains in Parel, Matunga and Worli to minimise waterlogging.