The reasons Mumbai floods every year

Why do the same scenes emerge from Mumbai every time monsoon rains arrive?

Transcript

00:00Streets disappearing underwater, train tracks getting inundated, people wading through waist-high water.

00:07Why do these scenes keep happening in Mumbai?

00:09It's nothing new. Every year, every day, when it rains, the water fills up here.

00:14The British Era Drainage System

00:16Mumbai's stormwater drainage system dates back to the year 1860.

00:20It is a network of underground and surface drains which open into the sea.

00:25But when it rains a lot, or there is high tide, the drains aren't able to flush out water.

00:50These drains also collect sewage and silt,

00:52which makes it impossible for them to carry the flow of the water efficiently.

00:56In 2005, monsoon floods in Mumbai killed more than 1,000 people and destroyed about 14,000 homes.

01:03Topography

01:05Another reason for the financial capital's ineptitude at dealing with heavy monsoon rains

01:11is its location. It's surrounded by the Arabian Sea on three sides.

01:15The city is built on low-lying as well as high areas.

01:19Some of the low-lying areas are those that were reclaimed from the sea

01:22and joined to form the city.

01:24Some of these areas are Khar Subway, Andheri Subway, and Sayan.

01:29When it rains, water naturally flows into these areas and clogs up,

01:33only to drain out at its own pace after the rain stops.

01:37Construction and Urbanization

01:39Construction in the densely populated city takes away the land's natural ability to soak water.

01:49The water that used to go inside the buildings has been sucked out by the rain.

01:58The water that used to go inside the buildings has been sucked out by the rain.

02:0590% of water is drained through the drainage system,

02:08adding more pressure on it instead of percolating in the ground like many cities.

02:12To add to it, construction waste ends up in the drains.

02:16The rivers that run through Mumbai are not able to act as natural drains

02:20because of sewage that fills them up.

02:22This is both domestic and industrial waste.

02:26Illegal construction, encroachment, and pollution add pressure on the rivers,

02:30and the buffer space between the waterline and localities is lost.

02:34So when it rains, settlements get flooded.

02:46The solution lies in desilting or cleaning these water bodies

02:49so they can carry out water without any hurdles or clogging.

02:53Apart from that, the Brihan Mumbai Municipal Corporation

02:56was planning on reconstructing the drainage system in four areas.

03:00This work would involve installing iron grills,

03:03widening nalas, making box drains, and building retaining walls.

03:16you