mumbai

Updated: Jul 05, 2019 08:26 IST

Heavy rain for the past few days brought the city to a virtual halt, with waterlogged roads, traffic jams and halted local trains. Municipal commissioner Praveen Pardeshi, in an interview with Hindustan Times, explained the reason behind this – “The city’s infrastructure is not capable of handling climate change and change in rainfall pattern.”

Since the 2005 deluge, Pardeshi said, the Brihanmumbai Municipal Corporation (BMC) has spent thousands of crores on monsoon preparedness, but expectations keep rising.

Edited excerpts:

During the 2005 deluge, the recorded rainfall in two days was 900 mm, but in these two days the rainfall was less and in some places even less than 50mm an hour, but still there was waterlogging…

Waterlogging stayed for a much shorter period. Our efforts worked. Water did not stay on the streets. Can you imagine what could have been the situation if the pumping stations and stormwater drains did not work? Water does not stay in low-lying areas because it is being pumped out. Of course, we need to do much more, and that is the expectation. I agree that we cannot keep increasing the capacity of drains alone.

The recent downpour brought the entire city to a standstill. What measures is the BMC taking to ensure such incidents are not repeated?

We have identified big-picture problems. One is the central areas of the city which face waterlogging during the monsoon. These areas will get relief once the pumping station at Mahul is ready. Work on the Mogra pumping station will help the western suburbs. As a long-term plan, protection of mangroves, ensuring Sanjay Gandhi National Park (SGNP) is encroachment-free, creating urban forest areas and expediting work on sewage treatment plant is the solution. The SGNP alone adds more green area compared to whatever work you do across the city in redevelopment. There are 15,000 people living in slums in the SGNP, who need to be rehabilitated to make it a 103-sqkm ‘Human Habitation Free Area’. The third idea is to create 100 urban forests. In addition, the BMC is planning to socialise mangroves because what is out of sight is out of mind. We will build walkways on the landward side along the edge of the mangroves. The continuous walkway through the coast will be owned by everyone, which will ensure protection. Lastly, the entire sewage treatment plan needs to be completed on priority. My target is to have a treating capacity of 2,200 million litres. The city receives 3,500 million litres of water on a daily basis, of which two-third goes into our stormwater drains such as Mithi River, which decreases its capacity to carry rainwater. Unless we are able to treat it and channel it through a different system, the existing SWD system will face problems in carrying rainwater to the sea. In the next two three months, work on all treatment plants will begin.

How is the BMC dealing with the change in the rain pattern in the city, which is infrequent and sporadic?

The earlier pattern of 90 to 100 rainy days in the monsoon has now come down to 25 to 30 days of heavy rain, but the amount of rainfall has not decreased. This is very bad because our infrastructure does not cater to such rapid run-off in such a small time. In Mumbai, it is easy to talk about water conservation, but where to put that water? So we have to think of innovative methods such as protecting mangroves through which our percolation rate will go up. The BMC has decided to stop concretisation of river beds. In Mithi, too, we will use gabion structures instead of concrete, which will have rocks and steel wire mesh. We are converting rivers into drains and so we need to revive the rivers, especially Mithi.

How are we factoring in climate change with regards to urban planning?

I believe our infrastructure is not designed to take any climate change that way and we have to work on it now.

Will the BMC make a policy-level decision to create more open spaces in housing societies that will be constructed henceforth?

For all new proposals coming for permission, we are denying concessions if they are on paved areas. We are making a circular now, and saying that open spaces and recreation grounds which are legitimately green, should not be paved. It is a small thing, but is doable.

Saltpan lands in the eastern suburbs are water-retention units. Is the BMC planning to make any policy-level decision to permit development there?

We have not opened up any saltpan land for development. We are refraining from development there. Right now, there is no fixed thought on that. I think we need a saltpan land for a pumping station in Mahul. So those sort of activities only will be permitted. The rest of it can remain as a natural green area, which will be much better in the light of the way Mumbai is developing.

Currently, Mumbai has 100% run-off to our drains. With increase in rainfall, our drains are not equipped to handle it. As a prospective urban planning tool, what can we do?

Of the 53 nullahs to be upgraded, 25 nullahs were upgraded to 50mm and 12 are in progress, and four are yet to be opened. Some of them came up because the problems in the original spots were not addressed or were partially addressed, so there is a ballooning effect. The most important thing we are missing out on is thinking what can be the maximum carrying capacity of Mumbai, both infrastructure and population-wise. Most cities work on that.

Public transport is a very good disperser of population. Not creating affordable houses in the city’s centre and increasing parking charges as a proxy to congestion tax will ensure the city is not overloaded.