By shash

4 February 2016

Two months have passed since the floods, and people have started moving on, rebuilding their lives and homes. Other problems, other debates have taken centre-stage in public discourse, and even the roads are being relaid. But have we moved ahead? Have we learnt anything from the devastation of the 1st of December 2015? Do we need to make any changes to the way we live, or to our infrastructure? Can the city be made safer? Is a course-correction necessary now? Over the last two months - and indeed, for several years before that, we have been struggling with these questions. The two Master Plans were the official attempt to answer these among several others, all related to the development of the city. Now, given all that we went through in these monsoons, some updation of these plans is probably in order. I'm not a PWD engineer or an IAS officer in charge of these questions, but this is an exploration of these questions from an ordinary citizen's perspective.

Floods and cities

Chennai is built on a large flood plain, and the very easy answer to why the city inundated is that the geological purpose of a flood plain is to be flooded. This answer is also rather unhelpful, because Chennai is not alone in being built on a flood plain; all major cities around the world are built in similar geographical areas. Indeed, civilisation itself began in the valleys of rivers. Annual floods of the Nile were so important to their society that the Egyptians based their calendar on the day that the waters reached Memphis. Through history, every city has had to deal with the fact that nature will occasionally try to wipe it off the map.

Despite this, we keep coming back to the floodplains to build our cities, because despite the danger, they are the place where most of our social and economic activities can best be performed; whether it's agriculture or industry, flat land with abundant water and access to riverine navigation is always nice to have. The flood plains of river valleys are the best places to live.

And yet, by living here, we do accept certain risks. Sometimes, these risks turn into disasters, as happened in December. Not only in Chennai, because there were several flooding events going on at the same time around the world, including a major one in Britain.

The questions we need to ask, and the answers we need to seek, are related to how we mitigate, minimise and adapt to the fact that we're living in a precarious situation. What do we need to do in terms of engineering, regulation, management, planning and so on, that will keep us relatively safe where we are?

The plan for the series

Initially, I intended to make this just one or two articles, but the space is so vast, that I'm going to have to split it up into many more. I will be taking up two different threads here, interwoven through these articles. First, I will talk about the geology and geography of how water flows, why and where flooding occurs in general, and what has been done to mitigate and adapt to these things, both in our neighbourhood, and around the world. I will be introducing different techniques we can use to map and understand these things, including maps, satellite images, ground surveys and so on. This is important because we need to know how to know all these things.

Second, Chennai is not a single entity, no matter how much we may wish it to be so. Different areas area vastly different in terms of drainage, and need to be treated very differently. We will explore the efforts of the past, and where they succeeded and where they have failed. Additionally, a personal qualm I have with the narrative to date is that it does not treat the city in relation to its surroundings, and to the larger watershed basin that it is a part of. We - including I myself - have focused very narrowly on just Chennai, and this is just not enough.

As I explore the history and structure of all this hydrology, even if I don't find any answers, I hope to at least be able to ask the right questions. Even at the end, we will only have begun.

Next time, I will start by talking about the structure of the city, and try to debunk a major myth about the flooding.


1 Shobana Ramkumar says...

Will wait for others

Posted at 8:28 a.m. on February 7, 2016

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