The article linked below asks the question whether Mumbai can really even be flood free and provides certain arguments to claim that making Mumbai flood free is indeed a hard task and a long way off since making it flood resistant is something that's going to be relevant in the future. The article also highlights the impending danger and the increasing trend of the severity of the floods
To this end we could perhaps discuss certain ways wherein we could aim to make the city flood resistant. First, the article talks about the saucer like topology of the city and how rainwater would naturally flow to the centre of the city and collect there. Since 2D modelling of urban floods is only a recent development, rainwater harvesting techniques have seen applications in not only preventing these floods, but also collecting rainwater for future use. Perhaps some RWH techniques could be used since there is a natural stable position for the rainwater to collect.
The article also cites recent construction projects, topsoil erosion and land reclamation which contribute to the increasing severity of floods. It would be nice to discuss certain ways to make these construction projects more environment friendly to the extent that it doesn't contribute to the flooding.
Article - https://www.moneycontrol.com/news/opinion/why-a-flood-free-mumbai-is-wishful-thinking-7032731.html
All thoughts and inputs would be appreciated!
That was very helpful, thanks!
That's a great question!
From an environmental point of view, possibly one of the best options to adjust to flooding would be floodplain regulation. This entails obtaining the most beneficial use of floodplains while minimising flood damage and costs of flood protection. Even then, however, structural controls might sometimes be needed.
But the main objective of floodplain regulation is that of reducing physical modifications of the floodplain, and this needs to start with flood hazard mapping. This would provide information on the floodplain for land use management and planning, as well as delineate past floods to identify reoccurring frequencies and patterns of flooding. This type of approach is very important and should be considered before any regulations and/or interventions are implemented.
I hope this was helpful!
That's really insightful and well written. Thanks!
Hi! I think this is a really interesting question. To be flood free implies either:
we have rainfall that is lower than the capacity of our natural and artificial drainage systems
Or
We have enough capacity in our drainage systems to accommodate the rain we receive
Therefore, this question becomes an issue of 'mitigation' and 'adaptation'. To address the first issue, we would need significant mitigation of greenhouse gases in the environment, through lower emissions and higher carbon sequestration or capture through natural or artificial means. When the carbon dioxide in the environment approach acceptable levels, it can help to stabilise the climate patterns on a global and local scale and thus also regulate climate on a more local level (i.e. microclimate).
The second issue is an issue of increasing drainage capacity. This is a relatively more easy and quick-fix solution, because municipalities can spend money on widening drains or removing blockages like plastic from them. However, there is very little awareness of ecosystem services provided by nature in and around the city, be it trees or mangroves. Thus, there is little emphasis on conserving and restoring nature in our cities as a natural way to deal with climate change induced heavy and inconsistent rainfall. When both natural and artificial systems are enhanced, it can provide a unique opportunity to deal with the monsoon.
It is important to note that both adaptation and mitigation are important to deal with climate change, because they are both in synchrony with each other. We should diversify our efforts to make Mumbai flood resilient or able to bounce back from adverse situations. It is easy to go for the artificial adaptation measures, as is seen in the strategy of Mumbai's municipal corporation. We must ensure that natural adaptation measures are also given equal importance, along with addressing the root of the problem which is climate change.
Also, me to climate change and bad urban planning: