Climate Change-Ways to Deal With Heavenly Flood Gates

The phrase “Climate change” does not need any introduction now. This global problem has stretched its leg since long but the world has taken initiative to solve it in true sense since just few years back. The bad thing about it is that it’s not local. It doesn’t only punish people contributing but each and every one.

India is affected in a big way from climate change as we see different seasons merging into two extreme conditions “Drought and Flood”. Being a huge landmass we have both of these extremes in our country. There is no escape from this global phenomenon and we have to adapt and use these two extremes to complement each other. As a nation we have to be ‘Climate –Resilient’, a new concept where we are able to mitigate and recover from shocks and natural disasters.

Use of green energy, building and eco-friendly options can reduce our footprints for future but we certainly need some immediate action to solve our water woes. Accepting the uneven distribution of rains in time and place is the first step, as both are here to stay for some time. This year there has been major devastation by floods in Assam and Gujrat and urban floods in Mumbai, Bengaluru , Chennai.

As a kid I always used to wonder that Egyptian and Indian civilizations thrived because of Nile and Ganges flooded leaving  fertile soil on its banks. Floods were a boon once upon a time and   the governing bodies should take immediate action not to waste this resource.

A flood resilient plan includes these important steps-

Restoring River and its Flood Plains-

Most of the rivers of northern India are flooded during rainy seasons for centuries. It has become a disaster now due to settlements’ made close to the banks and controlling the flows by multiple obstacles. Houses falling like a pack of cards on the banks in Uttakkhand floods 2014 is still fresh in our minds. These were made on the river flood plains.

Indus, Ganga and Brahmaputra – which originate in the Himalaya, drain nearly two-thirds of the land area and account for nearly the same proportion of the country’s total water resources. They form extensive floodplains and deltas their river basins are also among the most densely populated regions of the world where human activities have influenced the landscape for several millennia.

There are plenty of news about encroachments on various flood plains but no restoration project comes up while searching on the web.[1]

Floodplain and River restoration is the reestablishment of the structure and function of ecosystems and floodplains as closely as possible to its natural conditions and functions prior to being developed. The floodplains provides capacity for storing storm water runoff, reducing the

(Photo Ramachandra and Majumdar CSE, IISc Bangalore)

number and severity of floods, and minimizing non‐point source pollution. Restoring floodplains and wetlands and their native vegetation are the need of the day. Natural vegetation and ecosystem in the flood plains slows down the flow of water and allows storage of excess water naturally replenishing the ground water. At the same time excess water can be transported to a man-made reservoirs via temporary canals/drains dug up at flood prone places which will be the second step of flood management.

Flood Diversion and Storage projects

An ambitious plan of government is to connect all the rivers of India to divert flood waters to areas where there is less rain. This is wonderful as an idea but not a practical one. Firstly it’s going to take several years and people will keep on losing life and property till then. Secondly there will be no way of stopping hazardous pollutants of one river from polluting a pristine one. Thirdly which seems very insignificant but can change human life drastically is the marine ecology mix-up. We have already seen that effect on marine life by joining Krishna and Godavari rivers of south India.[3]

A quicker and better approach would be to drain flood waters into manmade reservoirs dug up mostly near the flood prone rivers. Water stored in these can be used for human uses or irrigation or just for recharging the ground water.

Urban floods started showing its teeth in 2015, starting with  Chennai .Then Bengaluru in 2016. This year Mumbai was the first to face faced unprecedented waterlogging within few hours of rains. Bengaluru residents woke up to a water logged city on the morning of Independence Day. As I am writing this Chennai is facing sever flooding for the past 4 days. In each of these cases problem starts after a few hours of rains which clearly are examples of water not able to enter into ground or collect in lakes or ponds. This happens when there is concrete everywhere and water doesn’t get open soil to get inside the ground. An area without concrete in every part of the city should be made mandatory as well as manmade Aquifer Recharge Systems. Weatherman’s data tell us that Bengaluru received a years supply of water within a month of rains starting. But instead of storing it we let it flood and then go waste.  Cleaning up the drains to for the quick movement of rain water to a collection pit is one action which can in short time solve the problems of urban flooding and also utilize the excess water.

(http://12.000.scripts.mit.edu/mission2017/depletion-and-artificial-recharge/)

Instead of linking rivers why not first make and link all storm water drains to ponds in each city making them self sufficient in water. Accepting the “Dumptruck Rain Pattern” as a result of climate change and working accordingly can make the society resilient. Some urgent steps to be taken-

Decentralize Disaster and Resilience management to local groups.

Permission for new constrictions only after due diligence of rain water management and storm water drains and aquifer recharge.

Vacant residential units to be taxed doubly.

Cleaning and desilting of lakes ponds etc.

Federal Emergency Management Agency (FEMA), an agency of the United States Department of Homeland Security, in its Climate Change Adaptation Policy, has developed initial guidance on Climate Resilient Mitigation Activities including green infrastructure methods, expanded ecosystem service benefits, and three flood reduction and drought mitigation activities. These are  Aquifer Storage and Recovery (ASR), Floodplain and Stream Restoration (FSR), and Flood Diversion and Storage (FDS). It’s encouraging communities to engage in projects on the storage of flood water to deal with drought conditions.

‘Climate resilience’ or the ability of people, cities and countries to mitigate and recover from shocks and crises should be developed in order to reduce chronic vulnerability and enable sustained development. It’s time for us to take action.

[1]http://indiatoday.intoday.in/story/delhi-learns-no-lessons-from-chennai-allows-construction-on-yamuna-floodplain/1/552139.html

[2]http://wgbis.ces.iisc.ernet.in/energy/water/paper/urbanfloods_bangalore/floods_city.htm

[3]http://epaperbeta.timesofindia.com/Article.aspx?eid=31809&articlexml=Interlinking-of-Krishna-Pennar-fraught-with-ecological-challenges-15082016005022

Featured Image source

http://www.firstpost.com/photos/india-gallery/heavy-rains-lash-chennai-leaving-large-parts-of-city-submerged-and-everyday-life-severely-impacted-4191059-2.html