Floods in Kerala: A few Thoughts: Part I

Disaster in Kerala, 2018: Natural?

"down poured the skies; we were least prepared to receive"

With a consistent heavy downpour, rise of water level in rivers and other water bodies is inevitable. But why flood? When there is not enough space (rather cross section) to accommodate the waters, water will spill over the banks, in to adjoining land (see causes of flooding, items 4,6 and 7 are of particular importance). It's sheer common sense, but where is land?

Dams and Flood Control

Dams do an awesome job of plugging outlets of rivers through valleys, thereby building reservoirs. But there is always a limit: Capacity. Rise of water level above the crest of spillways bring in an alert situation. The closer it is to the maximum allowable level, the greater the risk. Dam Safety Authorities are then forced to release excess waters in to the downstream by partially or fully lifting the radial/other gates (shutters). In essence, dams form by flooding upstream and empty by flooding downstream.

Monsoon Havoc

The recent rains: Monsoon in during June-September  is supposed to be the weakest of the two monsoons in Kerala, but this year the scenario was different. Continuous, heavy cracking down of skies resulted in excess runoff to the streams and then to rivers. Interestingly, the waters flowed in to the catchments of dams across the state, thus rising water levels that pressuriesd the gates and thereby the authorities: KSEB, Irrigation and Water Authority. As mentioned above, and it is again common sense that the excess waters need to be let out of the reservoirs, but slowly and safely. The authorities waited, as is normally done, till the very last moment, with hope that rains may subside ...but it went beyond all predictions.

With water levels reaching the alert situation, with Mullapperiyar Dam allegedly releasing waters in to Kerala Side, a trial run was done at Cheruthoni dam, after a gap of 26 years since 1992. Waters cascaded down the spillway to the pleasure of crowds cheering, and clicking snaps, welcoming the beautiful sight it was a feast to the waiting OB vans of media too. But behind this beauty lied a danger. The rains continued, and the other shutters were to be opened in succession. Waters started gushing down the spillways in to a narrow Cheruthoni river, with construction and other infrastructure flanking its banks. Flood waters made their way down, passing under the old Cheruthoni bridge, threatening its existence too. 

Above : Radial gate of Cheruthoni Dam opening

(Photo Courtesy: The  Hindu)

So far it was fine, but the anticipation of a dry land downstream had caused excessive constructions to spring up on either sides of the Periyar river, bringing the available cross section of the river to a bare minimum. As always, nature decided to work its forces: making way by washing away obstacles in front and on banks.

The opening of cheruthoni dam gates triggered emergencies in the dams downstream, and they all had to lift their gates to release the excess inflow. It may be just a coincidence that the opening of gates of cheruthoni dam was on August 9, the day a deadly bomb was dropped on Nagasaki, in Japan, seven decades back. Thus water bombs started ticking. Alerts changed colours again. Media hypes added to misery. The already choked Periyar river found this too hard a nut to crack, and continued eating away the banks. as on 22nd August, 

But that was not all. A story was evolving around the downstream side of the dams too. The rains came downhill, washing down debris in to streams that were tributaries of Periyar, and being victims of unscientific, illogical construction and fill ups (by wastes and earth).

The fate of other rivers in the state were no different too, most were overflowing, especially Bharathapuzha and Pamba. Shutters of many dams, especially Malambuzha were opened for the first time in history.

Rerouting rivers

Many rivers, e.g. in Kozhikode and Pathanamthitta, changed paths thanks to flood. The paths of least resistance were followed, and that meant human inhabitation would be under threat. All on a sudden people found water rising above ankle level and going higher and higher to fill half floor of houses....

Relief camps were called for. Many were on the brink of death, partially downed and chilled. 13/14 became the new fraction in the days to come.

Landslides

Landslides is no news in India. It happens almost any time, especially in monsoon. The land slopes yield to excessive pressure build up of ground water. This, coupled with levelling of hills, construction on top of unstable slopes, diverting streams and plugging of water outlets (nature's own pressure release), triggered massive landslides across the state that took a big toll on life and property. Many including children were buried alive in peaceful sleep. Idukki and Wayanad were the most affected. 

The impact

What was supposed to be a routine monsoon suddenly made Kerala witness streets becoming rivers, and house compounds islands. Boats on roads became a common scenario, and death tolls continued to rise with people attempting to get in to raging water in vehicles or otherwise. Life was brought to a standstill. Traffic (land and air) was totally disrupted, making life even more difficult. The waters continued to rise, and started affecting places that normally were least affected, especially Chengannur. At many places first floor of houses became flooded too. The water literally started defining it's own route and boundaries, and took away whatever was encroaching upon it's right of way. Mountains redefined their topography to a more stable lay-out. But the price paid was too big to handle by the state. Debris were carried away and deposited on bridges and banks, the rivers seemed to say: "it's your garbage, you keep it".

Above: A morphed version of satellite images, created from two images prior to and post disaster

Above Satellite images on disaster, edited
(original images courtesy: https://earthobservatory.nasa.gov/images/92669/before-and-after-the-kerala-floods)

"At least 357 people have died in just over a week as floods and mudslides hit amid a punishing monsoon season. More than 350,000 people have had to abandon their homes and are being sheltered in 3,026 relief camps. Thousands are still stranded, with The Times of India reporting at least 10,000 people are stranded in one village alone after all surrounding roads were submerged." reported express.co.uk

Photo Courtesy : DD News

 Above: Nedumbasseri Airport, On the bank of Preiyar was not surprisingly flooded

(Photo Courtesy: The  Hindu)

 Above: Flooding in Kochi
(Photo Courtesy: theatlantic.com)

Many buildings collapsed under water pressure. Many were wiped off and buried by landslides. Roads were cut through by gushing water, as if waters were building new culverts at the 'right' location. Railway tracks at places all on a sudden became bridges with no ballast.As waters receded, it left behind thick blankets of mud inside houses and damaged most of the household items and vehicles and what not!

 Above : Aluva inundated

(Photo Courtesy: Deccan Herald)

 Above : Flood waters circumvent a culvert
(Photo Courtesy: Youtube video)

  Above: Bridge approach Washed away,  Munnar
(Photo Courtesy: Outlook Magazine)

 Above: Bridge approach Washed away, Kozhikode
(Photo Courtesy: Mathrubhumi Daily )

 Above: Damaged Kollam Shenkottah Track 
(Photo Courtesy:The  Hindu)

 Above : Flooded Kuttand
(Photo Courtesy: theatlantic.com)

Above: Waters gushing down to Periyar; Cheruthoni

(Photo Courtesy: Indian Express)

Cheruthoni: Before and After

(Original photo courtesy: Video Vettai, youtube)

Above: Nature has blocked gates to gaining knowledge that makes us exploit and torture her
(Photo Courtesy: Times of India)

Lessons Learned

The floods and landslides taught us many priceless lessons, though not necessarily new:

1. If we don't give way to water, water will find it's own way.

2. If we level hills, hill will redesign itself.

3. If we dump wastes in rivers, they will come back to us.

4. We have to respect nature.

5. Our infrastructure is not adaptable, in many places.

6. above all: No one is invincible, and everyone is at mercy of nature.

The blame game

While there are speculations on the timing of dam shutter opening, let us focus on the other side.

Let us assume that the dams were operated sequentially in a technically sound manner. Why then there was this much of a flood? As the chairman of KSEB said, we are ignoring the rainfall outside the catchment of dams, that comprise 78 percent of watersheds. But is that all? We must be thankful that no big landslide occurred in the Idukki catchment, or like the Vajont dam disaster in Italy 55 years back, it would have proved all dam safety systems as useless.

Where are the wetlands?

With a lot of arguments going on as to if a land is "wet" or not, a lot of unauthorised landfill operations and subsequent constructions have taken place in agricultural fields and wetlands, which had made this sort of a Human Aggravated Disaster (HAD) , if not a man-made disaster. Wetlands are like sponges that absorb the rain waters, replenish ground water and prevent saline water ingress to land. They marshes are fed by narrow streams and rivulets, that bring water from the springs in hills. Our state has a blessed topography, but.. Human activity, excess use of plastic and ruthless dumping of garbage had filled up wetlands and clogged drains (natural and artificial); well many modern artificial drains had a history of being natural. Over the filled wetlands rose beautiful houses with compounds mostly laid by interlocking (?) blocks, all above road level with a smooth ramp going to the  roads.... An empty bucket, and a bucket full of dirt kept under tap will have more water and dirt flowing out of the latter. This happened in the case of wetlands too. Waters coming from the hills and compounds had no, or very few wetlands to absorb them, and they could not flow in to rivers which were already overflowing .... the result? welcome waters to our streets, homes, offices and business. 

Highways or continuous Earth/rockfill dams?

It must be noted here that while being an absolute necessity for the networking of places, highways pose a grave threat to the environment. In the first place, they divide a land in to pieces. Water finds it difficult to cross through the narrow culverts that are mostly incorrectly located. Besides, landfills are common alongside culverts. What are culverts for, then? As seen in the case of roads at Malappuram, and elsewhere (as shown in a video snapshot), the flood water made their own passages through roads, and around culverts and bridges (remember the Bihar floods?, if not, kindly see here : bihar floods). 

Design technologies for pavements are limited to a few centimeters, and do not normally cater to what happens underneath, even though there is a filling and compaction procedure for embankments. And obviously, they are not meant for natural disasters, or, are they? 

And railway tracks?

Though similar to highways, railway tracks do have an advantage that the ballast is permeable medium for water. That being said, the ballast found itself weak to resist the gush of flood water wich washed away the soil underneath. The culverts under railway tracks are much more well designed, compared to the narrow pipes or concrete boxes in highways. Where there was ballast-less tracks, the tracks got flooded. 

Flooding in the capital city

With very few and smaller dams unlike Idukki, Thrissur, Palakkad and Pathanamthitta, Thiruvananthapuram was expected to be least affected but for the routine city floods and those in low lying areas. But this time?

Above: Flooding in Killiyar
(Photo Courtesy: The  Hindu)

The rivers Karamana and Killiyar, and the ignored one, Thettiyar overflowed exposing many flaws in land and water resource management. The main thodus: Amayizhanchan Thodu, Ulloor Thodu and Pattom thodu grew wider, and entered houses. This certainly was HAD. The once natural thodus were "protected" by side walls (who is protecting what?) and thus narrowed, and the depth was reduced considerably by silting and garbage bags. Roads to Pattom, except the main road got cutoff, especially on the western side of the main road.  Amayizhanchan thodu overflowed and made streets it's new path near cosmopolitan hospital, treating compound walls as dams and demolishing them in the process of own route making. Parking lots got flooded at hospital. Waters flooded almost the entire ground floor. Pattom thodu, though less aggressive, flooded too, so did the kannammoola thodu. Floods in Thiruvananthapuram showed beyond doubt that rains and dams alone are not major cause of floods, but humans  are.

Above: a rough inundation map of the Thodus in thiruvananthapuram, near Pattom, 

based on physical observations (Thodus are the central lines).

Above: Rerouting (blue) of Amayizhanchan Thodu in thiruvananthapuram, near Pattom

 (a)

 (b)

(c)

 Above: (a,b) Overflowing Amayizhanchan Thodu, near Kannmmoola . 

(c) A road flooded by the thodu

Below: While thodu is full, the side drain isn't. No connection with dams, mind you.

Photo: Author

 Above: Road opposite Cosmopolitan Hospital, towards kuzhivayal.

Photo: Author

 Above: Amayizhanchan Thodu, A day after the flooding near Pattom

Photo: Author

Above:  The Thodu decided to take anew route here

  Above: Amayizhanchan Thodu left these debris on a construction machinery. 

A day after the flooding near Pattom

Photo: Author

   Above: This was once a road, now blanketed with sediments now

Photos: Author

Above: New route for the rerouted Thodu 

Photos: Author

   Above: Flood marks on compound walls, Kuzhivayal, near Pattom

Photo: Author

   Above: Why gates? A rerouted Thodu made it's own entry to the low-lying compound

Photos: Author

   Above: Rerouted Thodu found a stair down, through the porch

Photos: Author

 Above: A rerouted Thodu made it's own way out of the compound

(A pilaster supported compound wall proved no match to the rising water thrust, which came down as through a spillway)

Photos: Author

Leftovers in another compound

Photos: Author

Above: A recreation of rerouting of Amayizhanchan thodu near Pattom Cosmopolitan hospital.

Kazhakuttam area witnessed flooding over a wider area, thanks to unscientific diversions and constructions across Thettiyar (smart-city-we-killed-our-rivers) and its tributaries. Had the waters been from dams, the flooding would have known no bounds.

Above:  Inundation of Thettiyar in to Technopark campus is a tell tale sign that no rivers shall be attempted to be harnessed by massive sidewalls (Pic. Courtesy: The Hindu)

Above: Thettiyar and tributary overflowing resembling Bharathappuzha in Technopark

Photo: Author

 Above: Houses trapped in an overflowing thettiyar

Photo: Author

Above: Public intervention and Disaster Management Team was necessary to 

break a road to let waters flow (through an unscientific culvert, under water, Technopark)

Photos: Author

Above: the same place, 5 days later: who in the world could ever dream to contain a river in these two pipes and a portal, that too with a wall blocking the flow?

Photos: Author

Karimanal and Nalpathadippalam were no exceptions

Access to these places were cut off consecutively for the third time this year, but this time it was way too severe.

 Above: Flood waters from thettiyar spread far and wide in to the houses at

Thampuranmukku-Karimanal region

Photo: Author

   Above: Flood waters from thettiyar drowning houses near Nalpathadippalam (on higher side)

Photo: Author

   Above: Flood waters from Thettiyar flowing dangerously close to the foot bridge at Nalpathadippalam. Access to the houses near bridge and downstream was totally cut off

Photo: Author

   Above: Flood waters from Thettiyar reaching HFL at Railway bridge at Nalpathadippalam. 

Photo: Author

Above: Flooded houses near Thettiyar, Nalpathadippalm. The last picture shows a house,whose rear wall had collapsed, and belongings were washed away 

(information Courtesy: Sri Sulaiman).

Photos: Author

Warnings were ignored

The flood raises many questions. Why were warnings from Ecologists and Environmentalists ignored? Is the land downstream of a dam to be treated as dry? A ten year old documentary says the land at Cheruthoni, downstream of Cheruthoni dam was demarcated as a no-construction zone. But the fact? How could people settle on the banks of Periyar, and Pamba, (or any flowing water body) assuming the river will always be outside their compound? What were the marks of "possible water level if shutters were opened" for if not for regulations? Why construct on the foot of a deep cutting? and worse, why dig slopes under buildings? Why banks of streams and rivers be "protected" by stones, and why are they diverted? Why fully cut open hills when there is a possibility of tunnels? This has reference to the Akkulam NH bypass. These questions need to be addressed while we prepare to avert future catastrophes. 

After the flood

Relief operations were executed by a wonderful teamwork. Every human had a part to play. Now life has to come back to normal. A huge task lies ahead: clearing the debris, mud, material and items rendered useless, and rebuilding the houses, other structures and infrastructure. Another big environmental issue is on the wait: threats of epidemics. Many animal carcasses and stagnant vegetation lie stinking. And the water supply and sewerage systems of cities? While relief camps are a success, is anybody bothered about the massive amount of solid wastes that would result once camps are closed? every snack pack, food bags, packing material, drinking water bottles, diapers, napkins, cleaning tools, and even masks and other gear will be left out, leave alone the organic wastes. Yes, it is illogical to think of a sustainable packing at an emergency, but the aftermath? 

As for future floods, a regulation (or its enforcement) on river banks, and hills, and other sensitive areas near dams,  is a must; so is the establishment of a disaster mitigation, monitoring and management facility. Adaptive construction should be made mandatory at river banks. But everything will be like lines on water, if human "intelligence" outshines technological advancements. 

Let us conserve what we have, let us make this flood a turning point to build a Sustainable Kerala. We need to reclaim our wetlands and rivers. As always, we have to uphold and comply with "Prevention is Better Than Cure". Else, until we find a way to send water to outer space to be stored there until demand arises, we will have to stay in waters with more and more area being submerged over years to come. 

(Continues in to Part II with more information I am currently compiling from various sources on floods in the capital and other districts)

Special thanks to Mr. Sanjeev SJ of Environmental Protection and Research Council, who had been with me always, and in the quest at Kazhakuttam, and to my brother K. Mohanakumar, for the updates on floods at Pattom. Feel free to comment, your comments make me do better.