Thread by @jamewils

"There are reports that 12 generators on Idukki are not functional, which reduces release of water for power generation. High water levels in Idukki dam just before monsoon are not good as the dam does not have spillway," said Thakkar.

#thread 👇

m.economictimes.com/news/politics-…

This Himanshu Thakkar, coordinator at South Asian Network of Dams, Rivers and People (SANDRP) is given space by even by @epw_in.

He is a chemical engineer from IIT Mumbai, making statements with out studying systems.

Let's examine the facts.

First of all, Idukki is having 6 generators, each with 130 MW and total installed capacity is 130 MWx6 = 780 MW.

So I don't know from where Thakkar find additional 6 machines.

Then now out of that 6 machines, 3 are working see the KSEBL Load dispatch centre data

Now his statement that Idukki has no spillway.

My dear @Indian_Rivers people, please understand that, spillway is provided for the reservoir.

As far as Idukki reservoir is concerned, its spillway is situated in Cheruthoni dam of Idukki reservoir.

Idukki is the biggest reservoir of Kerala. This reservoir is formed with three dams viz. Idukki, Cheruthoni and Kulamavu.

The spillway is in the Cheruthoni dam.

So Thakkar statement is false & misleading because this guy made allegations about Idukki releases during flood 2018

Then Idukki is today have 40% of its live storage as of today.

This is true for many reservoirs in India. Why?

Because there was less demand for electricity due to lockdown.

Let that explain by someone.

I will speak about Idukki

Today's Idukki water level is 713.994 meter or 2342.5 feet

Understand that Idukki spillway level is 2373 feet, so the water level is around 30 ft below reservoir spillway level.

Now let's see whether this is extraordinary?

During 2 years, it was higher than today's level of 2342.5 ft

22/5/90 - 2345.92 ft
22/5/93 - 2342.61 ft

2 other years, it was below but close to Today's level

22/05/15 - 2340.86 ft
22/05/82 - 2338.62 ft

None of these years Idukki spilled. Let that sink in

Idukki spilled on 3 occasions, viz, 1981, 1992 & 2018

In the first two occasions, the spill was so negligible as it was 1.196 MCM & 2.774 MCM respectively. Both times this took 13 days to spill this negligible quantity of water.

Then 2018...understand it was repeat of 1924

2018 - seen 3 days extreme rainfall event and Idukki spilled for 30 days and the quantity of spill was 1063.23 MCM.

This is like an epidemic, when your whole State gets 3 days rain which if you place over entire landmass of Kerala, will be around 4.5 m high!

Understand that Idukki catchment then received 800 mm rainfall in 3 days, which is around 26.7% of the average annual rainfall Kerala usually gets!

Relate it with a pandemic & how health systems of Italy & US overwhelmed

Also understand that when Idukki got around 2500 cumecs of inflow, it attenuated the flood by 1000 cumecs and released only 1500 cumecs through the spillways. Please see CWC report.

You should also understand that though Periyar is having 12 reservoirs under control of Kerala and 3 reservoirs under control of Tamil Nadu.

Any type of flood regulation is possible at Idukki & Idamalayar reservoirs. Except Mullaperiyar rest are having insignificant storage

Idukki & Idamalayar holds 2483.29 MCM while rest of 10 Kerala reservoirs in Periyar holds only 172.75 MCM.

Periyar is having 5398 sq km catchment and out of that Idukki intercepts 648 sq km & Idamalayar 381 sq km.

Rest is unregulated, means no regulation possible there

So there is a study done by IIT Madras, which states that if there were no dams the virgin flows at Neeleshwaram (near Kalady) will be 11990 cumecs but the observed flow on 16th August measured at CWC site there was 8800 cumecs.

Blame dams for reduce 26.6% of floods in Periyar

Look at the flood releases from Perinjankutty 3500 cumecs, Muthirapuzha 2037 cumecs, Pooyankutty 1328 cumecs - all unregulated catchment with Idukki outflow of 1500 cumecs!

No we don't bother facts, we love fiction!

IIT Madras categorically says that the river bank capacity of Neeleshwaram is 4200 cumecs. So any flood happen beyond this will flood downstream of Periyar. Look at the quantity of water from 3 unregulated tributaries.

Thakkar came to fish in muddy waters with his expertise then

Also sink in that the floods we had in 1924 & 2018 are 1 in 500 year events, an extremely rare events.

Also understand that 1 in 500 year does not mean that it will happen once in 500 years. I done a thread on that hydrology terminology long back.

Please see this #thread to understand about the flood frequencies

https://twitter.com/jamewils/status/1028660823038746625?s=19

It is easy to sell a perception that the dams caused the floods, curse them, mock the Engineers who manned those dams taking their once in life time chance!

Kerala never recognizes expertise, it is our biggest bane! We love mediocrity and we are jack of all trades!

Literacy without scientific temper, logical reasoning and ability to analyse facts are of no use my dear people.

We will buy the Thakkar as the last word on Idukki and we buy their agendas!

Do you have any doubt? Look at the experts you see in prime tv debates!!!

In my 26 year long career, I dealt with inter State water disputes between 2001-2019.

Let me disclose that I draw more respect from opponent State Engineers, Lawyers, Administrators & Ministers than what I got from my State.

Some allege that I am an agent of TN 🤣

Who cares

I believe that at the end of the day, I have to answer to my conscience.

That only matters to me.

So I don't have a baggage, I don't need anyone's patronage, I did not pledge my allegiance to any ideology.

I am in peace with me.

Let facts speak!

END.

PS: If you want to understand the complex Periyar hydro development, please read my this article in @ThePrintIndia

theprint.in/opinion/in-mon…

This is the article I written in the @NH_India about the Kerala floods. Read to understand the nuances.

I written another detailed piece for the @frontline_india but unfortunately it is behind the paywall.

nationalheraldindia.com/india/in-keral…

I don't agree with the heading of this interview of mine!

Because the Engineers manned these dams got brickbats, they were mocked again and again.

No society will collectively engage to demoralise their Engineers like ours

But listen this interview

Then @EconomicTimes should seriously think about their editorial standards as they give headlines to people, who is peddling certain narratives which is far away from the truth & facts!

But less said the better about our mainstream media.