Thread by @jamewils

I am ready for a debate with any of these experts who are blaming KSEB for mismanagement of dam operations.

Stop sweeping statements! Come out with data and talk sense!

Don't lead a literate society to blind spots!!

When our catchment areas had experienced one third of the annual rainfall within 4 days pinch yourself...Can you believe it?

& the Engineers managed efficiently and contained these floods even when you had a 1 in 1000 year flood!

Please don't destroy their morale!!

This is the hard evidence of 4 days of non-stop extreme rainfall

Idukki -811mm (Idukki Dist)
Pamba - 344 mm (Pathanamthitta Dist)
Kakki - 915 mm (Pathanamthitta Dist)
Kuttiyadi - 954 mm (Kozhikode Dist)
Idamalayar - 644 mm (Ernakulam Dist)

Understand how much water is received at Aluva-Kochi belt

U have controlled releases from Idukki & Idamalayar reservoirs (1460+1019 MCM)- which u gets once in a blue moon.
Mudirapuzha system of 6 small reservoirs with total 162.5 MCM - spills in every year

U have a Lower Periyar Dam with just 4.5 MCM capacity which receives Idukki and Mudirapuzha flows. This dam also receives uncontrolled releases from Perinjankutty tributary!

Then there is a Pooyankutty tribuatry with no dams, drains along with Idamalayar to Bhoothathankettu

So Bhoothankettu Barrage receives spill water from Idukki & Idamalyar, Uncontrolled Pooyankutty & Perinjankutty, Lower Periyar, Mudirapuzha group. This is the last point of control in Periyar, with no appreciable storage

Upto Bhoothankettu, your Periyar catchment is 56%. But understand that there is only two storage reservoirs, we have any control over flow...LP spills during all monsoon, Mudirapuzha group spills more than 50% of years.

U have a 44% catchment below Boothathankettu- UNRESTRICTED

So let's look at how much water was discharged by Boothankettu when Idukki & Idamalayar spill peaked?
Idukki - 1500 cumecs (52972 cusecs)
Idamalayar - 1400 cumecs (49440 cusecs)

Boothankettu - 7700 cumecs (27192 cusecs)

&Imagine contribution of that 44% catchment below to Aluva

If you had flood say thank you all these enviromental champions who sabotaged Pooyankutty and Perinjakutty reservoirs and say thanks to that unrestricted flows from these rivers!!

I am still searching for hard data of how much received after Bhoothankettu, if I analyse the trend of what Idamalayar experienced close to Kochi, we can guess 50% inflow from upstream catchment..That is more than 1 lakh cusecs!

So you had anything like more than 4 lakh cusecs in Kochi as in 1924. Just remember that Idukki at that point of time

Got: 89417 cusecs
Released: 52972 cusecs

If it failed to do so & pushed another 40,000 cusecs, imagine the catastrophe!!

When you say 800-900 mm rainfall in 4 days as man made disaster & blaming the Engineers who manned these dams whose heroic acts given you at least some relief, however small, it's so significant in a flooding, I am sorry to say WE BECOMES A THANKLESS SOCIETY WITH QUACK THEORIES

My Excel Table has an error, 2017 should be read as 2018...error due to oversight regretted

PS:

I am just talking of Idukki alone here, I will soon collect the data from Idamalayar & other 3-4 reservoirs in Periyar System which had some absorbing capacity. They all played their own small role, to avert this disaster turning into a catastrophe