Thread by @jamewils

Understand your rivers and reservoirs.

KSEBL has 18 reservoirs, Irrigation Department has 16 reservoirs and KWA has 1 reservoir and TN PWD has 4 reservoirs in Kerala. These 39 artificial lakes are only storing water, dont confuse with dams & reservoirs.

There are many small diversion structures and small barrages too. But they do not store water, they are regulation structures.

Some reservoirs in Kerala under KSEBL is formed with multiple dams. Eg: Idukki has 2 dams, Kakki 2 dams, KL Sholayar 3 dams, Banasurasagar 8 dams

During 2018 floods, we started making hue and cry about opening 59 dams!

Understand that spillways are provided for reservoirs to negotiate the floods, so the single reservoir formed with multiple dams are having a single spillway & so it's reservoirs are spilling

Also understand that out of 39 reservoirs, only 7 reservoirs have more than 200 MCM capacity & they together store 74% of the storage capacity of the State.

Rest of the 32 reservoirs are very small ones & they mostly spill during every monsoon season.

Many in media and public confuse with installed capacity of the power house and storage capacity of the dam.

Lower Periyar 180 MW has a 4.5 MCM reservoir.

Idamalayar 75 MW has 1018 MCM reservoir.

This confusion creates wrong perception too!

There is a sea difference between a run of the river scheme and a storage reservoir.

Both constructed with different roles attached to them.

Lower Periyar is a peaking station gets water from 4 upstream power houses and its storage capacity exhaust if I run 180 MW for 12 hrs

While Idamalayar is a storage reservoir created to cater mainly the Irrigation and drinking water needs of Kochi city. It is a low headed station and the water stored here in monsoon season has a lot of bearing on the water security of Kochi. So this is a conservation system.

Similarly Kerala Sholayar is the lone storage reservoir for Kerala in Chalakudy river, once monsoon is over Poringalkuthu and Chalakudy river depends the storages from this dam for its lean needs. Understand that there was no Athirappilly water falls in summer before Sholayar dam

But those are historical facts, still records available in Govt archives the letter wrote by a trade union leader describing their plight of drinking water scarcity in Chalakudy river & urging then CM EMS to construct Sholayar dam to ensure drinking water for them.

How many of you know about the roles played by Idukki & Idamalayar dams in 2019 floods to absorb a huge portion of the flood in Periyar without a spill discharge when Kochi airport closed for more than 10 days.

Perception vs facts is always in battle here.

Kerala just stores 6.6% of its runoff in its reservoirs, without that stored water we will struggle in summer.

As our ground water recharge is limited to below 6%, thanks to steep topography & porous soil strata, we have huge limitations here too.

Idukki has 3, sorry for typo

Our neighbour TN stores around 75% of the runoff as ground water due to their topographical & geological advantage. They also stores almost 30% of the runoff and benefitted from the storages in neighbour States.

So as far as water conservation is concerned, they are far superior

Many accuse KSEBL as greedy ones only having an eye on profit when our reservoir storages are concerned.

There will not be no Muvattupuzha Valley Irrigation Project without Idukki storage.

No Pamba Valley IP w/o Kakki storage.

No Chalakudy IP w/o Sholayar storage

No Periyar Valley IP w/o Idamalayar.

A good portion of Kuttiyadi Irrigation Project & drinking water supply of Kozhikode is met from storages at Banasurasagar & Kakkayam by KSEBL.

They cater multi purpose needs, we judiciously manage our reservoirs for meeting lean period needs

Before we talk off late about integrated river basin development, our engineers in 60s & 70s sat together and formulated projects which meet this present day integrated basin development.

There are historical & economical reasons for that approach too.

Because of the undulating topography and narrow width, here stand alone Irrigation projects has its own limitations. If you charge dams cost to an Irrigation project, the project most of the time fail to meet cost/benefits ratio. This was valid in 60s/70s, when funds were scarce.

So Kerala gone ahead with power projects taking advantage of high heads in short distance, to build economically viable HE Projects, which gets planning commission approval w/o much issues then.

So we consciously build small weirs/barrage using tailwater for Irrigation

That time the lean flow in rivers were sufficient to meet our drinking water needs. More over we had wet lands, Wells and less population, so we did not bother much about drinking water releases/environmental flows from Irrigation Projects under HE Storages.

When we entered into interstate agreements our forefathers did not blindly signed them. They analysed it thread bare & fought for fair share with tooth and nail.

Diwan of Travancore then tried to study the effect of summer flow in Periyar due to Mullaperiyar. Surprised? True!

Parambikulam Aliyar Project Agreement was heavily bargained with C. Subramanian & Kamaraj by none other than Late Justice V.R. Krishna Iyer.

Mullaperiyar bargained over 24 years with British.

All these has interesting histories, but none in Kerala care to learn.

How many of us know how the Travancore Chief Engineer, a British man fought with Madras Presidency against altering Mullaperiyar storage level in 1908 from 144 ft to 152 ft?

The story of 999 lease deed? In Kerala many believe its an additional 9 by some mischievous fellow :p

Like Tamils believe that Major Pennycuick sold his property to build a dam in Kerala?

Even a dam built in 1895 has many myths associated with it to suit our narratives. We look at it through a convenient prism suiting our beliefs.

Facts are a casualty here.

None in Kerala made any attempt to study these instead we listened to fictional narratives.

Kerala has no institutional memory, no documentation, no continous strategy.

We are like those blindmen narrating about that proverbial elephant.

When I appear before the Parliamentary Standing Committee on Water Resources to depose on floods of Kerala, the intelligent and probing questions posed by most of the MPs, was an absolute surprise!

They want to understand the nuances & listened and appreciated our answers.

While Kerala shrunk that debate to score mere political brownie points & rather than understanding the complex limitations.

So we blame many things, from the poor farmers struggle to meet their ends at ghats to dam engineers.

We are cyclops as we don't want to see the truth.

These are the details of 18 reservoirs which are the control of KSEB

Biggest Idukki - 1460 MCM
Smallest Sengulam - 0.39 MCM

There is a typo came in this tweet, due to oversight, I said Idukki has 2 dams, sorry.

Idukki reservoir is formed with 3 large dams viz. Idukki Arch Dam, Cheruthoni Dam and Kulamavu Dam.

https://twitter.com/jamewils/status/1307665627927072768?s=19