One of my first blogs was on this subject only. Now in the wake of
Kaveri issue again raised, am tempted to write another on the same subject with
different details.
The point remains the same that we need to seriously assess the serious
impact of large dams over the society & country as a whole Vs the benefit
it brings. And assess alternatives also. Several water experts over recent
decades have damned the large dams. Large dams across India (world) experienced
a lot of ill effects to the society, decreasing soil quality, decreasing agriculture
yield, decreasing fisheries, bringing riparian states on almost war. Is it
really a boon or a bane?
The concept of building these large dams itself is modern & is from
British colonial era. It was never there in the ancient past nor in medieval
period. And it is wrong to say, it is a modern science & technology
evolution & a great gift to mankind. Indians & Chinese have built
formidable walls, forts like, Kumbalgod fort, Chitradurga fort &
magnificent temples. Could they have not
build a simple 120ft height by 150ft length dam? They have indeed. But not
rampantly like modernists. The Great Cholas have built several miles long tank bund which is standing formidable
even after a millennium (not decades, not centuries but millenium). It has come
to rescue the water guzzling metro, Chennai today. Refer the Ref2 &3 links in
end below. But the difference is they built scientifically a tank bund but
not a DAM unscientifically across a large river.
So the point is – All that is British OR all that is modern is not
really scientific. All that is ancient is not just aesthetics and art. It has
science & long, very long, very very long vision for the society, its
prosperity & harmony.
Now the world is seriously debating it. If you google for “decommissioning
large dams” there are several scholarly books & articles you get, but most
importantly ‘developed’ nations like US & European countries are marking
several dams for decommissioning due its hazards outweighing its utilities.
Pity is that in India, government in 2004 commissioned some 100+ major
dams in pristine, virgin Northeast region rivers. We are more British than the
Brits themselves now. Should we not rather follow our own ancient scientific
approach?
Kaveri River Case Study
Here we’ll take Kaveri as a typical river system for study. It is very
typical & our understanding here can be applied across any river system anywhere
in the world. The purpose is to understand whether large dams benefit society
in long run OR they are futile & unsustainable.
Across Kaveri we have 2 major dams – KRS in Karnataka and Mettur dam in
TN. Some details on history, river dispute, tribunal reward, issues, and
solutions are given in the Reference links in the end. Almost all of them deduce
that the tribunal award is equitable in good monsoon condition. But in a bad monsoon
year like 2012, 2016 it is not proven good for Karnataka. So the ‘distress
formula’ is not good. The solution is – all Karnataka MP s should put up a
united front, call for friendly resolution with TN MP s with central
arbitrator. Propose solution to Tribunal and get ‘distress formula’
reformulated. That’s it. But the first step – ‘Karnataka MPs’ putting up a
united front is where we fail. If we pass that, then all else will pass.
Now it will be foolish to talk about decommissioning the dams. But is
it fully utilized? What it takes to utilize fully. Let’s focus on those
answers. For that let’s understand some of the basics. Then it will be easy to
understand if it can be utilized fully. If so, what it takes.
Natural River Course: Kaveri runs for about
700+Kms. A river starts from mountains. It gathers waters from several streams
along. After long, it hits plains & it widens. Along the route several ‘tributaries’
join it to make it a big river. As it nears the end of its journey, at the
mouth of its joining the sea, it divides into ‘distributaries’. These
tributaries and distributaries make up the natural river system. The fig1 shows
the same.
Tributaries are the wealth of the agriculturists. Distributaries are
life line for fisheries.
The socially best and scientific way to sustain
good economic life is to build small check dams or tanks along all tributaries.
The main river will have primary tributary for which secondary will be there
for which tertiary will be there and so on. Our ancient kings used to aid villages
build & maintain their own tanks, bunds, Kalyani, Pushkarani, etc., and
there used to be beautiful connected tank system too. This would ensure
excess water flows to the next lake and then next and so on until it reaches a
tributary. This controls flooding also. Since all along 700+Kms of Kaveri
running, there are tributaries, it is prudent to implement it in a harmonious way.
Advantages of this system are:
- The tanks would ensure ground water level increase in entire surrounding area, giving equitable ground water to all agriculturists. However no bore well should be allowed. Else it would make unequitable share in favour of the rich
- Social harmony: Small tanks maintenance is in hands of villagers. So they would maintain only their water and not fight for others.
- Decentralized water governance at local level. No fight with central/ state government/ Supreme Court etc., what you get from God through good rain is what you manage with.
Limitations of this system are:
- It cannot provide water for large cities like Bangalore, Mysore. They have to manage their own lake systems.
- Large amount of water flows in the Main river to the sea. Modernists term it as waste of water going to join sea. But traditionists argue it enriches the estuary & fishing; and economic water transportation can be encouraged all along 700+kms;
But if villages are made self-sufficient and prosperous, then cities
will not become behemoth centralized population crumbling by its own
unmanageable weight.
Large Dams System: Here the large flow of water in
the main river is envied. A large dam is constructed across. The purpose is to
hold and distribute water to arid areas. So large dam system means – Hold large
water and create artificial complex distributary system. Scientific way implemented
in ancient times is to do small check dams across small tributaries & leave
governance to locals. So comparison is quite stark. Few points for comparison
given below:
|
Large
Dam System
|
Connected Tank System
|
|
Large onetime cost; Decades of Time to construct;
|
Small time; Small cost; Multiple places
|
|
Artificial distributary system; Large land
acquisition & displacement, rehabilitation
|
Natural tributary system; No land acquisition; No displacement, no
rehabilitation
|
|
Desilting is army like operation once in a decade or
mostly never
|
Desilting is every year service by few, creating job
for locals & incentive is the silt as fertilizer
|
|
Distributary canal maintenance is by State
Government
|
Maintained by locals; By the people, for the people
|
|
Area coverage is for max 40-50kms length; And area
in that length; About 2000sq Kms;
|
Area coverage is all along 700+ kms; Lakhs of
sq.kms;
|
|
Worker is employee for salary
|
Worker is the beneficiary of canal system
|
|
Farmer breaches canal, bribes official. Diversions are
done illegally. Locals don’t govern anything. So illegal guy doesn’t fear wrath
of locals. Government cannot punish him for his illegal structures, bunds,
diversions. So illegal thing is incentivized and not punished leading to
social disharmony
|
Locals govern canals & tanks. Locals admonish illegal
guy locally. So farmer is incentivized to be righteous and admonished for being
wrong.
|
|
Distress time, Rain deficit time: Blame government,
supreme court, burn buses; Anger spills violence
|
Distress time: Stay put & pray for better rains; Equitable impact
to all farmers; Consume less;
|
|
Encourage large cities; Concentrating large populace
in one place & provide piped drinking water; Pumping stations increase
carbon footprint. Consumers don’t realize cost of complexity
|
Encourages decentralization of water management.
Encourages villages, towns & cities to feed themselves by their own indigenous
systems. Consumers will be aware of water value.
|
|
|
|
Distribution system is key to success. For KRS there are 3 main canals.
Apart from these 3, one overhead canal built is dysfunctional from the day 1 of
the water release. One can see the overhead canal on way to Mysore after crossing
Srirangapatna.
The 3 canals run for about 40kms. That’s it. But it divides into distributaries
at secondary, tertiary levels. Along the way it irrigates the farm land. So
total length of these distributaries is about 300+kms.
So for example, KRS dam canals irrigate Mandya district and KR Nagara
in Mysore and a bit of southern Hassan. It doesn’t reach Ramanagara,
Kanakapura, Bangalore rural, Tumkur etc., The biggest advantage of KRS is it
gives drinking water to guzzling cities of Bangalore, Mysore, Mandya.
Few more disadvantages & complexities of this system are:
- Distributary has to reach last mile from central reservoir. So a complex distributary system has to be built & maintained. Crores of Rs go down the drain. For example, Bennehole canal system (Bijapur) no longer exists today, but there is a department with officials drawing salary for maintaining it. There are several such examples.
- Distribution system at secondary & tertiary levels is always in serious problem in almost all canals around the world. You take any status report of any irrigation department any day, this is the case. Water doesn’t reach the last man properly due to various reasons.
Solution?
- Don’t build any more new large dams. It is even suggested by UN since 90’s after disastrous results over several decades in several countries.
- Those built have to give local governance over the distributary canal system. Only dam maintenance should be with the central/state government.
So if you weigh options, you find the large dams are disastrous in the
long run. It serves very little for humanity. That is the main reason the Kings
in the ancient & medieval times didn’t build these monstrous unscientific crass.
Besides the most critical responsibility of the Kings was welfare of the people,
their law abiding nature, and their self-governance. So it was detrimental to
these social aspects. Hence they didn’t invest on this “Mad Science”.
It will be good if our today’s politicians learn a bit from our ancient
kings and their governance. Most importantly they take back any new large dam
construction projects. More than environment disaster it is the social harmony
which gets affected.
Reference:
Ref3: Grand Anicut – The world’s oldest functioning dam - https://en.wikipedia.org/wiki/Kallanai_Dam
Ref5: KRS & its canals details from karanataka govt
site: http://waterresources.kar.nic.in/salient_features_krs.htm
Ref6: Very detailed analysis on whole Kaveri Issue, Tribunal award its
history etc., https://kiranasis.blogspot.in/2012/10/kaveri-river-water-sharing-what-are.html?showComment=1474124186149#c6163037838018736733
Kaveri River Basin.PNG
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Tribunal award
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Bangalore Connected Lake system (Which is now dysfunctional)
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Rough interventions to control water flows on proportional system
 |
Field inlet from a lined tertiary canal
| 
A partitioning
structure along a secondary canal exhibiting few problems. Left and
front offtake have
been gated after NWMP but gates are blocked open (spindle is twisted) -
Right offtake is not
gated – Left offtake is temporary closed with vegetation
|
