From: budaraju@cae.wisc.edu (Srinivas Budaraju)
Newsgroups: soc.culture.indian
Subject: Sardar Sarovar Project - An Overview - 5/7
Date: 12 Oct 92 19:09:24 GMT
Organization: U of Wisconsin-Madison College of Engineering


II..	LARGE DAMS:  THE CASE AGAINST AND ALTERNATIVE OPTIONS

II.1.	The Case Against Large Dams [Singh 1990, Agarwal 
1985, Agarwal and Narain 1991]

Large dams are built in India on the premise that they are 
necessary for irrigation, power generation, and flood 
control.  The argument used is that since rainfall is non-
uniformly distributed and very seasonal, the only way to 
achieve these benefits is by storing water in the reservoirs 
created by such dams.  However, the short-term and long-term 
benefits of large dams are increasingly in dispute.  This 
section explains why the large dams built so far have not 
only failed to achieve these objectives but have created new 
problems as well.

Irrigation   Canal irrigation made viable by large dams may 
seem crucial for any increase in crop yields (particularly in 
low rainfall areas).  However, it has been widely found that 
the long-term effect of canal irrigation on increasing crop 
yields is marginal.  The main problems are water logging and 
salinization of the soil due to water that seeps out of the 
canals and distributaries, and due to inadequate drainage.  
Studies have shown up to 71% water loss in transit from the 
reservoir to the field.  In some cases, up to 18% of land 
that utilizes the irrigation has been lost to the above 
problems.  Particularly, in some semi-humid and humid areas, 
there has been an actual decline in crop yields.  In arid 
areas, dams have produced positive results in the first few 
years, but eventually the above problems have taken over.  
While theoretically, seepage can be reduced by lining the 
canals and through other distribution methods, practically 
this is uneconomical and therefore often knowingly not 
undertaken.

Power Generation  There have been large discrepancies between 
the projected and actual power generation of large dams.  The 
main reasons are frequent breakdown of turbines, inadequate 
maintenance, ignoring transmission line loss, and reduction 
in the life of the dam caused by siltation.  With regard to 
the latter, the government has recently found that in many 
cases, the inflow of sediment into the reservoir is four 
times higher than expected.  The life of the Bhakra dam has 
been halved and that of Hirakud's reduced to a third of its 
original due to excessive siltation of the reservoir.  Also 
note that contrary to popular view, hydro-electric power 
generation through large dams is not environmentally clean.  
As the following paragraphs show, large dams involve 
extensive deforestation leading to environmental disasters.

Flood Control  Large dams aggravate rather than control 
floods.  Water logging results in reduced capacity of the 
soil to hold any more water.  Extensive deforestation (for 
reasons explained below) takes away the trees that would 
otherwise soak up rainwater, recharge the ground water, and 
eventually release it slowly to the river below.  Dams have 
also contributed to floods due to the steady deterioration of 
the drainage systems downstream.  Over the years, the 
drainage capacity goes down because of continued silting of 
the river bed due to lack of adequate round-the-year flushing 
by perennial river discharges.  Often hydro-electric power 
generation receives greater priority because of which 
reservoirs are maintained at high levels even during the 
monsoon.  This means that with a little excessive rain, the 
reservoirs reach levels where the dam is threatened and the 
water has to be suddenly released, further aggravating the 
situation downstream.  This can also happen when there is 
sudden excessive off-season rain.

Deforestation Large dams result in extensive deforestation.  
A primary reason is the extensive forest covers that the 
reservoir itself often submerges.  Besides, due to the long 
time for construction of these dams (often spanning decades), 
large forest covers are cleared in the surrounding 
countryside for accommodation of on-site workers.  
Furthermore, to rehabilitate people who are displaced by the 
dam, other forest areas are cleared.  Between 1951-1976, the 
amount of forest cover depleted was as much as 10% of the 
area that was brought under irrigation.  This deforestation 
results in loss of valuable resources, soil erosion, and 
increases the incidence of floods.

Displacement of People Large dams have large reservoirs which 
result in submerging huge areas under water.  This often 
requires the displacement of hundreds of thousands of people.  
Since dams are usually constructed in remote, hilly areas, 
these people are tribals and rural villagers.  The Government 
of India only provides cash compensation for people with land 
and houses that are submerged.  No compensation is given to 
landless laborers, cattle grazers, and fisher folk.  Even 
where cash compensation is given, there is widespread 
corruption and exploitation.  When land is given in 
compensation, it is often unproductive or inferior.  There is 
no effort to help the oustees to settle into their new lives.  
For example, oustees from the Poong dam in Himachal Pradesh 
used to hill cultivation were sent to Rajasthan without any 
notion of how to survive the rigors of the desert.

Other Problems  To justify the large dam projects 
economically, sub-standard materials and technology are used 
which have resulted in many disasters.  Particularly, 
increased seismic activity in the area of large reservoirs 
has led to many earthquakes.  While there have been 
technological advances to counter such activity, the use of 
such technology is expensive.  The Machu dam disaster of 
August 1979 which killed several hundred people is a result 
of such negligence.  Finally, the incidence of water-borne 
diseases such as malaria is known to have increased at the 
sites of large-scale dams.

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This report on the Sardar Sarovar Project is available through 
anonymous ftp from nacho.cs.wisc.edu (128.105.8.15) in directory pub.
If you want a hard copy of the report, send me e-mail.

-Srinivas				budaraju@cae.wisc.edu