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West Seti & India's River-link Project By AB Thapa Very recently two
important news have appeared in the news media
that very much concern water resources of
our country. It is reported ( INDIA TODAY
dated January 20, 2003) that the Government of
India has appointed in December,2002 a
three-member task force headed by the former
power minister Suresh Prabhu. The task force, which
has to submit its report by June 2003, is
expected to address the issue to obtain
the consent of Nepal (also Bhutan and
Bangladesh) perhaps through a revenue sharing
pact to divert water of the major rivers
for irrigation across the India. Needless to
say that the storage dams proposed to be
built in Nepal in future would have to
play the decisive role for this type of
grandiose project to succeed. Until now
India was seen to be hesitating to accept
the idea of buying water stored in the
reservoirs proposed to be built in Nepal. Both
the countries had not yet taken up
this matter very seriously. They have
not done enough homework to resolve this
issue Now India itself appears to
be taking the initiative to find a
way to share benefits accruable from the
water delivered from Nepal for distribution
across India. Thus we could expect a
significant shift in India's policy that
would certainly help to bridge the gap
that exists in the perception of Nepal
and India on the development of very
large storage projects in general and the
Karnali High Dam Project in particular. The above reporting
provides a good ground to hope that India
might be working to develop a new policy
to pave the way to give the regulated
water supplied to India from the storage
reservoirs proposed to be built in
Nepal the same type of treatment as
the United States is now giving to the
regulated water of the Columbia river
supplied by Canada. The Columbia river treaty
has granted the Canada the right to
recover 50% benefits accruing from the
use of the Columbia river water in the
United States virtually in perpetuity. There
is another important news reported in the
ģInternational Journal on HYDROPOWER & DAMSī
that directly concerns our country. It is
reported that the SMEC (a private engineering
consulting firm) has signed a Memorandum of
Understanding (MoU) in India opening the way
for the purchase of electricity from the
proposed West Seti hydro-plant in the far
western region of Nepal. It would be the
severest loss to the nation if the
private developer is allowed to take up
the implementation of the West Seti project
ignoring the irrigation and other downstream
benefits. The downstream net irrigation benefit
accruable to Nepal could be far
exceeding the net power benefit Nepal
could hope to get. It has
been explained about it in the WECS
bulletin dated May, 1995 (Volume 6, Number 1&2). Feasibility Studies of
the Project The West Seti high
dam project is among the very few schemes
in Nepal which have been extensively studied.
It has two major components. They are the
irrigation and power. A study at feasibility
level on power was carried out by
SOGREAH of France, whereas the Karnali Multipurpose
Project study fully covers the irrigation
component of this project. Feasibility level study of
the Karnali Multipurpose Project had been done
thrice in the past. One of the main
objectives of the latest feasibility study was to
involve India in the studies to determine the magnitude
of the irrigation benefits accruable to that
country from the regulated flow of the
Karnali River and obviously it also
denotes the regulated flow of the West
Seti River which is a tributary of the
Karnali River. The West Seti High
Dam Project It has been proposed
to build a 187 meters high gravel
filled dam across the West Seti river
in the feasibility study carried out by
the SOGREAH. The total storage capacity of the
reservoir will be 1,600 million cubic meters. The
power station will be underground type. The
power station will produce 2202 GWh firm
energy annually. The total annual energy
production will be 2,402 GWh. After the
regulation of the West Seti run-off the
present dry season flow at the dam site
of about 45 cubic meters per second will
be increased to about 135 cubic meters
per second. Thus the net augmentation of the
dry season flow could be about 90 cubic
meters per second which is about 40%
dry season flow of the Karnali river. Downstream Irrigation
Benefit There will be
significantly large downstream irrigation benefit
accruable to India after the completion of
the West Seti Storage Dam Project. Such benefit
has been quite thoroughly evaluated in
the Karnali Multipurpose Project study.
Agricultural production over a vast area
adjoining the Karnali river in the Indian
territory is at present greatly constrained
by the scarcity of water needed for
irrigation particularly in dry seasons. The regulated
West Seti flow could be used for
increasing the cropping intensities of the
Sarda Sahayak irrigation system or the Saryu
irrigation system already provided in the Utter
Pradesh province of India. It is not
necessary to build a new barrage for the
diversion. The West Seti regulated flow could
be diverted for irrigation from the existing
Girjapur barrage into the Sarda Sahayak
canal or the Saryu canal. Additional
canal network also would not be needed
for the delivery of water. The existing
capacity of the canal system would be
adequate. According to the
study carried out by the SOGREAH,
if the year 2003 is taken as
the reference year and the 1989 price
level is adopted at a discount rate
of 10%, the total discounted power
benefit of the West Seti project would
be 912 million US Dollars against a
discounted cost of the project estimated at
456 million US Dollars. Thus the total
net discounted power benefit of the project
could be 456 million US Dollars. Based
on the feasibility study of the Karnali
High Dam project the total net discounted
irrigation benefit of the West Seti project
at 1989 price level for the
reference year 2003 could be as high as
720 million US Dollars. It implies that the
net irrigation benefit of the West Seti
project could be much greater than the
net power benefit. Now a very big
question arises. Should we ignore the West
Seti downstream benefit? Will we be
morally correct to do so? Will it be
a treason apart from being in breach of
the Clause 126 of our constitution? These
are the questions that should be answered
by the legal and constitutional experts. From
the engineering view point there are few
more very serious problems to be addressed.
The first is about the dam safety. The
proposed concrete faced rock filled dam (cfrd)
is a completely new venture for dam of
this height. Some time back WECS had
given its opinion about the safety of the
proposed West Seti dam. It is hoped
that the decision makers will take seriously
the opinion expressed by the WECS. The second
equally serious problem is the present flooding
in the western Terai. It would surprise many
of us to learn that the true cause
behind the present flooding in a vast
region of the western Terai upstream of
the Laxmanpur barrage in Banke district, and
Khurdlotan area of the Kapulbastu and
Rupandehi districts could be the proposed
West Seti Project. It is explained below
about it. Western Terai
Submersion Nepal is embarked
on a plan to launch three major
storage dam projects in the western
Nepal completely disregarding how the
vast quantity of regulated water is
going to be utilized in India.
The feasibility study report of the Karnali
Project carried out at an enormous
cost provides in depth information on
downstream uses, but we are not
interested to look into them. Our
concern is only electricity. While the
fate of the Karnali and Pancheshwor
projects are yet to be decided, the
West Seti project is virtually in
the hands of a private developer.
The decision to go ahead with the
West Seti project should be
immediately revoked until the matters
related with the downstream uses remain
unsettled because this project is directly
linked with the submersion of lands
in Western Terai near the border
with India. Layout of the
Saryu Canal The Girjapur barrage
across the Karnali river is located 1.2 km
downstream of the confluence of the channel
Girwa and Kauriala and 8.8 km downstream of
Katarnia Ghat railway station of North Eastern
Railway in India. The site of the barrage
is about 16 km from the Nepal border
along the River Kaurila. There are two irrigation
canals taking off from the Girjapur barrage . On
the left is the Saryu canal
running to the east beyond the
Banganga river and on the right is the
Link Canal connected with the Sarda
Sahayak canal planned to irrigate about
2 million ha of lands. At present
only the right bank canal is
operational because the dry season flow
of the Karnali river is quite insufficient
for both the canals and there are
technical difficulties to utilize the monsoon
flow of this river. The year round
operation of the Saryu canal
depends entirely on availability of the
regulated flow from the proposed storage
reservoirs in Nepal. The construction of
the Saryu canal, that started a
long time ago, is still continuing at a snail's
pace perhaps due to uncertainty about
the date when the West Seti project
would be ready for operation.
Nevertheless, it appears that the Saryu canal
could be made operational at short notice after
the completion of the West Seti Storage Project
because most of the structures of the
Saryu canal might be already ready. After
that our people near the border area would be
forced to live virtually in swamps throughout
the year. The Saryu canal project consists of a canal
network that connects the head regulaters of the barrages
across the Saryu (Babai river) , West Rapti and Rohini
(Banganga river). A link channel 48.4 km long taking
off from the left bank of the Girjapur barrage
outfalls into the Saryu river just upstream of
a barrage across it. A link canal 56 km
long taking off from the left bank of the
Saryu river outfalls into the West Rapti river
just upstream of the Laxmanpur barrage.
Beyond that a 125 km long canal
taking off from the left bank of the
West Rapti river extends up to the Banganga
river. How the Submersion
is Caused The total length of the
Saryu canal running almost parallel to
Indo-Nepal border is about 230 km. In the
original design the barrage across the Saryu river was at
a location about 328 meters to the south of the railway
bridge at Nanpara. Later, the design was modified and the location of
the barrage was shifted 10 km to the north from the
original site. The longitudinal gradient of the Saryu canal
has been reduced to a minimum. It is only one meter
on a stretch of 9 km. The adoption of such extremely
mild slope permitted the alignment of the canal to be pushed as far as possible
to the north very close to Indo-Nepal border specially in its middle and lower
reaches. Normally siphons are provided to deliver
canal water across a river. A much higher average slope of the canal is
required for the operation of this type of cross drainage
structure, which has to operate under pressurized
condition. A free flow hydraulic regime
needs to be maintained at the river
crossing if the average gradient of the canal
is to be reduced. For reducing the average slope
of the Saryu canal an altogether a different type of
structures has been devised, which at first glance drives
anybody crazy. Barrages have been built
across the rivers to elevate the river
water to such a level that would allow
free passage of canal water across the river into the
canal taking off from the other side of the river The
contentious Laxmanpur barrage is one of such structures devised to
deliver the water from the Girjapur barrage across the West
Rapti river. It would be necessary to maintain all the
time pond water upstream of the barrage above certain fixed level to keep the Saryu
canal running at desired capacity. Thus the pond would always be full, with the result
that a sizeable area of lands in Nepalese territory could remain perpetually submerged.
When the river is in flood, the water would be spreading out onto the lands that were
never before regarded prone to flooding. The Saryu canal is expected to cross
innumerable small rivers and drains on its way. Embankments and dikes are needed to
train these drains and small rivers for the protection of the Saryu canal. These
river training structures could also result in widespread flooding
inside Nepal where the canal route is close to the border. |
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