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Kala Bagh Dam Project
INTRODUCTION
Irrigated
agricultural is the backbone of Pakistan’s economy. At the same time with
word’s fastest growing population estimated to touch 150 million marks by
the turn of the century, there is a dire need to increase agricultural
production. If nothing is done, there would e approximately 25% shortfall
in food grain requirements by the year 2000, Judging from current (1997)
two million tones import of wheat, by that time, Pakistan could be one of
the major food deficit countries in the world.
Due
to complete stoppage of any sizeable surface water resources development
after full commissioning of Tarbala Dam during, 1976, even sustainability
of existing irrigated agriculture is in serious
jeopardy.
With
a large arable land, Pakistan still has the potential of bringing several
million acres of virgin land under irrigation. An important impediment in
the way of this development is insufficient control over flood water of
the rivers. With virtually no limit on availability of land, it is
unfortunate to willingly let large quantities of water into the sea. In
post-Tarbala 20 years, an annual average of over 38 million acres feet
(MAF) escaped below Kotri; after adjustment of future abstraction out-side
Indus Basin, this could still be around 32 MAF. Out of this, an average of
over 26 MAF per year could be effectively controlled and efficiently
utilized to bring about prosperity to millions, particularly, in backward
areas of Pakistan through national water resources development
approach.
Besides
recurring irrigation water shortage, the country passes through periodic
calamity caused by the phenomenon of floods (1992 followed by 1994 very
large floods should act as eye-openers) Monsoon rains result in swollen
rivers which spill over their banks, bringing in the wake loss on a
colossal scale. Floods are detrimental, not only in financial terms, but
also in the form of sever undermining of productive system, which should
logically be free from uncertainties and frequent dislocations. In the
context of Peshawar alley above Nowshera, frequent flooding takes place
due to entrance of Kabul river into confined channel below this
point.
Similarly,
national demand of electricity gas been and would keep in growing rapidly.
From the present 10500MW, peak power requirement of the country is
estimated to cross 13000 MW by the year 2000. Recently, Federal Government
has entered in to a number of agreements with international private sector
to install over 3,000 MW of thermal power over next 3-4 years. Though it
may help in overcoming the load-shedding, the power cost is increasing
substantially. Therefore, a large scale injection of cheap hydropower
through multi-purpose storages is the only answer if the cost of electric
supply is to be kept within affordability of the
consumers.
If
the present inaction towards development of national surface water
resources continues, Pakistan would be faced with innumerable
socio-economic problems at the dawn of 21st Century. It is,
therefore, imperative to launch urgently a national water resources
development programme including major multi-purposes storage, remodeling of some existing
projects and construction of new irrigation schemes, particularly in
backward areas of all provinces.
River
Indus and its tributaries, un-questionably, are the larges national
resources. Besides sizeable surplus water still going out to sea, Indus
System has over 30,000 MW of economically developers hydropower potential.
For effective harnessing of this renewable resources, most of which is
run-of-river type, it would be necessary to build multi-purpose storage.
These would generate sizeable blocks of cheap electricity and thus check
the excessive tariff increases due to anticipated large scale induction of
costly thermal power. In particular, these would provide means for;
substituting the continuous capacity loss of on line storages to sustain
the existing irrigation; development of new irrigation projects, and
effective flood control.
Taking
into account all the above factors, a 25-year (2000-2025) National Water
Resources Development Programme (NWRDP) has been formulated including
multi-purpose projects. It is a package, including Kalabagh Dam Project,
based on the concept of unified approach to tackle the threatening water
shortages and anticipated large increase in power tariff due to
predominance of thermal power.
THE
PROJECT
Kalabagh
Dam Project would be located on river Indus 100 miles south-west of
Pakistan’s capital Islamabad.
This
multi-purpose project would have a live storage capacity of 6.1 million
acre feet (MAF).ides making up for the capacity loss in reservoirs, it
would make substantial contribution to firming up the irrigation supplies
not only for new projects but additional allocation agreed by the
provinces under Water Apportionment Accord (WAA) of 1991. Further, it
would add a large amount of cheap hydropower to the National Grid through
its 2400 MW (Ultimate 3600 MW) installed power.
KALABAGH
DAM MULTI-PURPOSE PROJECT
SALIENT
FEATURES
HYDROLOGY
(Indus River At Site):-
Catchment Area
110,500 sq. Miles
Maximum Recorded Flood (1929)
1,200,000 Cuses
Average Annual Flow
91.4 MAF
RESERVOIR
Storage Capacity
Gross
7.9 MAF
Live
6.1 MAF
Retention
Level:
Maximum
915 Feet Above Mean Sea Level
Minimum
825 Feet Above MSL
DAM
Type
Zoned Fill Embankment With Clay Core
Maximum Height Above River Bed
260 Feet
Total Length
11,000 Feet
Total Fill Volume
60 Million Cu. Yds
SPILLWAYS
Overflow Spillway Capacity
1,070,000 Cuses
Orifice Spillway Capacity
980,000 Cuses
POWER
FACILITIES
Unite Size
300 MW
Penstocks
12 No.
Turbines
Francis Type
Turbine Design Head
170 feet
Power
House
Indoor Type
Installed Capacity
2400 MW (Initial); 3600 MW (Ultimate)
Average Annual Energy
11400 GWH
COST
Estimated Total Investment (June 1997)
Rs. 250 Billion
*
June 1992 cost converted at Rs. 45 per US dollar
ITS
ROLE
Utilization
of the irrigation and hydropower potentials of river represents the least
cost option available to Pakistan to sustain as well as expand its
irrigation and power generation capacity. Whereas the Indus Basin Project
in the late 1960’s provided basic infra-structure for integration of our
largest irrigation system. Kalabagh Dam could assume similar role for
making an earnest start towards further unified national water resources
development-cum-management. As the project is ready for implementation
since late 1980’s effort should be to have it commissioned by the start of
21at Century.
Kalabagh
Dam Project would play very important role by way of:-
a.
Replacing
storage lost by sedimentation in existing reservoirs at Mangala, Chashma
and Tarbala (estimated about 3 MAF by the year 2000).
b.
Providing
additional storage to meet existing water shortages during early Kharif
sowing period of April-June (particularly critical for cotton crop in
Sindh).
c.
Providing
effective regulation of Indus river to meet additional Kharif allocations
of the provinces under WAA, 1991.
d.
Regulation
and control of high flood peaks in the Indus to enable provision of
perennial tubewell irrigation to the riverain area in Sindh.
e.
Generating
a large chunk of hydro-power for meeting the growing demand of
agricultural, industrial and domestic consumers through low cost
option.
f.
Reducing
dependence on imported fuels.
g.
Creating
employment for 30,000 persons during construction and significant numbers
after commissioning.
APPREHENSIONS
As
part of controversy on Kalabagh Dam, a number of apprehensions/doubts have
been expressed both by upper (NWFP) and lower (Sindh) riparian provinces.
Most of these are based either on lack of information or hear say. In
addition, there have been reservations in the mind of some quarters
without any apparent rhyme or reason. Consequently, the Project has been
thoroughly reviewed and revised/modified to remove the apprehensions and
doubts, which in the pat may have blocked its
implementation.
The
apprehensions and the factual position, in the light of critical
examination/supporting studies, are presented in the
following.
Apprehensions
of NWFP
i)
It
is feared that historic flooding of Peshawar Valley including Nowshera
town would be aggravated in the event of recurrence of 1929 record
flood.
ii)
Drainages
of surrounding area of Mardan, Pabbi and Swabi plains would be adversely
affected by the reservoir thus creating water-logging and
salinity.
iii)
Operation
of Mardan SCARP would be adversely affected.
iv)
Fertile
culturable land would be submerged.
v)
Large
number of people would be displaced.
Answer:
i)
a.
In the modified design of the project the reservoir conservation
level has been lowered by 10 feet from 925 to 915 feet above mean sea
level (MSL) thus eliminating the need for construction of any protective
dyke near Nowshera. At maximum conservation level of 915 feet, the
back-water effect of Kalabagh lake would end about 10 miles downstream of
Nowshera (refer Illustration-I). A state-of-art computer based study,
backed by physical modeling in Pakistan, has established that recurrence
of record flood of 1929 would not affect the water level at Nowshera even
after 100 years of sedimentation in reservoir (refer Illustration-II). It
may be noted that this completely ignores the effect of Tarbela reservoir,
which is now factually providing relief by attenuating flood peaks. It is
also notable that flood warring system at Tarbala provides a minimum of 48
hours advance warning before the arrival o large flood
peaks.
b.
Real causes of flooding at Nowshera and Peshawar Valley upstream entrance
of Kabul river at Nowshera into confined channel at the end of Peshawar
valley; and backing effect of Attock Gorge downstream through which Indus
river has to pass after its confluence with Kabul river (refer
illustration I). Before the confluence, Indus river flows through a wide
valley of over 8,000 feet and is then forced to pass through 1000 feet
wide gorge for 5 miles. This constriction forces the river water to back
up thus raising flood levels in Kabul river upto Nowshera. Whereas
Kalabagh should not adversely affect flooding in Nowshera and Peshawar
Valley above, an upstream dam on Swat river could provide effective
assurance against this chronic inherent problem. Consequently, Munda Dam
multi-purpose project is being included in NWRDP.
ii)
Lowest ground levels at Mardan, Pabbi and Swabi areas are 970,962
and 1000 feet above MSL respectively, as compared to the maximum
conservation level of 915 for Kalabagh (refer Illustration-III). This
maximum Kalabagh reservoir level would be maintained only for 3 to 4 weeks
during September and October after which it would deplete as water is
released for Rabi crops and power generation (refer Illustration-IV).
Ultimately it would go down to dead storage level of 825 feet by early
June. This operation pattern of reservoir, by no stretch of imagination,
could block the drainage and thus cause water-logging or salinity in
Mardan, Pabbi and Swabi areas.
iii).
The invert level of main drain of the Mardan SCARP are higher than maximum
elevation of 915 feet. Thus, these drains would keep on functioning
without any obstruction.
iv)
Total culturable land submerged under the reservoir elevation of
915 feet would be 27,500 acres (24,500 acres in Punjab and 3000 acres in
NWFP). The submerged irrigated land would be only 3000 acres (2,900 acres
in Punjab and 100 acres in NWFP). It may be noted that about 1,000 acres
of irrigated land acquired for Mardan SCARP alone.
v)
a. The estimated population to be affected by the project would be 83,000
with 48,500 in Punjab and 34,500 in NWFP. A liberal resettlement plan
would provide alternate irrigated lands to the affected families. The
affected population would be resettled along the reservoir periphery in
extended/new model villages with modern facilities of water supply,
electricity, roads, dispensaries, school and other civic amenities. The
affectees would enjoy and improved environment.
b. Another major incentive provided
for the affecters in this case, not previously practiced in Pakistan,
would be to fully compensate the frames for the land on the reservoir
periphery above normal conservation level of 915 feet that could be
flooded once in five years. This land would remain the property of the
original owners for cultivation with the only undertaking that they would
not claim any damages to crops for occasional flooding.
c.
The comprehensive resettlement package proposed for Kalabagh is in fact
most innovative and attractive then those previously adopted for Mangla
and Tarbala Dams. The basic objective being that “a the end of day”, the
affectees should find themselves in a better socio-economic
environment.
Apprehensions
of Sindh
i)
The
anxiety that the project would render Sindh into a
desert.
ii)
There
would be no surplus water to fill Kalabagh reservoir.
iii)
High
level outlets would be used to divert water from the
reservoir.
iv)
Cultivation
in riverain (Sailaba) areas would be adversely affected.
v)
Sea
water intrusion in Indus estuary would accentuate.
vi)
Mangrove
forest, which are already threatened, would be further affected
adversely.
vii)
Fish
production and drinking water supply below Kotri would be adversely
affected.
Answers:
i)
Dams
don’t consume any water. Instead these store water during flood season and
then make it available on crop demand basis for the remaining dry periods
of t years. The real demonstration of this came after full commissioning
of Tarbala Dam in 1076. during pre-storage era of 1960-67, average annual
canal withdrawals of Sindh were 35.6 MAF. After Tarbala the corresponding
figure rose to 44.5 MAF with over 22 percent increase in the Rabi
diversions alone increased from 10.7 to 15.2 MAF. It is estimated that
after Kalabagh, canal withdrawals of Sindh would further increase. A
indicated in Illustration-V, most of this increase would come in regarding
desertification of Sindh defies even the basic logic of a storage
reservoir.
ii)
A.
WAA of 1991 has allocated, on the average, about 12 MAF additional
supplies to the provinces almost all of which is in Kharif season. On the
other hand, factually the surplus water is a available only within 70-100
days flood period. It is estimated that to provided additional allocated
water over the year, a storage of about 3.6 MAF would be needed (out of
this, 2.2 MAF would be in the early Kharif season of April to
July).
iii)
Initial
studies have indicated that construction of high level outlets at Kalabagh
is economically unviable. Notwithstanding this, if any province wants to
build, then its share of water would be strictly governed by WAA,
1991.
iv)a An
impression is also prevailing that with Kalabagh Dam, riverain areas of
Sindh, commonly called “ Sailaba” would got out of production due to
control over floods. It can be appreciated from configuration of riverain
area (refer Illustration-VI) that “Sailaba’ crops are grown on the land
adjacent to main river and the creeks. Though crops are sown on the soil
moisture soon after the floods, these need more than one watering to
mature. As a result ‘ Sailba’ lands give poor yields. Consequently, frames
are generally required provide irrigation facility through shallow tube
wells or lift pimps. Prime movers on these tubewells have to be removed
during the flood season to avoid damage.
b Sindh has
presently 660,000 acres of ‘ Sailaba cultivated area form Guddu Barrage to
sea. This area is initially sown due to the moisture provided by flooding
with river stage of 300,000 cusecs and above.
c. Flood peaks
above 300,000 cusecs would still be coming after Kalabagh, without much
detriment to the present cultural practices, while large floods would be
effectively controlled. This would, in fact, be conductive to installation
of permanent tubewells to provide pernnial irrigation facility in riverain
areas. Towards this end, a separate scheme is being included in
NWRDP.
v)a. The
fear that present extent of sea water intrusion in the Indus Delta would
be further aggravated by Kalabagh is not substantiated by factual data.
Studies indicate that presently the total effect of Indus estuary is only
limited to the lower most portion of Delta and gets dissipated below Garho
and Chowgazo gagues heights
at Garho are completely insensitive to Indus discharges of upto
700,000 cusees (refer III ustration-VIII). Therefore, the sea water
intrusion, which seems to be at its maximum even now, is unlikely to be
aggravated further by Kalabagh Dam.
b Another
apprehension is that sea water intrusion into existing aquifer system
would cause serious quality deterioration. The groundwater contained in
the aquifer is effectively saline as far north as Hyderabad. Therefore,
intrusion of sea water along shore line of Delta is of little consequence.
This is further supported by the the fact that there is southward oriented
groundwater gradient throughout this aquifer. Considering the very low
transmissivities of the aquifer in Delta region, upward sea water
intrusion can be almost ruled out.
vi)a. Out of the
total 1.53 million acres(MA) tidally inundated historic Indus Delta,
Mangrove forest cover an area of almost 0.32 MA In this forest, spreading
from Karachi in the west to Rann of Kutch in the east, 95% of the
population now consist of a salt tolerant variety.
b. Extent of
the active delta area(as distinct from the historic delta area described
above) is about 294,000 acres. Out of this, the mangroves cover only 7,400
acres or 2.5% of the area. Most of the remaining area is in form of
mud-flats. The reason for this area being too small could be a combination
of factors. Recently, NED
University of Engineering and Technology has carried out a study
titled “ What Realy Threatens us and Our Mangroves” This brings out that
reduction in mangroves in essentially due to frequency of tidal inundation
being too small instead of fresh water reduction caused by upstream
abstractions, which started with Sukkur Barrage in 1932. Other major
causes are uncontrolled overgrazing and cutting due to extreme population
pressure of Karachi.
c. Therefore,
in order to revive the mangroves, real need is for replanting salt
tolerant varieties with provision for controlled doses of fresh water.
Obviously, this possibility would be much enhanced with an upstream
storage facility like Kalabagh.
vii)a. A recent
study has shown that there is no clear evidence to suggest that fisheries
stocks in the river reach below Kotri have declined due to progressive
reduction in the surface water supplies. On the other hand, fish
production has been constantly increasing as indicated by statistical
data. As such, Kalabagh Dam is unlikely to have any adverse effect on fish
production in the area.
b.
In the riverain area downstream to Kotri Barrage, groundwater is
predominantly saline or brackish and as such unsuitable for either
irrigation water supply. After Kalabagh, winter supply in the river would
improve thus assuring more drinking water.
PROJECT
BENEFITS
Kalabagh
would store surplus water in the flood season and make it available for
controlled utilization during the low flow season. This water would thus
be used for sowing and final maturing of the Kharif crops and entire Rabi
crops.
Irrigation
oriented operation of the project gives the highest overall economic
return. Thus the full live storage of 6.1MAF would be available for
guaranteeing assured irrigation supplies throughout the year including
replacement of the storage loss on the three existing
reservoirs.
Power
Kalabagh
wit its installed capacity of 2400 MW (ultimate 3600 MW) would add to the
system a very large chunk of cheap hydro-power. In an average year, 11413
million kilowatts hours (MKWh’s) of electricity would be generated at
Kalabagh. Further, as a result of conjunctive operation an additional 336
million MKWh’s and upto 600 megawatts (MW) of additional peak power would
be generated at Tarbela. To put these figures in perspective, if Kalabagh
was in position today, there would have been no load-shedding in
Pakistan.
The
energy generated at Kalabagh would be equivalent to 20 million of oil per
year.
Flood
Alleviation
Kalabagh
would reduce the frequency and severity of flooding along the Indus
particularly between the dam site an Indus/Punjab confluence, 300 miles
downstream.
For
the riverain areas lower down in Sindh, it would enable conversation of
the existing ‘Sailaba’ areas to the year round tubewell
irrigation.
Overall
Benefits
On
a conservation basis, the overall direct benefits of Kalabagh Dam would be
around Rs. 25 billion per annum. Thus the investment cost of project would
be repaid within a very short period of 9-10 years.
CONSEQUENCES
OF NOT BUILDING KALABAGH DAM
i)
National
food security would be jeopardized, thus subjecting the economy to
additional burden of importing food grains.
ii)
Loss
of storage capacity of the on-line reservoir due to sedimentation would
result in shortage of committed irrigation supplies causing serious
dropeven in existing agriculture production.
iii)
For
implementation of water Apportionment Accord 1991, a new storage project
like Kalabagh is essential. In its absence it would give rise to bitter
inter-provincial disputes and recriminations particularly in a dry water
year. Dispute between Punjab and Sindh on shortage of about 0.2 MAF water
during Rabi maturing/Kharig sowing 1993-94 should eye-opener. It may be
worth mentioning that Rabi 1993-94 had a normal river inflow
pattern.
iv)
The
annual energy generated at Kalabagh is equivalent to 20 million barrels of
oil. This annual import of fuel for thermal generation, including
augmentation of transportation infrastructure, would be an additional
burden to the economy.
v)
Recently,
Federal Government has entered into agreements with international private
sector to install over 3,00o MW of thermal power over next 3-4 years.
Though it may help in overcoming the load-shedding, the power cost will
increase substantially. Therefore, large scale injection of cheap Kalabagh
hydropower would help to keep cost of electricity within affordability of
the consumers.
vi)
Growth
of domestic industrial and agriculture sectors would be impended due to
high power costs.
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