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Water resources of Pakistan
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Present status and future strategies
By Dr. Muhammad Saffar Mirjat
and Abdul Samad Chandio
Professor and Assistant Professor,
Sindh Agriculture University Tandojam
May 14 - 20, 2001
Indus valley, cradle of ancient civilization: The
Indus valley has been the cradle of ancient civilization like those of
the delta area of the Nile and the valleys of the Tigris and
Euphrates. These three areas were the contemporary regions in which
great civilizations flourished, about four to five thousand years ago.
However, recent archaeological findings reveal that the Indus valley
civilizations probably antedated that of the Tigris and the Euphrates.
Excavations in the Indus valley have revealed that the dwellers of
Moenjo-Daro, Kot Diji, and Harapa had established powerful empires. A
stroll through the ruins of Moenjo-Daro and Harapa reveals that the
houses in these cities were provided with all types of amenities.
There were comfortable bedrooms, guestrooms, dinning rooms, porter's
lodges, lavatories, handsome courtyards, drainage, fresh water wells,
and tanks. The dwellings of Moenjo-Daro period are found so well
finished and highly polished that these even match with that of
today's then of prehistoric.
It is believed that the ancient people of the
valley of Indus were outstanding in the field of agriculture and
industry as compared to the civilization of contemporary period in
Egypt and Mesopotamia. The textile crafts made from cotton are living
examples of their expertise. Such was the glory of the ancient people
of Indus valley; perhaps they were the first sedentary farmers of the
world. The richness and wealth of the Indus valley was the greed of
the foreigners. The valley of Indus has always been the cherished goal
of the invaders and conquerors that followed one after another from
the northwestern passes through the mountain ranges. The Aryans, the
Iranians, the Graeco-Bactrians, the Parthenians, the Kushans, the
white Huns, Muslims emperors, and Britishers plundered the rich valley
of the Indus from time to time and ruled over the valley and northern
India. Entire history of Indus valley reveals that one invader or
another has treaded the present Pakistan. The Muslims of the
sub-continent first tried to shake off a century old rule of British
in 1857 and finally succeeded to drive them away in 1947, and the
great valley Indus became part of Pakistan. Pakistan lies between
latitudes 24 degree and 37 degree North and longitudes 61 degree to 76
degree East. Its surroundings include Iran on the west, Afghanistan on
the northwest, Gilgit Agency, Azad Kashmir and disputed territory of
Jammu and Kashmir lie on the northeast, India on the east and the
Arabian Sea exists on its south.
Catchments of Indus river system: The Indus
basin is a part of the catchments of the Indus river system that
includes the northwest mountains, the Katchi plain, desert areas of
Sindh, Bahawalpur, and the Rann of Kachh. The Indus and its major
tributaries flow in longitudinal valleys in structural troughs
paralleled to the mountain and invariably take an acute bend
descending to the alluvial plains by cutting through mountains. These
plains are stretched over a distance of 1528 Kilometers (950 miles) to
the tidal delta near the Arabian Sea. The total catchment area of
Indus River system spreads over 944,573 square kilometers (364,700
square miles). Of which 553,416 square kilometers (213,674 square
miles) exist in Pakistan with a varying width of over 320 kilometers
(nearly 200 miles) in the Punjab to about 80 kilometers (50 miles) in
the narrow neck between the Thar Desert and the Khirthar mountains.
The flat plain of Indus basin is made up of highly fertile alluvium
deposited by the river Indus and its tributaries. Agriculture is
concentrated essentially to this plain, where it has been developed by
harnessing principal surface water resources available. Since,
evaporation is high with meager and unreliable rainfall over Indus
plains, hence, agriculture is wholly dependent on irrigation supplies.
The river Indus and its tributaries are like a funnel, they rise in
the northern mountain areas, receive water from various resources
(snow, glacier melt, and rainfall), converge into a single stream at
Panjnad (Mithankot), cover about 1005 Kilometers (625 miles) through
the Sindh province, and finally discharge into Arabian sea.
Historical perspective: The Almighty Allah has
gifted Pakistan with abundant water resources with water flowing down
the Himalayas and Karrakurram heights from the world's largest
glaciers, a free and unique bounty of nature for this land of alluvial
plains. As a result of this natural resource, today we have the
world's marvellous and the largest contiguous irrigation system that
currently irrigates over 16 million hectares of land, out of 34
million hectares of cultivable lands available. This land lies within
the plains formed by river Indus and its tributaries. Britishers
started the barrage irrigation system during 1930s. However, before
that the residents of Punjab, Sindh, and Frontier had constructed a
number of inundation canals to irrigate their lands. In the Punjab, 38
such canals had been taken out of Sutlej, Indus, and Chenab rivers to
irrigate areas around Bari Doab, Multan, Muzaffargarh, and Dera Ghazi
Khan. In Sindh, water level of the Indus during summer had always been
higher than the surrounding lands, thus, 16 inundation canals in this
area had conveniently carried out the irrigation water during past
century. However, British Army Engineers undertook construction and
improvement of several irrigation canals in the sub-continent.
Subsequently, remodeling/construction works on Bari Doab Canal;
Sidhnai Canal, Lower Sohag, Ramnagar Canal, Lower Jhelum Canal, Kabul
Canal, and Lower Sawat were completed by the end of l9th century.
However, at the time of independence country had 29 canals to provide
regulated supply to an area of about 11 million hectares, beside an
area of about 3.2 million hectares irrigated through inundation canals
leading from Indus and its tributaries. These main inundation canals
included Upper Sutlej, Lower Sutlej, Shahpur, and Chenab in Punjab;
whereas, Rohri, Fuleli, Pinyari, and Kalri in Sindh. However, after
the construction of barrages these canals are no more inundation
canals but get regulated water supply and some of them have become
perennial while few are nonperennial.
We have entered into 21st century with world's
largest and unified irrigation system that consists of three major
reservoirs (Chashma, Mangla, and Tarbela); 19 barrages (Ferozepur,
Sulemanki, Islam, Balloki, Marala, Trimmu, Panjnad, Kalabagh, Sukkur,
Kotri, Taunsa, Guddu, Chashma, Mailsi, Balloki, Sidhnai, Rasul,
Qadirabad, and Marala); 12 link canals; 45 irrigation canals; and over
107,000 water courses and millions of farm channels & field
ditches. The total length of main canal system is estimated about
585000 Kilometer (36932 miles) and that of watercourses & field
channels exceeds 1.62 million Kilometers (over 1.02 million miles).
Surface water resources: Irrigated agriculture
was, still is, and will remain in future the backbone of Pakistan's
economy. Nature has blessed Pakistan with abundant surface and
subsurface water resources. These resources had been exploited and
utilized for agricultural, domestic, and industrial purposes in the
past and will continue to be explored in future. The river Indus and
its tributaries provide the surface water. At the time of
independence, we had about 67 MAF water available for diversion, this
amount increased to about 85 MAF by the year 1960. At this juncture,
the right of three eastern rivers (Beas, Sutlej, and Ravi) was given
to India under Irrigation Water Treaty 1960, during this period, Indus
Basin Project (IBP) was implemented with international assistance of
the Wold Bank. IBP enabled Pakistan to acquire significant capability
of river flow regulation through integrated system. By the dint of
river regulation-cum-storage facilities of IBP and other irrigation
developments on the river Indus, canal diversions progressively
increased and peaked to about 108 MAF. The recent statistical data
shows that the River Indus and its tributaries provide about 147 MAF
during flood season. Out of which nearly 106 MAF is diverted into
canals and is available for agriculture, while, about 32 MAF outflows
into sea, whereas, over 8.6 MAF is considered as evaporation and
seepage losses in the river system. It is worth mention here that
during last 3-5 years hardly 2-5 MAF water has flown into sea,
whereas, at least 12 MAF must be left to sea in order to control
intrusion of brackish water.
Ground water resources: The Indus plains
constitute about 34 million hectares (over 85 million acres) of
cultivable land, which is under-lain predominantly by sand alluvium to
a considerable depth. Annual recharge to ground water system of this
Indus plain is estimated around 55 MAF, out of which about 48 MAF is
within the commands of Indus basin irrigation system (IBIS).
Presently, 39 MAF is being extracted annually. Ground water is also
found in some rain-fed (Barani) lands, and inter-mountain valleys at
depths varying from 100 to 200 ft. During 1950s, large area in the
Indus basin became waterlogged and soil salinity increased adversely
affecting the agricultural productivity. It was the time when
government got involved and took initiatives in the ground water
development. The efforts began to control the twin menaces of
waterlogging and salinity by the way of providing drainage facilities.
Government embarked on a series of SCARPs in the late 1950s aimed at
lowering the ground water table by providing "vertical
drainage" through large capacity deep tube wells. Because of
better economic returns, priority was given to locating SCARPs in the
areas with ground water quality suitable for supplemental irrigation,
making the drainage a by product in effect. During past four decades,
about 15000 SCARP tube wells have been installed by the Government in
57 projects covering a gross area of about 7.7 million hectares
affected land for putting it back into production. Almost 75% of all
SCARP tube wells were installed in the Punjab. About 81% of total tube
wells installed in Punjab province are located in fresh ground water
areas, whereas, remaining 19% tube wells have been installed in saline
ground water areas. The tube wells installed in the fresh ground water
areas have been pumping water directly into watercourses; thus, they
are being used for irrigation in addition to canal water. However, the
tube wells installed in the areas with saline ground water, discharge
saline water directly into drains, from where it is being disposed of.
Soon after the initiation of the SCARP program,:
Large-scale development of ground water was started by the private
tube wells. According to latest reports issued by the Government of
Pakistan, the number of private tube wells has increased from 27000 to
over 400000 during period between 1964 and 1995. All of the 400000
private tube wells have been installed in fresh ground water zones and
are being used for irrigation purposes. About 80 per cent of these
tube wells are located in Punjab and supply around 40 per cent of
total irrigation in the province.
Future of water resources and needs: One of the
key issues to Pakistan is the growing population pressure, which is
responsible for driving its water resource development. It has the
world's fastest growing population that has surpassed the 140 million
mark by now and is still increasing at an alarming rate of around
2.8%, which needs to be checked, whereas the growth rate in
agriculture sector remains somehow lower than the demand due to
limiting irrigation water. To keep up the pace of agricultural growth
comparable to population growth, we must bring additional lands under
cultivation. In order to achieve the required growth targets in
agriculture, we will need estimated amounts of about 149 MAF by 2000,
215 MAF by year 2013 and about 277 MAF by year 2025. This scenario
warns that Pakistan has already slid from water affluent country to a
water scare country and already a shortage of over 40 MAF persists and
it will increase to a projected water shortage of over 108 MAF, and
151 MAF by years 2013 and 2025, respectively. Since no additional
water is available, it is better to improve the existing water system
and land capabilities; otherwise, Pakistan will be facing acute
shortages of food, fiber, and edible oils in near future. It is time
to recognize our responsibilities and start taking steps in right
direction. We must keep eye on the issues such as, inadequate
management and inefficient operation of irrigation systems, poor water
application & unequal water distribution, depletion of ground
water resources, reduction in storage capacities of existing system,
and wastage of summer river surpluses and slow agricultural growth.
Development potential and future strategies
Improve surface storage capacity: Future
development of the country depends on water resources expansion and
management. It has been recognized that more than 83 MAF water can be
generated through various resources (See Table). These potential
resources include; surface water 33 MAF, ground water 9 MAF,
watercourse improvement 15 MAF, minor canals 5 MAF, and distributaries
21 MAF. According to a report of working group on water resources for
the 7th five year plan (1987), no new storage have been created after
the completion of Tarbela due to rising controversies over the
construction of such reservoirs. Thus, it has become necessary to
focus on small size irrigation schemes (storage on rivers). There is a
need to construct small dams on rivers Indus, Jhelum, Chenab, and
their small tributaries. The potential sites for these small
reservoirs/dams need to be surveyed. However, some of these sites are
located at "Sehwan-Manchar Lake, Chotiari depression, Hamal Lake,
Skardu, Bunji, Kohala, Kunhar, Rohtas, Neelam Valley, Ambahar, Dhok
Pathan, Dhok Abakki, and Thal Reservoir" those may be
explored/utilized. The level of Mangla dam can also be raised to
increase its storage capacity. Another option is to manage the
existing irrigation system in a better way and undertake new schemes
wherever possible.
Conjunctive use of ground water: Conjunctive
use refers to the co-ordinate, combined, creative exploitation, and
judicious use of ground water for sustained development. It deals with
neither over extraction nor under extraction of the source. This
option has technically and economically been considered as the most
viable strategy in the past studies. But, the tragedy of this source
is that the government has no effective control over the excessive
pumping of ground water in some areas, hence, it has started to
diminish in those areas. The ground water table has already started
declining in 14 out of 45 canal commands. Due to over-exploitation of
this resource, the sustainability of irrigated agriculture is facing a
new threat in some of the canal commands in Punjab. This situation
needs to be checked and addressed urgently. However, Indus Basin
Irrigation System (IBIS) has a potential of around 48 MAF water within
its commands and nearly 39 MAF of ground water is being extracted
annually. This leaves with 9 MAF of water still available at this
source. This amount could be extracted and utilized for irrigation
purpose.
Increase the efficiency of existing system: The
unchecked growth of population has increased pressure on land and
water resources throughout the world; thus, it has become imperative
to conserve our water supplies. New sources of supply are becoming
scare and are unlikely to be constructed in the near future due to
geopolitical reasons, naturally, the emphasis must be given on methods
that can salvage the supplies already being lost within the irrigation
system in the form of seepage. Several reports have shown that about
25 to 30% of the water is being lost in the conveyance system of the
different countries of the world. A considerable amount of water is
lost during its conveyance due to seepage in lengthy canals; lining of
the system channels could reduce these losses. As reported by WAPDA,
more than 5 MAF of irrigation water could be saved by lining the minor
canals only, and additional amount of about 3.6 MAF could be saved by
water course improvement (see, GOP, Sixth five year plan, 1983-88),
this makes a total saving of over 8.6 MAF. However, due to financial
constrains, it is not possible to line entire canal system thus, the
portions with high potential of seepage and those located in the areas
with high salt content could be lined, by doing so, not only huge
quantities of irrigation water could be saved but also the risk of
water logging and salinity could be reduced. This would result in
saving of huge investments that otherwise are required for drainage
projects. Also, the existing system requires development of new
irrigation projects on non-perennial basis. It has been stemmed out in
the Water Apportionment Accord (WAA) of 1991, that remodelling /
construction of non-perennial canals should be taken, this would not
only provide additional water for agriculture but also save a bulk
amount (derived during monsoon) from flowing into sea. In this regard
construction of Thar Canal in Sindh (non-perennial canal) should be
undertaken to carry the additional water during monsoon season.
Water distribution: The proper management,
efficient application, and uniform distribution of available water at
farm-gate have remained major problems since the existence of the
irrigation network. Increasing water demand, deferred maintenance,
siltation of channel prism, excessive water by tampered outlets and
illegal water extraction & theft all lead towards inequity in the
system. It has even become increasingly significant over last two
decades. There is inequity in distribution at all levels in the
system. Inequity in water distribution between head and tail is of the
order of between 20 to 50 %. The water is distributed amongst the
farmers "as per turn system" on a watercourse and each
farmer receives his share on the basis of the area owned by him. Each
farmer is allotted a specified time period, in proportion to his land
holdings. In other words, this system disregards the crop consumptive
use, frequency, and timely application of irrigation water. The tail
enders however, receive 10 to 12 % less share of water, because the
allowance is based on the theoretical losses, whereas, the actual or
operational losses are high due to silt deposits at the heads, grass
growing on banks and in the beds, trees taking their toll of water,
rodents, snakes and other insects having their abodes in the banks,
variety of irregular cuts (nuccas) with borrow bits full of water,
overtopping on banks, and seepage through bed. The present situation
is that the head reaches are waterlogged and the tail enders do not
have enough water to meet their minimum requirement which results in
low crop yields. For maximizing crop production, this constraint in
the system would have to be removed. Government should take measures
to bring flexibility in the existing system to meet the crop water
requirements. Similarly, outlets on a minor or distributary receive
different amounts of water. Illegal pumping from canals and excessive
losses add to the inequity in distribution. Also, due to poor
operation and maintenance of irrigation systems, the water
distribution is not equitable and reliable. This has shaken the
confidence of tail users and has discouraged them to use nonwater
inputs for increasing crop yields.
Due to shortage of water, the tail enders have been
forced to use poor quality water without proper mixing, which has
given birth to salinity in such areas. This problem could be overcome
by lining the whole watercourse, again the investment becomes a
constraint, it is not possible to line the whole or optimum length of
the watercourses. The logical reaches need priority lining are the
head sections where silt deposits and raises the bed level which
reduces the flow of water, the sandy areas where the percolation
losses are too high. The watercourse improvement, proper maintenance,
and equal distribution would result in saving of more than 15 MAF of
water.
Adoption of water conservation techniques: Water
conservation can play an important role in sustaining agricultural
development. This requires substantial improvements in water use
efficiency, choice of suitable cropping pattern, growing
water-efficient crops, and introducing modern irrigation application
techniques (trickle. sprinkler etc.). It has been observed that once
water reaches at the farm gate, then, it becomes the responsibility of
farmer to use it. Farmers in Pakistan generally practice basin, border
or furrow methods of irrigation but the application efficiency of
these methods is very low and the water applied this way is not
distributed uniformly on their fields. It is quite common to find a
combination of over and under irrigation within a single field. Over
and under irrigation conditions results in poor crop germination that
causes yield reductions.
Recommendations
The unchecked growth of population has increased
pressure on land and water resources throughout the world; thus, it
has become imperative to conserve our water supplies. New sources are
becoming scare and are unlikely to be constructed in the near future
(except small dams) due to geo-political reasons, naturally, the
emphasis must be given on methods that can salvage the supplies
already being lost within the irrigation system in the form of
seepage.
The second largest contribution to the total water
availability comes from the ground water resources. This source has
been exploited and very well utilized by the public SCARP and private
tube wells. It can still provide over 9 MAF of water. This source
could be exploited and judiciously used for irrigation purposes.
However, in some areas groundwater is rapidly depleting due to
excessive pumpage, government should take control in such areas to
save them from depleting.
Water conservation programmes, such as, lining of
minor canals. distributaries, and water courses should be accelerated,
this would not only save the huge quantities of water, but would also
help reduce problems of water logging and salinity in the country.
Conjunctive use of water based on scientific lines should be
encouraged. Efforts should be made to convert the present
rotation-based-irrigation system to demand oriented system. Besides
that, the modern irrigation application techniques (trickle, sprinkler
etc.), that have potential to improve water distribution and water use
efficiencies, should be introduced in the areas with water scarcity.
Particularly, in Sindh province, for the development of Kohistan areas
of Dadu and Karachi districts, such techniques would be beneficial,
thus, may be initiated.
Since, improper management, poor operation and
maintenance of irrigation systems, inefficient application, and
inequitable distribution of available water at farm gate have remained
major problems since the existence of the irrigation network.
Increasing water demand, deferred maintenance, siltation of channel
prism, excessive water by tampered outlets, and illegal water
extraction all lead towards inequity in the system. Similarly, outlets
on a minor or distributary receive different amounts of water. Thus,
it is need of time that government should take appropriate measures to
ensure equitable distribution, to stop illegal extraction, and to
improve system efficiency. One way to over come these problems is to
empower water users so that they can play effective role in managing
the proper water supplies in their distributaries, minors, and
watercourses. The past experiences show that irrigation department has
failed to stop illegal theft and extraction thus irrigation
distribution system needs to be privatized through water users
associations. Also, irrigation water is supplied at negligible cost to
irrigators that is why they do not treat water as a precious resource;
therefore, there is a need to increase the water prices to make
irrigators realize the importance of this asset.
Inspite of continuous efforts, the desired national
targets have not been achieved. Low crop yields, decreasing fertility
of lands, onslaught of water logging & salinity problems coupled
with environmental degradation, improper water management, and
miserable economic conditions of the farmers are the indicators that
we have to work harder and go a long way to make improvements in
agriculture sector through development and transfer of modern
technologies of agricultural lands. However, to enhance optimum crop
production per unit volume of water consumed, high yielding varieties
should be introduced and better agronomic inputs (fertilizers and
pesticides) should be applied on scientific basis. It is also
recommended that the crops should be irrigated as per their
requirements. The existing crop water requirements can theoretically
be met by converting the existing irrigation system to crop
consumptive use based system. This will allow water to be delivered at
time of requirement and the amounts nearly matched to crop needs.
Farmer's organizations, water user associations,
and private sector be involved in construction, operation, and
maintenance of irrigation system. Such associations are conceived as a
mechanism for creating a co-operative framework for improvement of
watercourses.
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Table. Scenario of water resources of the country
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Surface water resources |
Annual water flow
MAF |
| Water
available at canal head (1947) |
67 |
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Water available at canal head
(1960) |
85 |
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Rim station flow (1997) |
147 |
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Water diverted to canals (1997) |
106 |
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Water flow to the sea (1997) |
32 |
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Losses in the river system |
8.6 |
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Ground water resources |
MAF |
|
Recharge to groundwater |
55 |
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Recharge to groundwater within
canal command |
48 |
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Groundwater pumping |
39 |
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Water required in future
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|
Year |
Water required |
Water available
Surface + Ground |
Shortage |
| . |
MAF |
MAF |
MAF |
|
2000 |
149 |
109 |
40 |
|
2013 |
215 |
107 |
108 |
|
2025 |
277 |
126 |
151 |
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Potential for water development per annum
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|
Water source |
MAF |
|
Surface water reservoir (Kalabagh,
Basha, and Dassu) |
17 |
|
Surface water reservoir (12 small
dams sites proposed) |
16 |
|
Water lost in canals and
distributaries |
21 |
|
Water lost in minors |
5 |
|
Water lost in water courses |
15 |
|
Groundwater |
9 |
|
Sub-total |
83 |
ITarar, 1997; 2Afzal, 1997; 3Khalid 1997; and
4WAPDA 1987; MAF = Million acre-feet.
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