INTRODUCTION
THE DEVELOPMENT OF
THE IRRGATION SYSTEM
Controlled year
round irrigation began in 1859 with the completion of the Upper Bari Doab Canal
(UBDC) from Madhopur Headworks (now in India) on Ravi River. Until that time,
irrigation was undertaken through a network of inundation canals, which were
functional only during periods of high river flow.
These
provided water for kharif (summer) crops and some soil moisture for rabi
(winter) crops. The last inundation canals were connected to weir
controlled supplies in 1962 with the completion of Guddu Barrage on Indus
River. UBDC was followed by Sirhind Canal from Rupar Headworks on Sutlej in
1872 (also in India) and Sidhnai Canal from Sidhnai Barrage on Ravi in 1886.
The Lower Chenab from Khanki on Chenab in 1892, and Lower Jhelum from Rasul on
Jhelum in 1901 followed suit. Lower and Upper Swat, Kabul River and Paharpur
Canals in KPK were completed between 1885 to 1914.
By
the turn of the century, it became apparent that the water resources of the
individual rivers were not in proportion to the potential irrigable lands. Ravi
River, serving a large area of Bari Doab, was deficient in supply while Jhelum
had a surplus. An innovative solution was developed in the form of the Triple
Canal Project, constructed during 1907 –1915. The project linked the Jhelum,
Chenab, and Ravi rivers, allowing a transfer of surplus Jhelum and Chenab water
to the Ravi. The Triple Canal Project as a land-mark in integrated interbasin water resources
management and also provided the key concept for the
resolution of the Indus Waters Dispute between India and Pakistan in 1960.
The Sutlej
Valley Project, comprising of 4 barrages and 2 canals, was completed in 1933,
resulting in the development of the unregulated flow resources of the Sutlej
River and motivated planning for the Bhakra reservoir (now in India).
During the same
period, the Sukkur Barrage and its system of 7 canals serving 2.95 million
hectares of land in Lower Indus were completed. Haveli and Rangpur from Trimmu
Headworks on Chenab in 1939 and Thal Canal from Kalabagh Headworks on Indus
were completed in 1947. This comprised the system inherited by Pakistan at the
time of its creation in 1947.
At independence,
the irrigation system, conceived originally as a whole, was divided between
India and Pakistan without regard to irrigated boundaries. This resulted in the
creation of an international water dispute in 1948, which was finally resolved
by the enforcement of Indus Waters Treaty in 1960 under aegis of the World
Bank. The treaty assigned the three eastern rivers (Ravi, Beas, Sutlej) to
India, with an estimated total mean annual flow of 33 million acre feet (MAF)
and the three western rivers (Indus, Jhelum, Chenab) to Pakistan with a
transfer of irrigation supplies from the western rivers to areas in Pakistan
formerly served by the eastern rivers as well as some development potential to
compensate for the perpetual loss of the eastern waters. The Indus
Basin Project including
Mangla Dam, 5 barrages, 1 syphon and 8 inter-river link canals, was completed
during 1960-71, while Tarbela Dam started partial operation in 1975-76.
After partition,
Kotri, Taunsa and Guddu Barrages were completed on the Indus River to provide
controlled irrigation to areas previously served by inundation canals. Also,
three additional inter-river link canals were built prior to the initiation of
Indus Basin Project. DISTRIBUTION OF AREA AND
WATER
During
the year 1999-2000, the total irrigated area from all the sources, including
private canals, schemes, wells and tubewells and publicly owned infrastructure
was of the order of 18.06 million hectares. About 77.4% of the total irrigated
area of Pakistan falls in Punjab, 2.8% area falls in KPK and 19.8% in Sindh/
Balochistan. Based on the statistics of the last 10 years, the area irrigated by
canals has increased slowly by an aggregate of 6% but its share in irrigated
area has remained constant due to the continuous increase in the number of tube
wells which now irrigate 20% more area than 10 years ago.
IRRIGATION SYSTEM OF KHYBER PUKHTUNKHWA
Irrigation system of Khyber
Pukhtunkhwa comprises of 09 canals, with total length of 1847 miles and total
discharge of 12948 cusecs. These canal systems are listed below.
S.No
|
Name
|
Length (miles)
|
Discharge
|
1
|
Upper canal system(swat)
|
526
|
3600
|
2
|
Lower swat canal system
|
193
|
1940
|
3
|
Pehur main canal system
|
76
|
250
|
4
|
Pehur high level canal system
|
16
|
1000
|
5
|
Warsak canal system
|
124
|
595
|
6
|
Kabul river canal system
|
76
|
800
|
7
|
Tanda dam canal system
|
56
|
363
|
8
|
Marwat canal system
|
167
|
800
|
9
|
Bannu canal system
|
160
|
600
|
EXISTING IRRIGATION INFRASTRUCTURE IN KHYBER PUKHTUNKHWA
S. No
|
Item
|
Description
|
1
|
Flow Irrigation system
|
83
|
2
|
Length of canals (KM)
|
4335
|
3
|
Lift Irrigation schemes (NOs)
|
45
|
4
|
Storage Dam (NOs)
|
14
|
5
|
Irrigation Tube well (NOs)
|
356
|
6
|
Scarp Tube wells/Dug Wells
|
606
|
7
|
Private Tube wells (NOs)
|
14000
|
8
|
Surface Drains (KM)
|
2818
|
9
|
Sub Surface Drains
|
2045
|
10
|
Flood Protection Embakment & Spurs
|
332
|
FLOW IRRIGATION SCHEMES
KPK has five publicly owned
irrigation system in the Indus River, which serve a total area of 0.34million
hectares. These systems receive water from two head works across river swat and
Warsak dam. In addition there are six other canal systems, which serve a total
of 0.13million hectares of land.
KPK has over 200 canals
called "civil canals" which are community or privately owned. These
irrigate an aggregate area of .83million hectares. There are four surface
drainage systems in KPK comprising of 456 drains. These serve a total area of
.37million hectares.
During the year 1999---2000,
the total irrigated area, using all the sources in KPK was of the order of 0.89million
hectares. This included 0.39million hectares of land in the canal commands, private
canals, tube wells and wells irrigated .47 million hectares during the same
period.
LOWER SWAT CANAL SYSTEM
The lower swat canal system 1st came
into operation in 1885. It was manage for 62 years under the British periods. The
system is supplied from Munda headwork on Swat River. The system has a
cultivable command area of (123600 acres). The lower swat canal system was
completely redesigned during 1987---1992, to overcome the capacity constraints,
which resulted in the water shortage and inequalities in irrigation supplies in
relation to crop water requirements.
The length of the channel in operation at the
close of the British period was 312km, comprising 35km of the main canal and
its branches and 277km of its distributaries. The major channels on the
watershed b/w the streams. The channel are graded to a general slope of about 1
in 1000.the lower swat canal has a full discharge of 1940 cusecs.
Sheikh Yousaf minor is a small secondary canal
in lower swat canal irrigation system.it is situated along distributary 8 and
represents the condition typical of middle portion of system. The total command
area of the channel is 853ha and has eleven outlets. Nine of the eleven outlets
are barrel type equipped with upstream sliding gates and two tail outlets are
open flumes.
KABUL RIVER CANAL SYSTEM
The Kabul river canal system is one of the
oldest irrigation systems in the province. It has played an important role in
the agricultural production of the area. At one time it was known as the
Michni-Nowshera canal. It takes off from the right bank of the Kabul River
where it debouches from the hills, a short distance above the Michni Fort at
the village of Warsak about 24 km north-west of Peshawar.
The scheme was
originally designed to extend the irrigation to a small district known as the
joe-sheikh, but later an extended project was prepared to command much larger
area of over 9713hectares with a discharge of 330cusecs.
In KPK Kabul
river irrigation three main districts i.e., Peshawar, Charsada, and Nowshera.in
Peshawar 80%,Nowshera 47.83%,and in Charsada 84.67% cultivable land is
irrigated from Kabul river.in terms of irrigation the total contribution of
Kabul river to the total of KPK is 16.92%.
TANDA DAM CANAL SYSTEM
Tanda dam has been constructed in the river Kohat 6miles away
from the city at Tanda Banda. It was completed in 1965.it is a earth filled dam,
115ft high with a supplying capacity of 2000cusic water. This dam irrigates
32,000 acres of land in Kohat district.
WARSAK DAM CANAL SYSTEM
The Warsak dam is located on Kabul River, about
30 kilometer North-West of Peshawar in Khyber-Pukhtunkhwa province.
It is a mass concrete gravity dam with a height
of 250 feet and length 460 feet. The project was constructed in 1960 under the
Colombo Plan, which was financed by the government of Canada.
In phase-I, the dam, irrigation tunnel and four
power generating units, each of 40 megawatt (MW) capacity, had been constructed
at a cost of $98.75 million, while in phase-II, two more units, each of 41.5MW
capacity, had been installed in 1980-81 with an expenditure of $10.6 million,
thus raising the total installed capacity of the project to 243MW.
The canal system of the Warsak
dam project is irrigating at least 119,000 acres of land, and has, thus,
contributed $2.3 billion to the national economy since its commission.
Similarly, the Warsak hydal power station has so
far generated about 40 billion units of electricity, earning revenue of $3.5
billion.
LIFT IRRIGATION
SCHEMES
In
most cities of KPK lift irrigation schemes are using.in lift irrigation schemes
water is lifted from lower level to higher level with the help of pumps and other
equipment, construction of dams and canal helped emendously to increase the
irrigated area lying at lower level than the dam level ,but scarcity of water
remained the problem for higher level areas, so as to bring higher level under
irrigation, lift irrigation schemes are taken up.
ADVANTAGES OF LIFT
IRRIGATION SCHEMES
1.
LIFT irrigation schemes made
irrigation possible at higher level.
2.
Land acquisition problem in lift
irrigation schemes is less.
3.
Water losses are low.
4.
LIFT irrigation schemes made
irrigation possible at higher level.
5.
Land acquisition problem in lift
irrigation schemes is less.
6.
Water losses are low.
CLASSIFICATIN OF
CANALS IN KPK
The canals are classified in the following
categories.
PERMANENT CANALS
Permanent canals are
those which are fed by the permanent source of supply such as ice fed, river, and
reservoir.it is a well graded canals and is provided with permanent head works,
regulators and distribution system. These types of canals are mostly found in
Abbottabad, tribal areas and in Kohat. These canals are present in hilly areas
where natural reservoir is present.
PERENNIAL CANALS
These are also termed as
permanent canals which get continuous supply from the river throughout the
year. Such canals can irrigate the crop field all the year round.
INUNDATION CANAL
These are the earliest type
of irrigation canal which is dependent entirely on the periodical rise of the
water level in the river during flood period. Construction of permanent
regulatory works is rare in those channels.
MAINTENANCE OF
CANALS IN KPK
When
irrigation canal is put into operation after construction, it is essential for
its maintenance for proper and efficient functioning. Canals are required to
maintain regularly due to the following causes.
SILTING IN CANAL
In unlined channel, silt creates
a regular problem as the velocity of water is not enough to carry the silt
along with water to the crop field.in the canal headwork silt excluder and little
downstream of headwork silt ejector are provided to arrest the silt from
entering the canal. Yet a part of silt enters the channel, removal of which is
necessary.
WEED GROWTH
Weeds are unwanted plants that grow
profusely in water under some favorable condition. Weed decrease the area of
flow, offer resistance to flow. The deposition of silt and light encourages the
growth of weeds. If velocity of flow is
increased, fine silt is held in suspension, water becomes turbid, and
light cannot penetrate to help the growth of weed.
Weed control may be done by manual labor
and burning them when dry.
OVERFLOW OF CANAL
BANKS
If canal over flow during heavy
rains, bank height is required to increase.
BREACHING OF CANAL
BANK
To reduce the
failure of bank, banks can be strengthened by formation of internal and
external berms by silting and extra earthworks. When berms are formed, canal
banks cannot breach due to seepage or piping.
Feel free to write