Irrigation System Management Problems
An Indus Basin Model has been developed by the Development Research Center of World Bank in 1982, which stands as the only major optimization exercise for the Indus Basin Irrigation system, so far.
According to Pakistan Statistical YearBook, the country’s water resources are divided into two major commands, the Mangla Command and the Tarbela Command. This classification does not include the NWFP canals above Kalabagh.
The Mangla Command includes the link canals and the canals originating from the upper reaches of eastern rivers. Whereas, the Tarbela command includes Thal, Haveli, Rangpur, Paharpur, Taunsa, Punjnad, Guddu, Sukkar and Kotri canals.
The following table gives the command wise withdrawals in MAF, for these two command areas.
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Command wise Canal Withdrawals (MAF)
|
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| Year |
Mangla Command |
Tarbela Command |
||||
|
Kharif |
Rabi |
Total |
Kharif |
Rabi |
Total |
|
| 1980-81 |
19.27 |
11.98 |
31.25 |
48.48 |
24.74 |
73.22 |
| 1981-82 |
19.34 |
10.89 |
33.23 |
46.01 |
22.79 |
68.80 |
| 1982-83 |
18.80 |
11.62 |
30.42 |
46.82 |
23.19 |
70.01 |
| 1983-84 |
16.44 |
11.73 |
28.17 |
44.41 |
25.11 |
69.52 |
| 1984-85 |
19.70 |
10.88 |
30.58 |
44.54 |
23.59 |
67.93 |
| 1985-87 |
18.53 |
12.49 |
31.02 |
40.14 |
22.45 |
62.59 |
| 1986-88 |
18.81 |
12.76 |
31.57 |
46.70 |
24.85 |
71.55 |
| 1987-89 |
18.78 |
12.36 |
31.14 |
50.66 |
24.48 |
75.14 |
| 1988-89 |
18.55 |
10.74 |
29.29 |
46.42 |
26.77 |
73.19 |
| 1989-90 |
19.14 |
11.24 |
30.38 |
44.20 |
24.57 |
68.97 |
Reference: Saeed A. Rashed; KBD; A Scientific Analysis, 1995
It is a fact that the period of maturation for Rabi crops varies considerably from south to north, and the Rabi wheat matures in lower Sindh by end of February, while in north Punjab it matures by end April.
Given the crops’ requirements, any addition to the waters of Mangla Command for meeting the water shortages will be of no beneficial use, since the already optimized model of Indus Basin caters fully for the water requirements in these two command areas. And any random figure of water addition to the command water will only result in spoiling the balance of the optimized Indus Basin Model, and wastage of precious water.
In this respect, apart from bringing additional areas under the direct command of left bank KBD off-take, through the utilization of 0.78 MAF of water, the addition of 4.64 MAF water into Jehlum at Rasul Barrage will have no significant impact on our irrigation system management.
Therefore, the utility of a 15000 cusecs left bank canal from KBD will be nothing more than the provision of 0.78 MAF waters to its direct command and a little replenishment of Mangla storage’s in the Jehlum River command.