Pakistan's irrigation system consists of several rivers, dams, irrigation and link canals, millions of tube- wells and thousands of irrigation channels. It is considered to be the largest irrigation system in the world in terms of water supply and length. Following are the main sources of irrigation in Pakistan.
1. Rainfall
Rainfall is an important natural way to get water. In our country, monsoon rains are very common. Water from rain in the mountains and melting snow flows into rivers, keeping them full all year round. We build dams to store this water. Then, we use this water for farming and factories by digging canals from dams.
Unlike areas with canals, farms that rely on rain do better when it rains at the right time. Sadly, our country doesn't get as much rain as we need. In of Pakistan, the average yearly rainfall is even less than 200 millimeters. Only of the higher mountain areas get 500 to 1000 millimeters of rain each year.
2. Canals
These are main types of canals according to their performance.
(i) Perennial Canals
These are the irrigation canals that run throughout the year and are important source to carry river water to the fields. Main perennial canals of the country are Upper Chenab, Lower Chenab, Upper Jhelum, Lower Jhelum, Lower Bari Doab and Pakpattan canal etc. that flow all the year.
(ii) Non-Perennial Canals
Non- Perennial Canals are also called six monthly canals, because water is released in them only in summer and rainy season. Bahawalpur and Qaimpur canals flowing from Islam Barrage on the Sutlej River and few canals flowing down from Kotri Barrage and all canals of Guddu Barrage are non- perennial canals (canals not flowing through out the year).
(iii) Flood Canals
In summer and rainy season, when the water level in the rivers rises or when the water reaches the danger mark in the rivers during severe floods, water is released in these canals to protect the barrages from damage. In addition to it, link canals are found in Pakistan.
3. Tube-well
It is inevitable to use ground water through tube- wells to meet the shortage of canal water. Currently, there are millions of tube- wells installed in the country, most of which are in Punjab province.
4. Karez
In Pakistan, this system is used in the province of Balochistan, where due to the specific geographic conditions and severe shortage of canal water, water is brought to the fields through underground drains. These drains are called karez. The sources of these karez are springs flowing from the mountains which are mostly made in Pishin and Quetta districts.
Indus Water Treaty
In 1948, India withheld the flow of water of those Pakistani canals whose sources were located in India. These canals include Upper Bari Doab flowing down from Madhupur Barrage on the Ravi River and Depalpur canal flows out from the Ferozpur Barrage on Sutlej River. Pakistan raised the issue at international forums. As a result, Indus Water Treaty between Pakistan and India reached in September, 1960 under the support of the world powers. Under this treaty three eastern rivers; the Sutlej, the Ravi and the Beas became the part of India. Three western rivers; the Indus, the Jhelum and the Chenab were given in control of Pakistan. Thus, Pakistan's property rights over these rivers were recognized. An irrigation network was formed in Pakistan to meet water shortage in eastern rivers, which provided financial assistance as well as necessary technical guidance to Pakistan. Following strategies were formulated to meet the water shortage in the eastern rivers:
Our eastern rivers which are now owned by India under the Indus Water Treaty, these three rivers were irrigating our about 8 million acres before given to India. If we did not build link canals to supply water to these rivers, the area would not only become barren, but people would also have difficulty in obtaining drinking water.
Civil works have been completed under the Indus Water Treaty. Pakistan has always been sincere in its commitment to this treaty and has never violated it, while India, being at the upper reaches of our rivers, does not miss any opportunity to take advantage of our rivers.
Barrages and Canals on River Indus and its Eastern Tributaries
The details of the barrages and canals on the Indus and its eastern tributaries are given below:
Barrages and Canals on River Indus
1. Jinnah Barrage
This is the first barrage of Punjab province located on the Indus River. Mianwali, Bhakkar and Layyah districts are being irrigated by the Thal canal flows out from the Jinnah Barrage.
2. Chashma Barrage
Chashma Barrage is located on Indus River. From this barrage, the Chashma Right Bank Canal has been taken out to supply water to Dera Ismail Khan. While the Chashma- Jhelum Link Canal has been taken out from the left bank, which further supply water to the Greater Thal Canal. This canal irrigates the districts of Layyah, Bhakkar, Khushab and Jhang.
3. Tounsa Barrage
This is the last barrage of Punjab province on the Indus River. Dera Ghazi Khan Irrigation Canal, Muzaffargarh Irrigation Canal and Tounsa Panjnad Link Canal have been taken out from here. The Kachhi Canal is also being drained from the same river.
4. Guddu Barrage
This is the first barrage of Sindh province on the Indus River. Water is being supplied to Naseerabad division of Balochistan province and northern areas of Sindh province by taken out four canals from here. The Rainee Canal is also being taken out from the left bank of the same barrage.
5. Sukkur Barrage
This is the biggest Barrage of Sindh. From here, seven irrigation canals have been constructed. These canals supply water to the provinces of Sindh and Balochistan.
6. Kotri Barrage
This is the last barrage of Sindh on the Indus River. Water has been supplied to the southern areas of Sindh province by taking out four canals from here.
Diagram image pending upload by Admin.