Nestling between the Ravi and Chenab rivers, the Rachna doab, meaning two waters in Persian, takes its name from the first syllable of the former and two of the latter. Despite the poetic reference, this thickly forested land was once notorious country infested with brigands and wild beasts.
Travellers braving its deep, leafy recesses, where the peelu (Salvadora persica), acacia and mango grew profusely, were routinely set upon and deprived of all they had. The pious 7th century Chinese Buddhist pilgrim Xuanzang, himself a victim, leaves behind a doleful account of losing all, including much of the clothing he wore.
From classical times, we know the Rachna was watered by inundation canals radiating outward from the river no farther than a few kilometres to irrigate cultivated plots. The area beyond the canals remained virgin forest and partially desert.
After the annexation of the Punjab in 1849 and the establishment of the revenue system, Raj authorities were quick to recognize that their successful experimentation with irrigation channels in Sindh and the resultant spike in revenues could be duplicated here. Though great schemes were still more than a decade away, the Chenab River and Rachna doab came in for the first experiment.
In 1875, an ambitious project titled the Triple Canal System was conceived to pool the waters of the Jhelum, Chenab and Ravi. The still-to-be-excavated Upper Jhelum Canal was to deliver surplus water to the Chenab while the Upper Chenab Canal would supply its excess to the Ravi. The plan envisaged a headworks for Upper Chenab Canal at Marala. As that was the time when large outlays on irrigation headworks were still unfavoured, mainly because of the low cost of effective rehabilitation of existing inundation canals in Sindh, the project was scrapped.
Some seven years later, an inundation canal was excavated with its head near Khanki village 13 kilometres downstream of Wazirabad. However, unlike the Indus in spate in Sindh, the Chenab did not oblige: the new canal failed due to the lack of a control mechanism and was soon abandoned. What was needed was a permanent headworks where one or more canal could be diverted from the river.
Meanwhile in 1869, canal engineers had successfully completed a weir on the unruly Ravi at Madhopur and taken off the Upper Bari Doab Canal to create farmland in the wastes of Gurdaspur, Amritsar, Kasur and Lahore. That became a model for the wonder that we today know as Khanki Headworks on the Chenab, the sole example of what can only be called primitive canal engineering, inherited by Pakistan at Partition.
In layman terms, a barrage is essentially a bridge across a river with gated archways to control flow and raise the level of water upstream. A weir, on the other hand, is simply a wall across the river with steel shutters hinged along the bottom with supports to keep them upright. In case of flood, the support is removed to drop the shutters. Except lifting up the shutters is cumbersome and time consuming. A derrick boat with a diver on board goes out to gaff the loop atop each shutter to be winched up one by one.
Constructed between 1889 and 1892, the Khanki weir raised the upstream water level substantially, letting in flow into the abandoned inundation canal through a gated regulator on the left bank of the river. So it was that Lower Chenab Canal came into being with a command area extending all the way south through Sheikhupura to Sahiwal and westward to the newly established colony of Lyallpur, thereafter renamed Faisalabad.
Within a decade of its opening, Lower Chenab Canal was commanding an area of nearly 14,000 square kilometres, making way for the greatest colonization initiative ever attempted in Raj India. Entire clans were moved into the newly irrigated country with sizeable land grants with grantees divided into three classes: capitalists, yeomen and peasants. A district officer writing in 1905 noted that the peasant class proved to be the most assiduous tenants.
Raj authorities made no secret of the fact that their irrigation projects were a means of enhancing revenues. A report shows that the capital cost of building the Khanki weir and Lower Chenab Canal stood at Rs 28 million in 1892. By 1905, return on investment accrued from worked lands was 24 percent.
With periodic maintenance and remodelling to overcome problems of erosion and silting, the headworks at Khanki has withstood unprecedented flows during monsoon floods. What is more, it has kept the river level just right for Lower Chenab Canal to flow year round barring the annual winter closure.
In 2010, plans were afoot to replace the structure with a modern gated barrage. Work started in 2014 and is scheduled to be completed in three years. Word has it that once the barrage is operational, the old weir, 122 years old and operational at the time of writing, may be dismantled.
This remarkable piece of early canal engineering should be preserved for posterity. However, that may unfortunately not come to pass, despite the fact that the Khanki weir is the first-ever canal engineering project in the Punjab that came into Pakistani territory post-Partition.
In fact, the images you see here may well be the last reminders of a great feat of civil engineering that transformed a large part of central Punjab from primeval forest to breadbasket.
Top: The Khanki weir is an early form of irrigation structure. Its shutters that fall in case of flood can be seen held up by supports on the downstream side. The top of each shutter has a snag for the winch to pull it back into upright position.
Middle: A plaque on the Khanki Headworks gives the construction dates and other details.
Bottom: A boat with an antiquated manual winch to raise the dropped shutters. The snags on top of the weir shutters are just visible against the water.
Labels: Book of Days 2015, Punjab, Waters of Empire
posted by Salman Rashid @ 12:00 AM,
At March 2, 2015 at 9:54 AM,
There were two great development in this sector by the British , one the Railway net work for communication/ Industry and Head works/ canals for irrigation/ Revenue. These are still the great asset to the regon.
At March 2, 2015 at 10:41 AM,
Muhammad Imran Saeed said...
Sir, a great piece on the architectural cum engineering assets of Punjab. It is such that through your writings I have come across two beautiful terms, 'Wheels of the Empire' n 'Waters of the Empire'. Both these terms are enough to keep a stir within me, me! who is entagled in the romance of Railway and the lands of Sandal Bar.The former being my father's profession n the latter being chosen by my elders to settle as they migrated at the time of partition.
At March 2, 2015 at 1:56 PM,
Salman Rashid said...
Thank you very much, Athar.
Imran, we have two things in common: One, my father was also a railway engineer. And secondly we also migrated from the other side of the border at Partition.
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