The Sukkur Barrage, officially named the Lloyd Barrage, on the Indus about three miles below Sukkur Gorge, is the pride of Pakistan irrigation system. It is the largest system of its kind in the world. It is the backbone of the economy of the entire country, providing, through its network of canals, irrigation to an area of 7.63 million acres, approximately 25 percent of the total canal irrigated area of the country. The Nara Canal, which is one of the seven canals absorbing the run off from this barrage, is the largest in the country, carrying a discharge almost equal to that of the River Thames. Its bed width is 346 ft.one and a half times that of the Suez Canal. It is not a man made Canal, but the south western arm of the Hakro, the Lost River of the Indian Desert. The idea of a barrage at Sukkur was first conceived by Lieutenant J.G Fife in about 1855, but a complete scheme was not made for another sixty years. Sir Arnold Musto, an engineer, was then appointed to develop the project. His plans were submitted to the Government of Bombay, and in April 1923 the Secretary of State for India sanctioned the project at an estimated cost of Rs 200 million. Work started in January 1925 and was completed by 31 December 1931. An unanimous resolution of the District Local Board was passed that the barrage be named after Sir George Lloyd, the Governor of Bombay, who had taken an active interest in the scheme.The barrage comprises sixty six spans, each sixty feet wide and each divided into three sections by the two divided wall on its upstream. The right pocket, the left pocket, and the main weir have five, seven, and fifty – four spans respectively. The central section is further divided into six bays of nine spans each. These bays are separated from each other by abutment piers that are twenty-five feet thick and ninety-seven feet long. An ordinary pier is ten feet wide and seventy seven feet long. Abutment pier number 32, which is one hundred and ninety feet long, has eight pipes for indicating uplift pressures. The weir bays have upstream floor at Reduced Level (R.L) 176.0 with no crest, and the downstream floor slopes to R.L 172.39 in a gradient of in 70 up to the of the flexible talus. There is a lower bridge with a sixteen-foot roadway enabling vehicles to drive between the two banks. The bridge is just under a mile in length. Masonry walls joined to the abutment of the barrage on either bank enclose the main regulators of the various canals. Thirty two thousand laborers worked year-round on the project. In addition, a total of seven thousand men were employed daily to work on the large, medium, and small-size machines. Primitive methods, including bullocks drawing a metal edged board scoop, were used side by side with huge machines each excavating seventy-four tons of earth per minute. The total amount of earthwork done came to 569 crore (5,690,000,000) cubic feet, of which 312 crore cubic feet were excavated by machines and the rest by human labour.

There are four off take canals on the left bank

There are three off take canals on the right bank

On Wednesday, 13 January 1932, His Excellency the Viceroy of India graced the opening ceremony. Activities began at 10.50 a.m. with the Viceroy s tour of the barrage and the left bank canals, after which the Viceroy threw the switch operating the regulator gates and declared the canals open. At noon, a special lunch was served at the residence of the superintending engineer of Northern Sindh Circle.On 9 April of that year a memorable dinner was held at the Karachi Club, given on behalf of the people of Sindh to celebrate the successful completion of the Lloyd Sukkur Barrage and canals. Two elaborate menus were served, including one vegetarian, but the most striking feature was the table plan: the top table represented the Barrage, and five offshoots represented the Nara, Rohri, Dadu, Rice, and Northwestern Canals. Opposite each canal sat its engineer in charge, while the guests of honor, six Charlton Harrison and Sir A.K. Musto, the legendary executive engineer, sat in the middle of the barrage. The Golden Jubilee was celebrated in some style on 30 and 31 March 1982, with a lunch, a dinner, and speeches. The guest of honor was the Governor of Sindh for whom the throne of the ex-ruler of Khairpur State was specially sent for and Sir Arnold Musto s two daughters attended as guests of the Provincial Government. At about the same time, it became apparent that the gates of Sukkur Barrage had lost their utility , and a project involving Rs: 482 million was planned to replace fifty-five of the sixty-six gates, to be launched in fiscal year 1986-7, and completed by 1992. Besides the replacement of the barrage gates, the central leaves of the gates of the canal head regulators were also to be replaced. The upper and bottom leaves of the gates did not need replacement. The British Government, which had funded the barrage in 1932, agreed to provide a foreign exchange component for the financing of the replacement work. These gate and the central system were to be designed and fabricated in the United Kingdom, by an agency which had agreed to provide the necessary materials, but the fabrication of the gates was to be carried our in Pakistan using expertise acquired from the UK. In the event, work on the project did not start until 1990, by which time the cost had risen to Rs: 612 million, but it was completed in 1993.

Note: 33 thirty three regulator gates in the range of Rohri and thirty three regulator gate in the range of Sukkur District.