IRRIGATION experts are finalising a feasibility report for the modernisation and rehabilitation of Guddu Barrage, funded by the World Bank at an estimated cost of $203m.

The project is designed to strengthen the barrage so that it can face exceptional water flows that are becoming imminent due to global warming.

The draft feasibility report has been submitted to an advisory committee formed by the Sindh government. Its members include Punjab’s former secretary irrigation Syed Mansab Zaidi, Sindh Irrigation Drainage Authority’s managing director, superintending engineer mechanical circle Zamir Memon, and Baghar circle’s superintending engineer Abdul Qadir Palijo. The committee discussed the draft report on January 23, for presentation of the final report.

The project includes major works: replacement of all 65 gates; building of spurs in upstream Guddu to centralise the river’s approach from the current left side tendency in water flows to avoid silting on the right side; re-building of the dividing wall at the seventh bay instead of the existing fourth to provide water to Reeni canal (being built by Wapda on the barrage’s left bank and which is near completion); and raising the height of marginal bunds to increase retention time.

Previously, the divide wall was facilitating flows for Ghotki Feeder alone on the barrage’s left side. Spurs would push the main current of water to the centre of the river.

A divide wall is to be built at the barrage to create a spilling pond/pocket for meeting the required supplies to some canals with specific velocity in discharges. Since Reeni canal is an additional channel on the left bank along with Ghotki Feeder, the size of the spilling pond is to be enhanced to supply water to both channels.

With the replacement of the gates of Guddu Barrage and its off-taking canals, the operation of water channels would become easier

Sindh’s irrigation authorities are mulling raising the discharge capacity of the barrage, considering similar increases in capacities of other barrages located upstream on the Indus and on other rivers in Punjab. The completion of the Guddu project would withstand discharges of fluctuating flows along with synchronisation in capacity enhancement.

Punjab authorities are also said to have raised the heights of dykes at different barrages and are doing so at some other places as well. Such unusual discharges in Punjab have been, historically, handled by controlled breaching in dykes at different locations to avoid damage to the structure of their barrages.

Last year when floodwaters had threatened certain waterworks over Jhelum and Chenab, authorities resorted to breaching to manage the situation. Sindh had a bitter experience of the 2010 super floods when a breach at Tori bund in downstream Guddu had caused widespread damage to the standing rice crop and displaced millions of villagers.

The Guddu Barrage is the first controlling point on the Indus, and irrigates lands in Sindh and Balochistan simultaneously. In Sindh, it mainly feeds the rice-growing areas, though wheat is also grown there.

It is basically the deferred maintenance of barrage(s), says an expert, that has reduced the thickness of its skin plates by 30-40pc due to ageing. The barrage has completed 50 years, coming into operation in 1962, and the gates need to be replaced now.

With the replacement of the barrage’s gates as well as its off-taking canals, the operation of water channels would become easier. The revision in the cut-off difference between the up and downstream water levels would provide cushion for storage. Solar panels are to be installed for regular electricity supply.

Normally, water supplies are first ensured to Sukkur Barrage — considered the lifeline of Sindh’s agriculture, with seven major canals — and then to Kotri Barrage, because the early sowing of kharif crops takes place in the command areas of these barrages. Their command areas produce major crops like cotton, rice and sugarcane, in addition to mango, banana and date orchards.

“We are also thinking of enhancing the capacity of Guddu owing to global warming. Punjab is also rehabilitating its barrages as well. It has already raised the capacity of Kalabagh and Taunsa barrages on the Indus and Khanki over Chenab. It is also doing so at Trimu and Panjand barrages over Jhelum,” says Noor Mohammad Baloch.

He heads the Sindh government’s advisory committee that would vet the feasibility and PC-1 report of the rehabilitation of Guddu Barrage.

The capacity of Taunsa Barrage has been raised by 100,000 cusecs and Trimmu’s being increased to 1.1m from 900,000 cusecs, he said.

Guddu Barrage’s capacity enhancement from the current 1.2m cusecs to 1.5m cusecs is being considered, while a Sindh government committee headed by irrigation expert Idris Rajput has proposed the construction of a ‘new’ Sukkur Barrage, as the current one is over 80 years old.

Published in Dawn, Economic & Business, February 2nd, 2015

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