HYDERABAD: Considering paramount importance of Sukkur Barrage for the irrigation and overall agriculture sector, the June 20 heavy damage to its seven gates must have forced government to bring its operations into safer limits that have seemingly been eluded.

While the ongoing ‘technical inquiry’ into the damage is yet to come up with its findings, some indicators tend to suggest that the barrage is hit by deferred maintenance and serious operational issues like pond level raising.

The level is raised exceptionally every summer. It has the potential to undermine upkeep of barrage notwithstanding the fact that Sindh is dependent on this colonial era (1932) structure directly as around 7m to 8m acres of its command area is irrigated by the barrage.

Information gathered by Dawn and the background interviews with several serving and retired engineers show that the ‘pond level’ methodology has become a problem.

Experts say serious issues were acknowledged in January but ignored; strongly criticise pond level methodology

Come Kharif season and authorities raise the level up to 199-200 RL plus to feed canals. It necessitates closure of gates and this actually develops pressure on them.

Signs of rust on barrage’s gates were evident as if they had not been painted for long. According to a senior officer, life of gates increases if they are regularly painted and that is what is seen in developed world.

The upper portion of gate No. 47 washed away when the river had a flow of just around 100,000 cusecs on June 20. Six more gates were damaged. It’s reflective of their vulnerable condition.

Serious issues ignored?

Surprisingly, an inspection report of Jan 2023 closure of barrage didn’t point to any serious issue in gates, said an officer while sharing the report with the writer. He, however, quips: “I must admit Sukkur Barrage is under stress. We need to rescue it”.

Officials admit that annual maintenance was in fact a case of ‘deferred maintenance’. “This has been going on for several years and that’s the reason that gates are getting prone to issues. June 20 is a warning for all of us to take measures for better management of barrage’s operations”, says a senior engineer.

Weir is sensitive region in barrage’s component falling between two divide walls of barrage and it is where gate No. 47 stands, according to Sattar Sario, a retired executive engineer officer, who has served at Sukkur barrage and now monitors its operations and is producing brief research papers on it. He explains that recommended designed pond level is 194.5 but it exceeds the benchmark.

Written permission, argues Mr Sario, is to be sought from irrigation secretary as per rules if its level is to be raised even by an inch.

“The level is raised up to 199 RL and over 200 RL. To me, raising of pond level comes directly at the cost of barrage’s upkeep,” he says. He says a study covering 4kms upstream and downstream each of barrage must be conducted to analyse problems confronting the barrage. Pond level is raised upstream barrage to feed seven canals.

“This raise is achieved artificially as well. For a long time, wooden planks are attached over gates to achieve this raise,” discloses a barrage official.

Silt load

Historically, the barrage has been facing heavy silt load ever since its construction, leading to closure of 10 of its gates out of 66 but has successfully withstood pressure of high floods and super flood in recent times. Ten gates were closed after a study in Pune (India) in 1938. Later, a submerged weir was built inside Indus river upstream. Accumulation of silt is seen in right pocket of the barrage which feeds right bank canals.

Crest level for right and left pocket of the barrage is 176 RL. Left bank’s Nara canal’s crest level is 181.34 RL; Khairpur Feeder East 187.28 RL; Rohri 188.11 RL; and Khairpur Feeder West is 185.28 RL. Of right bank canals, the North West Canal (NWC) crest level is 183.75; Rice Canal 183.13 RL and Dadu Canal 184.32 RL. Due to lowest crest level, Nara kept getting better flows from the barrage even when the pond level had dropped the post-June 20 emergency.

“Actually bed flow of Indus upstream the barrage moves towards its right side having heavy silt loads whereas surface flow which is relatively free of silt travels towards left side. So, right pocket canals get more silt than left side,” explains Mr Sario. Nara canal has a lowest crest level of 181.34 RL but it gets silt-free flows because of surface flows that go into left pocket and flows with silt loads ending up in right side, he says. The submerged weir was a wall sort of structure under river built to block the silt loads. “This weir is damaged apparently,” he says.

Difference of opinion

Pond level up to 199 or 200 plus is needed if NW Canal and Dadu Canal are to be fed, insists Chief Engineer Right Bank Mukhtiar Abro. “Dadu is silted by 5ft-7ft so 198 RL pond level can’t work. NW Canal is silted, too,” he says. “We need to desilt these canals only then we won’t need to hit higher pond level,” says Abro.

Rice crop

Rice can’t be grown in perennial Dadu canal’s command. It didn’t get water timely to grow cotton but when area growers get flows in June; cotton sowing period has already passed thus they turn to rice cultivation which requires plenty of water.

Sindh Barrages Improvement Programme (SBIP) is being executed with World Bank’s loan of Rs74bn. It has been delayed since 2018 when the gate No. 39 was damaged on June 18, 2018. The delay is attributed to force majeure factor.

“Contractual obligations and then Covid19 upset things. That’s why the Karachi Shipyard & Engineering Works (KS&EW) was tasked to replace six gates between 2020 and 2021 as their condition was weak,” says SBIP chief Mohiuddin Mughal. Rice canal was desilted at a cost of around Rs2bn with SBIP funds, he adds. Initially, RD-0 to RD-82.5 were to be desilted but it was extended up to RD-92.5. “The canal will function normally for at least 4-5 years,” he says.

According to him, Rs26,601m, inclusive of Sindh government’s share in SBIP, were spent on Guddu and Sukkur barrages. Now after the June 20 incident, he says, 18 gates of Sukkur Barrage would be replaced by May 2025. “Gates can only be replaced during low flows period starting in Rabi season [October-April] and that’s why the project will be completed by 2027,” he says.

‘Rehabilitation of weir more important’

Mr Sario, however, insists that instead of desilting, rehabilitation of submerged weir should have been done. Now height of gates at Guddu and Sukkur barrages is being raised by 2ft which is a serious matter as it has direct impact on the entire barrage. And no feasibility study is done for it.

Sindh Abadgar Board (SAB) President Mahmood Nawaz Shah urges authorities to ponder over how this problem has occurred. “It’s no joke and has not occurred overnight,” he says, acknowledging that officials made the barrage operational within eight days. SAB’s delegation was given briefing by irrigation secretary Zarif Khero.

“Irrigation officials will have to operate barrage very carefully as its gates have turned old,” he says.

He is worried about the pond level methodology and observes that the level is maintained in a way that it doesn’t impact gates. He believes that any malfunctioning of barrage could be disastrous. “We have to remain vigilant,” he says.

Published in Dawn, July 1st, 2024