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Today's Paper | November 23, 2024

Published 12 Dec, 2011 12:26am

Rehabilitation of Sukkur Barrage

A STUDY on rehabilitation of Sukkur Barrage has been initiated by the Sindh Irrigation and Drainage Authority under its Water Sector Improvement Project. It will focus on the structure of the 80-year-old barrage.

The study includes environmental management plan (EMP), issues relating to water shortage and its impact on flora and fauna, and strategy to mitigate the problem. It will also seek solutions to address the seepage problem. Consultants will collect data of last 100 years historical records for a comprehensive analysis.

Smart solutions are needed to simultaneously address the problems experienced in 1932 when 10 gates had to be closed and in 2010 when increased floodwater hit the barrage. With a properly functioning barrage structure, there are lesser chances of water shortage problem and subsequent outcry of farmers.

Pending for some years, the Water Sector Improvement Project (WSIP) is undertaking the study in the wake of 2010 floods when the barrage withstood a pressure of over 1.1 million cusecs against its present capacity of 0.9 million cusecs. The barrage is faced with the problem of silt deposit on its right pocket. With seven major canals, the Sukkur Barrage is considered the lifeline of Sindh’s agriculture. It irrigates areas up to Badin and Naukot on the left side and Mehar and Dadu on its right side with a gross commanded area of eight million acres and 7.5 million acres of cultivated command area.

This study has primarily to focus on technical issues keeping in view the latest methodology to ensure smooth operation of this giant barrage through which 1.2 million cusecs of floodwater has passed twice so far, first in 1976 and then last year during the super floods.

When constructed by Britishers in 1932 with 66 gates, the barrage had the capacity of 1.5 million cusecs. Then its right pocket canals started having silt deposits and choked completely.

British experts decided to close its 10 gates in mid-40s following a model study in Puna, India. They created a river training works (an island) upstream.

The river training works were aimed at diverting water with lesser amount of silt towards right side canals. It was to be done through a tail channel that was to take heavily silt water downstream Sukkur and the remaining water was to go to the right side canals.

For this purpose a submerged weir was also built to regulate tail channel. New SOPs (standard operating procedure) was designed by British engineers under which tail channel was to be supplied 1.5 times more water than allocated for right pocket canals i.e. Rice, Dadu and north western canals.

Water experts say the barrage must be safeguarded in view of water levels that were recorded in 2010 during super floods.There are proposals to re-open its ten gates to cater to more flows of flash floods. “I think we should review the theory on the basis of which the barrage was initially built; now as the barrage has withstood the test of times, we need to give serious attention to it now,” says former chief engineer Noor Mohammad Baloch. “Ever since we gave away our three rivers to India in 1960, the problem of water shortage has become perennial and the quantum of water needed is not available,” he says.

According to Idris Rajput, former secretary irrigation, the ten gates of the barrage had to be closed and a bifurcated point [an island] was created upstream Sukkur to reduce flows of water having strong silt content. A tail channel was created there. But this channel doesn’t get the required water flows and problem of silt deposits was being experienced on the right pocket.“Consultants will examine this issue which is very important,” says Rajput, associated with one of the consulting firms engaged by Sida.

Abdul Majeed Nizamani, president Sindh Abadgar Board (SAB), says the barrage has the potential to irrigate around 10 million acres. SAB general secretary Syed Mehmood Nawaz Shah raises technological advancement issue on the ground that barrage’s operation should be designed in line with advances in the field of engineering. “Currently it remains absolutely below par. An efficient working is required now,” he says.

He emphasises that the study should focus on what will happen in case these gates are re-opened. How will the barrage be managed then in case of increased flows?

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