HYDERABAD: An investigation committee of senior irrigation officers has ruled out possibility of any “serious threat” to the structure of Kotri Barrage in the wake of reports of development of a ‘pit’ in the riverbed upstream barrage during this summer.

The committee comprising Sindh Irrigation and Drainage Authority’s (SIDA) managing director Pritam Das (chairman of the committee) and members Sajid Ali Bhutto, chief engineer of Barrage Management Unit; Habib Ursani, former superintending engineer, Abdul Sattar Sario, former executive engineer and Tariq Asad Ursani, executive engineer Kotri Barrage division, called for a ‘detailed numerical hydraulic model study as well as physical model study’ of the barrage.

The inquiry was conducted on the directives of irrigation department after Caretaker Sindh Irrigation Minister Eshwar Lal asked secretary of irrigation through a letter on Nov 30 to issue instructions to CE Kotri Barrage and other officers to complete model study of the barrage within three days well before closure and make necessary arrangements for repair and rehabilitation of the ‘damaged area’ in the barrage.

The committee head confirmed to Dawn that the probe report had been submitted to the department and said that the pit was located upstream on left bank side of the barrage. Unfortunately, he said, work on model study had been stalled. The minister noted during a recent visit “lack of interest by barrage authorities” in this regard and ordered completion of the study before the barrage closure and beginning of rehabilitation work during forthcoming closure, he said.

In June this year, the ‘pit’ had developed near the barrage structure upstream but the then CE Haji Khan Jamali had denied the existence of the pit and claimed that “it was a deep channel created by Indus River on the left guide bank and this ‘channel’ was 100ft away from the barrage”.

The inquiry report concluded that as per available historical record received from executive engineer Kotri barrage and sounding data collected at upstream of the barrage specific to scour the pit “there is no such emergency or threat to the barrage particularly after recent dumping of boulder stones”.

“However, the committee recommends detailed numerical hydraulic model study as well as physical model study in order to probe causes and mitigation during the barrage closure period. The committee also suggests detailed bathymetry and cross-section survey of entire barrage be carried out,” said report, a copy of which was available with the Dawn.

The members said that the phenomenon of aggradation or degradation used to happen since the commissioning of the barrage at observed location which needed to be monitored regularly as per previous practice.

The pit “… is located 250 ft away from left divide wall and 300 ft away from the barrage structure after stone apron line upstream which clearly indicates that ‘no serious threat’ exists to barrage components”, said the report.

The committee conducted comprehensive bathymetric survey, which identified ‘deepest levels’ (of pit are 300 ft away from the barrage structure after stone apron line upstream barrage) identified through Acoustic Doppler Current Profiler device which gave digitized values and then a river survey was conducted manually at the same sections to ensure accuracy and reliability of gathered data.

Published in Dawn, December 29th, 2023