Second phase underwater survey of Hirakud dam begins

Hirakud: The second phase underwater survey of the Hirakud dam at Burla in Odisha’s Sambalpur district began on Saturday.

A two-member team of the Central Water Resources department, led by Dr Alex Varghese, head of the department of Engineering Geophysics, will conduct the second phase survey of the dam on behalf of Central Soil and Material Research Station (CSMRS).

Notably, in the first phase underwater survey, which had begun on December 7 last year, the CSMRS team had examined the dam’s left and right spillways to assess the condition of the cracks that have developed on them. The survey was completed on December 27.

In the second phase, underwater survey of the power channel of the dam would be conducted.

The survey work would be conducted through a remote operated vehicle (ROV) with a state-of-the-art underwater camera, which receives instructions from the control room, inside a vehicle placed on the top of the dam and changes its direction in the water and takes underwater photos of the upstream face of the dam including the sluice barrel. Through the photos taken by the RVO, the present condition of the power channel and its weak portions can be detected.

The survey team would submit its report to the state Water Resources department.

It may be mentioned that prior to this survey by the Central team, another survey was done under the Dam Rehabilitation Scheme (DRS) in 1990 by a team of expert divers.

Some wide and fine cracks were found on the concrete portion of spillway of the dam before 1990s. The Hirakud Dam Cracks Review Panel and Dam Safety Review Panel had suggested treatment of the wide cracks, sources said.

Subsequently, the wide cracks were treated in 1990s. However, the fine cracks had not been treated at that time.