If the rains are bountiful this monsoon and if the world’s largest masonry dam gets full, irrigation engineers will try out remote control of the huge dam gates.
For five decades, the Nagarjunasagar dam gates – 38, including 26 main crest gates - had been operated manually with each gate needing to be manoeuvred individually. Thanks to the World Bank-funded modernisation project, the gates’ operations have been automated so that the main gates, as well as those to control water flows into the left bank with three canal regulator gates, and right bank with nine canal regulatory gates, can be operated by engineers sitting in the centralised control room.
Apart from introducing remote control operations for the gates, authorities have installed measuring devices at all the strategic locations alongside the perimeter of the dam so that the precise flows into the right and left bank canals can be checked. “Moreover, it will help us to use the available water more judiciously with efficient monitoring at each and every stage of the water flow,” says Project Director G. Malsur. It could perhaps be the first among the older dams across the country whose operations and maintenance have been automated for optimum usage of water along with generation of electricity, since it is a multi-purpose project. “It is an ageing dam which needed retrofitting to meet present-day demands during times of flood as well as dry season when the available water has to be managed efficiently,” he explains.
With the completion of work costing about ₹8 crore, real-time data of the operations of the dam, water flow etc. can be found out from any part of the world through the net. Automation is built on the installation of computerised remote control system for flood and discharge regulation from the dam through data received from local sensors at the main dam, gates - crest gates, chute gates and right canal gates - directly wired from the Master Control Facility (MCF). Data can be received any time from five-minute to 24-hour intervals using GSM/GPRS/VSAT wireless telemetry and also GSM-based information management system for transmitting on-line information to the cell phones of engineers concerned. Using real-time flood forecasting, the SCADA software installed has the capacity to operate gates to allow "moderate releases" from crest gates when it receives water. Authorities expect measurement errors will be minimised, as there will be less human intervention. According to Mr. Malsur, also the vice-chairman and managing director of the Telangana State Mineral Development Corporation (TSMDC), all the main gates have been digitalised and can be remote controlled as also all gates of the left bank canal right now.
Just a few gates of the right bank canal need to be automated and this too is expected to be completed within this month. In fact, a World Bank team that visited the dam last month has expressed satisfaction over the way things have panned out ever since the digitalisation work began more than six months ago. "Irrigation Minister T. Harish Rao, who has been checking on the progress of works almost on a daily basis, is very keen that we should be ready before the dam fills up this monsoon. We have conducted trial runs successfully," he adds.