The Central Electricity Authority (CEA) on June 24, 2024, issued the Revised Standard Operating Procedure for Early Warning System in Hydro Projects.
The following has been stated:
• Impact on Hydro Project
The Hydro Power Projects are constructed for harnessing electricity, located in hilly terrain and are associated with natural hazards such as landslides, floods, and earthquakes etc. which are to be considered in the design of the structures. Being young mountains, hydro projects in the Himalayan region are more susceptible to these hazards. Considering the above aspects, mitigation measures are to be adopted during the development of such projects. However, many unpredicted incidents in nature may also cause disasters.
As in the case of Glacial Lake Outburst Flood (GLOF), the velocity may vary from 10 to 15 m/sec. The lead time for the GLOF to reach the Dam body will be very less causing a significant impact on project components because of the flood water carrying large amounts of sediment/debris.
The hydro project in a basin shall be set up at a safe distance from the glacier so that information regarding Lake Burst etc. is received in advance. The first dam in every basin shall be a Concrete Dam based on a solid rock formation and shall be constructed at least 15-20 km away from the glacial lake mouth so as to have a sufficient lead time for responding to the situation and for evacuation of peoples and shifting of important infrastructures/equipment’s/machineries in the downstream area.
• Satellite Based Image Processing and Analysis
Early information can be gathered through acquisition of satellite imagery from concerned agencies such as ISRO, IMD (Indian Meteorological Department) etc. by the project developers and interpreting the satellite imagery shall inform about the increase in size of lake and other activities so that necessary action can be taken. This would provide a broad overview of weather patterns and potential flood areas and may be useful for monitoring large geographical regions in inaccessible locations. However, they do not provide real-time data in a short span of time (minutes/hours) and require highly skilled professionals. Further, satellite imageries are limited by weather conditions & visibility and their initial investment & operational costs can be significant.
The Project Developers shall explore the possibilities of collaborating with various agencies such as ISRO/IMD for obtaining satellite imagery on a daily basis during critical periods in a single licence and shared to others on common platforms to optimise the cost.
