Subansiri Hydro Project Targets March Finish With Flood Controls

Itanagar: The Subansiri Lower Hydroelectric Project hits full stride by next March. Four of the eight power units currently spin. The fifth comes online in August, followed by the sixth two months later.

Engineers built a massive reservoir capable of holding 1,365 million cubic metres of water. They will keep the top 15 metres empty during monsoon months to act as a flood cushion. This space captures excess water and keeps downstream flow within a safe limit of 7,000 cubic metres per second.

Officials issued a warning regarding the limitations of this engineering feat. "The flood cushion is designed to handle normal flood conditions and cannot prevent flooding caused by exceptionally heavy rainfall." Massive weather events hitting once a decade may still overwhelm the banks.

Winter operations follow a different rhythm. Rainfall drops, so crews hold water in the reservoir during the day. They push power production to its peak between 5 pm and 10 pm to meet evening demand. This strategy differs from the Ranganadi and Kurichu dams, where small reservoirs force rapid releases that heighten downstream flood risks.