GUWAHATI, July 20 - On July 9 this year, the North Eastern Electric Power Corporation (NEEPCO) allegedly released about 10,000 mm (that is � 10 metres in height) of water from its 450-MW Ranganadi Hydroelectric Power Project (RHEP) dam within a very short span of time and this resulted in the two breaches in the Ranganadi embankments causing havoc in a vast Lakhimpur district area, said highly placed sources in the State�s Water Resources Department (WRD) here.
However, sources in the NEEPCO have maintained that under no circumstances the NEEPCO had released floodwater from the RHEP that attained a height of ten metres that day.
It needs mention here that the WRD authorities were in the process of strengthening the Ranganadi embankments under an estimated Rs 36-crore Flood Management Programme (FMP). The State Government had a share of 30 per cent in this scheme.
WRD sources maintain that in 2008 also flood created havoc in North Lakhimpur town and other areas adjacent to this district headquarters town, when the NEEPCO authorities released around 5,000 mm (five metres in height) of water from the RHEP dam in a short span of time.
This time, the NEEPCO authorities released water which was two times larger in volume than that of the 2008. But due to the partial strengthening of the Ranganadi embankments, the flood could not create havoc similar to that of the 2008, WRD sources claimed.
NEEPCO sources, on the other hand, claimed that the RHEP is a run-of-the river scheme with a very small pondage. The full reservoir level of the project is EL 567 metre. This project generates highest amount of hydel power and contributes the highest amount of power to Assam, compared to other NE States. But it was not designed for flood moderation, they said.
Due to the incessant torrential rainfall in the catchment areas of the Ranganadi since June 30, 2017, the inflow of water in the river increased substantially and achieved the maximum to the tune of around 1511 Cubic Metres Per Second (cumec) at 3pm of July 9, 2017. After utilising the water required for power generation, excess water was spilled over through the gates of the dam in a controlled manner, duly maintaining the full reservoir level.
Of the 1511 cumec of water, 200 cumec was utilised as power draft and retained within the reservoir, thus controlling the downstream discharges. The natural flood occurring in the upstream of the project cannot be absorbed by the reservoir. Had the Ranganadi dam not been there, the downstream situation could have been worse, NEEPCo sources said.
They also maintained that numbers of tributaries have joined the Ranganadi in the downstream of the RHEP dam, which also carry sufficient water from their respective catchment areas to the Ranganadi.
In the wake of the 2008 havoc, several committees visited the affected areas and the RHEP as well. They maintained that the RHEP could not be linked with the catastrophe, said the NEEPCO sources.
Meanwhile, sources in the Brahmaputra Board maintained that the Ranganadi havoc could have been avoided, had the RHEP reservoir operated scientifically, by installing a network of designed rain gauge and pre-emptying the reservoir before the floodwater impinging on it.
