Flood warnings by the ESB underestimated the volumes of water being released from the Inniscarra dam, according to Cork city manager Joe Gavin.
Mr Gavin said the highest figure mentioned by the ESB was 450 cubic metres per second. However, that night, the ESB was forced to increase discharge levels to 535 cubic metres a second to avoid uncontrolled flooding as water was entering the catchment at over 800 cubic metres a second.
Mr Gavin said the ESB advised the council at 11.30am on November 19th that discharge levels would rise to more than 200 cubic metres a second over the next few hours and could later reach up to 300 cubic metres a second. At 5pm, the ESB said discharge levels would now reach 300 cubic metres a second, but within 30 minutes it had revised this and told the council that discharge levels would exceed that level.
At 10.10pm that night, council staff had to contact the ESB when they became concerned about water levels at the Lee Road pumping station. The ESB advised that water levels would now reach 450 cubic metres a second.
Speaking on RTÉ's Morning Ireland, Mr Gavin said "none of us could have predicted the degree to which the rainfall and the volumes that came down the lee would have happened".
The Government has been urged to hold a public inquiry into the ESB’s decision to release massive volumes of flood water from Inniscarra dam, which led to extensive flooding in western parts of Cork city last month.
ESB chief executive Padraig McManus today defended the handling of the crisis-situation, saying “our responsibility is to notify the emergency services that there is a serious flood happening and we did that”.
In an interview on RTÉ News at Onehe said the ESB made it clear at 5pm on November 19th, that water volumes were at flood level and discharge levels would increase.
“Our responsibility at that time is to manage the rate of water that leaves the dam so that we can keep back as much as we can but not risk the integrity of the dam," he said.