Report: Lowering of water in dam won’t prevent Cork flooding

Lowering the water level in the Inniscarra dam will do nothing to prevent another extreme flood in Cork, an ESB report into last year’s disaster has found.

The preliminary report into the Lee flood of November 19 last, states lowering the reservoir levels will help to manage “small to medium return period floods”. However, it will do nothing to prevent “extreme floods”.

The report, seen by the Evening Echo for the first time, states this is due to the “limited amount of storage in the reservoirs” in Inniscarra and Carrigadrohid.

It states the three-day inflow to the reservoirs was two-and-a-half-times the combined normal operating storage capacity of the reservoirs. The report also finds the disaster would have been a lot worse if the dams were not in place — and if it was not for the actions of the staff on the night.

The report states the staff at the ESB applied “discretionary clauses” of the regulations for the control of the dam. Water was spilled before the point of obligatory discharge under the regulations which helped to attenuate the flood.

“At Inniscarra the maximum recorded water level and discharge were significantly less than would have occurred if the regulations had been rigidly applied” states the report.

The report shows for three days prior to the flooding the dam was letting out 150 metres cubed per second of water — the maximum before overbank flooding occurs.

The study also states the risk of another significant flooding is of the order of 50 to 100 years. It was originally believed such an event would only happen every 800 years.

Property developer Owen O’Callaghan has again hit out the inaction of the ESB since the disaster.

He said Cork local authorities, together with business and community interests, should immediately demand a root and branch overhaul of operating procedures at the ESB’s Inniscarra Dam. He described the fact the ESB had indicated that it would continue to operate the dam as before as “arrogant, appalling and frightening”.

He said: “The ESB still doesn’t seem to get it. They do not exist in some sort of bubble. Yes, their brief is to generate electricity but they seem to be suggesting they carry no responsibility for public safety and the protection of businesses. There are many who would hold the ESB’s ineptitude last year in not controlling the outflow of water from the dam in appalling but forecast weather conditions put the safety of the citizens of Cork at risk and damaged the lives and livelihoods of hundreds of people.

“We were lucky that nobody drowned. They must understand if Inniscarra’s contribution to the national grid has to be temporarily stalled to allow a continuous, phased outflow of water from the dam to eliminate the risk of flooding, then so be it. There are 150,000 downstream of the dam and they have to be the priority,”

Mr O’Callaghan added the ESB should immediately put the measures recommended CFRAMS in place and work in parallel with Office of Public Works who he said also have a responsibility to do their job.

An ESB spokesman said they refute any suggestion of negligence in operation of dams.

“The Lee reservoirs have limited storage capacity relative to the size of the river catchment. Even with the reservoirs at low levels large floods would result in significant outflows that could contribute to significant flooding downstream.”

Article courtesy of The Evening Echo newspaper.