Indaver's proposal to set the floor level of its €160 million incinerator at Ringaskiddy in Cork Harbour at five metres above sea level will provide an extremely high level of protection against flooding, an environmental engineer has told the An Bord Pleanála planning hearing.
Ken Leahy, who leads Arup's Flood Risk Assessment and Management consultancy in Ireland, told the hearing in the Carrigaline Court Hotel in Cork that the 13.55-hectare site for the incinerator is in an area designated as Flood Zone C as it is outside the 1 in 1,000 year design tidal floodplain.
Mr Leahy said neither Cork County Council’s Local Area Plan nor the flood maps prepared for the Lee Catchment Flood Risk Assessment and Management show the site as being at risk of flooding in a 1 in 1,000 year flood event, even allowing for a 550mm change in sea level due to climate change.
One of the grounds that the board refused planning for the project in 2011 was that it found that Indaver had failed to address the risk of flooding on the road serving the site.
But Mr Leahy said it would take tide levels of 3.25m - approximately 400 mm over that predicted for a 1 in a 1,000 year flood event -for the sea to overtop the existing ground levels at the eastern end of the site and there is no record of any tidal level in Ringaskiddy in excess of 3m.
Mr Leahy acknowledged that pluvial flooding - caused by heavy rain - has occurred on the road leading to the site and in fields to the west of the site and that this is exacerbated by high tides, but he stressed it was not direct flooding from the sea.
He said an assertion by solicitor Joe Noonan in a submission on behalf of Cork Harbour Alliance for a Safe Environment (CHASE) that "the site floods literally every day from high tide" could not be substantiated and had no merit.
Mr Leahy also dismissed concern from Cork County Council that the site was at risk of fluvial or river flooding, pointing out that the nearest watercourse to the site was Glounatouig Stream, which discharges into Raffeen Creek 4km away and is separated from the side by elevated ground.
The minimum design flood defence level for the incinerator was calculated at 3.8m above sea level and Indaver was proposing to raise the footprint of the entire site to 4.55m above sea level with buildings being set with a minimum floor level of 5m above sea level.
Traffic expert Niall Harte, also for Indaver, told the oral hearing the company had amended its traffic management proposals since its unsuccessful planning application in 2011 and the new plan would see the company committed to a longer 14 hour opening period.
The expansion of opening hours to 6am-8pm was designed to mitigate the traffic impact of the facility and would result in an anticipated 71 HGV vehicles entering the facility daily, resulting in 142 round trips per day to and from the incinerator, Mr Harte told the hearing.