Homes and businesses around Lough Neagh may have to reassess the risk and adapt to cope with it, says the head of the Rivers Agency.
As scores of homes and business remain flooded due to the high levels of the Lough and severe flooding, he also dismissed claims dredging would have helped the situation.
David Porter told the Agriculture Committee that dredging would not have made 1mm of difference to flooding around Lough Neagh.
He said the problem was the levels of the lough and that the volume of water flowing into it is five times that which can flow out.
Nine rivers flow into Lough Neagh. Only one, the lower River Bann, flows out.
Last week, several businesses on the shores of Lough Neagh were damaged by floods leaving almost 30 jobs in jeopardy.
Mr Porter added that he did not want to give people “undue hope” that a promised review of the response to the flooding, which will include the lough levels, would lead to a significant change.
Farmers had claimed that a build up of silt in the lough, along with the rivers flowing into it, had contributed to the problem.
Mr Porter said that was not the case.
He said that any change to the lough levels would have to balance the competing interests of those who use the lough, including boating businesses.
He told MLAs that lowering the level of the lough would make access to jetties and quays difficult.
The levels of the lough were set in the 50s and reviewed in the 70s. Mr Porter said that the current levels, he believed, were the best compromise.
He said three winter storms in quick succession in December had led to an unprecedented rainfall and that sometimes it is not possible to provide an engineering solution to flooding.
He added that, in the future, homes and businesses may have to assess the risk and adapt to cope with it.
“If the climate change predications are true then we’re fighting a losing battle,” he said.