€4m plan to fix Fermoy weir to begin in 2021

The damaged Fermoy weir, on the River Blackwater. The plan to repair or replace the structure is due to proceed next year. Picture: Larry Cummins

Consultants have drawn up a series of design options for rebuilding a badly damaged weir on the River Blackwater and expect to apply for planning permission early next year for the project, which could cost up to €4m.

Diarmuid Cahalane, from consulting engineers TJ O’Connor and Associates, outlined the design options for rebuilding the 200-year-old weir in Fermoy, Co Cork, at a meeting of the local municipal district council.

Public consultation on the project will be carried out within the next six weeks, as will further consultation with the National Parks & Wildlife Service, Inland Fisheries Ireland and the county council's heritage officer.

Mr Cahalane said the weir had experienced “a rapid degree of erosion in particular in the recent couple of years.” 

The council must repair it because it is a protected structure, but it also has to be careful about the work it carries out as the River Blackwater is also a Special Area of Conservation (SAC) and any work on it will have to be compatible with the habitats directive.

Mr Cahalane said the options for the weir were to reconstruct it with original-type materials, or remove it completely and rebuild. The former is the preferred option.

This would involve placing rock armour at the downstream side of the weir and restoring the damaged areas with limestone.

While the existing fish pass will be repaired, a new one will be constructed on the northern side of the river, which will involve digging into the 'Triangle Field.'

“The existing one won't allow all salmon to pass up and, indeed, other fish such as shad, eels and lamprey. The new option is a gentle steps fish pass, which is viewed by Inland Fisheries as acceptable,” Mr Cahalane said.