DUBLIN City Council must make a decision on the Dublin Port tunnel next month if the £130 million project is to take its first traffic by 2003.
The details of the tunnel, which will run from near Santry to the north port, have been the subject of months of public consultation. Yesterday evening the recommendations were presented to a joint committee of the city council.
Councillors will be asked to approve a recommendation that the tunnel follow the original route, taking it from the Shantalla-Coolock area, under Collins Avenue, Swords Road, Griffith Avenue, Marino and Fairview to the East Wall port area.
It is the most expensive and ambitious project undertaken by an Irish local authority. If the council approves the route it will then have to decide which of three options will be adopted for the entrance to the tunnel, each of which has different cost and environment implications.
The first option would have both the northbound and south-bound tunnel openings at Shantalla, with noise barriers along the M1 motorway. It would add £1 million to the project's cost. Option two would involve extending the northbound tunnel a further kilometre, up to the Coolock Lane interchange. The southbound tunnel opening would remain at Shantalla. This would reduce noise levels as well as the pollution impact and would add £12 million to the cost.
The third option would involve moving both tunnel openings farther along the M1, at a cost of £23 million, taking the tunnels farther away from residential areas.
"All the options being presented to the city council have been formulated following intensive consultations with the public and address in a very significant and major way the concerns expressed by residents regarding air quality, noise and the construction fears of those living above the project tunnel route", said Mr Gerry Murphy, the Dublin Port tunnel project engineer.
Although the city manager will be recommending the original route, rather than the five other options that were considered, a number of changes are to be made based on the further studies undertaken following concerns expressed by residents.
The tunnel will be a further five to nine metres in depth where it passes under houses. This will bring the total depth to between 19 and 24 metres, equal in height to a six-storey building.
Mr Murphy said this was aimed at reducing residents' fears about possible effects during the construction.