Key flood prevention projects are set to run €15 million over budget, the Business Post has learned.
The extra costs have been defended by the Office of Public Works (OPW). They include having to build burial pits for Japanese knotweed and re-inforcing a railway bridge to ensure that it was not weakened by excavations.
The biggest overspend is a €7.5 million increase in works in Bandon, a Cork town which has been hit by severe flooding in recent years.
The budget for the flood relief project in Skibbereen in Cork has gone up by €4.5 million. There have also been a €2.6 million budget increase for the River Dodder flood prevention project in Dublin, and almost €1.4 million extra spent on the Bray flood prevention project in Wicklow.
The state has spent around €430 million on flood relief projects over the past decade. It plans to spend a further €1 billion over the next ten years to protect 95 per cent of properties currently at risk of flooding.
The Office of Public Works said flood relief projects were carried out in areas where ground conditions can be very challenging and much of the work is undertaken on private lands. A spokeswoman said this meant it was not feasible to investigate site conditions in advance of tendering and construction to the level which would eliminate this uncertainty.
“While allowance is made for this uncertainty in project budget estimations, additional delays and associated claims and costs do still arise,” she said.
In the Bandon flood relief project, there were extra costs dealing with “invasive species” – with contractors building a burial pit for Japanese knotweed. The OPW also had to pay more to the contractors for waste management and disposal of surplus excavated material, for changes to the design of wall types and for changes to the electricity and water pipe crossing at Bandon Bridge. The scheme is “largely operational” and is due to be fully completed next year.
In the River Dodder project, the OPW had to carry out extra work to stabilise the RDS wall. The OPW spokeswoman said that further investigations had revealed that the existing wall was “structurally unsound and therefore not fit for flood relief purposes”. This scheme is due to be completed next year.
In the Bray project finished in 2017, the OPW said that it had to pay more for sheet piling around the Harbour railway bridge because the full risks “were not known” at the planning stage.
In the Skibbereen project which is now up and running, the OPW found a large number of unforeseen water and gas pipes. It also had to change its building approach when covering over the fast-flowing Caol stream in the town because it found that further properties in the town were at risk.
There are currently 11 flood relief schemes under construction. Some 80 projects are at active design and planning stage, while a further 62 projects are due to be designed.
The OPW spokeswoman said it made every effort to manage costs on flood relief projects to ensure that any additional costs are limited to the greatest extent possible and that such projects deliver value for money to the state.