Council still undecided on how to strengthen Sandymount flood defences

It could be another three years before Dublin City Council is able to start improving the flood defences down in Sandymount.

Hopefully, the council will be able to start work on the flood alleviation scheme by 2029, senior engineer Gerard O’Connell told the South East Area Committee meeting on Monday evening. “We’d be very lucky to get it all completed in 2030.”

The scheme will cover the three kilometres of coast between Merrion Gate and Sean Moore Park, and will aim to deal with the issue of overtopping, which means when waves go over the floor defences, said Damien Keneghan, a senior associate director at engineering consultancy Jacobs.

Local councillors, as far back as September 2021, were informed that the council intended to raise the sea wall that runs along the promenade.

O’Connell, at that time, said works were expected to start before the end of 2021, with a second phase planned in the autumn of 2022.

But, by March 2023, the council was only at the stage of appointing a “multi-disciplinary consultant team”.

At a meeting of the council’s climate committee in November 2023, faced with doubts from Labour Councillor Dermot Lacey about the state’s ability to deliver large infrastructure projects like this one, council executive manager James Nolan, pushed back.

“I disagree. I think we can deliver and we will deliver,” Nolan said. “Within maybe 18 months we’ll be delivering the scheme in Sandymount along the promenade.”

In response to similar queries, a council spokesperson said at the time that the council already had a scheme planned, but before building, it’s planning to bring in a consultant “to determine if the design is in line with current national guidelines and standards”.

Jacobs was appointed in December 2024, Keneghan said.

In December of 2025, Jacobs was looking to identify the issues that affect this stretch of coast, and analysing events like the 2002 tidal floods, as well as conducting bird surveys since October, he said. “That will run for six months.”

They will also be doing flood mapping in the next few weeks, he said. “It will show us what we think is the flood risk at the area and what’s the overtopping.”

Then, this will feed into their assessment as to what is the most viable option for Sandymount, he said.

The firm also needs to study the make-up of the coastal protection wall to determine what it is made from, as well as identify what utilities are in the area, he said. “We have to know exactly where stuff is before we go building on top of it.”

More surveys are planned between now and 2027, but the next step is to bring some emerging options forward for public consultation during the second quarter of this year, he said.

That will inform the next consultation surrounding a preferred option in the fourth quarter, he said.

Slides shown to councillors at the meeting indicate that the council will then look to get permission for the project in either the second or third quarter of 2027.

Green Party Councillor Claire Byrne said it was great to see progress at last. But, why did the council need to do flood prediction modelling all over again when there already is existing flood mapping?

There are changes, like rising sea levels and wind changes that need to be looked at again, O’Connell said.

It was worth noting that the council does have climate targets to meet by 2030, Byrne said. “To me these timelines look like 2030 and beyond before we see any of the flood defences in place.”

The hope is to go to planning next year, and assuming that happens, it will depend on the size of the project, O’Connell said. “We don’t really know what that is yet.”

But they will be “very lucky” to get it completed by 2030.

There doesn’t seem to be any great sense of urgency surrounding a problem that has been ongoing for 20 years, Labour Councillor Dermot Lacey said. “I don’t understand why some initial works can’t be carried out.”

The wall will be higher, he said. “Why can’t you start raising the wall now?”

Fine Gael Councillor David Coffey asked if this would follow the existing wall, and was there any indication yet as to how high the walls would be?

Once the model is completed, they will be able to determine what options are possible, Keneghan said. “At the start, we are only focused on the coastal protection option. Is it a wall? Is it revetments? Is it beach nourishment? Is it nature-based solutions.”

That is the starting point, he said.