Residents Debate Environmental Impact of a Plan to Build Flood Defences on the River Poddle

Elaine McGoff, the natural environment officer with An Taisce, the environmental charity, sounds a bit surprised.

She isn’t used to approving of plans for flood relief schemes, she says – but she has welcomed the proposals for the Poddle Flood Alleviation Scheme as probably offering the best solution to tackle flooding in the area.

“I’ve reviewed several flood relief schemes, and have been harsh in my critique of those,” she says. “By comparison, this one really isn’t that bad.”

“Nor can I highlight a better way that they could alleviate the floods and protect biodiversity at the same time,” she says.

South Dublin County Council and Dublin City Council have applied for planning permission for the Poddle Flood Alleviation Scheme.

They plan to build flood defences on the Poddle River, which runs from Tymon Park near Tallaght into the city centre.

McGoff’s only criticism of the plans is that they deny the existence of Brent Geese in Tymon Park, she says.

Not everyone is happy with the plans, though. Róisín McAleer, of the local environmental group Save the Poddle’s Wildlife Sanctuary, is worried about the number of trees that face the axe under the plans.

“We were shocked by the number of trees,” she says. It’s hard to work out the exact number affected from the tree survey report.

The Plans

The Poddle Flood Alleviation Scheme is a joint project between South Dublin County Council, Dublin City Council, and the Office of Public Works.

In 2011, the River Poddle burst its banks, flooding homes in Harold’s Cross. The Poddle Flood Alleviation Scheme is being put in place to prevent that happening again there and elsewhere in the south-west of the city, at an estimated cost of €7 million.

According to the planning application, the councils plan to build flood defence embankments in Tymon Park near Tallaght, replace the existing control structure and footbridge, and construct an integrated wetland in the park.

The councils also want to install “nesting platforms” for birds in Tymon Lake and carry out “landscape mitigation and restoration” at Tymon Park, Whitehall Park, Ravensdale Park and St Martin’s Drive, including public realm improvements, biodiversity enhancements and tree planting works.

At Whitehall Park in Terenure, they plan to put up embankments and build flood defence walls on both banks of the river beside the Lakelands Overflow.

They also plan to build a flood-defence wall on the left bank of the river at the back of homes at Whitehall Road in Terenure and Glendale Park in Walkinstown.

The plan goes on: to knock existing walls at the back of Fortfield Road, south of Kimmage Crossroads and build new defensive walls there. To build flood defence walls at Ravensdale Park in Kimmage and replace an existing footbridge.

And they plan to build a flood defence wall at the right bank of the river at the end of St Martin’s Drive in Kimmage and to construct a flood defence wall on the right bank of the river at Mount Argus Close in Harold’s Cross.

At St Martin’s Drive

St Martin’s Drive, and surrounding parkland, may also prove to be a contentious leg of the scheme.

McAleer says her group is committed to saving that piece of parkland. She took a photo of a heron there recently and believes that the river should be “rejuvenated and supported,” she says, instead of “disabling wildlife.”

McGoff of An Taisce, says the main report shows that the plans were drawn up in the way they were at the request of the local residents of St Martin’s Drive, who had concerns about anti-social behaviour.

Green Party TD Patrick Costello, who represents the area, says that the plan for St Martin’s Drive isn’t consistent with using nature-based solutions.

Between the river and the houses, there is a small park and the plan is to put a wall inside the park at the river. Costello says the boundary wall should be at the outside of that green area, where the footpath is, to use the piece of parkland as a natural flood plain.

“If you look at St Martin’s, on one side of the river is a high bank and a path above it and a metal fence, if you replace that metal fence with a wall you are adding a flood barrier essentially,” he says.

Then put a small wall around the parkland, “one that you can step over, and which wouldn’t attract anti-social behaviour, and you are creating a flood plain on the park which is a much better way of doing it, instead of ripping up the entire bank”, he says.

This would mean losing fewer trees and “keeping the bank together with the trees makes more sense”, he says. Creating a floodplain at St Martin’s would benefit other areas downstream, where flooding is more likely to occur, he says.

And the Geese

McGoff says she is concerned about the quality of the bird survey used in the plans.

Brent Geese have been spotted at Tymon Park by the heritage officer at South Dublin County Council, and that is acknowledged in the Environmental Impact Assessment, she says.

The assessment says that the geese used to use Tymon Park but that there is no evidence of them using it between January and April of 2019.

However, McGoff insists that the heritage officer, also quoted in the report is a reliable source, and the potential that the geese do still use the park, needs to be acknowledged.

The Bigger Picture

Padraic Fogarty, campaigns manager with the Irish Wildlife Trust, says he hasn’t yet examined the detail of the plans but will be making a submission on it in due course.

He says it is essential to look at the entire catchment area. “If you want to tackle flooding you have to go right up into the Dublin mountains to look at where all the water is coming from,” he says.

“The Dublin mountains are a mess, if you wanted to promote flooding you would do what we have done to the mountains in Wicklow and Dublin,” he says.

Those areas should be healthy bogs and healthy woodlands, but between burning, overgrazing and cutting turf they have been severely damaged, he says.

“From a biological point of view, the place is half dead it should be an amazing amenity for people to visit,” he says.

There are very few trees left and that is part of the problem, he says. “We know that having trees and native woodlands would reduce the amount of water coming down from the hills in the first place.”

Instead, the soil is bare and that is why the water just straight off, there is no absorption, he says.

All this despite the fact that the mountains are supposed to be a national park, says Fogarty. “It is disgraceful.”

Fogarty says that we will continue to have problems with flooding if we do not tackle the wider issues in the ecosystem.