Soak it up! How Ireland’s cities can embrace the sponge revolution
Sections of Marina Park, Cork working as a 'flood storage basin for the south docklands during rainfall flood events'. Pictured in November 2024
Ireland’s cities are getting wetter. In Cork, flash floods have swamped streets such as South Terrace with alarming regularity, while Dublin’s commuter belts, from Swords to Tallaght, turn into shallow lakes after heavy rain.
Met Éireann’s data backs up the soggy reality: rainfall intensity has spiked by 10-15% in parts of Ireland over the last 30 years, a trend linked to climate change. Our drains, many dating back to the 19th century, can’t keep up, and neither can our concrete-heavy urban sprawl.
But what if we stopped wrestling the water and let it settle in? That’s the promise of the sponge city... a concept already taking root in Ireland, with room to grow into something transformative.
A sponge city is exactly what it sounds like: an urban area designed to absorb, store, and reuse rainwater instead of funnelling it as quickly as possible into overwhelmed drainage systems. Wetlands, green roofs, permeable pavements, and rain gardens work together to absorb, store, and even purify water.
China put this idea on the map in 2015 with its Sponge City Initiative. The goal? Capture 70% of rainfall on-site. And while China might be leading the global branding charge, the ideas underpinning sponge cities are rooted in sustainable urban drainage systems (SUDS), which is a concept already known to Irish planners but rarely seen beyond planning documents.
Ireland’s water woes have long met a reactive fix: patch the pipes, pump the floodwater, repeat. But climate change is rewriting the playbook, and our ageing infrastructure, with 40% of Cork’s sewers pre-dating 1900, simply can’t cope. Developers often pave over green spaces, with impermeable surfaces now covering 60% of Dublin’s urban area.
SUDS sit in planning guidelines, but cash-strapped councils and profit-driven builders sideline them. Still, where they’ve taken hold, the results are striking.
In Cork’s Glanmire, a SUDS retrofit along the Glashaboy River has tamed a flood hotspot. Since 2018, swales, detention basins, and permeable paving have slashed local runoff by 40%, sparing homes after 2022’s heavy rains.
Nearby, Marina Park doubles as a stormwater sponge, with its 2.5 hectares of green space and ponds designed to hold 10,000 cubic meters of River Lee flood waters. It’s a lifeline for a city where at least 1,500 properties face a 1% annual flood risk.
Dublin’s got its own wins:
- Northwest Business Park in Blanchardstown, built in the early 2000s, was a SUDS pioneer, using permeable paving and ponds to manage 80% of its stormwater on-site.
- Adamstown, a Strategic Development Zone since 2003, blends green roofs and tree pits across its 7,000 homes, cutting runoff by 30% compared to traditional estates.
- Along Clontarf Promenade, a 2022 retrofit added rain gardens that soak up 500 cubic meters of water per storm, easing pressure on Dublin Bay.
These projects are Ireland at its best — innovative, green, and practical. Yet here’s the catch: they’re not enough — not yet. These efforts are like lifeboats in a rising sea, saving patches while the bigger storm looms. The OPW’s 2018 National Flood Risk Management Plan calls for €1 billion in sustainable flood solutions by 2030, but SUDS uptake lags at just 10% of new developments. We need more and we need it at scale, more connection, more urgency, to match the 20% rainfall increase Met Éireann predicts by mid-century.
The world shows what 'more' can do.
- Wuhan, (yes that Wuhan in China), has sunk €2.5 billion into 389 sponge projects since 2015, holding back 80% of floodwater during 2020’s record rains.
- Copenhagen’s 2011 Cloudburst Plan, with 300 projects like sunken parks, has cut flood damage by 70%.
- London’s Thamesmead estates now boast 50 rain gardens, managing 90% of local runoff since 2019.
These aren’t experiments—they’re blueprints.
we could roll SUDS into every new build — imagine. Picture Irish Water, councils, and the OPW syncing up to manage catchments like the Lee or Shannon, with developers nudged by tax breaks (or firm mandates) to go green, backed by the €500 million Climate Action Fund.
There’s a quiet power in this shift, using nature’s softness to outsmart floods. Ireland is on the right track, and that’s worth shouting about. We’re proving SUDS can work.
Now’s the time to scale up, to turn small wins into a national wave. Because a little more sponginess could keep our cities dry, green, and ready for whatever the skies throw next.
