This piece originally ran in The Post & Waikato Times on May 21, attributed to Craig Mcilroy, General Manager, Health Waters and Flood Resilience, Auckland Council.
There’s a moment in every major storm when stormwater stops being an engineering term and becomes deeply personal.
For Aucklanders, that moment came during the 2023 Anniversary Weekend floods. For Wellingtonians, many experienced it again this year. One minute it’s heavy rain; the next, streets are rivers, parks are lakes, and people are wondering whether the water will stop at the driveway or come through the front door.
Fresh from speaking at the Water New Zealand Stormwater Conference, one thing struck me above all else: the conversations we’re now having about stormwater are fundamentally different to those we were having even five years ago.
Across the sector, there’s growing recognition that New Zealand has reached a turning point in how we manage flood risk in a changing climate.
I’ve worked in stormwater and flood resilience for a long time. It’s genuinely my favourite topic which probably places me in a fairly niche category of dinner party guest. But over the past few years, stormwater has become everyone’s topic.
Because the reality is this: the way New Zealand has traditionally managed stormwater is no longer enough for the climate conditions we are now living with.
For decades, we approached stormwater as an engineering problem solved underground. Bigger pipes. More pipes. Faster pipes.
But nature has started handing us a very clear performance review on that approach.
When Wellington received 77 millimetres of rain in one hour, people understandably asked whether larger pipes would have prevented the flooding. The uncomfortable answer is probably not.
At a certain point, no practical pipe network can cope with that volume of water arriving that quickly, particularly when drains and culverts become blocked during major weather events. Once systems exceed capacity, water simply finds another path.
And gravity, as it turns out, remains undefeated.
That’s why Auckland Council’s approach since the 2023 floods has shifted significantly. Through the nearly $2 billion storm recovery partnership between Auckland Council and the Crown, we’ve begun redesigning how we live with water rather than pretending we can completely control it.
That includes investment in “Making Space for Water” initiatives — restoring streams instead of burying them, protecting overland flow paths, upgrading culverts and creating wetlands and floodplains that can absorb and slow floodwater.
It also means designing parks and open spaces that can temporarily hold water during extreme weather, then return to being football fields or playgrounds the next day.
In many ways, we’re rediscovering lessons nature already understood.
Before urban development intensified, water had space. Streams meandered. Wetlands absorbed rainfall like giant sponges. Over generations, we straightened waterways, piped streams underground and built over natural drainage paths.
But the water never forgot where it wanted to go.
That’s why flood maps can feel confronting. They show streets becoming rivers and parks becoming temporary lakes. But there is value in that honesty. Water follows physics, not council boundaries or LIM reports.
One of the biggest shifts we need is understanding that flood resilience is not solely about infrastructure. It’s also about land use, planning, transport, parks and community behaviour working together.
Sometimes the best stormwater solution isn’t a giant concrete structure. Sometimes it’s protecting a low-lying park because one day that park may save homes downstream. Sometimes it’s ensuring a fence doesn’t block an overland flow path between neighbours.
And yes, sometimes it’s acknowledging that some land was never suitable for intensive development in the first place.
These are difficult conversations involving property, affordability and community expectations. But there is also a significant opportunity in front of us.
I believe New Zealand is at an inflection point on stormwater management. Climate change has accelerated public awareness, and recent reforms have finally recognised overland flow paths and watercourses as critical parts of stormwater systems.
There is growing recognition that flood resilience is not optional spending for some distant future — it is essential public safety investment now.
The challenge is that our systems and expertise remain fragmented.
Urban and rural stormwater are often managed separately, despite water obviously not caring whether it is flowing through a city or a paddock. Different councils apply different standards, and responsibilities overlap between councils, transport agencies and water providers.
That’s why we need a more integrated national approach — one that aligns stormwater management more closely with catchments and natural water systems rather than administrative silos.
In Auckland, one of the strengths of the Healthy Waters and Flood Resilience model is that stormwater sits alongside planning, parks and transport. That integration matters enormously. You cannot solve flooding through pipes alone.
We also need nationally consistent stormwater standards. At present, every jurisdiction effectively creates its own rulebook. That’s not sustainable in a climate where extreme rainfall events are becoming more severe.
To put it simply: everyone should be driving on the same side of the road.
Flooding is traumatic. Families can lose homes, possessions and peace of mind overnight. That’s why flood resilience cannot just be a technical exercise. Communities need transparency about risk and confidence that decisions are being made for the long-term public good.
No city can eliminate flood risk in an era of climate-driven extreme weather. The goal is resilience: reducing harm, directing water safely, protecting people and recovering faster.
Stormwater may never be glamorous. Nobody puts a culvert on a postcard. But increasingly, the resilience of our cities will depend on how seriously we take what happens when the rain arrives.