A hard rain is falling on Auckland. What will soon be dubbed the “Tasman Tempest” by weather forecasters and the news media is drumming loudly on the iron roof of my house. Outside the window, a hole in my rusty spouting is sending a cataract of water onto a paved path, where it pools before disappearing into a stormwater grate.

I know where this water is going: through a park, into a stormwater network one street over and eventually into Te Auaunga/Oakley Creek. I know this because I remember the pipes being laid when the house was built 30 years ago. This is the first time I’ve thought about it since.

I suspect I am like a lot of city dwellers: I pay for invisibility. I want to turn a tap and see freshwater appear. I want to flush a toilet and see wastewater disappear. I want my drains to whisk this stormwater away. Spare me the details.

But I am coming to reject this self-woven cloak of invisibility. I am thinking about the city’s plumbing as I never have before.

I flick to MetService’s rain radar and watch a royal-blue inkblot spread across the region. It looks like there will be at least another hour of heavy rain, so I decide to drive to Te Auaunga to see where my stormwater comes out of the underground city. I want to make a connection. I want to make eye contact.

As it happens, I am part of a volunteer group of river caregivers for Te Auaunga. I was in the creek the previous weekend pulling out tyres, jandals, rusty iron, plastic bottles, traffic cones and a wheelie bin, but giving barely a thought to the less-visible concoction of trace metals, greases, oils, nutrients, bacteria and whatever else flows into the stormwater system with every heavy rainfall. From the creek’s point of view, I’m part of the problem as well as the solution.

I take the path to the waterfall, but today, the path is a creek, the creek is a torrent, the waterfall is brown thunder—a Huka Falls of sediment-filled water. Just downstream, a stormwater pipe is shooting a jet of whitewater into the plunging river.

Streams like Te Auaunga (urban Auckland has 64 of them) are known in stormwater parlance as “receiving environments”. They are named for their drainage role. They themselves flow into the biggest receiving environment of all, the sea. The unswimmability of beaches is the direct result of our use of streams as drains. That’s how streams were regarded in past centuries, and it is a tough mindset to shift.

Urban planning academics say that cities go through six stages in their thinking about water—a kind of Maslow’s hierarchy based on human needs and aspirations. Cities start out with a focus on obtaining a secure supply of drinking water. They build sewers to protect public health. They build drains to mitigate flooding. At this point, with the fundamentals of drainage, sewerage and potable water in place (the “three waters” of city infrastructure), cities begin to think about the social and environmental benefits of their waterways. They wish to protect the water cycle in all its pathways through the urban landscape. At the end of this journey of awakening, a city might be called ‘water-sensitive’.

That’s the theory. According to a group of Melbourne experts who assessed Auckland Council’s stormwater management in 2014, the city is about halfway along the trajectory—it has high aspirations, but it’s entrenched in drainage issues.

For a long while, I have admired the haiku-like message imprinted in the concrete kerbing of modern stormwater drains: ‘Dump no waste, flows to sea’. This is water sensitivity distilled into six words. A plea for awareness of the interconnectivity of upstream and downstream, freshwater and salt, city and sea. A plea for visibility. And what is ecological thinking but making the invisible visible?

[Chapter Break]

The rain continues through the night, and a heavy fall wakes me before dawn. I drive the saturated streets of Mt Albert to check a stormwater overflow behind the St Lukes shopping centre. This is one of the largest overflows in a city of hundreds of such outfalls, designed to let water escape from the stormwater network during rain events. Were it not for outlets like these, pressure would build up in the pipes, bursting joints, popping manhole covers and flooding properties and homes. Overflows provide a controlled release. This one discharges around a hundred times a year, sending roughly a million cubic metres of water into Meola Creek.

And not just water. In older parts of Auckland, especially the suburbs near the central business district, stormwater and sewage flow in the same pipes. (Elsewhere they are separated.) This overflow—and 25 others in the Meola catchment alone—discharges stormwater and raw sewage into the creek. As a result, the estuary into which the creek flows has some of Auckland’s highest concentrations of Enterococcus, a type of bacteria that indicates disease-causing organisms in salt water. Anything above 280 bacteria per 100 millilitres of water is considered a health risk, and this estuary has reached 126,000 bacteria, more than 450 times the safe-swimming limit.

I hear the overflow long before seeing it, as one hears a waterfall when tramping. At the junction of multiple paths—one bearing away downstream, one to the shopping centre, one to some apartment buildings whose randomly lit windows gleam in the rain—I come to the outlet itself, and shine a torch on an opening the size of a double garage.

A river of stormwater is pouring through a grate, moving so fast it mounts half a metre up the steel bars. It speeds across a concrete apron—invisible under the turbid flow—and passes under the footbridge where I stand.

The water laps the edges of the bridge, and as I watch, it starts to wash across. It rises to my ankles, to my calves. The overflow and the creek are now one spreading sheet of swift brown water, spilling into creekside plantings, plastering fern trunks and tussocks with leaves, plastic bags and detritus.

A frog hops across the path in front of me, a splash of apple green. A woman walking two soaked Labradors stops to talk. She has the notion of bringing her child to see this flood. All one can think of at a time like this is the fearsome power of water.

Like most of Auckland’s streams, Meola Creek has a group of local residents who care mightily about its welfare and press the city council to address its issues. Meola suffers from what freshwater ecologists call “urban stream syndrome”. Symptoms include high nutrient loadings (leading to algal blooms), elevated concentration of toxic pollutants (fatal for aquatic life), increased water temperature (also inimical to freshwater insects, molluscs and fish) and heavy stormflows (leading to flooding).

Elizabeth Walker, a member of the St Lukes Environmental Protection Society, calls it “death by a thousand cuts”. Walker and her husband have lived a stone’s throw from the creek for 12 years.

“It was a drain when we came,” she told me. “Hardly a skerrick of vegetation.” Now, through the efforts of the society, and especially of its tree-planting enthusiast, Roy Clements, the stream is lushly fringed. Planted, flanked by boardwalks and paths, nourished by a nearby wetland—but still ecologically struggling.

Walker speaks of the “Christmas tree” effect after rain, where toilet paper clings to shrubs and grasses. It’s a common enough sight around the city’s worst-affected waterways and beach outfalls. But it is the effect on the creek itself that concerns her most. After overflows, dissolved oxygen in the water plummets, sometimes falling to zero. Bacterial levels skyrocket.

As we stroll the creek path, Walker talks history. A century ago, she says, Auckland faced a choice. Either keep the two plumbing systems of stormwater and wastewater separate, or cheat a little and combine both waters in a single set of pipes. Auckland chose the cheaper option: to combine. (Most other New Zealand cities reticulated stormwater and wastewater separately from the outset, or moved to separate them from the 1950s onwards.) Later administrations realised the error, and as Auckland grew, separation became the norm, but in older suburbs the combined network persists.

As for a stormwater network, this area doesn’t have one. Historically, it never did. In common with a few other suburbs near Auckland’s volcanic cones, Mt Albert relied on soakage into the porous underlying basalt. But as urban intensification has occurred, with larger houses built on smaller sections and the total area of permeable ground declining, soakage isn’t sufficient to replenish the aquifer that feeds the creek.

“The old landscape was a living, breathing sponge, and the creeks were full,” says Walker. “Today, in summer, the stream is a grey, stagnant trickle an inch deep.”

She shows me a 3D rendering of the aquifer. It’s vast, an underwater sea stretching between the volcanoes of Mt Eden, Three Kings, Mt Roskill and Mt Albert, gathering groundwater from those cones and their lava flows and percolating it to the sea at Meola Reef.

Sickly streams are surface indicators of what’s happening underground. In this case, says Walker, what’s happening is depletion of the aquifer by development. Who would imagine that in rainfall-blessed Auckland such an aquifer could suffer thirst? But each impermeable surface in each new development—each roof that sends its rainfall into a pipe or retention tank, each concrete drive or courtyard, each road or carpark—deprives the aquifer of input.

Impermeability in the Meola catchment is close to 50 per cent, says Walker. She has become an advocate of permeable paving, roof gardens, rain gardens, swales, wetlands—all ways to filter contaminants, recharge groundwater and revive streams, while managing stormwater flows.

What’s a rain garden? I ask.

She leads the way up a side path to the Morning Star Place apartments, where a patch of ground between the entrance and the road has been turned into a garden. To all appearances, it is just a collection of rocks with some mostly native planting and a ‘scruffy dome’—a curved galvanised-steel grate that covers a manhole. But underneath are several metres of carefully layered soil, sand and gravel. Stormwater flows into the garden, seeps through the soakage layers and finds its way—minus many of its contaminants—into the groundwater. Pipes connected to the stormwater network capture the overflow in heavy rain.

Rain gardens not only slow water down, they filter it, and a ‘water-sensitive’ city is built on this kind of at-source treatment of stormwater. Whereas traditional hard-engineered drainage systems rely on shifting massive volumes of water from collection to discharge as rapidly as possible—hence the reliance on pipes, concrete channels and streams straitjacketed into stormwater conduits—the modern approach is to retard the water flow. Think of it as the ‘slow-water’ movement. Think of it as quenching the land’s thirst.

Think of it also as a daunting infrastructural challenge. A good deal of Auckland’s stormwater—and much of its contaminant load—comes from roading. How will transport authorities retrofit permeability into a concrete-and-asphalt network of roads and footpaths? Is that even possible?

But just as the country has become aware of the fluxes of nutrients and organic matter that flow across agricultural land and into waterways—a rude awakening for many, and one that has proved as toxic politically as it is chemically—the same realisation needs to dawn for urban spaces.

[Chapter Break]

I am back at the starting point, the unswimmable beaches, wondering how this blight can be fixed. In the short term, much hope is being placed in the planned construction of the Central Interceptor, a 4.5-metre-wide sewer pipe that will run 13 kilometres at a depth of up to 110 metres from Western Springs to the Mangere wastewater treatment facility. Construction is expected to begin in 2019 and be completed by 2026.

If a city’s sewage system can be likened to human blood circulation, then interceptors are the major veins, and smaller collector sewers that reach into local catchments are the capillaries.

Auckland has several interceptors, but one of them, the Western Interceptor, is reaching the end of its life. The new interceptor will duplicate the role of the Western, as well as collecting wastewater and stormwater from some of the problematic combined sewers. It is supposed to solve most of the overflow problems from the combined network, reducing the number of discharges into streams by 80 per cent.

The scheme has its critics. Some say that total separation of stormwater and sewage is the only long-term solution. Others say the interceptor won’t deliver benefits for 10 years, and action is needed now.

Craig Mcilroy, manager of Auckland Council’s stormwater and environmental services department—newly renamed ‘Healthy Waters’—counters by saying the cost and social disruption of separating the combined network would be prohibitive, and that where separation has been tried for a network as labyrinthine and leaky as central Auckland’s, it hasn’t worked: stormwater and wastewater continue to infiltrate each other’s pipes.

Meanwhile, the council is working to improve its advice and communication to the public over swimmability. At present, people check the condition of monitored beaches on the council’s Safeswim website, which gives beaches a simple tick or cross—safe or unsafe. But this rating system can be misleading, because monitoring takes place only once a week, leaving six days where water quality could shift markedly.

If, for instance, sampling occurred immediately before heavy rain, the bacterial concentration might be minimal, leading to a ‘safe’ endorsement for the week, whereas in the days following the downpour, pathogen levels in the water might spike to dangerous levels. Although the council gives a general warning not to swim at any Auckland beach within 48 hours of heavy rain, the current approach is not much of a guideline for swimmers concerned about their exposure to bacteria on any given day.

Environmental consultancy Eiver has been working on an app which will provide a forecast of water quality so that people can make up their minds based on their risk tolerance. (A wetsuit-wearing windsurfer will have a different risk profile from that of a parent with a toddler.)

On the 11th floor of a downtown tower overlooking the Waitematā Harbour, environmental analyst Andrew Schollum and his colleague Martin Neale showed me a proof-of-concept version of the app, which bases its forecast not just on the latest water tests but on historical data and a range of environmental factors such as water temperature and upcoming weather and tidal movements.

Neale simulated a rain event and zoomed in on the Meola Creek estuary. As the simulation rolled, we watched a plume of pathogen-filled water—displayed in multiple colours, including fire-engine red where the concentration of Enterococcus was highest—waft up and down the harbour as the tides changed. It was a dramatic visualisation of the invisible forces of chemistry and microbiology.

“Auckland inherited a water-management philosophy of getting the sewage and stormwater away as quickly as possible,” says Schollum. “We’ve been investing in hard-engineered solutions ever since. And we’ve seen the results: blocked culverts, sinkholes, playing fields ankle-deep or more in wastewater, sediment-choked streams, estuaries that smell foul. Because when those engineered solutions fail, they fail catastrophically.”

We perpetuate a reliance on infrastructure—ever more costly and ambitious networks of pipes, pumps and, yes, interceptors. To move beyond this way of thinking, you need “circuit breakers”, says Schollum. And they are starting to appear. I visited one—a very modest one—in Green Bay.

In 2013, the council decided to showcase the practice of ‘daylighting’ a piped urban stream. Of the 16,500 kilometres of streams in Auckland, many flow underground in pipes. At La Rosa Gardens, in a quiet suburban street in Green Bay, a 90-metre section of two tributaries that feed the Whau River saw the light of day for the first time in decades. What was formerly a disused, soggy reserve with a pipe running under it has become a meandering stream with bankside plantings, boardwalks and areas for sitting and socialising.

In council-speak, the daylighting project has increased public amenity, provided outdoor classroom opportunities, assisted with water treatment, reduced flow velocities, diminished flooding potential, increased biodiversity and provided a terrestrial wildlife corridor. I cycle past a splendid 10-metre concrete eel—an all-hands-to-the-cement community effort—and past signage explaining that this is a place that celebrates “natural connections”.

The Auckland Plan espouses such connections. Its strategic direction for the environment, it says, is to “acknowledge that nature and people are inseparable”. Here, that connectedness is on display.

Three years ago, this stream was inside a metre-wide concrete pipe, a piece of hard-engineered utility that served one purpose: shunting water downstream. Now, it serves other purposes: the pleasure of the community, the flourishing of natural ecosystems, education for the kindergarten children whose voices drift down and mingle with the sounds of flowing water.

One of the city’s goals is “a beautiful Auckland that is loved by its people”. It is hard to love a pipe, but I could see many people coming to love this river reach, the living daylight that replaced the sterile darkness.

[Chapter Break]

To the east of La Rosa and the Whau—one watershed over—is ‘my’ creek, Te Auaunga, Auckland’s longest uninterrupted watercourse. Here another circuit breaker is being tripped. Behind a street where I cycled to piano lessons as a child, more than a kilometre of creek in Walmsley and Underwood Reserves is receiving a $25 million makeover. Earthmovers, rock crushers, pile drivers—the heavy machines of the construction industry—are deconstructing the stormwater solution of a previous era.

They’re here to enable more houses to be built by Housing New Zealand on flood-prone land. But the side benefits will be tremendous.

The awa will be liberated from its rock-lined, concrete-based channel to become a meandering stream with pools and riffles, point bars and islands.

Roadway runoff will be treated at source, sparing the stream from a witches’ brew of contaminants. Riparian vegetation, currently nonexistent, will be planted.

Increasingly, this is how environmental gains are achieved, Auckland Council project manager Tom Mansell told me. Housing intensification requires certain conditions to be met—in this case, flood mitigation—and environmental opportunities are included as part of the package.

“Because this project is under the banner of growth, no one argues with that,” he said. “The environmental improvement happens alongside, because it’s the way we do things now.”

For this project, Mansell explained, the driver was removing a flood hazard. “Then we asked, ‘Well, what are the social benefits that could come out of this?’ We consulted the community and mana whenua, and one of the initiatives that came out of that was an apprenticeship scheme. We trained several unemployed youth through Unitec, and Fulton Hogan employed eight of them on site.”

Another outcome was a collaboration between the council, Te Whangai charitable trust and a local school, Wesley Intermediate, to grow the 100,000 plants needed for landscaping. As well as setting up a nursery at the school, Te Whangai introduced horticulture education and training. The students will be the project’s landscape gardeners.

What could have been just a piece of engineered flood-proofing will soon deliver an adventure playground and outdoor classroom, recreational space for the local community, naturalisation of the waterway, riparian corridors, increased community access through cycle paths and pedestrian bridges, and daylighting of piped tributaries—“all at very little extra cost on top of the bulk infrastructure work”, said Mansell. “It just required a bit more thought, and a change in the way we have traditionally done things.”

What’s more, the community is behind it. There have been no problems with graffiti or vandalism. That’s because it’s not seen as a top-down exercise, but something a lot more indigenous.

“Community ownership is far more powerful than a council regulatory model,” Mcilroy told me. “An engaged community is the best advocate a stream can have.

“We’re trying to chart a new way of thinking. The more you treat the problem at source, the less of an issue it is in the environment. We see ourselves as an urban transformation agency. Okay, that’s a bit poetic, but in some instances we’ve started to walk the talk.”

I ask Healthy Waters strategy manager Andrew Chin, an engineer and planner by training, about uptake of these ideas by commercial developers. This, surely, is the acid test. It’s all very well what poets and planners think; what about investors?

He describes a large development at Flat Bush, in Manukau, which has adopted a ‘greenfingers’ approach, where natural waterways and gullies remain vegetated and intact, rather than being scraped, piped and filled for higher-density housing. At Flat Bush, these greenfingers make up more than a quarter of the area of the development—considerably more than the 10-15 per cent of green space in a typical suburban housing scheme.

“Initially, there was an outcry about the waste of developable land,” says Chin. “But if you analyse the most valuable parcels of land, it’s the ones next to the greenfingers and wetlands. Property developers are now saying they want wetlands and waterways because they provide such great amenity.”

The change in thinking is considerable, he says.

“Greenfingers replaces the old concrete-lined-channel approach, where all the houses have their backs to the watercourse and people chuck grass clippings and trash over the fence. Now, the focus of urban design is towards park-edged roads and public spaces, and you activate those areas of streams with the community’s informal surveillance. They don’t become full of rubbish, or tagged or vandalised, because the community values them.”

New rules in the Auckland Plan reflect this desire to shift from a drainage-oriented city to a water-sensitive city.

“We have this concept of stormwater neutrality, so when you do a development, the inflows and outflows from a hydrological point of view are balanced,” says Chin. “That means swales, infiltration trenches, rain gardens and the like—maintaining groundwater levels and slowing down the rapid runoff that causes streams to erode. You hold the small flows back but also try to get the water into the ground, or re-use it for watering the garden or washing the car. The idea is to guide Auckland towards a more distributed, at-source stormwater treatment system.”

This is exactly what I saw at Walmsley Reserve. The old straight-as-an-arrow channel hewed by workers during the Depression stood in the background as a relic of old-school thinking. In front of it, the new streambed wove and curved across the reserve.

I walked towards it, stepping on to basalt reefs that protrude into the water like a taniwha’s fingers. Mark Lewis, a landscape architect with Boffa Miskell, is proud of these reefs, which came to light only during the excavation work.

“We could have hammered through them,” he said, “but we chose not to. Just dug away the soft peaty material from around them.”

Like an archaeologist’s paintbrush, the earthmoving machines exposed what lay beneath.

An eel appeared, moving up the newly contoured channel, sampling the flavours of the new streambed. It seemed symbolic of the new way of thinking—slow, meandering, attuned to its habitat.

Perhaps the daylighting of streams could be a metaphor for the daylighting of attitudes to water—no longer a resource to be managed but an asset to be protected, and even more, in the case of the Whanganui River, a person to be honoured.

[Chapter Break]

What of the future for our cities? There is no shortage of innovation on the horizon. Waterless washing machines that clean with polymer beads. Toilets that separate liquids from solids. Recycling showers. Using greywater for non-potable purposes is already a feature of some housing developments. But stormwater harvesting has barely begun.

“We spend millions of dollars moving stormwater from where it falls on our houses out to sea,” said Neale. “On the other hand, we spend millions of dollars taking water out of the Waikato, treating it to drink, then using most of it for non-drinking purposes such as flushing toilets and running household appliances. Why can these two things not be brought together?”

Swimmability and the public health issues that prevent it are a trigger to produce change, Schollum told me. “I want to be able to swim in my river and at my local beach. Eventually, I want to be able to gather cockles and catch fish, and I want my children to be able to swim in those places without getting rashes. So, it’s about place for me. I want to be able to engage with my environment physically, without fear.”

That doesn’t seem too much to ask.