Cities around the world are using green infrastructure to combat rising temperatures, improve air quality, protect buildings, improve energy efficiency, help prevent flooding and reduce noise. Patricia Moore reports on the ongoing push to paint places green.
As Kermit the Frog famously croaked, ‘It’s not easy being green’. Nevertheless, local authorities across the country, and around the globe, are rising to the challenge as innovative infrastructure solutions are developed and the benefits of thinking green become better understood.
“There’s a real elegance to innovative green infrastructure solutions – and they translate into improved environmental health, cost savings and better human health and safety,” says John Mauro, Auckland Council chief sustainability officer.
Green infrastructure is evolving because our understanding of natural systems is evolving, he says.
“We’re getting smarter at mimicking and integrating the efficiency, resilience and brilliance of nature into built environments.”
Green infrastructure is evolving because it has to, says John. “We’re dealing with different and more complex challenges like climate change, rapid urbanisation, and infrastructure funding constraints. This pushes us to think in smarter, more long-term, more integrated ways.”
John argues that green infrastructure should be multi-functional as this increases an asset’s value.
“Cities are depending on their public spaces in new and innovative ways. For instance, low-lying cities with significant flood risk, like New Orleans and Rotterdam, are designing areas like public spaces and sports facilities that can fill with water during severe rainfall events.
“That water is slowly returned to the ground, or stormwater systems, helping control urban flooding and mitigating the associated safety and infrastructure impacts.”
Here, in Auckland a green infrastructure transformation at Te Auaunga / Oakley Creek not only helps mitigate local flooding impacts but provides wide-ranging benefits. John adds the project is “overwhelmingly supported” by the community.
And all these new flourishing green roofs and walls are more than just a ‘nice to have’, he says.
“Cities around the world, like Hamburg, Paris, Singapore and Chicago, are using them to combat seriously rising temperatures, improve air quality, protect buildings, improve energy efficiency and savings, help prevent flooding and reduce noise.”
However, as AECOM associate director, sustainability and resilience Marta Karlik-Neale points out, it’s important to understand that green infrastructure is not simply a natural system.
“It’s a modified system that constantly wants to go native,” she says. “When it’s allowed to do this it stops performing the precise functions we need in an urban system, like specific water flow or water quality.
“That’s why it requires constant modification. It’s often this part that is forgotten in green infrastructure projects.”
Marta says changing social and economic environments mean the requirements for the functions will also change, and this will require a new approach: real-time design where the system is continuously optimised to a set of pre-agreed functions.
Traditional ‘grey’ infrastructure is static; green, which needs to fill the same functions, is a living, evolving and ever-changing system, says Marta.
“As a result, its design needs to be a continuous process. To fully realise the potential of green infrastructure to deliver on many different objectives, local governments need to ensure it is designed with multiple benefits in mind.
“Melbourne’s Urban Forest Strategy, for instance, designed to help reduce the urban heat island effect, will also improve access to nature and the city’s biodiversity.
“And in Wellington, green infrastructure is proposed to cope with slope stability and surface run-off from increasingly intense rainfall.”
But, she says, appropriate financing mechanisms need to be put in place for ongoing maintenance and real-time design.
Advances in technology, particularly the Internet of Things, are an opportunity to create solutions that cost less to establish, with costs spread over a longer period of time, says Marta. “That requires new models of financing.”
There are also innovations on this front. “By understanding the services a specific green infrastructure provides, we can investigate who benefits from it, and how much they value it.”
Marta cites as examples, water purification services provided by a wetland that could be of value to a water company. Recreational space brings value to a community and carbon storage benefits everyone.
Meanwhile, AECOM’s Daniel Chapman points out that developers also recognise the value of green infrastructures.
Daniel is the firm’s principal landscape architect and leader of design and visualisation.
“The closer houses are to high-quality green or blue open spaces, the higher their value,” he notes. “If strategically planned, the uplift in development value generated through the creation of new green infrastructure with recreational and amenity value, can be captured through developer contributions and directed towards the ongoing costs of adaptation and operational expenses.”
At Fulton Hogan, Auckland regional manager Matthew MacMahon is seeing a growing appetite, albeit “a pretty slow one”, for innovative green infrastructure solutions.
These include: recycling; the growing use of electric vehicles (“I think the electric revolution will come faster than we expect”); and the use of renewable energy and bio-fuels.
Invariably it’s about the economics. “We’re in the phase where there’s a trade-off between knowing what we want and how much we’re prepared to pay for it. There are probably not too many tenders won or lost on green initiatives – but that’s changing.”
Recycled materials such as gravel, asphalt and concrete are increasingly being used in infrastructure projects, says Matthew.
“We can get up to 35 percent recycled asphalt pavement [RAP] into our current mix designs.” Including crumb tyre rubber in bitumen is another example. Widely used overseas – it will be a compulsory element of chipseal in Victoria [in Australia] within five years – it’s being trialled here but comes down to economies of scale.
“If you can shred 20 tonnes – and there are massive amounts of tyres sitting around mining towns in Australia – it’s a lot cheaper than shredding three tonnes.”
John Mauro believes embracing green infrastructure solutions opens up a range of opportunities for local authorities, providing the right approach is taken.
“With new technologies becoming available, the private sector continuing to upskill and come to the table with more sophisticated solutions sets, and the sharing of ideas between international peer cities, innovation is being accelerated,” he says.
“But it needs to start with a return to basic principles; what’s local government’s purpose and how can it deliver value, multiple outcomes and excellence to ratepayers indefinitely?”
- Patricia Moore is a freelance writer. email@example.com
This article was first published in the September 2017 issue of NZ Local Government Magazine.