Increasing the likelihood of success: delivering green infrastructure in high-density urban environments
Richard Brown, ARUP
What I have learnt from working on several of Arup’s Green Infrastructure (GI) and Sustainable Urban Drainage (SuDS) projects – in locations ranging from Wales to San Francisco – is that the most significant challenges these projects face don’t generally arise from the complexities of the engineering or urban design. Time and again, local mechanisms for delivery, or the lack of such mechanisms, represent the biggest obstacle.
I am not saying that delivering retrofit green infrastructure is not technically challenging. There are far too many botched examples demonstrating what happens when a team without sufficient technical expertise or without a multidisciplinary approach to design is given responsibility for leading a project. But technical quality can be managed. Where GI retrofit projects frequently stall – or shudder to a complete stop – is when non-technical issues associated with funding or governance become too serious to ignore.
If we want to make retrofitting of GI in high-density urban environments a more successful field we need to draw lessons from completed projects and ask how these were made to work. From increasing tree canopy cover in Melbourne’s streets, parks and iconic laneways, to introducing 578 rain gardens into New York City streets, to installing sustainable urban drainage features at Welsh schools as part of a catchment- wide intervention, we have good examples from a diverse range of urban environments and climatic zones.
It is my belief that GI can be delivered via a number of funding and governance mechanisms – there isn’t a single ‘right’ answer. The most appropriate delivery mechanisms depend on a project’s required delivery timelines, the political and regulatory environment, the types of outcomes required, and the receptiveness of beneficiaries to providing in-kind funding or ongoing management.
It’s also important to acknowledge that GI can be delivered, and land uses targeted, in more than one way. Incremental and opportunistic installations can be sequenced to take place in parallel with other infrastructure upgrades, or GI can form part of large-scale streetscape retrofits that are centrally funded, or as part of a suite of projects at various scales that together form a larger initiative.
A project’s ultimate success can also be support by designing delivery from the outset in ways that link any silo-driven cultures or policies. This will increase the likelihood of the project achieving multiple long-term benefits. Also, though local contexts always vary, implementing new GI using resources, delivery mechanisms and policies that are currently in place is usually the most successful approach – even if you have to join them up in new ways.
Regardless of who is delivering the intervention and its primary purposes, all GI projects produce a range of direct and indirect benefits. Naturally, this means that success relies on a number of elements being considered at the outset – not just one, highly-visible outcome. A shared vision of a project’s multiple benefits, coupled with a commitment to multidisciplinary collaboration, and a willingness to explore the potential of innovative funding models is often the recipe for success.