Greening Our Gray Cities with Nature-Based Solutions

GREENING OUR GRAY CITIES WITH NATUREBASED SOLUTIONS

BY ROBERT BREARS

Cities around the world are turning to nature-based solutions to enhance resilience to climate change while creating livable spaces for their residents.

Traditionally, cities rely on gray infrastructure —pipes and drains—to move stormwater from houses, buildings, streets, roads, etc., into the nearest waterway to stop localized flooding. These systems combine with wastewater sewer systems, and all this water is led to a treatment plant before being discharged into the natural environment. In most cities, this water leads into streams and local waterways, which causes some major issues.

For example, these combined systems impact water quantity and quality, are easily overwhelmed during heavy rainfall, and increase downstream flooding risks. They also transport excess stormwater into waterways, which exposes people and aquatic life to toxins, chemicals, rubbish, pollutants, oil spills, etc.

Nature-Based Solutions: Blue-Green Infrastructure

Cities are turning to nature-based solutions to manage water quantity and improve water quality at the same time. These solutions, commonly referred to as BlueGreen Infrastructure (BGI), are semi-natural or natural systems designed to restore the natural landscape while improving water quality and managing excess water. BGI projects come in various shapes and sizes. They range from rain gardens to green walls, green streets, and urban forests. Combined, they can manage our excess water and clean the water simultaneously, and it’s all for free because nature’s doing it for you.

Multifunctionality of BGI

A key aspect of BGI is multifunctionality, which means one BGI site can provide multiple benefits and serve numerous functions. For instance, a green wall can reduce stormwater runoff, improve water quality, reduce the urban heat island effect, insulate the building, and provide a habitat for species. During the warmer months, the wall can reduce cooling costs, and in the cooler months, it can reduce heating.

BGI can also provide enhanced biodiversity in cities. It can protect your buildings and infrastructure from climate change. It can create green jobs with people getting training and education and then careers in this field. It can reduce infrastructure costs because gray infrastructure is more expensive than BGI. It also provides space for recreational and social activities.

Fiscal Tools to Encourage BGI

Fiscal tools are financial tools that cities can use to encourage uptake of BGI. They come in stormwater fees, grants, or subsidies, and they encourage BGI on private properties, public spaces, new developments, and retrofits. They’re easy to implement because you can tailor the fiscal instrument to the type of community you serve. They also provide an opportunity for a city to pilot small projects, and if they take off, BGI could become a citywide thing.

In Berlin, they encourage businesses to incorporate BGI on the premises as part of the Berlin Strategy for Biodiversity Preservation. The city’s water utility has increased its rainwater fee to incentivize companies to provide BGI in their private premises.

Raleigh, North Carolina has created the Raleigh Rainwater Rewards program, where a business or organization that implements BGI is reimbursed up to 90% of those costs for the project. The person has to put the money down first and then make the project happen, which takes the risk away, rather than having a grant that could lead to a project that fails.

Non-Fiscal Tools

We also have a range of non-fiscal tools to encourage BGI, such as information and awareness campaigns and fast-tracking of BGI project applications, which encourages new developments and retrofits to get BGI installed quicker than going

©PUB/ABC WATERS

Robert Brears

Founder, Our Future Water

Christchurch, New Zealand

Singapore: Greening Gray Infrastructure

Singapore’s Public Utilities Board has an active BGI program called Active, Beautiful, Clean Waters, where they are finding ways to incorporate BGI into existing gray infrastructure. This particular project took part of a flood diversion canal designed to prevent localized flooding and installed BGI features: rain gardens, new shelters, benches, fitness equipment, and jogging and cycling paths. They’ve created a wetland that’s designed to bring people closer to the water, experience nature, and restore the natural habitat but also prevent localized flooding. Robert Brears is an International Sectoral Expert (Water) Consultant with the Green Climate Fund, established within the framework of the UNFCCC. He is the author of nine books, including Regional Water Security, The Green Economy and the Water-EnergyFood Nexus, Blue and Green Cities: The Role of Blue-Green Infrastructure in Managing Urban Water Resources, and Developing the Circular Water Economy. He is the founder of Our Future Water, which has knowledge partnerships with the World Bank’s Connect4Climate initiative and the OECD/World Bank/UNEP Green Growth Knowledge Platform.

New York City: Green Infrastructure Grant Program

NYC’s Department of Environmental Protection offers the Green Infrastructure Grant Program to encourage private property owners to retrofit with green roofs. They provide the grant but also offer workshops to explain how it can be done. through a slow regulatory process.

They can also be seen as pilot and demonstration projects to show how effective BGI can be. These tools are less intrusive and create less resistance from stakeholders because there are no fees attached. For instance, you might encourage the uptake of green roofs for a grant program and then say, “In two years, we’re going to make green roofs mandatory for new developments or retrofits.” It gives time for people to get used to it, installing it, and seeing how it runs, but it gives a leeway of a few years.

San Francisco’s BGI projects are always tested against a triple bottom line analysis. The San Francisco Public Utilities Commission ensures its BGI fulfills multiple community, environmental, and economic benefits. One of the community benefits is an opportunity for stakeholder engagement but also for training, education, and awareness-raising. To really get the community involved, they’ve created the Rain Guardians program, which fosters community spirit where businesses or individuals look after rain gardens in their neighborhoods. That also helps maintain them, so it’s a way of reducing the costs.

Melbourne is getting people involved and up-close with BGI by creating a movable green wall that can be taken across cities to show people what it’s actually like. They take it to different neighborhoods to expose people to see how it works and the multiple benefits it provides. They have city representatives on hand to answer questions.

Sometimes demonstrations come in other forms. For instance, a city may say, “For our City Council buildings, we will have green roofs or rain gardens.” That means that people can see not only a demonstration of how it works but also see the government leading by example, which is another non-fiscal tool that cities can use to encourage people to think about BGI.

Overall, we can see that BGI allows cities to manage stormwater or improve water quality. But BGI cannot be done on its own. It has to become a network of things. That network accentuates that multifunctionality. The sum is greater than the parts. You will create huge economic, environmental, and social benefits.