What is blue-green infrastructure?

Blue-green infrastructure is a network of natural and semi-natural spaces meant to manage water sustainably while offering many societal benefits. It refers to the use of blue or aquatic elements (like rivers, ponds and wetlands) and green or terrestrial elements (such as trees and plants) in designing urban spaces.
green city with trees and solar panels
Unlike traditional “grey” infrastructure, which depends on conventional engineering solutions such as concrete drains and pipelines, blue-green infrastructure combines nature-based systems that replicate natural water-management processes. This novel solution lessens the pressure on traditional drainage systems while improving city sustainability and resilience.
Unlike traditional “grey” infrastructure, which depends on conventional engineering solutions such as concrete drains and pipelines, blue-green infrastructure combines nature-based systems that replicate natural water-management processes. This novel solution lessens the pressure on traditional drainage systems while improving city sustainability and resilience.

Examples of blue-green infrastructure

Green roofs

Green roofs, or rooftop gardens, feature flora grown on rooftops to absorb rainfall, minimise stormwater runoff and regulate building temperatures. This lessens the load on drainage systems during heavy rain and aids in mitigating the urban heat island effect.

Sustainable urban drainage systems

Another example is the creation of sustainable urban drainage systems (SUDS), which include elements such as swales, permeable pavements, and rain gardens. These features collect and store rainwater, letting it gently permeate the earth and reduce flooding while increasing water quality.

Wetlands, riverside parks, and urban ponds

Blue-green infrastructure also includes wetlands, riverside parks, and urban ponds. These features provide recreational opportunities for communities, increase biodiversity, and act as natural pollution filters. Wetlands, for example, may cleanse wastewater while capturing sediments, fertilisers, and pollutants, making them an environmentally acceptable alternative to typical water treatment systems. Furthermore, urban green areas such as parks and gardens help to improve air quality, reduce noise pollution, and promote physical and mental well-being.

Notable blue-green projects

Across the globe, you can find excellent examples of blue-green infrastructure. Some notable projects include the following:

The Chicago Riverwalk expansion

The Chicago Riverwalk initiative has converted the city’s downtown waterfront into a bustling public space. The project entailed constructing pedestrian-friendly pathways, green spaces, and recreational areas along the river to provide inhabitants and visitors with options for leisure, relaxation, and water-based activities.

The Olympic Park in London

The Olympic Park was built for the Summer Olympics in 2012. The park contains a large network of wetlands, ponds and rain gardens intended to regulate stormwater runoff and increase biodiversity. These green spaces not only provide recreational opportunities but also help to improve flood resistance and water quality in the area.

The Copenhagen harbour baths

The Copenhagen harbour baths are a collection of open-air bathing facilities in Copenhagen’s waterfront region. These blue-green infrastructure initiatives seek to take city dwellers closer to the sea while encouraging active lives. The baths integrate environmentally friendly design ideas such as the use of natural materials, water filtration through plants, and marine-life habitats. The Copenhagen harbour baths have helped regenerate the shoreline and promote an environment-friendly urban life.

Benefits of blue-green infrastructure

Blue-green infrastructure can provide a host of benefits:

Environmental sustainability

Blue-green infrastructure contributes to environmental sustainability by preserving and restoring natural habitats. It helps conserve biodiversity by providing habitat for plants and animals, particularly pollinators. These habitats are also important in the water cycle since they enhance water quality and reduce flooding and erosion.

Climate-change adaptation

Blue-green infrastructure can assist communities in adapting to the effects of climate change. Wetlands and forests, for example, operate as carbon sinks, absorbing carbon dioxide and lowering greenhouse-gas emissions. They also provide natural cooling through shading and evapotranspiration, which contributes to the reduction of the urban heat island effect.

Water management

Water resources can be properly managed with blue-green infrastructure. Wetlands, rain gardens, and green roofs catch and store rainwater, relieving pressure on typical stormwater systems. They also filter contaminants before they enter rivers, lakes, or groundwater reservoirs, thus enhancing water quality.

Improved air quality

Green infrastructure vegetation helps improve air quality by absorbing air pollutants such as particulate matter and toxic compounds through photosynthesis and other processes. This can potentially improve the general well-being and health of city dwellers.

Community cohesion and well-being

Blue-green infrastructure promotes community cohesion and well-being by offering venues for social interactions, community events, and cultural activities. Access to nature has been related to improved mental health, stress reduction, and general quality of life.

What does GHD do about blue-green infrastructure?

At GHD, we offer a range of services that contribute to the creation and implementation of blue-green infrastructure, and we’ve successfully assisted our clients in various blue-green projects:

Blacktown Native Institution Plan of Management, Australia

Since 2012, GHD has collaborated with Landcom and the Dharug community to draft a Plan of Management for the Blacktown Native Institute (BNI) site in Western Sydney. The Draft Plan of Management was created to guide the proper future uses for the site and assure its conservation and acknowledgement, all while improving the community’s social, cultural and economic outcomes.

Comprehensive Large-Scale Wetland Restoration, USA

GHD oversaw a habitat mitigation and restoration project encompassing 17 acres of protected wetland and four acres of dune habitat, making it one of the largest and most difficult projects of its sort ever constructed on the Northern California coast.

Designing more sustainable roads, Australia

GHD is a member of the Metropolitan Road Improvement Alliance (MRIA), a consortium formed to design and build three projects in Perth, Western Australia. The Infrastructure Sustainability Council of Australia’s (ISCA) Infrastructure Sustainability framework has been formally approved by the projects.

Designing the future of Sydney’s Central Station, Sydney, Australia

The most important renovation of Sydney’s iconic Central Station since its opening in 1906 will result in a sustainable, world-class transportation hub. Laing O’Rourke has commissioned GHD to carry out a comprehensive design of the works in collaboration with Aurecon. By considering concerns over sustainable development `GHD is working to produce a high-quality, sustainable asset for Sydney Metro.

To learn more about our different blue-green projects, visit our projects — sustainability page. We’ve assisted our clients with our expertise in the following areas:

Urban water management

We provide expertise in designing and implementing sustainable water-management strategies in urban areas. This may include stormwater management systems, green roofs, rain gardens, and permeable pavements to capture and treat water.

Landscape architecture and design

GHD’s landscape architects can contribute to the planning and design of blue-green infrastructure projects, integrating green spaces, parks and urban forests with water-management systems.

Environmental assessment

By considering future climate projections, GHD can assist in developing climate-resilient strategies and plans that incorporate blue and green elements. We can help design infrastructure that can withstand extreme weather events, adapt to changing climatic conditions and reduce vulnerabilities in urban areas.

These are just some areas where GHD can help create better infrastructure with blue-green elements that every community can utilise and enjoy. To know more about our services, visit our website, and browse through our projects. Together, let us build a sustainable future for communities around the world.

Articles referenced

Dolman, Nanco and O’Donnell, Emily n.d., ‘5 lessons learned from blue-green infrastructure’, retrieved June 15, 2023, from https://www.ice.org.uk/news-and-insight/the-civil-engineer/july-2021/theory-and-practice-of-blue-green-infrastructure

GHD n.d., ‘Projects’, retrieved June 15, 2023, from https://communications.ghd.com/sustainability/projects.html

GreenBlue Urban n.d., ‘Chicago Riverwalk’, retrieved June 15, 2023, from https://greenblue.com/gb/case-studies/chicago-riverwalk/

GreenBlue Urban n.d., ‘Queen Elizabeth Olympic Park’ retrieved June 15, 2023, from https://greenblue.com/gb/case-studies/queen-elizabeth-olympic-park/

GreenBlue Urban n.d., ‘Why green and blue’, retrieved June 15, 2023, from https://greenblue.com/gb/about-us/why-green-and-blue/