Under pressure - how to make urban nature flourish

Urban Life 7 November 2017 Peter Forfang Sørensen

As urbanisation increases, the challenge to keep green areas green gets more complicated. However, it can be done - and with added benefits.

6 mins

A s cities all over the world grow and attract more people, the natural environment is increasingly under pressure. It is a global goal for the UN and the EU to stop the decline in biodiversity by 2020 at the latest. The fulfilment of that goal can be helped by a strengthened focus on urban nature. 

It is Ramboll’s stated mission to make people and nature flourish, and the company has acted on many projects that deliver net positive environmental benefits, enhance wildlife and add to public enjoyment. These include projects that support oases of urban nature as well as greening of the road and rail routes into city centres. 

Network Rail’s GBP 7-billion Thameslink Programme in Greater London has been testing the potential of biodiversity offsetting since 2012 when it published guidance for developers. One of the most successful examples was part of the project that untangled the tracks approaching London Bridge station – thus ensuring Thameslink rail lines can cross over Kent lines unimpeded and run more efficiently.

Ramboll’s prime contribution to the infrastructure challenge for this Bermondsey Dive Under project was engineering design, but when construction started in 2012, the Thameslink Programme also sought to improve the site’s low conservation value and limited botanical diversity. 

This was challenging because the site contained the previous tenant’s debris, and the soil was heavily contaminated with asbestos, hydrocarbons and Japanese knotweed. 

Overall, 21,900 tonnes of contaminated material were removed and replaced by 765 m2 of green walls and a colourful mix of native wildflowers. Furthermore, the railway embankments now function as green corridors and stepping stones to the wider area.

A global trend

London is far from the only place where biodiversity and urban liveability go together. “There is a large potential to improve biodiversity outside the traditional sites of conservation interest, and the benefits are multiple, since nature, people and society at large need stronger ecological coherence,” explains Kristine Kjørup Rasmussen, Chief Consultant on urban nature at Ramboll. 

In Offenbach, Germany, an industrial peninsula on the River Main presented an almost equally challenging environment with contaminated soil. Ramboll is now converting the area into a new, sustainable city district based on a holistic climate adaptation concept, developed to create ‘soft’ city spaces and streetscapes while retaining and cleansing stormwater before releasing it to the river and harbour. Innovative natural water treatment systems such as cleansing biotopes are being integrated into the park spaces, and new, natural habitats are being created for riparian flora and fauna while also giving the city a refreshing green oasis. 

In Singapore Ramboll has finished a similar project. As elements of an award-winning climate adaptation and green-area restoration project, added plants and a healthier river in Bishan Ang Mo-Kio Park have improved the city’s biodiversity, attracting many different species of birds and insects – which also keep the mosquitos at bay. 

In Denmark too, biodiversity projects are often combined with measures to address climate adaptation and expand recreational areas. 

This is the case in Kagsåparken, northwest of Copenhagen, and in Tommerup on the island of Funen, where habitats for wild species are planned as part of the new green and blue corridors crossing the town and thus increasing local biodiversity. 

Awards for double benefits

In the UK the Bermondsey Dive Under project has been rewarded with three awards in the first half of 2017: the project team from Network Rail, Skanska and Ramboll was presented with the ICE London Civil engineering Infrastructure Award for the most innovative, creative and sustainable contributions to the physical and social environment in the UK Capital. The project also won the Ground Engineering - Sustainability award, not least because the benefits were achieved with significant innovations, including cost reduction from reduced piling and pile depth, reduced material movement and impact. 

Finally, having increased biodiversity in the area by 113%, the CEEQUAL Excellent Whole Team Award secured a score of 96.6%, the highest ever granted to a completed project on the Thameslink Programme. 

“The fantastic score of 96.6% is the result of our collaborative way of working to not only protect but enhance the environment and the community whilst delivering this complex project”, says Gerardo Austria, Consents & Sustainability Manager, Network Rail.

Advantages of urban nature

  • Strengthens local, national and global biodiversity and demands less maintenance than traditional parks.
  • Holds large amounts of water and creates natural shade that cools areas and thus serves as a buffer against climate change. 
  • Helps renew air and thereby improves air quality. More plants in the cities can also curb emissions and contribute to cleaner air. 
  • Has a calming and healing effect with regard to a number of disease symptoms and stress. 
  • Supports several of the SDGs and thereby helps cities follow a sustainable development strategy. 

Written by Michael Rothenborg.