Wildlife takes the podium

Atkins | 15 Sep 2010 | Comments

Wildlife is returning to London’s Olympic Park, the first since its transformation from an industrial, brownfield site into one of the largest urban parks to be created in Europe for more than a century. Biodiversity is at the heart of the vision for the new park – and it’s a vision that’s being brought to life with Atkins’ know-how.

You wouldn’t normally expect to see otters and water voles in east London’s industrial hinterland. But that could be about to change, thanks to one of the most ambitious habitat creation projects ever undertaken in the UK.

London’s new Olympic Park, the stage for the 2012 Olympic and Paralympic Games, is being designed with wildlife as well as athletes in mind. To the immediate west of Stratford and spread along the Lower Lea Valley, the Olympic Park is just two and a half miles from Canary Wharf and London’s bustling docklands.

As the official engineering design services provider for London 2012, Atkins has played a major role in protecting, conserving and now encouraging the biodiversity and habitats within the Olympic Park area. The Park covers more than 100 hectares and the river Lea is a central feature, meandering through the area and fanning out into a latticework of channels – the Bow Back rivers – on its journey to the Thames.

Provision of wildlife habitat is one of the building blocks of the Olympic Park masterplan. The Olympic Delivery Authority (ODA) has adopted an overall target to create at least 45 hectares of new habitat by 2014, which will eventually mature to meet stringent nature conservation benchmarks.

“Biodiversity is a central theme and it goes right back to the original design intent,” explains Alison Braham, director of Atkins’ landscape architects team. “The emphasis is on the extent and quality of what you can create, and its sustainability.”

The Park is set in an area that has been subject to decades of neglect and it includes a high proportion of former industrial land, some of it heavily contaminated.

Transforming this space into something not only suitable for a major event but that works as a living, breathing habitat for wildlife has been a vast undertaking, one that is only beginning.

This year is a milestone. With principal earthworks and landscaping nearing completion, the coming months will see a flurry of activity as the site is brought to life with more than 300,000 carefully cultivated native plants.

Habitat creation is a key element in the Olympic Park Biodiversity Action Plan (BAP). The BAP has statutory force – it was one of the planning conditions for the development – and provides a blueprint for sustaining wildlife and habitats.

Atkins has worked with organisations including Natural England and the Environment Agency to protect the site’s indigenous wildlife. And the re-greening of the site – the bulk of which is taking place during 2010 – marks a critical phase.

“As well as encouraging natural colonisation by species such as otters and water voles, we want to attract species that were here prior to any works,” says Kim Olliver, specialist ecological supervisor with Atkins. “To do that, we have to make sure the ecosystem we have here is as healthy as possible. If you create the right habitat, species will move back.”

The big attraction

As well as being one of Europe’s biggest public realm projects, the new Olympic Park is one of the most complex. Within the Park, high-tech venues such as the Olympic Stadium and the landmark Aquatics Centre will rub shoulders with a remarkable variety of natural habitats, most of them being created, or re-created, from scratch.

Bulldozers and biodiversity have long occupied opposite ends of the ecological spectrum. And the idea that large construction projects inevitably lead to habitat destruction is entrenched in the public consciousness. But as the Olympic Park projects shows, it doesn’t have to be that way.

“It’s always a balance,” stresses Atkins’ Alison Braham. “And with something on this scale, there are losses of existing habitat. So the first step is always to know what you’ve got in the first place. The process of environmental assessment provides a very clear picture of what will definitely be lost, what can be protected and what can be created. And the value of what you create can frequently be greater than what is actually lost.”

The list of different habitats being created is impressive by any standards. It includes ten hectares of native trees and shrubs, reed beds and ponds covering nearly two hectares, more than 8km of carefully restored riverbanks, 20 hectares of species-rich grassland and 9,000 square metres of rare native wet woodland.

Among the species highlighted in the Biodiversity Action Plan are the brown banded carder bumble bee, the tumbling flower beetle, the European eel, amphibians including the common frog and toad, the smooth newt, five priority bat species, and reptiles including the common lizard, grass snake and slow worm.

Otters are one of the larger species singled-out in the action plan. Currently rare in London, it’s hoped that the creation of more than 2km of new soft river banks along with reed beds and wet woodland will encourage these elusive creatures to colonise the Olympic Park site.

Although there are no plans to import otters from outside the Park, there’s an emphasis on making the site as attractive as possible. Two artificial holts (dens for otters) are being created in river banks in the north part of the Olympic Park. Water voles, meanwhile, may be re-introduced once new waterside vegetation is established. There’s a major focus on encouraging bird life as well. Kingfishers, already present in small numbers, are high on the list.

“They’re a difficult species to see – you’ll often just see a blue flash going up and down the river,” says Olliver.

Replanting the riverbanks with native species will provide the network of camouflaged green corridors offering the freedom of movement that kingfishers and other species seek. As with the otter, the strategy includes positive inducements.

“We’ll be constructing kingfisher nesting banks within the Park,” says Olliver. “In the meantime, we’ve created a kingfisher bank just to the north of the Park in Hackney Marshes, which has been a real success.”

Sand martins, summer visitors from Africa, have not been deterred by the Olympic Park construction programme.

“They’ve been coming back year after year,” notes Olliver, who has worked on the Olympic Park project since its inception.

Currently, pairs nest in drainage holes in the concrete walls of the Bow Back rivers, but it’s hoped the provision of two artificial nesting banks each with 50 nesting holes, will attract a breeding colony of sand martins.

Fixing up the neighbourhood

Bringing the site to life is a massive collaborative effort that involves everyone from civil engineers and geotechnical experts to horticultural specialists and utility teams.

“As an ecologist, I work with all of them,” says Olliver. “If there’s an issue, I do my best to work around it to make it work for the team.”

The Park that’s now emerging as a result of these efforts is very different from the site acquired just four years ago. This included derelict land, with landfill sites, former railway sidings and abandoned industrial buildings.

But sites of this sort can turn out to be surprisingly rich habitats, partly because they’re seldom disturbed by humans. Even apparently hostile environments, such as railways, provide a haven for certain creatures.

Thornton’s Field railway sidings near Stratford is a case in point. With the trains gone and track lifted, it’s now part of the southern section of the Olympic Park. Its potential was spotted during an ecological survey, part of an ongoing programme of site surveillance that has characterised the project since its inception.

“It looked like a completely different habitat, similar to a heathland site,” recalls Olliver.

It turned out to be a rich haven for invertebrates, including “at risk” species such as the toadflax brocade moth. Ballast, soil and timber sleepers from the sidings were carefully removed from the site and transported to a part of the Park where they wouldn’t be disturbed.

Initiatives of this sort underline an increasingly open-minded approach to building biodiversity: it’s not all about creating pristine natural habitats from scratch. In some cases, going green actually means going brown, because many derelict manmade environments are beneficial to wildlife.

The black redstart – a member of the thrush family – is an example. It’s nationally rare with fewer than 100 breeding pairs in the UK. Unusually, it’s a bird that thrives on dereliction.

To encourage its return to the Park, some 50 nesting boxes are being set up, along with more than five hectares of its favourite brownfield habitat.

For Atkins, creating new habitats – and making the most of existing ones – has meant taking a flexible approach. And it’s all been achieved with one of Europe’s biggest building sites as a backdrop.

“We started off with a derelict site,” says Atkins’ Alison Braham. “You have to take cognizance of what’s already there and what you can create. It’s a combination of big strategic thinking and also really looking at the nitty-gritty level. That means preserving things wherever possible to the last possible moment, so you’re not losing things unless you absolutely have to.”

Approaches of this sort could have important implications for cities in the 21st century. And if 2012 proves anything, it’s that large-scale urban development and the creation of diverse – and lasting – natural habitats are not necessarily mutually exclusive if the model is right.

“Derelict land may have areas of biodiversity interest, but it’s not always sustainable in the long term,” says Braham. “The key thing about our proposals here is that what is being put in now will be there for years to come. This is all about creating habitats that will last.”

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