Calculated risks in reclamation
Brown land into green land was the theme of this day, with - as a subtext - an exercise in mutual congratulation by the Stockley Park team. Don’t ask why the public-transport connections are so bad or why we were advised to book a taxi two hours ahead; don’t ask why the work areas and the adjacent housing are so divorced, or why the business-park area is not integrated with the golf course, or why there is no acknowledgement of the cultural and landscape history of the site.
What we saw here was the best of the British business parks in its fourteenth growing season, profiting from continuing intensive managment and development control. In Michael Lowe of Arups, John Worthington of DEGW, horticulturist Charles Funke and landscape architect Bernard Ede, we have a design team that has leapfrogged successive changes of ownership to make a pleasant and profitable place out of a rubbish tip.
What is hidden at Stockley Park (because you can’t see the befores and afters) is the scale of the land reclamation. And left unasked at this day were some fundamental questions.
Why transform post-industrial gravel/ landfill sites into an avowed semblance of a Stourhead or Stowe? Does it really make the land safe, and for what? Does it make money? (Yes). Is there greater biodiversity?
(Doubtful). Is it a good example of sustainable development? (Arguably not).
Such questions are relevant because they are what the Earth Centre is trying to grapple with, and what the Greenwich Millennium Project may or may not be tackling.
The function of the Earth Centre is didactic - demonstration and education. This 170ha site of old coal workings west of Doncaster is about play, water management and food production, so becoming a sort of Centre for Alternative Technology on a big scale.
The afteruse of Dominic Papa’s vast Zaanstad landfill project near Amsterdam is recreation (with extraordinarily steep 1:1 slopes, way beyond the angle of repose of most consolidated material).
By contrast the Greenwich Millennium landscape is about celebration of an anniversary and, according to Paris-based landscape architect Michel Desvigne, about gridded forestry patterns - or, as Bernard Ede related, about landscape structures as an armature holding various developments.
This Greenwich project is the big one. In the 1970s, coal gasworks, tarworks and a chemical fertiliser plant were there, and the result was land polluted by coal tar, by its derivatives (such as benzene, landfill gases, lime and cyanide), plus the impediments of concrete foundations (180 tar tanks discovered to date). All this on a site of multiple ownership with no clear long-term after-use, and everything to be executed within a fixed 20month programme.
The aim for David Barry and his reclamation design team at W S Atkins was to minimise the environmental liability. The reclamation programme deals with the whole eastern peninsula site: 40 per cent is the Millennium Experience and 60 per cent is housing, infrastructure, and commercial development. Barry was very open about the process.
There’s no such thing as a ‘clean-up’; there will always be a risk. He related that the main lessons of Greenwich were to maximise site investigation ( a 25m grid of boreholes); to investigate historical records; to use a range of remediation technologies; and to choose a good contractor (the techniques are largely those of conventional engineering: it is the ‘mindset’ of the contractor which is significant). In addition one should make a site-specific risk assessment (eg, it does not matter if there is some toxicity left if you are going to place a huge oconcrete slab over it) because that is more economic than working to ‘Dutch-type’ absolute standards .
It is the last point which is the most controversial. Barry acknowledged that environmentalists would be worried about this; what he failed to point out was that insurance markets also worry (that is post-1960s history). Arguably, a site-specific risk assessment does not allow for such financial uncertainty in the medium to long-term, especially if the afteruse is unresolved, the site is in a flood plain, and sea levels are rising.
The lesson of this conference is that you can make money from reclamation and landscape design if you are close to Heathrow and the M4: the wider issues were insufficiently faced, and the accounts of the Earth Centre and the Millennium Project were just tasters. The Landscape Foundation should organise two more seminars: one this century at the Earth Centre, one in the next millennium at Greenwich.
Robert Holden teaches at the University of Greenwich and is a partner in Holden Liversedge