Friday, 11 March 2011

water, water... everywhere?

The continuous process of overlaying, re-drafting, overlaying and re-drafting is always augmented by research and re-consideration of existing precedents. My drainage strategy for the site involves the harvesting and re-circulation of rainwater and grey water combining organic filtering (reed beds and grey roofs) and more traditional,, grey infrastructure (gullies, rills, storage pounds and pumps.

(This image and all subsequent images- except where noted- courtesy Dreiseitl, H. & Grau, D. 2009. Recent Waterscapes. Berlin: Birkhauser

Jamie Liversedge directed me towards Potsdamer Platz earlier on in the term, but I was unable to find anything in the library or on the web with any degree of detail. I raised the issue at a tutorial today, and Julia Fogg handed me a book:

"Potsdamer platz- might be in there. think it was Herbert Dreiseitl"

"No... that doesn't sound familiar... I'll have a look anyway..."

And, of course, i opened the page on Potsdamer Platz... the humanity...

Okay: here is the site in plan form. The brief was to re-design this urban plaza in the heart of a very corporate area that provided leisure facilities for the general public. In addition to these concerns, the design had to "come close to meeting ecological aims".

Dreiseitl does not specify what these initial aims were: reading between the lines, one can infer that perhaps corporate interests were keen to have "something environmental" within the design to address corporate-social responsibility factors. Examining the site and its proximity to the Landwehrkanal, it seems Dreiseitl (and the other planners, designers and engineers not mentioned in the text) concluded that water management and rainwater harvesting were the best ways of giving the design an "ecological edge" (my quotes) without compromising the other areas of the brief.

Herein I think there are strong parallels with Jubilee Gardens. Like the Potsdamer Platz, there is an active corporate presence fringing the site (Shell etc.). Like the Potsdamer Platz, the site has to provide programmatic leisure facilities. Of course, the heavy volume of tourists at Jubilee Gardens (and the fact that businesses seem to face away from the site) mean the bias is much more towards leisure rather than business, but still worthy of consideration. And finally, the two sites both abut an important watercourse.

(an aside- is it me or do European cities have more waterways than London? Central London is crossed by the Thames and the Grand union canal, with the River Lee running down the eastern extremity... compare this aerial view of Berlin)

The original master plan I drew up for Jubilee Gardens (which I am hoping to revise in light of recent design developments) was very much concerned with reconnecting with the river specifically and water generally. The idea of harvesting rain and grey water, filtering and redistributing was a very attractive one. Potsdamer Platz in Berlin sets a very useful precedent, especially as it combines some biological (soft?) techniques in a "hard" environment... I want my designs for Jubilee Gardens to complement (and compliment) the aesthetic of the South Bank, which is essentially urban.


Above is a simplified diagram of the water management strategy at Potsdamer Platz: grey water is collected from adjoining buildings along with excess rain water from green roofs, and collected in underground cisterns. These cisterns act as both a storage buffer (capacity of 2600 cubic metres, with "900 cubic metres left free in their turn for cases of heavy precipitation") and repository for accumulated solids (presumably the cisterns have to be cleaned on a scheduled basis). This water is pumped back through the site and cleansed via "planted purification biotopes"


The precise nature of these planted biotopes is not fully explained and it is this area that i shall have to research if i want to implement the scheme at Jubilee Gardens, and the effectiveness of these is really the deciding factor. The text notes that "technical filters can also be used", with the implication that this is a necessity to avoid algal build up in summer months. Essentially, the "green-ness" of this method hinges on the amount of energy that this system consumes.

People love water. As some of the (admittedly small) images show below, water is utilised beautifully in Dreiseitl's design. Its interaction with light offers infinite possibilities- in a sense, water and light offer third and fourth material categories beyond the traditional hard and soft designations.
How the human race manages water supply will prove to be crucial over the coming decades. Even disregarding their impact of climate change the burden on supply precipitated (pun intended) by increased food production (demanded by the exponential growth in human populations globally) will severely stretch resources. recently, drought in China has damaged their wheat crop, leading to increases in price as China has sought to import grain (see this article in the guardian). Water is also used for cooling and cleaning in industrial processes, and water consumption by the rapidly industrialising eastern economies is increasing exponentially,

I believe it is the role of landscape architects to demonstrate- even if only on a small scale- how old and new technology can be incorporated cheaply into their designs. In the United Kingdom, from whence I blog, the first heavy downpour is accompanied by dramatic flooding. Conversely, hosepipe bans implemented nearly every summer. It is estimated that a third of Thames Water's (an Australian owned firm supplying most of the water in the south east of England) mains supply is lost before it reaches the faucet. 33%! and yet we still deem it necessary to flush our lavatories with high quality, filtered drinking water! (See BBC News article from 2005 )

Yet again I have deviated on my derive... fun as these meta-literal psychogeographic ramblings are, I have a degree to (barely) pass. In the meantime, please enjoy this picture of a Berliner appreciating the tactile qualities of water... (if that's what floats your boat)

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