Transitions: Green elements for a Christchurch rebuild

Christchurch residents’ desire for a greener central city – clearly expressed through the Share an Idea programme and translated into a very green Draft Central City Plan – inspired Landcare Research to design an Ellerslie International Flower Show exhibit that showcases some of the possibilities.

Exhibit designer Colin Meurk, a Landcare Research ecologist (pictured), says that in redeveloping the central city Christchurch has a unique opportunity. “We can transition to a new, more confident, multi-layered city that is an attractive, relevant and viable place for people. One of those story layers is our unique natural history.

“It’s great that the Christchurch City Council, with its Draft Central City Plan, is embracing concepts like green roofs and living walls, sensitive stormwater treatment trains and pocket parks,” says Colin, who co-authored the urban greening manual, How to put nature into our neighbourhoods. “We want to show people what’s possible and stimulate some discussion.”

Entitled Transitions, the Landcare Research exhibit will feature a shop frontage, with green roof and living wall, looking out onto a pocket park, an attractive way of bringing nature into the confined spaces of a central city. “A green roof reduces stormwater run-off, provides energy savings through the insulating effect of the growing medium and plants, is unaffected by UV, provides a habitat and food for insects, lizards, plants and birds, moderates the urban heat island effect, and muffles noise within the building.

“With our low rainfall, Christchurch doesn’t have as many green roofs or living walls as some other New Zealand cities. But, we will display examples that stem from our research into appropriate plants and substrates for our local environment.”

A demonstration water treatment train – a scaled down version of what has been proposed for the city – will also be displayed. “As our city has grown, so has the amount of impervious surface area such as roofs and car parks that channel water straight into our periodically stretched stormwater system. But we can use plants and substrates to detain, filter and reduce the amount of stormwater and suspended contaminants that flow into our drains and waterways.”

Green tram tracks – a concept taking off in Europe and North American cities – will be demonstrated. “Why do tram or light rail tracks need to be paved or bordered by asphalt or concrete? They can use pervious and interesting waste materials with plant life snaking up through crushed brick – an abundant resource in the city!

“Prior to human settlement, Christchurch had a wealth of native plants and wildlife. We now have the opportunity to restore some of what has been lost so that in the future our city attracts eco-tourists as much as enjoyers of our conventionally coloured parks and gardens.”

Colin hopes that elements like the green tram tracks, biodiverse lawns and piles of heritage rubble forming a substrate for rare riverbed and cliff plants will titillate the senses and attract debate.

“A key question with green rubble is how do we want to commemorate the awful events of the past year – think Athens, Berlin, Coventry and Dunkirk; how do they display their historic tragedies and grief? Seeing what’s possible in sympathetic yet poignant ways will help inform and promote that discussion.

“So be prepared for surprises and challenges; ours won’t be a traditional Ellerslie International Flower Show exhibit but we hope to create something that is interesting and provocative. We’ve got great support from the show organisers, the Christchurch City Council and some other enthusiastic supporters, and we’re having a lot of fun pulling this together.”

Ellerslie International Flower Show, North Hagley Park, 7 to 11 March 2012. For more information: www.ellerslieflowershow.co.nz