Along Hackney Road, between the National Wine Centre and the wedding-cake Goodman Building you can see excavators working in an endeavour to revive the swamps that were drained to establish Adelaide’s botanic gardens.
The short explanation for this activity is that the regenerated wetlands (as swamps are now called) will ensure the Botanic Gardens has an independent water supply, will improve water quality entering the Torrens and Torrens Lake and will allow landscaping of First Creek that currently ends up as a concrete drain through the Gardens. A better explanation places the role of wetlands into context as one of the pillars of life on Earth.
Water, food, energy (in the form of fossil and biofuels) and biodiversity provide the basis for human endeavour. Indeed, if you care to think this through, despite the successes of the industrial and digital revolutions, regardless of the value of social and institutional frameworks, we can’t escape our needs for water, food and energy, and the platform that’s provided these services, past and present – plants.
Connecting people with plants is the business of a botanic garden. The big story that the pillars of life on Earth are delivered through the intercession of chlorophyll in plants capturing sunlight and converting it into stored energy is an easy one to miss in a city. While the links to food, energy and biodiversity are already well told through the collections in the botanic gardens, the link to the role of plants in regulating water flows and quality and the role of wetlands in sequestering carbon has been missing. The draining (and drying) of wetlands as demands for land (and water) expand has seen the loss of both flood control and effective filtering and cleaning services from wetlands.
Surrogate measures such as stormwater drainage and water purification are both expensive and, commonly, less effective. The loss of wetlands has also seen a loss of biodiversity, and, as there are around 800 billion tons of carbon stored in Earth’s wetlands, one-fifth of the Earth’s carbon and roughly the same amount as in the atmosphere, the destruction of wetlands presents a potential “carbon bomb”.
While the Australian and South Australian Governments have supported the new First Creek wetland to provide water security for the Adelaide Botanic Garden, the compelling argument was the development of the wetland as an educational resource integrated with the Gardens’ living collections that already attracts an audience of 1.5 million visitors. This project was conceived during the development of the Gardens site master plan in 2003 by Professor Tony Wong from Monash University. The Gardens was fortunate that the space between the National Wine Centre and the Goodman Building remained unresolved after these developments.
Space is a rarity in Adelaide Botanic Gardens as it is in Adelaide more generally. The demands of a growing population and our ability to service that population put pressure on space that the 30 Year Plan for Adelaide endeavours to address. The potential to re-imagine green infrastructure in a city is really another story. However, our ability to re-imagine Adelaide’s watercourses, an element of this story, is worth touching on here. While wetlands provide the infrastructure capable of cost-effectively improving water quality, enhancing biodiversity and even regulating flows in Adelaide’s watercourses, our ability to develop wetlands is severely constrained by the premium on city land.
Colonel Light (or was it Kingston?) had great foresight. However, the foresight fell short on an understanding of ecological processes and ecosystem services. He was hardly alone. Nevertheless, the Kaurna people’s traditional ecological knowledge did recognise the values of these wetlands, and a unifying perspective on the connections between water, food and energy. Uncle Lewis O’Brien has generously shared some of the perspectives of the Kaurna people to contribute to the First Creek wetland concepts and interpretive plan. The project is especially important in integrating and communicating cultural, ecological and technological concepts. Other unifying perspectives for environmental reconciliation range from Linnaeus’s Oeconomy of Nature to James Lovelock’s Gaia.
However, it’s only by pulling these apart that we can see our future. And the reeds I hate, mint sheaves, human-high palisades that would close in round the water, I could fire floating petrol among them again, and savage but not beat them, or I could declare them beautiful. Les Murray, Water-gardening in an Old Farm Dam.
Originally published in The Adelaide Review on 2 May 2011.