Our cities have altered their original landscapes so greatly that their natural systems are profoundly compromised. These systems – such as swamps, rivers, creeks, aquifers and bushland corridors – need more space to function properly. Sometimes they assert their underlying presence through land subsidence, floods and fires. As Margaret Cook wrote in her history of Brisbane floods, the Brisbane River is “a river with a city problem”.
In Australia, Melbourne in particular has been hugely altered. Historian James Boyce wrote:
Of all Australia’s major cities the natural environment of Melbourne before British settlement is perhaps the most difficult now to imagine. This is in part a product of the city’s size and flat topography, but it also reflects the extent to which the region was dominated by swamps and grasslands – the two ecosystems that were most comprehensively transformed by the conquest.
