As the stormwater industry evolves to meet the needs of modern society, the industry is gaining a better understanding of how actions downstream can have major environmental impacts upstream – leading to a considered approach to managing the impacts of urban runoff.
What do Melbourne’s Royal Botanic Gardens and the Great Barrier Reef have in common? Of course there’s the tourism dollar that each attraction brings to its respective state; but there’s actually another strange connection that links with the way we should be managing run-off impacted by human activities.
Each year many of the eels that make the Botanic Gardens their home set off on a long journey back to their spawning grounds in the Coral Sea to lay their eggs. Like many migratory spawning sea creatures, the adults never return, but the young elvers, once hatched, spend the early parts of their lives in the protection of the coral nurseries before returning to river basins around the country.
Prior to European settlement the eels were an important source of food for Aboriginal people; often important ceremonial gatherings were held after annual flooding events where eels were directed into billabongs and waterholes by stone weir traps and the floodwaters receded.
In the Coral Sea, the Great Barrier Reef is a world-renowned attraction that is worth literally billions of dollars to the Australian economy through tourism. Coral reefs located many kilometres off the coast close to the Australian continental shelf abound in a spectacular display of colourful corals and fish that is amongst the best in the world. A unique ecosystem, many of the fish species spend different parts of their life-cycle in open ocean, the coral reefs, shallow seagrasses, estuarine mangrove areas, and even many kilometres inland.
With governments around the country gearing up to embark on a period of infrastructure growth that is intended to increase the country’s productivity and support economic growth, it will be important to make sure this does not come at an untenable cost to our country’s natural capital.
In addition, the focus on infrastructure does little to resolve the insidious environmental creep that occurs through unfettered development in urban areas. With a significant growth in Australia’s population post World War II, many would be able to remember walking creeks and streams in urban fringe areas, catching tadpoles and yabbies and even spotting the occasional platypus. Through this same period we saw a move to engineering approaches to drainage which aimed to convey nuisance waters quickly and efficiently away from urban settlements.
The paradigm for the modern stormwater professional is different. Rather than trying to control nature we try to mimic it. Recognising that the impacts can be felt far beyond a project of immediate focus there are challenging intellectual and technical conundrums that need to be resolved to ensure a balanced amenity and environmental outcome can be achieved.
Many would appreciate the fact that decisions taken today have the potential to impact through the ages. The country to which the first Australians connect has been significantly impacted by development, just as many of the places we remember from yesteryear have been changed through urban expansion.
As we embark on what may be remembered as the infrastructure decade we should be mindful of our impacts, and look to ensure that the underpinning ecological functions of our landscapes are maintained. Good and bad outcomes have the potential to resonate many times over, and nowhere is the mantra ‘think globally, act locally’ more relevant than in managing the impacts of urban run-off which is generated where it falls.