Championing Urban Rivers: Historically Maligned as Natural Drains, Our Urban Rivers Are in Fact Fundamental Ecological, Social and Economic Assets That Need Protection, Appreciation and Enhanced Management Approaches
Taylor, Robin, Ecos
Good rains across much of eastern and southern Australia over the last year have allowed many rivers to flow for the first time in years. But in major cities where roads and pavements have replaced the natural vegetation, a sudden heavy rain spells bad news for river quality, and by extension impacts on the coastal areas that receive river water.
Sydney's urban runoff has been likened to secondary treated effluent (1)--the capacity of sewerage systems is exceeded during peak flows resulting in overflows to creeks and rivers. And the situation is similar for most of Australia's major cities, where people would not think of swimming in, let alone drinking, from suburban rivers.
Unlike rural catchments, where most of the rainfall soaks into the ground, in cities even small amounts of rainfall generate runoff. Particularly for small urban streams, small amounts of impervious surfaces can have dramatic impacts on the streams' ecological health.
In fact, Alan Hoban, Manager of Water by Design at the South East Queensland Healthy Waterways Partnership, says results from studies of streams in Victoria have shown that if even one per cent of a catchment is comprised of impervious areas connected to the stream by pipe work, then those streams are significantly less likely to have important species such as platypus. He believes the solution is to harvest stormwater and reuse it--a convenient fit to the growing need for more urban water supply.
'It is an important case for water sensitive urban design, to redesign the way our drainage systems operate,' says Mr Hoban.
In a session on urban rivers at the 12th International Riversymposium, held in Brisbane in September, presenters from Australia spoke about issues such as design challenges, setting long-term visions for urban rivers and improving river health monitoring.
Dr Shadananan Nair from the Nansen Environmental Research Centre in Cochin, India, discussed the very different challenges of managing urban rivers in developing countries where many cities face serious shortages of reliable water.
The huge issues for urban rivers in India and other parts of Asia are associated not just with surface pollution and massive rates of urbanisation, but also with rising sea levels and other climate change impacts, poverty, corruption, poor sanitation and chronic health problems.
Managing our urban rivers
In Australia, partnerships between government, industry and community are forging the way to improve the health of urban waterways.
The Healthy Waterways Partnership (winner of the 2009 Banksia Environmental Award for Water), for example, produces annual report cards for freshwater as well as estuarine and marine waterways in south-east Queensland, giving them a grading from A to E
Alan Hoban says that over the past 10 years, in response to water quality monitoring, there has been significant investment in upgrading wastewater treatment plants to reduce discharge loads, and that the report card played a significant role in recognising and addressing this important issue.
In Tasmania, the Derwent Estuary Program--a regional estuary management partnership between local and state governments, commercial and industrial enterprises and community-based groups--has a similar scheme, producing an annual report card, to provide information on the river's health.
Brisbane City Council's Creek Ranger program is a community capacity-building environmental initiative, led by council officers--the 'creek rangers'--who monitor reaches of their waterways and lead community activity along them. Meanwhile, the Hunter and Central Coast Regional Environmental Management Strategy (HCCREMS) is a larger regional initiative being implemented by 14 councils in the Hunter, central and lower north coasts of New South Wales. …