Kelvin Thomson (Wills, Australian Labor Party) Share this | Hansard source

I want to report on two of the visits which the Standing Committee on Climate Change, Environment and the Arts undertook. The first one, which has been commented on by the member for Shortland, was the visit to the greenfields wetlands in Adelaide. The City of Salisbury is located on the northern fringes of Adelaide. With approximately 130,000 residents it is the second-largest local government community in South Australia. It has experienced rapid residential and commercial growth and it is South Australia's most productive manufacturing region. The city has established a stormwater recycling program that provides business and community customers with non-potable water. This has contributed to reducing Adelaide's overall reliance on the River Murray to meet its water requirements and delivered biodiversity benefits for the area and for the adjacent marine ecosystems.

The committee inspected the wetlands on 17 May this year. We saw that it is one of over 50 constructed wetlands that help the city to manage its water supply and improve water quality. We received a briefing from Colin Pittman, the General Manager of City Projects at the City of Salisbury. The wetlands are located approximately one kilometre inland from the sea on a site that previously consisted of hypersaline soils. The area is slightly below high tide level, which historically made industrial and residential development in the area problematic. Overdrawing from aquifers in the area had resulted in depleted reserves, risking saltwater intrusion into the aquifers.

The city's stormwater recycling program involved the construction of wetlands. The urban stormwater run-off is treated in these wetlands through a range of natural processes: filtering of larger particles by riparian vegetation; aquatic plants and animals absorbing nutrients and organic matter; the effect of sunlight and oxygen on bacteria; and suspended clay particles settling on the bottom of the wetland. As a consequence the greenfields wetlands are able to remove approximately 90 per cent of pollutants and nutrients within a 24-hour period. This treated stormwater is then either distributed throughout the city to government or industrial consumers for irrigation and non-potable commercial use or stored in depleted underground aquifers during the wet season for later use during the dry season.

It was very interesting to note that during the drought in South Australia, which impacted on many of us, the City of Salisbury not only had enough water to meet all its municipal needs but was able to sell water to industrial customers. I thought it was a terrific project. As well as this, you still have the situation of a lot of stormwater run-off being discharged into Gulf St Vincent. The City of Salisbury has adopted a policy to clean all the stormwater run-off before it is released into Barker Inlet, which is an estuary of Gulf St Vincent. So they are able to clean up any of the stormwater before it does in fact go into Barker Inlet.

The committee noticed that urban stormwater, which has traditionally been regarded as something of a problem, can be harnessed and managed through constructed wetlands, and therefore you get the sustainable use of water resources, enhanced urban design, biodiversity benefits and so on. It really was a great project. I particularly want to commend the member for Makin because, in his previous local government life, he was one of the architects of this project. I think it really is a model for other councils, potentially right around Australia, to pick up how you can use stormwater better and harness it to your own advantage.

The other visit the committee undertook was to Westernport Bay, in my home state of Victoria. Westernport Bay is home to many migratory shorebirds, including the red-necked stint, the eastern curlew, the curlew sandpiper, the great knot and the red knot. These birds undertake remarkable journeys, as many members would be aware. They breed in the Arctic during the northern summer and then migrate up to 12,000 kilometres to spend the non-breeding season in Australia's intertidal wetlands. Over a 30-year period volunteers have been collecting data around Westernport Bay about these species. It is a matter of regret that nearly all the migratory shorebird species have been declining in numbers. The committee was informed that the species that have seen particularly dramatic declines include the eastern curlew, the curlew sandpiper and the red knot.

The major route taken by these birds during their migration from the Arctic to southern Australia is known as the East Asian-Australasian flyway. The problem appears not to be changes to their habitat in Australia but the question of the weakest link in the chain. The loss of habitat in East Asia and South-East Asia appears to be the primary cause of the declines in our migratory shorebird numbers. Tidal mudflats around the Yellow Sea are key stopover sites for many birds on the East Asian-Australasian flyway. If they do not have access to adequate food sources along the journey, they are simply not able to travel the distances required.

The committee heard that between 50 and 60 per cent of the total zone around the Yellow Sea has been reclaimed, and BirdLife Australia provided examples of recent large-scale industrial developments on sites which were once important feeding grounds. Australia does have bilateral agreements in place with the governments of Japan, China and the Republic of Korea for the protection of migratory birds but the evidence suggests that the agreements have not been effective in preventing the destruction of key stopover habitats. The committee noted concerns about the adequacy of international agreements for the protection of these habitats and intends to consider this matter carefully in the context of its inquiry.

That is very helpful from my point of view. I welcome the committee's consideration of this issue because, amongst other things, some of the bodies who do the best work in this area—Wetlands International and BirdLife Australia—have written to me in my capacity as chair of the Joint Standing Committee on Treaties pointing out that we are experiencing these declines in migratory birds as a result of the reclamation of land in South Korea and the Yellow Sea and so on. They are seeking that the Treaties Committee become involved in this issue. Much as I would like the Treaties Committee to be involved in this issue, to date our workload commitments have prevented us from getting involved in this issue in the way that I would like. So I am very pleased to note that the standing committee on climate change does intend to do further work in this area.

There is no doubt that it is a serious problem. Something like 45 per cent of the world's population lives in the geographic area covered by the East Asian-Australasian flyway. This has given rise to escalating pressure and adverse impacts on the migratory waterbirds. There are 17 species listed as in decline and five species listed as threatened. The loss and declining condition of habitat is a consequence of impacts from pollution; increasing expansion of industrial and port facility development; oil production; agriculture; agriculture and fishing operations; urban growth; and direct competition between people and birds for the tidal flat marine resources. All those things are factors contributing to the disturbing trend of waterbird population decline.

As these bodies have pointed out, economic development pressure in many flyway countries does not take into account biodiversity considerations or the importance of conservation of priority habitat for a wide variety of species. So I welcome the indications from the committee on climate change that it intends to do more work in this area, and I look forward to its further report. I commend the current report to the House.

Debate adjourned.

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