New South Wales Sites
Sydney
Olympic Park, Homebush Bay, Sydney
article published Landscape Australia no 22 (3- 2000)
by Maria Rigoli
Denton Corker Marshall, Sydney, were commissioned by the OCA to develop the design of the Haslams Creek Precinct a partial development of the Millennium Parklands concept design prepared by Hassell.
significant portion of the Precinct had already been designed and constructed, therefore the brief was to assess strategies to bring together disparate parts through the use of connecting path systems and planting strategies. The brief also required the design and documentation of the redevelopment of the former archery site (now known as the Village Green) and a path to link the Hill Road carpark with the Sydney International Archery Park.
Haslams Creek Precinct
Haslams Creek, which is the focus of the precinct, is an important and sensitive mangrove habitat. It is a remediated creek-transformed from a concrete-lined stormwater channel to a 'natural' mangrove habitat.
Frog Habitat
A number of constructed frog ponds have been created in the vicinity of Haslams Creek under the guidance of the Australian Museum and OCA Environment Branch, to encourage the establishment of the endangered Green and Golden Bell Frog (Litoriu aurca) population. Some of these ponds have been more successful than others in becoming active habitats for the frogs. The movement of frogs around the site has been controlled by a network of specially designed frog-exclusion fences, so that frogs are not accidentally injured by construction works and equipment or on roads. Fences are likely to remain in place until all construction works have been completed.
The Village Green, which is hounded by Haslams Creek and the Eastern Water Quality Control Pond to the north and west, Bennelong Road to the east, and Marjorie Jackson Parkway to the south, is adjacent to the most successful frog ponds in the Haslams Creek Precinct. These ponds, to the east of the horse trail, were constructed as a series of three stormwater detention basins, part of earlier construction works in the area to collect sediment and nutrients before slowly releasing the water into Homebush Bay. The ponds then became one of the most successful habitats for the Green and Golden Bell Frog in the Homebush Bay area.
Redevelopment Issues
The original concept design for the redevelopment of the former archery site (Village Green) indicated the retention of the existing horse trail, which was to form the perimeter to the Village Green and one of the Millennium Markers. Although the brief and design appeared to be relatively straightforward at the commencement of the project, a number of complex issues evolved as the project progressed.
The Village Green is located over a former small brick pit, which had been filled over time. During the development of the Homebush Bay site, the movement of fill material was a major issue. As the earthworks on major construction projects were nearing completion, areas for the disposal of fill material on-site became scarce. The Village Green became a storage area for excess fill and a temporary storage site for fill while remediation works were being carried out on other sites.
Consequently, the Village Green site had some 15 000 cubic metres of fill material that had not been accounted for in the concept design or the design development phase. The cost of moving the material off-site was prohibitive. To accommodate the fill on-site, it was accepted that the level of the proposed Village Green would have to be raised relative to the existing horse trail. This provided opportunities for EDAW to design the Millennium Marker-Old Archery Marker-from a level plane, and for DCM to adjust some of the grades of the horse trail to minimise erosion, which occurred in the steeper sections.
However, the re-grading exercise was not straightforward. There were tight site constraints. To accommodate some of the excess fill material, the Millennium Marker had to grow in size. Its location was fixed between the frog ponds to the east and Haslams Creek to the west. The area remaining at the base of the Marker was restricted. This area had to accommodate the four-metre wide, decomposed granitic gravel horse trail and an additional cycleway that was to be constructed adjacent to the horse trail. Any changes in levels had to be accommodated within this zone, without disturbing the levels and vegetation around the frog ponds or along the creek banks.
Design Solutions
The solution was to construct a boardwalk that would become part of the cycleway and would conceal the retaining wall required to support the raised horse trail, while maintaining the existing levels along the creek and beside the frog ponds. This boardwalk has provided an opportunity to control access to the frog ponds and the creek and to provide a vantage point to view the established areas.
The second major addition to the design was the requirement to incorporate sediment ponds. Two sediment ponds have been constructed between the Millennium Marker and the playing fields to collect water from run-off and the sub-soil drainage.
These ponds are planted with macrophytes to collect sediment and nutrients from the water before slowly discharging into the frog ponds and Haslams Creek. Over time, it is expected that these ponds may become frog habitats.
Although the initial constraints of the site seemed unworkable, the end result is a pleasant environment that protects the sensitive habitats while providing a facility to suit all users.
Client
Olympic Co-ordination Authority
Landscape Architect: Denton Corker Marshall Pty Ltd
Civil & Hydraulic Engineer: Maunsell McIntyre (Canberra)
Masterplan: HASSELL
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- Sediment pond that drains to Haslams Creek (Photo courtesy: Denton Corker Marshall).
- Boardwalk and horse trail between Old Archery Marker and Haslams Creek (Photo courtesy: Denton Corker Marshall).
- Village Green Plan, Haslams Creek Precinct (Plan courtesy: Denton Corker Marshall).
