Water and catchments
A locally integrated approach to water conservation applies at the Park and incorporates stormwater harvesting and re-use, wastewater reprocessing and reducing water demand.
We seek to mitigate the detrimental local and downstream impacts on the environment from poor quality and/or excessive volume of stormwater flowing from developments during and after construction.
Our Stormwater Management and Water Sensitive Urban Design Policy specifies requirements for stormwater management from development sites. This policy:
- Promotes appropriate water sensitive urban design in development,
- Seeks to optimise local harvesting and on-site utilisation of stormwater, particularly from catchments that are not part of a centralised water harvesting system, and
- Requires proper management of stormwater from construction sites and appropriate management of stormwater discharge post-construction
Technical guidelines to assist in implementation of this policy are available.
|Stormwater Management and Water Sensitive Urban Design|
Stormwater runoff from the Park drains to the Parramatta River via Haslams Creek, Powells Creek, Boundary Creek, and the Park’s freshwater and estuarine wetlands. There are two different approaches to stormwater management within the urban areas of the Park:
- A whole-of-catchment approach has been built into the design of the northern catchments. This land was developed with a centralised and integrated stormwater management system designed to protect the receiving waters from development impacts. This system links management of potable water, rainwater harvesting, water recycling, irrigation water, building design, landscape plantings and aquatic habitats.
- The southern catchments are not within this centralised system, and retrofitting such a system is not possible due to topography and land availability constraints. Local stormwater management solutions that incorporate stormwater harvesting and reuse are required at individual development sites in the southern catchments to protect the Park’s wetlands and waterways.
Pollution-control devices including gross pollutant traps (GPTs), continuous deflective separation units (CDS units), bioswales and water quality control ponds have been installed throughout the Park to capture locally generated pollutants and protect local waterways.
However, the Park is situated at the lower end of highly-urbanised catchments and significant quantities of rubbish are carried into our creeks from upstream. Such rubbish can smother the Park’s endangered saltmarshes, pollute its mangrove forests, and pose a risk to wildlife that ingest or become entangled in it. We have installed stormwater litter booms and GPTs where these creeks enter the Park, and in 2015-16, intercepted and removed over 45 tonnes of rubbish carried into the Park from upstream.
The Park’s Water Reclamation and Management Scheme (WRAMS) commenced operation in 2000 and was Australia’s first large-scale urban water treatment scheme.
WRAMS recycles water from sewage and stormwater to supply irrigation, ornamental fountain and toilet flushing applications across Sydney Olympic Park and in the suburb of Newington. Office buildings, sporting and entertainment venues and Newington residences are all connected to this recycled water, which is supplied to customers through separate meters and at a lower cost than potable water supplied by Sydney Water.
WRAMS saves more than 850 million litres of potable water annually by avoiding its use for non-drinking purposes. In addition, the sewer-mining function of WRAMS treats approximately 550 million litres of sewage each year, which would otherwise be discharged to ocean outfalls.
Large water quality control ponds collect stormwater runoff from the pavements, roads and rooftops of the northern part of the Town Centre as part of a centralised stormwater management system. These ponds are planted with aquatic plants and are designed to collect the ‘first flush’ of stormwater – they allow sediments to settle and nutrients such as nitrogen and phosphorus to be removed. Harvested stormwater is then re-used for irrigation or for the production of recycled water. The ponds also provide important habitat for the endangered Green and Golden Bell Frog, and breeding habitat for a variety of waterbird species.
Stormwater runoff from the 14-hectare P5 carpark and from much of the suburb of Newington is collected into irrigation storage ponds in Narawang Wetland. From here it is used to fill the 22 wildlife habitat ponds within the wetland, and for irrigation of parkland landscapes and the Wilson Park playing field.
Reducing water demand
Less than 5% of all water used at Sydney Olympic Park is potable water –it is typically only used where recycled water or harvested stormwater cannot be used – such as for drinking water, showers and handbasins, and by the sports venues to top up swimming pools and to provide the correct surface moisture for hockey playing fields. Design and management practices which reduce water demand include:
- Widespread use of drought-tolerant native plants in landscape plantings across the Park. These plants are already adapted to the rainfall patterns of the area and have little need for irrigation once established.
- Irrigation of lawns and plantings is generally undertaken at night, when evaporation is low.
- Use of permeable paving and porous gravel in much of the Town Centre, to provide rainwater infiltration for street trees and to reduce the volume of stormwater runoff generated from hard surfaces.
- Sub-surface irrigation of the Wilson Park playing field, installed because it requires significantly less water than a surface irrigation system.