FAQ

Sydney Water is working with the Department of Planning and Environment and local councils on acquisition planning and time frames for Aerotropolis stormwater. We will have more information to share with landowners in early 2024. For more information on acquisition please visit https://www.nsw.gov.au/housing-and-property/property-acquisition

Stormwater infrastructure helps control rainwater runoff from urban areas. This is because these areas include many hard surfaces such as roofs and roads and rain events generate large volumes of polluted, fast-moving water.  

In the past, this was achieved via concrete channels and pipes. However, this approach is very destructive to the ecology of creeks and waterways downstream. The stormwater infrastructure planned for the Aerotropolis includes natural channels and creeks to convey stormwater, and wetlands to collect, treat and store surplus water to protect downstream ecosystems. This allows the water to be sustainably harvested to be used in surrounding urban areas. 

Parts of the stormwater drainage system in the Aerotropolis are considered to be trunk drainage when the catchments being drained are 15 hectares or greater. This threshold is related to the overall volume of water that drainage infrastructure will need to convey. 

In the Parkland City, trunk drainage will be delivered via naturalised open channels or creek lines. The use of natural drainage features, instead of buried concrete pipes or drains ensures the safe conveyance of flood flows, protects creeks and waterways, recognises Country, and contributes to the overall amenity of the precinct.  

The trunk drainage system also includes stormwater treatment wetlands where water will be treated, harvested and available to be re-used as recycled water.  

It will then be distributed to adjacent urban areas with other recycled water. This is essential to meet the requirements of the NSW Government waterway health targets for the Wianamatta South Creek Catchment. 

The Aerotropolis integrated water system will be the largest stormwater harvesting scheme in Australia.  

Stormwater infrastructure in the Western Parkland City will be focused on maintaining the layout and appearance of natural creek lines. It will be designed to complement the natural environment and provide thriving and liveable spaces for our new communities to enjoy. It includes: 

• Regional Wetlands 

Constructed wetlands will collect, treat and store stormwater which can be used for non-drinking purposes through the regional recycled water network. The wetlands will have a natural look using native plants to blend into the landscape and include shallow marshes and deeper pools. Public access, including cycle paths and viewing areas, may also be built to integrate the wetlands with surrounding open spaces. 

• Creeks or Naturalised Drainage Channels  

Creeks and naturalised drainage channels will take stormwater from roads and developed areas and carry it to larger waterways downstream. The creeks and channels will vary in size depending on where they are in the catchment. They’ll have very little flow during dry weather but will be able to accommodate higher flows in storm and rain events. Natural creeks will support the local ecology providing an attractive environment for wildlife and native plants will be used in and around the creeks to create cool, green areas. 

• Adjacent Stormwater Land 

State Environmental Planning Policy (Precincts – Western Parkland City) 2021 also identifies additional open spaces which are adjacent to the core stormwater infrastructure including the riparian corridor and some land that has high biodiversity value vegetation, Aboriginal heritage sensitivity and heritage-value lands. 

The stormwater infrastructure will be distributed along natural drainage lines to achieve the waterway health targets with a minimal footprint. Most assets will be located close to existing creek lines, and some will be distributed across low-lying areas throughout the precincts, sometimes where there are existing farm dams.  

The nature of the Aerotropolis is a unique opportunity to evolve the way we manage and reuse stormwater to help improve resilience, waterway health and improve liveability for our communities. It also needs to be part of an integrated water system to meet waterway health targets set by the NSW Government. Sydney Water has determined the most efficient way to do this is through the establishment of regional wetlands which are integrated with the recycled water networks via a centralised recycled water reservoir. 

Regional wetlands were sized to be able to service the amount of stormwater that they will receive from their local sub-catchment. They are located on suitable land which avoids constraints, such as valuable bushland, and are in locations which minimise their impact on development.  

The key benefits of this strategy are the consolidation of stormwater infrastructure in centralised locations, integration with the future road network, and the co-location of wetlands and creek lines with open space to create multi-functional areas.  

The alternative is putting stormwater infrastructure within development sites which would be more expensive and significantly impact upon otherwise developable land. 

The stormwater infrastructure has been identified as part of the long-term strategy for the Aerotropolis and will be provided as development occurs across the precincts over the next 10-20 years and beyond. It is expected that all open space will be delivered by 2056 in a staggered approach which aligns to the predicted completion of the precincts. The stormwater infrastructure will be delivered gradually to minimise and manage the impacts of development as it occurs in the Aerotropolis.  

Sydney Water will be Trunk Drainage Authority for the initial precincts within the Aerotropolis (including Mamre Road). The local councils, Liverpool City and Penrith City will continue to manage localised stormwater in roads and streets and for catchment areas less than 15ha in size.  

Sydney Water has already developed the high-level plans for the precincts’ integrated water systems which are available with the Precinct Plans. Sydney Water is now progressing the first Stormwater Catchment Scheme Plan and the supporting Business Case for the Mamre Road Precinct. This will detail the infrastructure to be built as the precinct develops.  

Sydney Water is continuing consultation with DPE and WPCA on the process for acquisition. The stormwater schemes are still in the planning phase so it will be some time before there are construction activities or acquisitions.