Finalising the concept design

Following topographical and geological investigations and working closely with the community, the solution design to divert the last three untreated wastewater coastal outfalls in Sydney is nearing completion.

Given the limited open space, geology, as well as the highly sensitive heritage, coastal and harbour iconic locations, the main challenge was always to find suitable sites to locate two underground pumping stations.

In determining those sites, we listened to our Community Reference Group (made up of local residents as well as representatives of Woollahra and Waverley Councils) to minimise possible construction and environmental impacts, while designing solutions that enhance our amenity at sites where work needs to be done.

Almost all the new infrastructure will be located below ground. Anything above ground, such as valves or electrical kiosks, will be minimal and designed to blend as much as possible with the existing environment.

New wastewater pipes, ranging between 20cm to 37.5cm in diameter, will be laid using trenchless technology up to 80m below ground, so there will be minimal construction impacts during or after construction. There will be some short sections of open trench work on the road verges where we connect to the existing network.

Sydney Water will continue to work with the community, as well as local councils to refine design aspects. The final solution design will be displayed in March 2020, when we seek formal submissions from the public as part of the environmental approval process. Construction is expected to occur in the second half of 2020. Click here to view or print the concept design map.