Johnston's Creek Sewer Aqueduct

Johnston's Creek Sewer Aqueduct is a concrete structure with eight large arches spanning across the valley in Annandale. It carries wastewater from western Sydney suburbs through its passage to the coastal outfall system.

William Julius Baltzer designed this component of the Northern Main Sewer expansion, built by the Public Works Department in 1897. The project was part of efforts to serve Sydney's growing population with proper sewage systems.

The structure shows engineering techniques from the late 1800s and ranks among Australia's first major reinforced concrete buildings. It represents a period when infrastructure transformed cities and shaped how they functioned.

The aqueduct is visible from outside and can be viewed from different points around the valley. The best access is from footpaths near the valley where you can see the structure from various angles.

A large fig tree grows near one of the middle arches, creating an unexpected blend between industrial structure and nature. This natural element gives the facility a different appearance than typical sewerage infrastructure.