Mosman Bay Sewage Aqueduct, Sewerage aqueduct and pedestrian bridge in Mosman, New South Wales, Australia

The Mosman Bay Sewage Aqueduct is a steel arch structure spanning the bay that combines sewage pipes with a public pathway for pedestrians. The bridge was built with multiple curved supports to handle both functions while providing safe passage across the water.

The structure was built between 1899 and 1901 as part of a new sewage system serving Sydney's northern suburbs. Its construction solved the challenge of carrying waste over the water while allowing foot traffic to cross the same span.

The aqueduct is listed by the National Trust of Australia (NSW) and was added to the New South Wales State Heritage Register on 18 November 1999. It remains a pedestrian right-of-way through Reid Park, and its setting, including views from the arch, is part of its heritage value.

The footpath is open to the public and provides a direct route through the adjacent park area. The crossing is walkable most times, though occasional closures may occur due to maintenance work.

This structure is unusual because it serves as both a sewage transport system and a walkable bridge at the same time. Few other such structures in Sydney combine these two purposes in the same way.