In 1935–1936, the southern system of supply mains needed major adjustment to use water from the Pressure Tunnel, including an offtake to Petersham Reservoir.

The curtilage includes the covered reservoir, the brick wall, WSO cottage, valve houses and gates.

[1] Petersham Service Reservoir was listed on the New South Wales State Heritage Register on 18 November 1999 having satisfied the following criteria.

[1] The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales.

Architectural detailing (polychrome brick walling and location of valve houses on either side of gate) demonstrates excellence in design, fitting in with the surrounding streetscape.

[1] The place has potential to yield information that will contribute to an understanding of the cultural or natural history of New South Wales.

All covered reservoirs are highly significant within the SWC system, since all differ in construction technology, design and architectural detailing.

[1] The place possesses uncommon, rare or endangered aspects of the cultural or natural history of New South Wales.

One of a small group of large covered reservoirs in brick or concrete, each demonstrating differences in construction, design and architectural detailing.

[1] This Wikipedia article was originally based on Petersham Service Reservoir & Site, entry number 01331 in the New South Wales State Heritage Register published by the State of New South Wales (Department of Planning and Environment) 2018 under CC-BY 4.0 licence, accessed on 2 June 2018.