[2] The Metropolitan Water, Sewerage and Drainage Board's first office, occupied in April 1888, was at Circular Quay, close to the present Overseas Passenger Terminal.

Additional land and buildings at the rear of the office were acquired in 1929 and 1936, and that part of Stewart Lane separating the Board's property was resumed, thus providing a block approximately 160-ft. square.

Howie Moffat & Co. were the builders, and sculptor Stanley Hammond was responsible for the prominent bas relief over the Pitt Street entrance.

Bas relief panels are strategically placed above the entrance in Pitt Street which depict the water industry and its progression of technology.

[2] Internally, in the entrance foyer marble and travertine surfaces are located on the floors and walls, and late 20th Century suspended ceilings have been fitted.

[2] On the ground floor, a number of original surface finishes remain behind superficial fitout including highly significant scagliola clad columns.

[2] Alterations include new fire door installations in the southern ground floor facade, and evidence of some louvres and air conditioning systems fitted to windows.

The building in its aesthetic, historic and scientific (technical/research) qualities is an outstanding example of architectural growth and development for its values which are reflected in its original design, materials, construction techniques, evidence of use, movable relics and siting within the City of Sydney.

[2] Sydney Water Head Office was listed on the New South Wales State Heritage Register on 15 November 2002 having satisfied the following criteria.

), the completion, quality of finishes and successful operation of the building is a testament to the initiative and vision of these elected and appointed board members.

The building accommodated the corporation's technical staff which have been responsible for the design, construction and ongoing maintenance of metropolitan Sydney's water and sewerage infrastructure.

[2] Through its remnant fabric, the place retains tangible evidence of the influences and conflict of Government administration of the day, given the major need in supply and management of Sydney's water, sewerage and drainage, at the time of its construction.

The size of the building reflects the demand for increased staff and responsibility levels during that part of Sydney's expansion and development.

The continuing use of the buildings by a government authority demonstrates the practice of centralising head offices in purpose built accommodation within the Sydney central business district.

The longevity of uninterrupted operations (over 110 years) by the Sydney Water Corporation and its predecessors at the Pitt Street site is now unique in New South Wales in regard to a large Government authority.

It has a relatively high state of integrity, the building's fabric continuing to provide an excellent example for the study of the development of modern Australian architecture.

The building is recognised by the Heritage Council of NSW as significant to New South Wales in relation to its historical, scientific, cultural, social, archaeological, natural and aesthetic values.

Given the strong sense of identity of former and present employees and management with the corporation and its predecessors, the building is likely to be held in some regard by these members of the community.

The building is recognised on the Register of the National Estate as a place which is a component of the cultural environment of Australia, that has aesthetic, historic, scientific and social significance for future generations, as well as for the present community.