the mid 1980s, consisting of the insertion of a plastic liner in the flume. The arches are in a stable condition. Description A series of slender reinforced concrete arches supporting the reinforced concrete sewage carrier seated on substantial mass concrete piers situated across Hogan Park through which the stormwater channel of Johnstons Creek is situated. The western terminus of the aqueduct is the western side of Nelson Street (which the aqueduct crosses), where there is a concrete retaining wall and public stairs. The aqueduct then crosses the shallow valley of Johnstons Creek continuing to the eastern terminus near Taylor Street. The aqueduct is a prominent feature within Hogan Park. There is a mature fig street situated close to one of the main central spans, its canopy encroaching over the sewer carrier. Heritage listing The Johnstons Creek sewage aqueduct was completed in 1897 and is a major and visibly strong component of the Northern Main Sewer extension of the Bondi Ocean Outfall Sewer. The aqueduct arches and carrier are one of the first major constructions undertaken using reinforced concrete in NSW and one of the first in Australia. The slender proportions of the supporting arches and sewage carrier along with its historic technological value are a major landmark for Sydney. The aqueduct is a major element of the historic built environment of the local area, and a long held part of the recreational reserve . The significant elements are its location within a park setting, technology of construction and past and ongoing use. Johnston's Creek Sewer Aqueduct was listed on the New South Wales State Heritage Register on 18 November 1999 having satisfied the following criteria. The place is important in demonstrating the course, or pattern, of cultural or natural history in New South Wales. The aqueduct is particularly associated with the engineer W. J. Baltzer, and the firm Carter Gummow & Co. early advocates of the use of reinforced concrete (the Monier system) in this country, of which this is one. The Johnstons Creek sewage aqueduct is a major and highly visible component of the Northern Main Sewer extension of the Bondi Ocean Outfall Sewer completed in 1897. The extension provided for the sewerage of the areas of densely populated inner-western suburbs of Balmain, Annandale and Glebe. The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales. The sewage