Prospect Reservoir

Shortly after 1808, William Lawson was appointed aide-de-camp to George Johnston and was granted at Prospect. He built a large house there in the 1820s, which he named Veteran Hall. He died on the property on 16 June 1850 and the property was eventually acquired by the Metropolitan Water Board. The house was demolished in 1929 and most of the low lying surrounding property is submerged. In 1867, the Governor of NSW appointed a Commission to recommend a scheme for Sydney's water supply, and by 1869 it was recommended that construction commence on the Upper Nepean Scheme. This consisted of two diversion weirs, located at Pheasant's Nest and Broughton's Pass, in the Upper Nepean River catchment, with water feeding into a series of tunnels, canals and aqueducts known as the Upper Canal. It was intended that water be fed by gravity from the catchment into a reservoir at Prospect. This scheme was to be Sydney's fourth water supply system, following the Tank Stream, Busby's Bore and the Botany (Lachlan) Swamps. Between 1893 and 1916, extensive remedial works were carried out in order to correct slumps in the upstream face. == Description ==

With the completion of the main storage dams, the reservoir's function has changed from largely being a storage apparatus to the main service reservoir and sedimentation basin for the metropolitan system. Prospect is an earth dam 2210 metres long and consists essentially of a puddle clay core with shoulders of selected earth placed in layers 300mm thick. During construction these were compacted by rolling. It was completed in 1888, and in 1898 the crest level was raised by 0.5 metres. ==Continuing use==

Since the Prospect Water Filtration Plant was completed in 1996, untreated water is generally not drawn from Prospect reservoir any more. Instead, the water is piped to the filtration plant directly from Warragamba Dam. The reservoir remains a part of Sydney Water's storage network, however it is anticipated that it will only be utilised for water supply purposes on average of five days in any five-year period. As the site attracts up to half a million visitors annually, recreational use of the site is carefully managed to ensure the water remains suitable for supplementing Sydney Water's requirements. Recreational use The reservoir has a large recreational area on its eastern side with a number of park precincts that feature picnic spots, lookouts and BBQs. The reserve is accessed by William Lawson Drive from Reservoir Road, which can be entered from Western Motorway to the north or Prospect Highway to the southeast. The Prospect Reservoir is open to public during the week and weekends (but not on public holidays) from 6:00 AM to 6:30 PM during daylight saving time and from 7:00 AM to 4:30 PM during non daylight saving time. == Heritage listing ==

Prospect Reservoir is historically significant at the state level as it is a central element of the Sydney water supply system. As a part of the Upper Nepean Scheme, the Reservoir has continued to supply water to Sydney for over 120 years, and generally still operates in the same way as it was originally constructed. That it has continued to be used since its construction reflects the inventive and progressive way in which the reservoir was designed and built, and this contributes to its significance greatly. The Reservoir reflects three significant changes in municipal life during the late 19th century; the development of water and general public utility services; the importance of ensuring an adequate and dependable centralised water supply; and the collective bureaucratic response to the delivery of capital works of this nature. Built between 1882 and 1888, it was an outstanding achievement in civil engineering technology at the time, using innovative design and construction methods. It has a high level of historical engineering significance. Prospect Reservoir is strongly associated with the Harbours and Rivers Branch of the NSW Public Works Department, particularly Edward Orpen Moriarty, Head of the branch at the time of the Reservoir's construction, and later with the Board of Water Supply and Sewerage (later the Metropolitan Water and Sewerage Board) and most recently, with the Sydney Catchment Authority. The Reservoir area is aesthetically significant, as a picturesque site with a large expanse of water, parklands, landscaping and bush. The place is valuable for its recreational amenity for passive recreation, punctuating the monotony of the surrounding urban landscape. It has been used for recreation by the community for generations. It continues to regulate the release of water from Prospect Reservoir to the Lower Canal and the Sydney Distribution system. The place also contains examples of functional colonial architecture. The listing includes Prospect Reservoir, landscape elements and all associated structures, including pumping stations, to the property boundary. The environs of the reservoir and hence this listing also include a wide range of items, which relate to later amplification of water supply. These include examples of 1920s and 30s pumping stations, a residence, and the main, constructed between the Upper Canal and Pipe Head in 1937. Later items associated with the Warragamba Supply Scheme and more modern developments include several more recent pumping stations, screening and boosting plants on the eastern and southern sides of the Reservoir, and the water main from Prospect, to Pipe Head, completed in 1958. Prospect Reservoir and surrounding area was listed on the New South Wales State Heritage Register on 18 November 1999 having satisfied the following criteria. The place possesses uncommon, rare or endangered aspects of the cultural or natural history of New South Wales. This item is assessed as historically rare state-wide. This item is assessed as scientifically rare state-wide. The place is important in demonstrating the principal characteristics of a class of cultural or natural places/environments in New South Wales. This item is assessed as aesthetically representative locally. == Engineering heritage award ==

The dam received a Historic Engineering Marker from Engineers Australia as part of its Engineering Heritage Recognition Program. ==See also==