The raising of the dam in 1898 using a concrete arch on its crest, was part of a program of thin arch dam construction in NSW by the Public Works Department which attracted international attention because of its reliance on the cylinder formula. The high quality of the design and construction is demonstrated by its ability to meet modern safety standards after 140 years of service. The place has strong or special association with a particular community or cultural group in New South Wales for social, cultural or spiritual reasons. The Institution of Engineers has declared Lake Parramatta Dam a National Engineering Landmark. The completion of Lake Parramatta Dam in 1856 was an important event for those living in the Parramatta district. The previous water source, the Town Dam on the Parramatta River, was polluted, unreliable and unhygienic, whereas the new source supplied pure and wholesome water, and its storage enabled the supply to continue through the drought years. The breakthrough came when the citizens finally persuaded the government to fund the cost. Twenty-five years later a pump house and reticulation system brought the water from the dam to the streets of Parramatta. The dam is now a central feature of Lake Parramatta Reserve park which is visited regularly by tourists and picnickers. The birdlife (mainly waterfowl) and native fauna around the dam and fish in the lake are pleasant distractions from the otherwise drab suburbia of western Sydney. A nature trail follows the perimeter of part of the storage. The Reserve forms an attractive recreation area in the Parramatta district. The amenities include a small beach, barbecues, picnic areas, car parking facilities, a kiosk, and children's playgrounds. The most popular activity is bushwalking, and there is also an orienteering track within the Reserve. Following on representations made by the Wild Life Preservation Society of Australia, the Parramatta Council in 1958 adopted the bushland area and the maintenance and development of the recreation area as one of its objectives. The Council also applied to the Fauna Protection Panel to have the area proclaimed a Complete Sanctuary and it became the first wildlife refuge in the Sydney area. The place possesses uncommon, rare or endangered aspects of the cultural or natural history of New South Wales. Lake Parramatta Dam is a rarity. It is the only masonry arch dam in Australia. It was the first large dam, one year ahead of