Melbourne's Yan Yean Dam. (Strictly speaking, large dams are over 15m high above lowest foundation level, which Lake Parramatta Dam became in 1898, after a 3.3m raising). It was the first arch dam and 40 years passed before the next arch dam was built (Lithgow Dam, 1896). While Lake Parramatta Dam is the only masonry arch dam in Australia, it is a cylindrical arch dam of which many more were built, but in concrete and several decades later (13 in NSW and one in SA). Consequently, Lake Parramatta Dam cannot be compared with any similar dams in Australia. As such it set a valuable design precedent. The place is important in demonstrating the principal characteristics of a class of cultural or natural places/environments in New South Wales. The dam is a fine example of its type. Its thin section and appropriate curvature provided Parramatta with an economical dam. The original stone work is clearly visible from the downstream side and remains in good condition. The dam demonstrates the application of the stonemason's craft to a water-retaining structure of some magnitude. The choice of Roman cement mortar bonding between the stones has proved to be an inspired choice, having withstood 140 years of use with a minimum of leakage or deterioration. The essential character of the dam was retained when the raising was carried out in 1898. Although concrete was the chosen material, it was sympathetically applied. The arch form was maintained, the stones courses were simulated and the original stonework remained in full view, reminiscent of Fort Denison in Sydney Harbour. Considering its age, the condition of Lake Parramatta Dam is very good. The integrity of the original sandstone masonry blocks is excellent, with no significant signs of weathering or spalling. Likewise the condition of the mortar is also very good with only minor leakage emanating in various locations. Gallery See also Chipping Norton Lake Prospect Reservoir Bents Basin Geography of Sydney References Bibliography Attribution External links [CC-By-SA] 35 year ban on swimming in Lake Parramatta ends on 3 December from Parramatta City Council website news release 22 November 2006. Retrieved 09 Feb 2007. Includes a 2003 report to Council on public safety risks at Lake Parramatta. Geography of Sydney North Parramatta, New South Wales Parramatta Parramatta 1856 establishments in Australia Urban forests Parks in New South Wales Parks in Sydney Nature reserves in New South Wales Forests of New