Medlow Dam is a heritage-listed major gated concrete-walled arch dam across the Adams Creek in the Blue Mountains region, located at Beauchamp Road, Medlow Bath in the City of Blue Mountains local government area of New South Wales, Australia. The dam was designed and built in 1907 by the NSW Department of Public Works. The dam's purpose is primarily for the potable water supply of the upper Blue Mountains region. The impounded reservoir is called Medlow Bath Reservoir. The dam is also known as Medlow Bath Dam, Lake Medlow Dam, Adams Creek Dam and Medlow Bath Reservoir. The property is owned by Sydney Water, a state-owned corporation of the Government of New South Wales. The dam was added to the New South Wales State Heritage Register on 18 November 1999. History Medlow Dam is a thin-wall arch concrete dam constructed by the Public Works Department of NSW in 1907, for water supply to nearby townships and possibly also for ornamental purposes. Control was vested in Municipality of Blackheath in 1940, then transferred to the MWS&DB; in 1980. Water supply was first furnished to Medlow Bath in 1907 and subsequently extended to Blackheath, Megalong and Mount Victoria. Medlow Dam is one of the series of so-called "Wade Dams", constructed in the late years of the nineteenth century and the early years of the twentieth century by the NSW Public Works Department under the supervision and/or design of Mr L. A. B. Wade, for water supply to country towns. They were remarkable in pioneering the general use of thin-arch concrete walls under high stresses. It is claimed that this dam, when constructed, was the thinnest of its type in the world and the basic design attracted grave misgivings in the engineering world. Both this dam and a similar example at Lithgow are recognised in the standard engineering work "A History of Dams" as world leaders in dam design and construction and they excite continuing engineering interest for the thinness of their wall section. It is stated in the 1909 Institution of Civil Engineers paper that Mr C. W. Darley, Engineer in Chief of Public Works, was responsible for initiating the construction of this type of dam in Australia and for the completion of the earlier structures. The paper's author (L. A. B. Wade) acted under Mr Darley as Supervisor of Works and subsequently succeeding to the latter's position, was responsible for the