Commenced in 1943, completed over two stages in 1959, and upgraded in 1996, the Oberon Dam is a major dam on the Fish River (formerly, Fish River Creek), located approximately upstream, south-east of Oberon. The dam was built by the NSW Department of Public Works on behalf of the New South Wales Department of Land and Water Conservation. The original intent of the works was to supply water to the National Oil Proprietary Ltd's refinery at Glen Davis in the western coal fields, factories at Lithgow, and supporting populations. Water from Oberon Dam feeds the Fish River Water Supply, which is a unique regional water supply scheme and is the only scheme in eastern Australia to transfer western flowing water to areas east of the Great Dividing Range.