Chichester Dam
Chichester Dam is a minor concrete gravity dam across the Chichester and Wangat rivers, upstream of Dungog, [New South Wales|Dungog], in the Hunter Region of New South Wales, Australia. The dam's main purpose is water supply for the Lower Hunter region. A mini hydro-electric power station operates at times of peak flow and is connected to the national grid. The impounded reservoir is Lake Chichester.
Location and features
The dam wall is high, long, and was constructed using a cyclopean system of interlocking concrete blocks and large boulders with a volume of. The wall is anchored to the bedrock below it by 93 stressed tendons. At 100% capacity the dam wall holds back of water at Australian Height Datum. The spillway is capable of discharging. The surface area of the reservoir is and the catchment area, largely located within the Barrington Tops National Park, is. The dam is connected to reservoirs in Maitland, Cessnock and Newcastle by an gravitation main.History
Land for the water supply scheme was appropriated in the Gazette of 6 October 1916. To safeguard the purity of the water the populated part of the Wangat Valley, including the old goldmining town of Wangat, and the greater portion of the populated part of the Chichester Valley were resumed. The Act appropriated £A as the estimated cost of construction of the dam, with additional funds set aside for land resumption.In 1965 the spillway was lowered by to increase flood capacity. In 1985 the dam was post tensioned with cables and the spillway was relocated to the centre of the dam and returned to its original height. In 1995 the seepage potential was reduced under the northern abutment and in 2003 an improved drainage system for the dam's foundations was installed and the left parapet wall was raised to prevent overtopping in a major flood.