Lostock Dam is a minor rock fill and clay core embankment dam with a concrete-lined, flip bucket spillway across the Paterson River upstream of the village of East Gresford in the Hunter region of New South Wales. The dam's purpose includes flood mitigation, irrigation, water supply and conservation. Mini hydro-power facilities were retrofitted in 2010.
Commenced in 1969 and completed in 1971, Lostock Dam is a minor dam on the Paterson River, a tributary of the Hunter River, and is located approximately 65 kilometres from both Maitland and Singleton, also 93 kilometres north-west of Newcastle, on the upper reaches of the river.
The dam was built by Dumez Australia under contract to the New South Wales Water Department of Land and Water Conservation following the drought of 1964 to 1966. At that time there was a need for a water conservation storage in Paterson Valley to stabilise and further develop rural productivity. Walk or drive across the dam wall for views of the lake and rolling countryside. The wall is 38 metres high and 701 metres long.
Lostock Dam is a popular inland sport and recreation dam.