Lostock Dam is a minor rockfill 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, Australia.

The dam's purpose includes flood mitigation, irrigation, water supply and conservation.

At that time there was a need for a water conservation storage in the Paterson Valley to stabilise and further develop rural productivity.

The ungated concrete lined, flip bucket chute spillway is capable of discharging 2,860 cubic metres per second (101,000 cu ft/s).

[4] A mini hydro-electric power station generates up to 2.2 megawatts (3,000 hp) of electricity from the flow of the water leaving Lostock Dam.