Ogston Reservoir is a reservoir operated by Severn Trent Water in Derbyshire. It is near the villages of Brackenfield, Ashover and Clay Cross. The reservoir takes its water from the River Amber and was originally created to supply the National Coal Board's Carbonisation Plant at Wingerworth; the reservoir now supplies water for the local area and is used as a holding ground for water for nearby Carsington Reservoir. The reservoir covers 200 acres (800,000 m2) and holds 1.3 billion imperial gallons (5.9 billion litres) of water.