Castlereigh Dam
Location of Castlereigh Dam in Sri Lanka
Country	Sri Lanka
Location	Hatton, Central Province
Coordinates	06°52′24″N 80°33′59″E / 6.87333°N 80.56639°E / 6.87333; 80.56639
Purpose	Power
Status	Operational
Opening date	January 1965
Owner(s)	CEB
Dam and spillways
Type of dam	Gravity dam
Impounds	Kehelgamu Oya
Wimalasurendra Power Station
Coordinates	06°54′31″N 80°31′30″E / 6.90861°N 80.52500°E / 6.90861; 80.52500
Turbines	2 × 25 MW
Installed capacity	50 MW

The Castlereigh Dam (also spelled Castlereagh) is a gravity dam built across the Kehelgamu Oya, a major tributary to the Kelani River, approximately 3 km (1.9 mi) south-west of Hatton, in the Central Province of Sri Lanka.^[1]

Reservoir and power station

The dam creates the iconic Castlereigh Reservoir, which is almost entirely maintained by the inflow of water from the Kehalgamu Oya. Water from the reservoir is diverted to the Wimalasurendra Power Station, located approximately 12 km (7.5 mi) downstream at 06°54′31″N 80°31′30″E / 6.90861°N 80.52500°E / 6.90861; 80.52500 (Wimalasurendra Hydroelectric Power Station), near Norton Bridge. The power station discharges the water into the Norton Reservoir, created by the Norton Dam, located at the same site.^[1]

The power station consists of two 25-megawatt units, totalling the plant capacity to 50 MW. Both units were commissioned in January 1965.^[2]

Water airport

The Castlereigh Reservoir is also home to the Castlereigh Water Airport, registered under the IATA code NUF.^[3]