Inginiyagala Power Station

The Inginiyagala Hydro Power Station, a part of the Gal Oya Multipurpose Project from the 1950s, with an 11.25MW capacity, is the second major hydro power station built in Sri Lanka. Its reservoir, Senanayake Samudraya, created by the strategic damming of the Galoya River, serves a multitude of vital functions, including irrigation, flood control, drinking water supply, and hydroelectric power generation. Nestled in the Madulla Division of the Moneragala District, this project features four Francis type turbines, developed in two distinct phases. Phase I saw the commissioning of Units 1 & 2 in 1952, while Phase II added Units 3 & 4 in 1962.

Senanayake Samudraya, holding an impressive 949.7 million cubic meters (770,000 acre-feet) of water, proudly claims the title of Sri Lanka’s largest reservoir. Its catchment area spans 384 square miles, encompassing an earth dam stretching 3600 feet in length and standing 140 feet tall, comprising 2 million cubic yards of soil. With a net head of 89 feet, the Inginiyagala station anticipates an annual energy output of around 28GWh. Additionally, downstream waters from the station contribute to the irrigation of approximately 120,000 acres of paddy fields. Each turbine possesses the capacity to release around 350-400 cusecs, while two additional valves cater to irrigation needs by bypassing the turbines.
The Sluice tower, connecting to the power house, is linked by a 13-foot diameter underground tunnel spanning 750 feet in length. While the reservoir is owned by the Irrigation Department, water management falls under their jurisdiction, with the Ceylon Electricity Board responsible for the operation and maintenance of the dam and spillways.

• Installed capacity :  11.25 MW
• Expected annual average energy : 28 GWh
• Commissioned in 1952
• Main contractors
  • Civil – International Engineering Co, Inc.
  • Electromechanical – General Electric/Westing House
  • Hydro mechanical – Dominion Engineering
• Located 22 km From Ampara Town
• Reservoir
  •  Catchment area : 994 km2
  • Usable water volume : 844.9 MCM
  • Maximum level : 260 feet above MSL
  • Minimum level : 150 feet above MSL
• Penstock
  • Steel circular, 13 ft diameter,783 feet length, With surge tank (Height-120ft)
• Tailrace
  • Length : 720 feet ; Maximum level : 150 feet above MSL; Minimum level : 140.5 feet
    above MSL
• Generator 1 & 2 (General Electric)
  • Conventional vertical
  • 2750 kVA, 0.8 PF, 6.9 kV, 230 A
  • 50 Hz, 18 poles, 333 1/3 rev/min
  • Exciter : 125 V, 245 A
• Generator 3 & 4 (Westing House)
• Conventional vertical
• 3500 kVA, 0.8 PF, 6.9 kV, 292 A
• 50 Hz, 18 poles, 333 1/3 rev/min
• Turbine (Dominion Engineering)
  • Vertical Francis
  • Output : 3300 Horse Power @ 89 Feet, Rated discharge :  400 ft3/sec
  • 333 1/3 rev/min