Powerhouse, Main Dam and Spillway

Powerhouse

  • Length: approximately 120 m
  • Operating head (waterfall): about 22 m
  • Powerhouse upstream deck elevation: 235.5 m above sea level
  • Maximum height above structure’s foundation elevation:  57 m
  • Water passages: three intake structures, each with a set of vertical trashracks
  • Other installations: south transition structure and service bay
  • Service Bay / Intake / Powerhouse building envelope: precast wall panels, metal cladding and roofing.
Turbines and Generators
  • Generators: three
  • Output: 66 MW each, 200 MW total
  • Configuration: vertical shaft, fixed blade propeller turbine with a blade runner diameter of 6.7 m
  • Water passage configuration: semi-spiral scroll case in each unit distributes the water from the intake over the full circumference of the turbine
  • Turbine discharge: water passes through draft tube and into the tailrace.
  • Intake Guides, Gates, and Hoists:
    • Installation and “dry commissioning” completed June 2011
    • Headgate “wet commissioning” completed September 2012
  • Unit 1 inservice date: June 22, 2012
  • Unit 3 inservice date: August 22, 2012
  • Unit 2 inservice date: October 6, 2012.
Electrical and Mechanical Installations
  • Cable raceways, security systems and cabling for the communication system
  • The 600V distribution system and equipment
  • Heating, ventilating and air conditioning (HVAC)
  • Water treatment/wastewater treatment plant
  • Fire detection system
  • Roadway lighting, civil instrumentation and automatic security gate
  • Piping

Spillway 

  • Location: north of powerhouse
  • Construction: reinforced concrete
  • Length: 43 metres
  • Number of bays: 3
  • Vertical lift gates:  one in each bay measuring 9 metres wide by 16 metres high
  • Peak discharge capacity: about 2,700-cubic-metre per second (probable maximum flood rate)
  • Powerhouse and spillway interface: 42-metre-long reinforced concrete non-overflow gravity dam
  • Service functions: diversion channel during main dam construction; flood routing for the reservoir during operation.

Main Dam

  • Construction: earth and rock-fill embankment
  • Overall length: 330 metres
  • Maximum height above foundation level: approximately 14 metres
  • Crest width: 9 metres
  • Elevation: 236.6 metres above sea level.

Concrete Placement

Approximately 120,336 cubic metres of concrete were poured for all structures,
distributed as follows:

  • Spillway –11,150 cubic metres
  • Service Bay – 16,050 cubic metres
  • Intake – 29,000 cubic metres
  • Powerhouse – 34,200 cubic metres
  • Tailrace – 19,075 cubic metres
  • South Transition – 2,800 cubic metres
  • Miscellaneous Structures – 8,061 cubic metres.

Below is a link to download the Environmental Protection Plan for the Generating Station to ensure it has the smallest environmental impact possible.

Click to view or download Environmental Protection Plan –
Generating Station [1MB PDF]