Thursday, December 30, 2010

Victoria Dam (Sri Lanka)

Victoria Dam (Sri Lanka)

The Victoria Dam is the largest hydroelectric dam in Sri Lanka. Power is generated by three 70 MW francis turbines, totalling the installed capacity to 210 MW, thus playing a significant role on the national grid.[1] At a length of 520 m (1,706 ft), and a height of 122 m (400 ft), it is also the tallest dam in the country, while possessing the largest power station as well.[1] The dam is located across the Mahaweli River immediately upstream of the Victoria Falls rapids.

History

The construction of the dam was ceremonially inaugurated on the 14th of August 1978, by the former President Jayewardene. It commenced operations on the 12th of April 1985, and is still operating today. The main contractors were Balfour Beatty, responsible for the dam construction, and the Costan International, responsible for the construction of the power station. The dam is currently managed by the Mahaweli Project, headed by the Ceylon Electricity Board along with the Ministry of Power and Energy.[1]

Specifications
This arch dam consists of eight radial gates, each with a width and height of 12.5 m (41 ft), which automatically opens when water levels are high. The dam's gates, which needs power only to close, won an award for Innovative Design in Civil Engineering by the Institution of Civil Engineers. The total effective width of the spill-gates is 100 m (328 ft), which allows a maximum discharge capacity of 8,200 m3/s (289,580 cu ft/s). Two low-level sluices are constructed at the reservoir bed across the dam to pass silts which may accumulate behind the dam.[1]
The dam is located in the deep valley on the Mahaweli River, just above the Victoria Falls rapids. The reservoir catchment area tops to 1,869 km2 (722 sq mi). The reservoir feeds three turbines of 70 MW each, rotating at 333rpm at optimal capacity.[1]




Victoria Dam

The dam and reservoir
Locale
Coordinates
Construction began
14 August 1978
Opening date
12 April 1985
Dam and spillways
Length
520 m (1,706 ft)
Height
122 m (400 ft)
Base width
25 m (82 ft)
Impounds
Spillway capacity
8,200 m3/s (289,580 cu ft/s)
Reservoir
Creates
Capacity
722,000,000 m3 (2.55×1010 cu ft)
Catchment area
1,869 km2 (722 sq mi)
Surface area
23 km2 (9 sq mi)
Power station
No
Turbines
3 × 70 MW
Installed capacity
210 MW
Annual generation
780 GWh