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Mahaweli Authority of Sri Lanka

Bowatenne Project

	Victoria
	Kotmale
	Randinigala
	Rantambe
	Pollgolla
	Bowatenne
	Ratkinda
	Maduruoya
	Karagahawila Road
	Ulhitiya
	Ukuwela
	Uda Walawe
	Mahaweli Upgrading Project

Bowatenne

The Bowatenne Diversion Project lies in the northern part of the central highlands of Sri Lanka. The bowatenne Diversion Dam and Tunnel lie about 30 miles north of the Polgolla Project. The project area consist crystalline and foliated metamorphic rocks. This types and structures encountered in the area are often similar to those in the region of Polgolle project.

The Bowatenne Power Project had been designed to cater for the peak requirements of the country’s power demands and to operate only for 8 hours a day.

Description

The project comprises a 687 feet long 45 feet wide approach channel, a 18 feet diameter horse shoe concrete lined 4,535 feet long tunnel, surge chamber, a 40 M.W. Power plant, switch yard and transmission link between Bowatenne and Ukuwela.
The complex which has been sited on the left bank of the Amban Ganga derives its water requirements from the already constructed Bowatenne Reservoir which also supplies water to the Kala Oya basin through an independent irrigation tunnel
The water in the power tunnel will be emptied into the Amban Ganga about ½ miles downstream of the dam after the generation of power. The water in the river will be re-diverted along the Elahera-Minneriya Yoda Ela for irrigation requirements.

Reservoir

Reservoir to Tunnel Inlet
Type - Open cut
Material - Earth and Rock
Length - 687 ft.
Capacity - 3,350 cusecs

Turbines

Head Works - Rs. (‘000)
Equipment - 1
Dam & Control House - 68,479
Tunnel - 89,126
Roads - 2,207
Irrigation Canal - 8,999
Project management - 22,910
Land Acquisition - 5,812
Peripheral Works - 3,895
Administration - 541
Total - 201.970

Power Plant
Installed capacity - 40 M.W. (36 M.W –at 2004)
Average annual energy generation 143 G.Wh
Turbine type - Francis-Vertical type

Main Dam :Double Curvation Arch Dam

Type - Concrete Gravity
Height - 29.8
Length - 226
Gross Storage - 51.0
Live Storage - 34.0
Generating capacity - 40 (40 x 1)

Tunnel

Power Tunnel:
Type - Concrete lined horse shoe
Size - 18 feet diameter
Length - 4,535 feet
Capacity - 3,350 cusecs
Gradient - 0.0227
Surge Chamber
Type - Restricted orifice
Size - 55 feet
Height - 33 feet
Surge Chamber
Type - Steel Conduit
Size - 16 feet diameter reduced to 14 feet
at the Power Plant
Length - 485 feet.