Upper Kotmale

Upper Kotmale

The UKHP is a run of river hydropower project with an installed capacity of 150MW (consisting of two 75MW units) and It will produce 409GWh per year. It has the following components:

• A dam located close to the town of Talawakelle with a height of 35.5m and a crest length of 180m. It will have a gross storage of 2.5 MCM with an effective
capacity of 0.8 MCM with a surface area of 0.25 km2 (60 acres). Full supply level for the reservoir will be 1,194 metres above mean sea level (msl), the minimum
operating level will be 1190m msl and the normal tail water level 703m msl.

• A headrace tunnel 4.5m/5.8m in diameter lined and unlined and 12.89km in length, running north from the dam towards the Pundal Oya Falls before turning
to the northwest towards the existing Kotmale dam and reservoir. (The maximum gross head between the reservoir and the powerhouse will be 491m).

• An upstream surge tank 12m in diameter and 98m high with a restricted opening, located on the crest of the power house.

• The penstock formed by an underground incline shaft starting with a diameter of 4.5m and reducing to 1.45m. It will be 793m in length, consisting of one lane of
745m and two lanes of 48m.

• An underground powerhouse located at Niyamgamdora, (2km upstream of the confluence of Puna Oya and Kotmale Oya) with dimensions of 66.3m L x 18.8m
W x 36.5m H to house two units of 77,000kW turbines, two vertical axis three phase 88,000kVA generators, two 3-phase, transformers and a 220kV Gas
Insulator Switchgear (GIS) substation.

• An outdoor switchyard, 36.5m wide and 130m long, located at Niyamgamdora, to connect the Power House to a 220kV double circuit transmission line.

• 220kV double circuit transmission line of 18km length to transmit power generated to existing Kotmale Substation and the associated switch yard extensions.
Project Cost

• Total Project cost : Rs. Million 37,269

• Foreign loan provided by Japan International Cooperation Agency (JICA) : Rs. Million 28,721 (JPY Million 37,817)

• Government of Sri Lanka: Rs. Million 8,548 Expected date of completion: End of December 2011

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