Upper Kotamle hydropower Project
Project Description
The UKHP is a run of river hydropower project with an installed capacity of 150MW (consisting of
two 75MW units) and It will produce 528GWh 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 0.25km2 (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+.2m 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).
• The flow from the Kotmale Oya will be supplemented with water diverted from other
streams. A number of diversion intakes will be built to direct the additional flows to the
headrace tunnel. These include two intakes from Devon Oya and Kuda Oya to supply
additional flow into the Talawakelle intake dam, and four intakes from Puna Oya, Ramboda
Oya and Pundal Oya feeding into the headrace tunnel to the east of the penstock.
• 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 3phase, 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 Location
The UKHP is located in the Southern Highlands of Sri Lanka and is part of the Nuwara Eliya
administrative district. The project area covers some 540km2 of the upstream catchment of the
Kotmale Oya, a tributary of the Mahaweli Ganga. The infrastructure for the project is confined to a
much smaller area and is contained in a triangle with the A5 Kandy - Nuwara Eliya Road forming
the eastern side, the A7 Hatton-Nuwara Eliya road the southern side and a line running north-south
from the existing Kotmale power station to the Devon Oya completing the western side.
The topography of the project area is mountainous with a striking landscape of deep river valleys
running beneath high cliffs and escarpments. The establishment of tea plantations began in the
1850s and today the plantations still cover almost the entire district. The higher slopes and the tops
of the hills remain forested with most of the forested areas designated as reserves.
The project area is predominantly rural in character with the majority of the population living in
small rural communities or on tea plantations. The dam site is located on the edge of the town of
Talawakelle which has a population of around 3750. The only other town of any size is Pundal Oya
which has a population of 2000.
Details of Upper Kotmale Hydropower Project.
Progress of Upper Kotmale Hydropower Project as of end of September 2012
Item
Lot 1
Lot 2
Lot 3
Lot 4
Lot 5
Lot 1
Item
1
2
3
4
Lot 2
Item
0
1
2
3
4
5
Description
Preparatory works
Main Civil Works
Hydro Mechanical Works
Electro Mechanical Works
Transmission Line
Overall Progress of the Project:
% Completed
94
98
100
99
100
98
Preparatory works
Description
B � 412 Road & Access roads
Permanent Facilities for Resettles
Talawakelle
Devsiripura & Kumaragama
Rathnilakelle
Nanu Oya
Middleton Division
CGR Quarters
UC Resettlement
Common Buildings
Permanent Facilities for Employers & Engineer
Arussella Camp
Walkers Camp
33kV Transmission Line
Overall Progress of Lot 1:
% Completed
100
88
76
100
100
100
100
81
59
100
45
100
94
Main Civil Works
Description
Site installation and services
Intake dam
Head pond area
Headrace tunnel
Upstream surge tank
Penstock
% Completed
85
99
96
100
98
100
6
7
8
9
Powerhouse complex
Tailrace
Outdoor switchyard
Architectural works
Overall Progress of Lot 2:
Lot 3
Item
1
2
3
4
5
6
7
8
9
10
11
12
13
Hydro Mechanical Works
Description
Spillway Gates
Spillway Stop log
Sand Flush Gate
Stop log Sand Flush
Main Dam Outlet
Main Dam Intake
Trash rack & Raking m/c
Guide Frame for Intake
Access door & Drain
Steel Penstock & Lining
Draft Tube Gate
Tail race Gate
Controls & Power supply
Overall Progress of Lot 3:
Lot 4
Item
1
2
3
4
5
6
7
8
Electro Mechanical Works
Description
Turbine
Generator
Overhead Travelling Crane
Power Transformer
Switchyard Equipment
Power Plant Equipment
220kV Cable
Telecommunication equipment and flood forecasting
system
Miscellaneous Equipment
Intake Dam equipment
Expansion of Kotmale Switchyard
Nuwaraeliya grid station
Overall Progress of Lot 4:
9
10
11
12
100
100
92
95
98
% Completed
100
100
100
100
100
100
100
100
100
100
100
100
100
100
% Completed
100
100
100
100
100
98
99
97
80
96
100
97
99
Lot 5
Item
1
2
3
Transmission Line
Description
Design
Procurement
Construction
Overall Progress of Lot 5:
% Completed
100
100
100
100