Overview
of the Mahaweli Project
The Mahaweli
Project is the largest Multi Purpose Development Project ever undertaken
in Sri Lanka. Mahaweli Master Plan drawn up during 1964 1968
for harnessing the waters of the Mahaweli envisaged the development
of 365,000 ha for agriculture and installation of 600 MW of Hydro-Power
capacity.
The total Mahaweli Project Area covers 39 percent of the whole island,
55 percent of the Dry Zone, and encompasses 60 percent of the irrigable
land area of Sri Lanka
The Project is to provide Irrigation for agriculture and water for
domestic use, generate hydro-power for the whole range of agro-based
industry in the Mahaweli areas and elsewhere, provide effective flood
control and most importantly open up new land for agriculture development.
The project comprises five Major Dams; Kotmale, Victoria, RandenigalaRantambe,
Maduru Oya and Moragahakanda which has yet to be constructed.
Moragahakanda & Kaluganga Development Projects
Moragahakanda & Kaluganga Development Project is the largest reservoir
project to be taken up for development under the Mahaweli River Development
Programme.
A full feasibility study of the Moragahakanda Project combined with
the Kaluganga Development Project was completed in 2004 by the Lahmeyer
International, in association with the Central Engineering Consultancy
Bureau (CECB) of Sri Lanka, United Consulting Group (KUWAIT) and Chuo
Kaihatsu Corporation, Japan.
Objectives
of the Projects
- To
provide irrigation water facilities to 81,422 ha in the Dry Zone of
Sri Lanka
- Potable
and Industrial Water Supply to Anuradhapura and Trincomalee towns
- Generation
of electricity by hydro power
Location
The project
area is located in the Central and North Central Provinces in Sri
Lanka.
Project Configuration
The project
consists of
(a) Construction
of two major reservoirs namely; Moragahakanda and Kaluganga reservoirs,
(b) A
conveyance system consisting of two tunnels and transfer canals and
(c )
A power house of 20 MW installed capacity.
Principal Project Features
Moragahakanda
Reservoir
Type
of Dam: A roller compacted concrete main dam and two rock fill saddle
dams.
Maximum
dam height: 65 metres
Active
Storage : 521 million cubic metres
Kaluganga Reservoir
Type
of Dam A rock fill main dam and two saddle dams, one rock fill and
the other earth
Maximum
Dam Height 67 metres
Active
Storage 144 million cubic metres
Conveyance System
Tunnels 1. Kalunga Moragahakanda transfer tunnel 15 m3/sec.
capacity, length
3.2 km
2. Second
Bowatenna Tunnel 25 m3/sec. capacity, length 7.2 km
Conveyance
Canals : Total length approximately 50 Km.
Project Cost
Cost benefit
The investment
cost of the project is US $ 382 million. The Economic Internal Rate
of Return (EIRR) is 22%.
Direct Benefits
Agriculture
:
Cropping
intensity which varies less than 100% to 154% in the different areas
will be raised to around 181% on the average. The direct benefits
include increased rice yield per hectare with an additional agricultural
production of 109,000 tons annually. The net annual agricultural benefit
will be US $ 27.7 million in financial terms.
Inland
Fishery:
The average
annual fish production potential of the reservoir is estimated to
be around 4,700 tons per year, representing a net benefit of US $
1.67 million annually.
Potable
and Industrial Water Supply :
An increased
supply of 64 MCM (by the year 2032) could be ensured towards meeting
the potable and industrial water needs in the district of Matale,
Anuradhapura, Trincomalee and Polonnaruwa from the surface water sources
in the Ambanganga basin and its associated tanks and canals with the
implementation of the project.
Power generation:
Annual
fuel cost savings with the hydropower produced will be around US $
2.49 annual average.
Environmental Management Plan
The following
constitute the environmental management action plan that has been
proposed as part of the project :
a) Reforestation
of about 2000 ha in the Amban Ganga Basin
b) Clearing of elephant corridor between Giritale Minneriya
nature reserve
c) Habitat enrichment in proposed corridor between Wasgamuwa National
Park and Victoria Randenigala Rantambe Sanctuary.
d) Research and development in the proposed corridor
e) Establishment of a 100 m wide reservation around the reservoirs.
f) Rehabilitation of tanks in adjacent nature reserves
g) Establishment of electric elephant fence around the resettlement
area
Project Implementation
Project
implementation period will be 5 years which includes design and construction.
Expected year of commencement of work will be 2007.
Implementation
Responsibility
The project
will be implemented by the Mahaweli Authority of Sri Lanka under the
supervision of the Ministry of Agriculture, Irrigation & Mahaweli
Development.