II       THE PROJECT AREA AND ITS BASIC RESOURSES

 

2.1              The Project Area

            The project area covers 39 percent of the whole island and 55 percent of the Dry Zone. It includes the Mahaweli Ganga basin, the basins of the Maduru Oya and rivers in the north–central part of the Island.

 

2.2              Land Resources

            The area classified as suitable for irrigation extends to approximately 1.5 million acres of land, of which 900,000 acres would be commanded by the proposed irrigation systems (Of this 246,000 acres are at present partially irrigated).  There remains therefore 600,000 acres of land' of which 54,000 acres are presently cultivated' but not command by the irrigation system' It is envisaged that the balance of 546,000 acres will remain under forest's' Of the new land to be developed for irrigation' which 654,000 acres (900,000 – 246,000) 360,000 acres are in the basins of the Mahaweli Ganga and Maduru Oya, and 294,000 acres are in the north-central part', and 294,000 acres are in the north-central part. 

 

2.3              Water Resources

            The long-term mean annual yield of the Mahaweli Ganga River at the lowest diversion weir (Kandakadu) is 6,400,000acre-feet. By constructing reservoirs on the Mahaweli and its tributaries it is possible to obtain a regulated flow corresponding to a volume of 4,300,000 acre feet can be obtained as a result of the lateral inflow from intermediate catchments. Thus the total useful water resources of the Mahaweli and its tributaries are estimated at 4,700,000 acre feet per year. The yield of the rivers in the North central Province, Maduru Oya and the smaller streams in the Mahaweli basin, which has already been or would be stored and regulated amounts to 900,000 acre-ft. Finally the overall potential of water resources of the project area is around 5,600,000 acre-feet per year.

 

2.4              Hydro-Electric Power Potential

            The total hydropower potential of the rivers of Ceylon is estimated at about 6,000 million k W h per year; of the about 3,800 million k W h can eventually be obtained from the Mahaweli and its tributaries alone.