A. DENIS N. Fernando, Fellow of the National Academy of Science and leading cartographer in his lecture on, `Irrigation in Lanka ancient and modern' at the Agrarian Research Institute said recently that rice had been grown in Sri Lanka at least before the 6th century B.C. when Vijaya was fed on rice meals here. At that time the Yakkas were chiefly responsible for the irrigation system in the dry zone for the development of the famous Hydraulic Civilization of the country.
The Yakkas had established cities like Sirisavastu, Lankapura, Vijitapura and occupied an extensive settlement in the Mahaweli plain covering an area of over 1,000 sq. miles. They were expert horsemen who assisted king Pandukabaya with their technical skills to upgrade Anuradhapura to a city. In the Mahaweli plain there were hydraulic structures to divert water for irrigation within their settlement area and the Maduruoya reservoir used a unique technology in binding burnt terracotta bricks with resin or tar, which was prevalent in Persia. The Mahaweli Ganga was called Phasis fluvius by Ptolemy which means the Persian river, indicating a Persian connection. Hence it is reasonable to surmise that the Yakkas who dwelt there were connected to the Persians. One of the oldest seaports of Sri Lanka at Palavakki, the ancient seaport of Jambukola was used for foreign contacts from the 6th century B.C. he revealed.
The lecturer showed several slides to illustrate the development of the early Hydraulic civilization, with the distribution of irrigation structures. Subsequently, in the 13th century the Mahaweli had changed its course which caused the collapse of the major dry zone irrigation system. This exposed the population to disease and famine and the peasant had to abandon Polonnaruwa and other centres of rice production. The capital shifted to Dambadeniya and other capitals in wetter regions.
With the decline of the Hydraulic civilization, the people migrated to the wet zone in the southwest sector of the country, reestablished and built minor irrigation structres and resorted to rainfed cultivation also.
However the large and medium hydraulic structures were restored after 1930 spearheaded by Mr. D. S. Senanayake. The first modern river basin irrigation system, the Gal Oya scheme came up in politically independent Sri Lanka in the mid 40's. In 1970 the Polgolla Barrage and Bowatenne reservoir and associated tunnels and transbasin diversions were constructed and linked to cultivate 132,000 acres of existing fields in the Anuradhapura, Polonnnaruwa and Trincomalee districts. Local engineers and construction agencies were responsible for this exercise. In economic terms, it paid for itself in five years, a viable project economically.
In 1978 the accelerated Mahaweli project based on the Mahaweli Master Plan was launched and half the original plan saw completion in 1990. And this could provide irrigation for 450,000 acres and not 900,000 acres as envisaged originally. And the emphasis for hydro-power generation and the neglect of irrigation for rice cultivation has led to crop failures.
As at present the only salvation for the local farmer is rain water and well water where available. He will have to devise methods of storing and conserving rain water for his cultivations. Sri Lanka's rivers are unable to provide scientifically any more water for further irrigation expansion, for they have been tapped to the maximum and afforestation is a must. Finally, the speaker said that he was prepared to answer any question from local or foreign experts on the statements he had made.