By A. Denis N. Fernando,
Fellow National Academy of Sciences
1. Though historians abase their record of history on earlier writings, they are sometimes flawed as myths and even Gobelsian lies have been incorporated into it even in modern times. Thus there is the need to correct them when new scientific evidence and discoveries proved them wrong. Unfortunately it is not so in reality as psychologically there is a reluctance among historians to correct the historical record based on new scientific evidence. I would indicate in the course of my lecture especially the new scientific evidence using the new aerospace techniques.

2. The position of Sri Lanka on the Indian Ocean brought traders and seafearers from the Fertile Crescent who were drawn here because of our spices, gems and other curiosities. (refer RAS Journal Special Issue on "The Ancient Hydraulic Civilization of Sri Lanka" for details).

Claudius Ptolemy provided us with 3 dimensional coordinates of 49 places of interest in Taprobane (Sri Lanka) and were corrected by me mathematically for scale and azimuthal errors and plotted on a Transverse Mercator Projection. This provided us with the location of places with an accuracy of 10 miles in position. (refer RAS Scsquicentinial Commemoration Volume 1995 for details). What is significant is that it confirms what is stated in Mahavamsa which was written by Mahanama two centuries later in 4th century AD. Though the names of these places are indicated in the Mahavamsa, some of their locations have unfortunately been misinterpreted by historians and caused all the confusion.

4. Ptolemy clearly indicated our contacts with the rest of the Asian world which resulted in the development of our unique hydraulic civilization, which sublimated from the Stone Age to the Iron Age bypassing the Bronze Age. In the map of Ptolemy various tribes and nations had their harbours and settlements for trade, the capital metropolises of the kings, international emporia rivers and mountains, the source of rivers also includes the sacred Adam’s Peak foot print are clearly indicated.

5. It is foreigners who introduced paddy to Sri Lanka and cultivated it using the technique known to them in the cultivation of wheat in the Fertile Crescent and adapted it for the cultivation of paddy. Present evidence points to the Yakkhas to have introduced paddy who had a Persian connection as there was a very great demand of rice for export. (refer The Advent of Rice and Ancient Hydraulic Civilization - Asian Agro-history Foundation Volume 2 No.1 of 1998). While we from Sri Lanka taught the South Indians in the Kaveri Basin to grow irrigated rice when our experts were taken by force as indicated in the Manavamsa and created the Poduke, the new city in the Kavari in South India, which city is indicated by Ptolemy in the second century AD.

Irrigated technology in Sri Lanka existed here before the advent of Vijaya when she was occupied by indigenous Veddhas as well as Seafearers and Traders namely the Yakkhas who were sunworshippers who had a Persian connection. While the Nagas had a Red Sea Erythrien connection who were snake or naga worshippers and great builders. The oldest city of Vijithapura indicated in the Mahavamsa as having 3 moats, the remains of which are clearly indicated in the aerial photographs and located between Kaduruwela and the new town of Polonnaruwa.

7. The map showing the distribution of the different type of Ancient Irrigation Structures; indicates ancient canals from Yakabendi elas that provided irrigation from the Mahaveli Ganga like the Kalinga and Gomathi elas; while we had canals like the Yoda elas that took water from the Kala Oya to Anuradhapura by a canal having a gradient of half a foot to the mile which even today with modern technology is difficult to achieve. Then we have the ancient Maduru Oya sluice which I discovered in 1981 which had two sluices and built in three stages starting from the BC period. According to the Mahavamsa the Yakkhas had their annual new year (sun festival) at the Dolapabbatha even in the time of King Pandukabhaya which lies between the Maduru Oya and the Mahaweli Ganga indicating the antiquity of this region in the BC period, which area was occupied by the pioneers of irrigation technology in Sri Lanka.

8. While the distribution of the major reservoirs were in the Intermediate and Dry Zones. It must be mentioned here that there were no major reservoirs on the main Mahaveli Ganga as the ancients used the profuse base flow of the river to divert water using diversion canals to major reservoirs located elsewhere. It must be mentioned here in the time of the Parakramabahu I in the 12th century had cultivated more land than is now done under the present Mahaveli Project with large reservoirs on the main Mahaveli Ganga to capture the flood waters as today the base flow is small that was caused by the deforestation of the Upper Catchment.

The distribution of high density minor irrigation reservoirs is concentrated in the Intermediate Zone, while low density minor irrigation reservoirs are located in the Dry Zone. As the water resources available in these catchments are small, only about half of these tanks could be in operation at any one time. The ancients in their wisdom used them in cyclic rotation to recuperate their fertility by allowing the paddy fields under them to be in fallow alternatively. Todays attempts to rehabilitate all these minor irrigation reservoirs by solving the problem of fertility using inorganic fertiliser would fail because of the shortage of water resources. Therefore the restoration of all minor irrigation schemes would not help the farmer but will only bring misery to him which the bureaucracy do not understand. More of this could be referred to is the special issue of RAS Journal on The Ancient Hydraulic Civilisation of Sri Lanka.

The fall of the ancient hydraulic civilisation of Sri Lanka in the 13th century was due to sudden Natural Cataclysmic change of the river course of the Mahaveli Ganga and was not due to foreign invasions as historians would want us to believe. The scientific evidence is clearly seen in the aerial photographs of the old course of the Mahaveli Ganga and its new river course. The ancient Mahaveli with its ancient chaityas which were beside the old river like a string of pearls now lay stranded beside it. While the present river flows elsewhere with no chaityas beside it which event took place in circa 1220 AD. This sudden geological catyclysm that changed the river course that sustained our ancient hydraulic civilization, led to disease and famine. This resulted in the major part of the population to abandon these areas and move to the Wet and Intermediate Zones where the king also established himself at Dambadeniya, Kurunegala, Gampola, Kotte and Kandy.

9. With independence the revival of our ancient hydraulic tradition to construct large irrigation reservoirs began with Galoya, Walawe and finally Mahaveli Ganga, rehabilitating our ancient canals and reservoirs while also building new large dams built across the Mahaweli Ganga for the first time which did not exist before to capture the flood waters to resettle our people in the land of their forefathers.

10. Finally we must be warned that if the bureaucracy does not take the advise of our scientists, being penny-wise and pound foolish by not providing the necessary funds to purchase and replace disfunctioning monitoring scientific instruments to monitor the high dams as done in our neighbouring countries, a disaster can happen. The safety of our large dams especially in the high elevations have to be ensured. If not we would in the near future may be without any warning have to face a man made national disaster which could be worse than the one that took place in the 13th century due to natural causes. If any of our high dams in the higher elevation fail without warning it would result in the reservoirs below them falling like a pack of cards which would end our Mahaveli civilization, built at great cost.