Kalaweva Jayaganga Ecosystem

Learning from Ancient Hydraulic Civilizations -
Eppawala: Heart of the Ancient Cultural Landscape

The Kalaweva – Jayaganga Ecosystem

Emeritus Professor Dr. Caesar Voute
This gleaning is reproduced herein  by the kind courtesy of Dr. Caesar Voute

In view of the considerable international experience with the harmful effects of bad land and water management practices leading to soil erosion, water logging and soil salinisation, such as in Mesopotamia in the 1950’s and in India and Pakistan in the 1960’s, it might be astonishing to observe that similar errors are being repeated again in Australia in the 1990’s less than 35 years afterward. Motivated by the economic globalization and the liberalisation of international trade within the framework of the WTO it appeared attractive and highly profitable to increase agricultural outputs as much as possible in anticipation of an expected improved market access in Europe and in other regions of the World. In order to obtain a maximal production and high profits the Australians have been clearing native vegetation followed by extensive irrigation in large areas of the Murray-Darling Basin. However, the results are not only counterproductive
but even disastrous, rendering big areas  of Australian agricultural  land entirely  unproductive
because of soil erosion, water logging and soil salinisation.

Kalaweva ancient irrigation reservoir

This is in a strong contrast with the situation at Eppawala in Sri Lanka.Eppawala is situated in a relatively dry part of Sri Lanka called the Dry zone, with irregular seasonal precipitation, sometimes in the form of heavy rain storms during the northeast monsoon season. Under such conditions the land and the soils are sensitive to negative effects of poor water and soil management practices. There is no better proof of the wisdom of the ancient farmer communities and of the soundness of the old irrigation system, based on wise water and soil conservation techniques, that the system has remained sustainable during more than two thousand years ensuring all that time an optimal use of land, water and soil resources notwithstanding poor maintenance
in later centuries Some of the substantial economic surplus generated by these systems was used in the construction of the ancient Buddhist stupas, and other structures in the ancient cities, of which Anuradhapura near Eppawala, and Polonnaruwa, were once the capitals of ancient Sri Lanka.

The ancient works have been investigated, analysed, described and documented by a number of scholars. D.L.O Mendis has summarised their findings very adequately, adding many personal observations. Therefore, it will be sufficient for the purpose of this chapter to mention briefly some elements of the system which conserves excess precipitation from the northeast monsoon rain season. It also conserves the top soil which otherwise would have been eroded from the slopes by rapid surface runoff. In addition, the system permits the storage of water in surface reservoirs of various sizes and in the soil itself, by diversion of surface runoff in all parts of the dry zone by means of small earth embankment. D.L.O. Mendis uses here the very appropriate term water and soil conservation ecosystem. The overall system consists of a combs nation of interconnected rain-fed tanks, small village tanks often arranged as a chain or cascade of consecutive tanks
feeding each  the tanks situated farther downstream, intermediate reservoirs, large storage reservoirs, dams and weirs in rivers and large diversion channels, in several cases interconnecting large river systems.

Jayaganga ancient irrigation canal
The original creation of the Kalaweva-Jayaganga system, in the ancient Rajarata or king’s country, in Sri Lanka, which has taken place during about 15 centuries and in successive phases, must have been very labour intensive. Under present-day conditions the initial implementation of such a scheme - however sound and desirable by itself - might therefore become very expensive and the necessary capital investment might be less e less attractive from a purely economic point of view.

However, the maintenance of the system, once it is in existence, need not be expensive, especially if the local villagers and farmer communities are motivated to provide most of the labour on a voluntary base. This by itself would be sufficient reason for Sri Lanka to give the highest priority to the regular  maintenance and - where necessary - the rehabilitation of sections of the system which have fallen into disuse because of lack of maintenance, instead of investing in large, expensive and ambitious reservoir dams. Moreover, irrigation schemes and multipurpose schemes inspired by western hydraulic principles, based on designs involving large reservoir dams are not only very capital intensive. Very often they are less effective with regard to a proper
water and soil conservation, creating in addition new problems.

In comparison to the well-proven water and soil conservation techniques in the Rajarata system, the examples of the partial failure of  major irrigation systems in Pakistan and in Australia, based on modern hydraulic engineering concepts and techniques, are also ample proof that these concepts and techniques - developed in the industrialized West - are not necessarily the best adapted to local climatological, landscape and soil conditions in other countries.Rather than  copying blueprints of such schemes inspired by modern Western science and technology, the responsible Planners and engineers should use an irrigation system like the Kalaweva-Jayaganga irrigation, water and soil conservation ecosystem as a research and training ground to learn from concepts and techniques which have proven their value over a period of many centuries. In this sense the preservation of the ancient experience exceeds its importance for Sri Lanka. The related transfer of experience and technology from Sri Lanka to other regions represents also an important international interest, meriting international support.

The Eppawala region is not only an outstanding component of the Sri Lanka cultural heritage. It constitutes also one of the important phases of land use planning, water and soil management, as they developed in Asia in the course of several millenia. As such Eppawala merits also its rightful place in Mankind’s world-wide cultural heritage.

Unfortunately, the ancient Rajarata water and soil conservation ecosystems are today threatened in more than one way. The oldest and still persisting threat is that of lack of maintenance and of overdue repair works, due in part to a poor understanding of its functioning by modern engineers and politicians. As a consequence, the government is not undertaking the necessary action to improve the situation by stimulating the villagers depending on the system for their agricultural and domestic water supply to maintain it properly. Nor is any priority assigned to do the necessary repair and rehabilitation works for the parts of the system which have fallen into disuse due to neglect.

On the contrary, the existing systems are threatened time and again by the submitting of proposals and the preparation of projects to replace at least part of the ancient water and soil conservation ecosystems by so-called ‘modern’ water storage and supply systems based on the construction of large reservoir dams with associated water distribution canals. These proposals and projects are inspired by  recent hydraulic engineering concepts as practiced in the West. Moreover, no thorough analysis has been made of the economic consequences of the plans by comparing the capitalized costs of maintenance and repair of the existing ancient systems with the considerable capital lay-out required for the construction of the project or projects now envisioned. Furthermore, the planners also fail to assess the various potential negative side effects (it these new projects, notwithstanding the fact that many disappointing experiences with similar
reservoir dams have already been recorded elsewhere.

The third and most immediate threat, which would also be most destructive in its consequences is that of the planned large-scale open-cast strip mining of an important deposit of phosphate rocks (apatite) in Eppawala, in the central part of the water and soil conservation ecosystem. These phosphate rocks, consisting of apatite, were discovered in 1971 and have been mined since that time in small quantities using labour intensive artisanal methods and techniques for use on the local market in Sri Lanka. The micro-economic creation effects of these small-scale mining operations have been the of new job opportunities for local villagers of which much of the profits has gone to the local inhabitants. Since a few years back, a controversial and much debated proposal has been under consideration to grant a concession to an American and a Japanese corporation to exploit the deposit to exhaustion using advanced technical means in an approximately 30 years period and to  process the phosphate for export for the international market place. The macro-economic effects of this new project would be that the government would benefit from
the payment of concession rights and taxes by a foreign company which would expect to make sufficient profits on the required investments for the large-scale mining operations. However, at the micro-economic level the consequences would be loss of job opportunities and of modest profits the local inhabitants. Furthermore the project would involve the displacement of a number of villagers and the permanent destruction of a central part of the Kalaweva-Jayaganga water and soil conservation ecosystem.

Instead of protecting and rehabilitating the unique Kalaweva-Jayaganga cultural landscape, the decision to sacrifice it to economic short-term profi ts to be obtained by massive and unsustainable phosphate mining would be worse than another example of short-sightedness based on a desire to “reap a fast buck” within the network of the current processes of economic globalization and national trade and investment liberalisation in accordance with the WTO approach. As a matter of fact it would be another very serious symptom of Man the Maker being in reality Man the Destructor of Nature and of Civilization. Destroying a landscape and
an ancient cultural heritage it would amply demonstrate that Man the Maker is indeed a new and powerful geological agent, representing Dark Nature and being incapable of caring for the quality of life including environment, human rights and labour norms to borrow some terms from George Ter-Stepanian, Prof. Drs. R.F.M. Lubbers and Antony R. Berger refered to earlier in this chapter.

Above is a gleaning from

PROCEEDINGS OF THE REGIONAL PUGWASH WORKSHOP IN HONOUR OF JAYANTHA DHANAPALA PRESIDENT OF THE PUGWASH CONFERENCE ON SCIENCE AND WORLD AFFAIRS 2007 - 2012

SRI LANKA 22- 28 NOVEMBER 2007
This gleaning is reproduced herein  by the kind courtesy of Dr. Caesar Voute.

Links in this blog page are made by bunpeiris. The original page of the ACEDEMIC DOCUMENT http://www.pugwashgroup.ca/events/Water/2008-Water-DLOMendis-Book.pdf had no outbound links.