An archaeological insight into the coastal (Karavita) tanks of Sri Lanka

Abstract

Introduction

Sri Lanka’s irrigation system is a technical structure erected with the objective of fulfilling the challenges posed due to water scarcity in the dry zone. The main objective of our irrigation industry is fulfillment of water requirement in agriculture coupled with the idea of protection of the environment. Even in the present day, the dry zone of Sri Lanka has become a suitable place for habitation due to the impact created by huge tanks. The construction of tanks is done in order to save inland water. Though a number of scholars, R.L.Brohier, H.W.Codrington, C.W. Nicolas, Henry Parker have written about tanks in the coastal area, the object mentioned above has not been completely addressed by them. An important indicator of our ancient irrigation system are the Tanks in Sri Lanka. The construction of these tanks relates to the proto-historic period and terms such as Katakulu Wewa, Bandi Wewa, Biso Wewa, Kulu Wewa, Karavita Wewa were used according to their location, size and utility. The objective of this research is to analyze, from an archaeological perspective, the usefulness of small and medium size tanks called “Karavita tanks” and to explore the factors that led to their creation in proximity to the coastal areas.

Research Methodology

This research is based on field visits to the tanks situated in proximity to the coastal areas in the North-Western, Southern, South- Eastern, and Eastern provinces of Sri Lanka.

Results & Discussion

The main purpose in constructing the Karavita tanks which are either small or medium in size, was to prevent sea water from filtering through the soil from the coast to the land area. Karavita tank or Wewa hence means the bund which prevents sea water. When researching into the history of the Karavita tanks, the researcher noted that the tanks reconstructed by King Parakramabahu 1st, Karavitiya and Willaththawa Wapi ( MV. lxviii: 47) are important. The bunds of these two tanks run parallel to the coast which means that the water flow of the tank is directed towards the coast. A number of similar tanks have been constructed in the vicinity of the Karavita tank close to the coast in order to fulfill the above purpose. Similarly when looking at the smaller tanks in the Southern, South- Eastern, and Eastern coasts, there is evidence of human settlements around these tanks. Scattered pieces of clay pots can be found in these settlements and in addition there is evidence also of ancient Buddhist sites. The pieces of red clay pots excavated in this area hints to the fact that the history of these tanks dates back to the pre and proto-historic periods.

Magama Kingdom of Ruhuna is formed purely as a kingdom in the coast. Ancient kingdoms such as Bowaththegala, Kotadamuhela, Seruwawila were also positioned close to coastal areas. These tanks which were built parallel to the coast helped the people in obtaining desalinated water for their agricultural needs. A large number of small tanks now in dilapidated condition, inside Yala and Kumana national parks are also fine examples. Karavita tanks were constructed in the dry coastal areas in the country to obtain water for agriculture. They helped in storing inland water and rain water. Inland water in these tanks were stored on an elevated level in comparison to the existing land level. This helped in absorbing the water to the ground below so that the inland water travels to the coast through the earth by pushing the salinity of water back towards the sea. This natural system helped in agricultural activity.

One of the main factors that prove there were continuous settlements from the proto-historic times up to Anuradhapura and Polonnaruwa periods was the functioning of these Karavita tanks during these periods. The Mahavamsa mentions that king Parakramabahu 1st during his reign as the leader of Dakkhina Desha and as the heir to throne made arrangements to construct tanks. This shows that the importance of the tanks was felt not only by the common man, but also by the rulers.

Conclusion

It is evident therefore that a small network of tanks called “Karavita” has created an environmentally friendly approach to reducing the salinity of underground water in the tanks in coastal areas. There are archaeological evidences to show that there were settlements in the coastal zones. Certain small Karavita tanks were upgrade to medium sized tanks by its users who realized the importance of their existence.

However, a large number of these tanks are in a dilapidated condition since people are ignorant of the purpose behind these tanks. Certain tanks have been converted to agro lands and the salinity of water remains high in these areas. Karavita tanks function therefore as a fence which prevents the salt water from entering into the inside of the country.