TANK CASCADE SYSTEM

WILL IMPROVE WATER QUALITY OF DRY AND INTERMEDIATE ZONE OF SRI LANKA

Sri Lanka needs a water policy addressing water quality and identifying tank cascade system as lifeblood

According to world history, many civilizations such as Indus,

Mexican, Maya and Inca were originated with the association of rivers and had a long history and flourished with power and knowledge and faded away with the passing time.

Civilization in Sri Lanka is also associated with a Malwathu Oya river, but our civilization is referred to as hydraulic civilization mainly because of the tank cascade system and also the manmade incredible hydraulic structures present over the dry and intermediate zone of the country. Therefore our civilization did not vanish though it had risen and fallen during the past.

However, at present, an appreciable percentage of people in the dry zone of Sri Lanka- earlier known as Rajarata and Ruhunurata where hydraulic civilization that thrived- is suffering from Chronic Kidney Disease of unknown aetiology (CKDU). Analyzing its widespread geographical distribution and histopathological evidence, CKDU is considered a problem related to the environment.

We observed that many hypotheses have been proposed as causative factors for CKDU and

established at present as a multifactorial origin. However, these associated factors are related to water. We believe that this occurrence is due to the drastic changes that happened to the hydraulic system of the dry and intermediate

zone of the country. There is a growing concern over the high incidence of CKDU in the dry and intermediate zone of Sri Lanka, and the ancient tank cascade system with its ecological functions has a potential for controlling this disease.

This article discusses the components of the tank cascade system in improving the water quality of the area.

Figure 01 shows the divisional secretariat level distribution of CKDU patients in Sri Lanka, while figure 02 exhibits the distribution of small tanks in Sri Lanka.

People in the area used to get potable water from the tanks. …adverse changes that took place to the ecosystem of the tank cascade system and new commercial practices of agriculture have also become reasons…