Guidance on use of rainwater tanks for the Jaffna Peninsula

The Jaffna peninsula is characterized by erratic rainfall and high evaporation rates leading to unreliable water supply. The people of the Jaffna Peninsula have long recognised this need, and have developed water supply facilities well suited to these conditions. Numerous shallow, lowyielding wells distributed over large areas did not have the capacity to cause an imbalance of the dynamic conditions maintaining the fresh water lens. In more recent years the increased demand for water has led to pumping rates that have, in places, caused problems. An additional problem with the widely distributed shallow well system is that the groundwater is vulnerable to pollution without appropriate waste disposal arrangements. Therefore rainwater harvesting (RWH) and management offers an opportunity to mitigate present and future water demand in the Jaffna Peninsula. Rainfall data of the Jaffna Peninsula from 1941 to 1990 was analysed to prepare guidance on use of rainwater tanks. This paper presents rainwater harvesting guidelines for the Jaffna Peninsula