Last week the Department of Irrigation activated construction works related to the largest drinking water supply project in the Vadamarachchi lagoon to harvest rain water for drinking purposes expected to be completed in two years. The project when completed would enhance the available potable water to resolve lot of the drinking water issues faced by the peninsula people, was initiated to conserve and reuse rainwater as a solution to the prevailing drought. The project envisages making use of 20% of the annual rainfall in the Vadamarachchi lagoon which has a surface area of 78 sq. km.
Jaffna peninsula with an area of around 1,000 square kilometers of flat land having no rivers depends on ground water recharged through an annual rainfall of around 1,270 mm during the North East monsoon from October to December. According to statistics, the losses through evaporation year after year has never been taken into the water balance equation by experts who engaged in this field. Yet the issue is not inadequate water but the quantity of clean water which is fast running out due to over extraction of ground water which results in sea water percolating into wells, waste oil contamination and use of chemical fertilizer in agriculture. Over 30 percent of the estimated that there are over 100,000 wells in the peninsula are saline due to excessive drawing of water for domestic and agricultural use. Topological limitations make the task of finding a solution to the rapidly depleting clean water sources, difficult. The Jaffna peninsula receives more potable water following renovation of the Thondamanaru Barrages in 2018; a major relief to the people in the peninsula who continue facing a shortage of drinking water due to the contamination of ground water.
There is a long history and the Dutch and a number of British Government Agents had tried their hands before the country gained independence at implementing a water supply scheme with water from the lagoon but with little success. However, these specialists have established one important fact that the lagoon can be leached under controlled conditions. Since independence local specialists have studied this problem at various times in the past seven decades, most of them and potable water related issues were referred to in many posts in Northern Breeze. Lately Israeli, American, German and Australian consultants carried out feasibility studies to implement a water supply scheme for Jaffna. All these attempts were unsuccessful. The present project utilises a simple but brilliant engineering intervention, proposed by Prof. R.K. Guganeshrajah a Sri Lankan engineer of Surrey University; a new proposal to prevent evaporation partly, by storing 20% of total rainfall on 78 sq. km in a small tank of 10 sq. km, thereby reducing the surface area from which evaporation takes place.
Thamby Ramar
To read related posts visit Northern Breeze:
Dry zone farmers in Sri Lanka should adopt modern methods to conserve precious water resource @ https://northernbreeze.blog/2017/08/10/dry-zone-farmers-in-sri-lanka-should-adopt-modern-methods-to-conserve-precious-water-resource/
First resolve pollution at Chunnakam to sustain peninsula water resources @ https://northernbreeze.blog/2017/05/13/first-resolve-pollution-at-chunnakam-to-sustain-peninsula-water-resources/
Lack of Drinking Water will prevent development of Jaffna @ https://northernbreeze.blog/2016/10/21/lack-of-drinking-water-will-prevent-development-of-jaffna/
Taking Mahaweli water to the Dry Zones north of the country @ https://northernbreeze.blog/2016/07/28/taking-mahaweli-water-to-the-dry-zones-north-of-the-country/
Need planned large scale farming @ https://northernbreeze.blog/2016/04/02/need-planned-large-scale-farming/
Water crisis at Jaffna Peninsula! @ https://northernbreeze.blog/2016/03/05/water-crisis-at-jaffna-peninsula/
“FOG” halts water at Chunnakam @ https://northernbreeze.blog/2016/02/23/fog-halts-water-at-chunnakam/
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