Jaffna Peninsula’s freshwater problem: Focus on solutions
Freshwater is only 3 percent of the Earth’s water. But about 2 percent of it is in glaciers and polar ice caps, leaving only about 1 percent available for consumption. Of that, a significant amount is wasted as rainwater, and another portion is locked up in inaccessible places. Therefore, only about 0.08 percent is accessible to humans. With about 85 percent of the accessible water being used for agriculture, the United Nations Children’s Fund (UNICEF) estimates that some 783 million people are in need of safe drinking water.
If irrigation efficiency and productivity can be increased, 65 percent of Sri Lanka’s national water resources can be used for agriculture and 35 percent for social needs, experts believe.
For the Jaffna Peninsula’s people, groundwater has been a lifeline for a long time. Some 70 percent of the northern population is concentrated on the Jaffna Peninsula, and the reason for Jaffna being an agricultural area is the underground water resources available there.
However, many environmentalists warn that this rare resource is facing a threat from climate change. “It is worrisome to see the water quality of both groundwater and surface water in the Northern Province, especially on the Jaffna peninsula, decline as a result of recent climate change,” Jaffna University’s senior geography lecturer Nagamuttu Pradiparaja said.
He said the water quantity and quality were declining due to erratic rainfall, high temperatures, the high evaporation rate of surface water sources, excessive use of groundwater, and misuse by humans. At the same time, despite the current increase in demand, due to a lack of water replenishment activities, the northern region is facing a massive shortage of water, he noted.
“Many coastal and island wells have already fallen victim to salinisation. Toilets have mostly become flooding cesspools in urban areas, resulting in contaminated well water. Of late, an increase in the contamination of well water due to agricultural and industrial activities has also been observed.
“Especially during the period from May to October, several northern areas face a significant water shortage. The Northern Province receives very little rainfall from the southwest monsoon from May to September. Due to this, the replenishment of both groundwater and surface water is significantly low,” Mr. Pradiparaja said.
In recent times, the problem of groundwater salinisation has alarmingly intensified in many parts of the Peninsula. To face this challenge, extensive studies should be conducted on the use, management, and development of groundwater resources in the Peninsula, said Jaffna University’s sociology professor, I. Sivachandran.
He said the Water Resources Board conducted several studies on underground saline water, the feasibility of drilling tube wells, and irrigation development, but the reports had not been formally published to date.
“There is an unprecedented need to think anew about the problems related to water resources in the Jaffna peninsula and the ways to solve them,” he said. Environmental scientists are working to prevent the intrusion of seawater into the aquifers of the peninsula (Sundikulam in the Vallai-Navakkuli area), deepen the aquifers, and prepare the land in such a way that it could retain the rainwater to provide water to the people.
They demand that measures be taken to prevent groundwater pollution and implement public sanitation mechanisms by making water supplies available to the people.
Although the call for better management of water sources in the Northern Province and conservation of freshwater sources in the Jaffna Peninsula has intensified in recent times, the idea dates back to the time of the Dutch rulers about 350 years ago.
It is reported that Dutch Commander Kenril Vanreedil (Uiwayain Rnanesadaina Ein Sunananadana) had suggested that the peninsula’s freshwater resources could be protected by constructing flood control dams in the Tondeimanaru and Navakkuli watersheds.
In 1879, Governor Twinham of the Northern Province attempted to build a dam, but the idea was abandoned in 1883 after a major flood attributed to the eruption of the Krakatoa volcano in Indonesia.
In 1916, Governor Horace Berg built a dam across the Kavaccheri Road to manage and conserve the freshwater of Vadamarachchi. But the project was stalled after four years due to a lack of funding.
During the 1930s, Northern Province Regional Irrigation Engineer Webb initiated a project to build a dam at Thondamanar and Ariyalai. Due to the Second World War, the project was delayed, but was resumed in 1947 and completed in 1953. These wooden dams decayed over time due to seawater intrusion.
During the British colonial period, proposals to convert Aneiravu Nereri, Thondaimanaru Nereri, and Upparu Nereri (Navakkuli) into freshwater reservoirs were considered. In the 1930s, National State Council member K Balasingham suggested the need for the desalination of brackish water lakes.
In 1950, S. Arumugam, an irrigation engineer, proposed a water resource development plan for Jaffna. This project was later known as the ‘Arumugam Project’ and ‘the River Project for Jaffna.’
The Arumugam project sought to divert the river water flowing from Pudukudirippu in the north to the east of the Kandy road to the Aniyaru aquifer, turning it into a freshwater lake. But the project was not implemented.
Irrigation experts say if the 77-square-kilometer Aneiravu dam is built, rainwater from the 940-square-kilometer Vanni region will flow through tiny streams, notably Kanakarayan, to the Aneiravu Lake in the east via Sundikulam and to the sea via Aneiravu in the west. A large amount of fresh water can be stored in Aneiravu Lake by building dams across these streams.
The Aneiravu Road System prevents seawater from flowing into the Aneiravu Lake on the west coast. However, the embankment and the excess water disposal mechanism in the Sundikulam area have been damaged and sea water is entering through them. This must be fixed, the experts say.
They say that by constructing seawater retention dams in two layers, seawater can be prevented from entering the ground during droughts. That can maintain fresh water in the Aneiravu Lake.
The summer rainwater in the Aliawela area flows through Maruthangeni, Sembianpattu, Nagar Kovil, Amban, and Kudattanei, and then flows under the bridge, crossing Painthodi, Parutthurai, and Kodigamam before flowing into the sea through Mandan.
Thondiman Aru is a canal cut by Tamil king Thondaiman to prevent the fishing holes from being swept away by the strong sea winds during the northeast monsoon. Rainwater can be trapped by closing this and other canals under the current development projects.
The canal flows through Vannathipalam, passes through Puttur, Neerveli, and Koppai, crosses the Kaithadi Koppai Bridge, and joins the sea at Kaithadi and Navakkuli. It is known as Upparu.
In the cases of Thondeimanaru Embankment and Navakkuli Embankment, too, double-layer retention dams are proposed. By connecting the Upparu aquifer and the Vadamarachchi Lake, a huge freshwater lake of 170 square kilometers can be created from Aneiravu to Ariyalei, irrigation experts say.
Apart from that, some other lakes around the Jaffna Peninsula can be desalinated without much material cost, they say. For example, the water in the lagoon that separates the Mandaithiv and Velanai regions can easily be converted into fresh water.
Freshwater projects such as these can increase the availability of fresh water, remove the salinity of the land and turn it into fertile farmland. This will give hope for the Jaffna Peninsula, which is suffering from land and water scarcity.