Kantale Dam Disaster 35 years later

by R.C. Jayasinghe

The Kantale Dam disaster of April 20, 1986 is considered the worst dam disaster in Sri Lanka’s recent history.

The day before the disaster, a simple ceremony was held to distribute water for the Yala cultivating season from the Kantale tank, brimful at full capacity (114,000 Ac. ft. – 140.22 MCM – Head of Water 38.75 ft – 11.81 m).

At that time, I was working as a Divisional Assistant and late Mr. Senawatta was the Divisional Irrigation Engineer of Kantale. He and I attended this water distribution ceremony organized by the farmer community.

Early on April 20, Divisional Irrigation Engineer (DIE) Senawatte drove to my quarters at full-pelt with his vehicle siren screaming. Two other officers working with me were also in the quarters and we were reluctant to open the door due to the terrorist activity at the time in the Kantale area.

We heard Mr. Senawatta shouting and we rushed with him to check the LB (left bank) dam sluice. When we reached the bund close to the LB sluice, there was a crack on top of the bund and an unusual sound from the sluice.

Within half an hour Kantale dam began breaching with a gap about one meter wide which grew to 300 meters emptying the tank completely within 24 hours.

Later that morning the late Mr. Sinnappu, the Deputy Director of Irrigation DDI), visited the site and issued necessary instructions to immediately evacuate the people who were living downstream of the dam.

DDI Sinnappu informed the Government Agent of Trincomalee and other relevant line departments to assist an emergency rescue and evacuation program that was immediately begun. At the request of the GA and DDI, the Sri Lankan Army, Air Force, Navy and the Police joined the rescue effort..

On April 21, the Director of Irrigation with the Minister of Mahaweli and Irrigation late Gamini Dissanayaka visited the affected sites and provided instructions on immediate measures to be taken to assist the victims of the disaster and begin reconstruction of the breached dam, sluice and downstream system.

More than 100 people who lived in a village called Kovilgama, downstream from the tank lost their lives and about 1,600 houses were damaged. Around 2,000 acres of paddy land were silted..

Within a week of the disaster, we completed all the investigation work including surveying and leveling and in a month’s time all necessary technical data and completed estimates were read for approval.

Immediately after finalizing the design and re-construction plan, the work of rebuilding the breached bund and LB.sluice was assigned to the Swedish company, SKANSKA, and the late Mr. Samarasinghe was appointed as the Chief Irrigation Engineer for the Head Works. Downstream improvements were done by the Divisional Irrigation Engineer’s office, Kantale. The dam construction, sluice and downstream system, was completed within two years and the tank was again impounded in the 2008 Yala season.

After this major disaster, the Irrigation Department established a new division called Dam Safety which is now functioning effectively. In 2003 , I was transferred to Kantale as the Divisional Irrigation Engineer and with my past experiences and the guidance from the Deputy Director of Irrigation, Trincomalee Range, Mr. Shanmugasivanandan, Kantale and Vendrasan tanks were well maintained and lot of improvements were made with the support and directions of the Deputy Director (Dam Safety) Ms. Kamalasena.

When the tsunami struck on December 26, 2004 , people living downstream of the Kantale tank panicked due to the massive destruction in Thampalagama area fearing another dam disaster. But they soon learned that that what had happened was due to sea water coming inland as a result of the tsunami and not from a dam disaster.

Twenty years after the disaster, a ‘Review Session Program’ was organized in 2006 by the Dam Safety Division and late Mr. Senawatta and I attended it. Farmers and villagers were given the opportunity to speak there about safety concerns and convey their problems to Irrigation Department officials.

I hope that the Kantale Dam Disaster would be the first and the last major dam disaster in Sri Lanka because the Irrigation Department is now closely monitoring all major dams using modern technology.

(The writer is a former Irrigation Engineer now working as Quality Assurance Manager road projects of Nawaloka Construction Company (Pvt) Ltd. – 071-4465287)