By Ntaryike Divine JR
Nigeria’s National Emergency Authority (NEMA) warns that over 1 million people and 20,000 herds of livestock could perish if Cameroon’s Lake Nyos discharges 55 million cubic meters of water downstream because of unusually heavy rainfall worsened by severe disintegration of volcanic rock that forms the lake’s natural barrier.
The 200m-deep Lake Nyos captured global attention1986 when it spewed large clouds of carbon dioxide asphyxiating over 1,700 people and 3,500 livestock. It sits on a 1.5 square-kilometer crater on a defunct volcanic mountain in Cameroon’s remote northwest at the northern boundary of the Cameroon Volcanic Line, a zone of crustal weakness and volcanism.
Cameroon’s Lake Nyos (Top) threatens to kill over 1 million people because of flooding and disintegrating natural barrier. It asphyxiated thousands of people and animals in August 1986 (waterencyclopedia.com)
However, this doomsday scenario is already causing tension between Nigeria and Cameroon, a clear indication of the urgent need to harmonize or create regional water management policies as Nigeria fears that the damage to crops, buildings and infrastructure will run into billions of Naira.
“The eventual failure of the dam will result in the discharge of about 55 million cubic meters of water which will result in flooding downstream. It is estimated that between the Cameroon border and River Benue, some 50 settlements and over 15,000 hectares of land will be flooded,” said Zanna Muhammad, NEMA’s director of administration.
However, the Cameroon government has remained impassive, despite reiterated unease voiced by Nigeria over swelling of the collapse of a natural barrier retaining the waters at its Lake Nyos.
Amid ravaging floods that killed hundreds wrecked farmlands and subjected most of West Africa to increased disease and famine between July and September, Nigeria announced it had finalized a disaster-cushioning plan in expectation of an even more devastating calamity lurking just across the border with Cameroon at Lake Nyos.
NEMA warned that a volcanic rock forming the natural barrier containing the lake waters has severely disintegrated. It could snap at a short-notice or “any moment from now.” NEMA’s fears are hinged on a combination factors including ongoing erosion from rain, wind, the swelling lake waters, potential volcanic eruption and earthquake.
But one month after the alert was issued; the Cameroon government has remained aloof. An official with the country’s Institute of Mining and Geological Research [IMGR] which monitors the lake has however toned down the NEMA jitters.
“Nigeria’s preoccupation is based on findings dating back almost a decade. But we regularly survey the lake and I can confidently state there’s no immediate cause for concern,” he said on condition of anonymity because he lacked authority to speak on behalf of the government.
“Nonetheless, the government considers the matter sensitive. Nigeria has not contacted us to confirm anything, but unilaterally continues issuing these unscientific and dramatic alerts,” he added.
The NEMA panic has been regular since 2005 when the UN Office for the Coordination of Humanitarian Affairs (OCHA) and the United Nations Environment Program (UNEP) issued a joint report warning the lake wall had seriously sagged and could crumple within a decade. The report recommended the dike be solidified with concrete, or some of the lake waters released to ease the pressure on it.
“The government has the projects under consideration. But you’ll agree with me they are expensive ventures to undertake for a cash-strapped government, and besides it’s not a priority issue especially as our studies indicate there’s no immediate danger,” the IMGR source explained.
On August 21, 1986 when Lake Nyos coughed up large clouds carbon dioxide scientists thronged the scenefrom across the globe. They suspected that pockets of molten rock lying beneath the lake leaked carbon dioxide into the water, causing it to change into unstable and toxic carbonic acid. They concluded that degassing the lake by installing pipes to drain off gas-filled bottom layer watersand allow the carbon dioxide seep out in safe quantities atop was the best bet in avoiding a recurrence.
The installation of the self-powered vent tubes was completed last year. Michael Halbwachs of the French gas-extraction company DATA Environnement led the project that spanned a decade. He said some 200 million cubic meters of carbon dioxide ensnared beneath the lake will be pumped out within two years, eradicating all lingering dangers of another deadly outburst.
Meanwhile, an automatic alarm system has also been erected at the lake gateway to warn locals of any impending dangers.
However, the efforts have hardly mitigated the Nigerian apprehensions. In September, NEMA published a handbook designed to guide relief operations in the event of the Lake Nyos dam collapse. The document captioned, Lake Nyos Disaster Response Manual contains early warning system methods and detailed practical measures to abate the impacts of the imagined adversity in the Benue, Adamawa, Taraba, Cross River and Akwa-Ibom states close to the border with Cameroon.