Nigerian authorities are taking steps to prevent a possible humanitarian disaster ahead of the flooding that would result if a dike failed in a crater lake in neighboring Cameroon. There are new warnings that a natural barrier hemming in the lake waters is on the brink of collapse. The Cameroon government has said there is nothing to fear. From Doula, Cameroon, Voice of America English to Africa Service reporter Ntaryike Divine, Jr. says Nigerians are concerned about a new report that says the dam in Lake Nyos may soon collapse. 

The report was issued by the U.N. Office for the Coordination of Humanitarian Affairs [OCHA] and the U.N. Environment Program [UNEP].

If the dam did fail, lake waters would rush downstream, flooding several villages in Cameroon and Nigeria. Hundreds of thousands of people would be killed, and livestock and farmlands would be destroyed.

The large lake lies high on the flank of an inactive volcano. Its water is hemmed in by a natural dike of volcanic rock that geologists say has weakened considerably over time. Experts at Cameroon's Institute of Mining and Geological Research have downplayed these fears. They acknowledge the dam has weakened but deny there?s an immediate threat of collapse.

But a U.N. team inspecting the dam three years ago said it had sagged seriously and would not last another two decades. They said the slightest tremor would cause it to crumble and recommended that the dam be reinforced or some of the water be released to curb pressure on the dike. But the Cameroon government said those measures were too expensive.

Officials in Nigeria?s Benue State are taking preemptive measures. They?re building resettlement camps with a $500,000 allotment from the Federal Government.

At least 11 settlements in the state have been identified as high-risk zones. The governor, Gabriel Tor-Suswan, has urged the Nigerian National Assembly to authorize the purchase of relief equipment, including helicopters.

He told the Nigerian Daily Trust newspaper the U.N. report recommended the Federal Government spend $15 million over the next two years to prepare for the humanitarian help that might be necessary. The Benue State Executive Council has ruled that the threat is real.

Lake Nyos hit the headlines in August 1986 when it suddenly emitted large clouds of carbon dioxide. The gas killed 1,700 people and 3,500 livestock in surrounding villages in Cameroon. Scientists rushed to the area to study the event. They said it was the first-known large-scale asphyxiation brought about by natural causes. They suspected that pockets of magma - molton rock beneath the earth?s surface - lying beneath the lake leaked carbon dioxide into the water, causing it to change into toxic carbonic oxide.

To prevent a repeat, American scientists installed a degassing tube in the lake in 2001. It regularly siphons water saturated with carbon dioxide, taking the gas from the lake bottom to the surface and releasing it gradually in safe quantities. The same process is used at another Cameroonian lake at Mounoun. Experts say more tubes are needed. The government hopes relief and humanitarian groups will help.

Meanwhile, Cameroon continues its preparations for the current threat from Lake Nyos ? the possible failure of the dam.