Lake Nyos - Weakening Dam

Weakening Dam

On August 18, 2005, Dr. Isaac Njilah, a geologist at the University of Yaoundé, suggested that the natural dam of volcanic rock that keeps in the lake's waters could collapse in the near future. Erosion has worn the dam away, causing holes and pockets to develop in the dam's upper layer, and water already passes through the lower section. Meanwhile, landslides have reduced dam strength on the outside. Seismic activity caused by the lake's volcanic foundation could thus cause the lake wall to give way, resulting in up to 50 million cubic metres (1.8 billion cu ft) of water flooding downhill into areas of the Northwest Province and the Nigerian states of Taraba and Benue. Dr. Njilah estimates that the area is home to more than 10,000 people.

The Cameroonian government, speaking through Dr. Gregory Tanyi-Leke of the Institute of Mining and Geological Research, acknowledges the weakening wall but denies that it presents any immediate threat. A United Nations team led by Olaf Van Duin and Nisa Nurmohamed of the Netherlands Ministry of Transport and Public Works inspected the dam over three days in September 2005 and confirmed that the natural lip had weakened. Van Duin believed that the dam would breach within the next 10 or 20 years.

One possible means of averting such a catastrophe would be to strengthen the lake wall, though this would take much time and money. Engineers could also introduce a channel to allow excess water to drain; if the water level were lowered by about 20 metres (66 ft), the pressure on the wall would be reduced significantly.