Mystery rocks Lake Bogoria as geysers fade

The state of the geysers in 2019. Two years ago, they could go as high as 30 meters. [Kipsang Joseph, Standard]
Richard Yegon takes slow steps, his jacket hung on his shoulder, as he glances at a swollen Lake Bogoria.

His sight is still good, even under the striking sun rays, despite his age. Using his walking stick, he points at a lone bird perched on a tree sticking out of the water, almost 500 metres away.

“There! Over there by the Stone of Sandai, there used to be a geyser jetting over 30 metres high, but it has since been swallowed by the swelling lake. The lake has been swelling and swallowing the geysers,” Yegon, 72, says.

Wikipedia describes a geyser as a “spring characterised by intermittent discharge of water ejected turbulently and accompanied by steam”. As a fairly rare phenomenon, says Wikipedia, formation of geysers is due to particular hydrogeological conditions that exist only in a few places on earth.

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Yegon, an Endorois elder, was born and bred in Baringo County. Over the years, he has documented every development in the lake, with almost every spot having a landmark or name the community coined to help in giving directions.

“I have boiled maize and eggs using the geysers and licked the salt residue on the stones to cure stomach aches. I have also been bringing my cattle here to lick salt,” Yegon said.

Amidst the memories tied to almost every aspect of the expansive lake, also lies nostalgia of the once glamorous geysers jetting water so high “that we dared not to go nearby”.

Yegon laments that the swelling lake has slowly swallowed the hot springs.

Springs jetting

“There were uncountable geysers and hot springs jetting water with so much pressure. It was magnificent. We used to sit at a distance as we let the steam bathe us,” Mr Yegon says.

The increasing water volumes, he says, remain a mystery too. 

“It cannot be rain because the lake has never been this swollen, even during the Elnino rains that have pounded this area leading to formation of Lake Kamnarok and Lake 94. It is a mystery, although our fathers believed once in every hundred years, the lake would swell,” he says.

The heaviest rainfall Yegon ever witnessed was between 1960 and 1963 and in 1994, which lead to formation of Lake 94.

Johana Karatu, 67, has also lived around the lake since he was born.

“There were so many hot springs and geysers here then, but the pressure started slowing when geothermal explorations started in Baringo and Nakuru counties. Every year, things have been changing here with the geysers reducing almost to mere bubbles,” Mr Karatu says.

Since 2011, he says, water volumes in the lakes have also increased. Karatu says local communities still hope the water volumes will reduce so the geysers can erupt one more time.

“We do not know when the water will subside, but we hope the geysers will once again erupt. However, we suspect geothermal activities have had an impact on the the swelling of the lake and diminishing geysers,” Karatu says.

Currently, the springs have been reduced to bubbles. Some of the residents have called for research to explain the change.

Geothermal exploration

“Geologists and researchers should tell us what is happening. We also want to know the impact of geothermal exploration on geysers,” Karatu says.

Lake Bogoria National Reserve warden James Kimaru says geysers have been reducing over time.

“The water volume in the lake has been increasing, covering some of the geysers,” says Mr Kimaru.

Florence Tanui, a geologist, says geysers are rare due to a combination of hydrogeological factors, including water, heat and unexpected plumbing beneath the surface of the earth.

“This phenomenon only exists in very few areas on earth, including our own Lake Bogoria. The heat needed for geysers to form originates from the magma chambers close to 2,000 meters deep,” says Ms  Tanui.

Lake Bogoria, she says, is widely known for the high-energy geysers on its western shores. The area is covered by volcanic rocks with a shallow magma chamber allowing formation of geysers. 

She, however, says eruptive activity of geysers may change over time as a result of fissures, earthquakes and human activity such as geothermal power plants.

“Geysers can become extinct or dormant due to installation of geothermal power stations within their vicinity. This is because drilling at the geothermal sites for steam extraction robs the geysers the water and the heat needed to sustain the pressure and may potentially lower the local water table to the point that geysers activity become unstable,” she adds.

When that happens, she says, geysers stop erupting and occur as bubbles before becoming extinct.

“The steam extraction leads to slow cooling of the magma environment eventually leading to dormancy or extinction of once eruptive geysers.”

Some of the world’s geysers, Ms Tanui says, have been extinguished by geothermal energy development and tourism activities.

“The Wairakei geyser in New Zealand that hosted the world’s second-largest geothermal power plant in 1958 became extinct following the site activity. The Nevada-Beowawe in north eastern Nevada in the United States also became extinct due to several geothermal power stations that were set up across the area,” she says.

She says geysers require close attention to establish possible impacts of geothermal activities as well as other human activities.

Water quality

Joseph Edebe, a researcher from Kenya Wildlife Service, says the rising water levels in Lake Bogoria may also influence the water quality, reducing the food base for flamingos.

“Lake Bogoria is a wetland of international importance as a Ramsar site and World Hertitage Site. The rise in water levels may influence the water quality, hence reduce the food base of lesser flamingos that depend on spirulina, an algae that grows in alkaline conditions,” says Mr Edebe.

The decline of food base, he says, may also result in the decline in flamingo numbers as well as change in the ecological characteristics of the lake.

He says KWS researchers are partnering with other stakeholders in monitoring water levels and quality in the affected lakes.

“An integrated management plan for the Lake Bogoria ecosystem is also being prepared by the local community, the county government of Baringo with technical support from KWS, a plan that will enhance the conservation of the lake,” says Edebe. 

Lake BogoriaStone of Sandaigeyser