East Africa’s Rift Valley lakes are expanding, endangering the communities that live on their shores and the animals that exist alongside.
Marooned giraffes, fleeing flamingoes and stranded impalas: in recent years the rising water levels in east Africa’s Rift Valley lakes have become the norm, displacing people, threatening wildlife and submerging schools and hotels.
The gradual rise was first noticed 10 years ago but was accelerated by heavy rains in 2019, according to Kenya’s principal secretary in the ministry of environment and forestry, Chris Kiptoo.
This year Lake Turkana, the northernmost lake in Kenya, was six metres deeper than usual by November. The International Union for Conservation of Nature (IUCN) has described the threat to the lake as “critical”. Its 2020 conservation outlook, published this month warns: “Lake Turkana’s unique qualities as a large lake in a desert environment are under threat as the demands for water for development escalate and the financial capital to build major dams becomes available.”
Experts have also expressed fears that two other Rift Valley lakes, Baringo and Bogoria, could merge with catastrophic ecological consequences. Comparative images taken by Nasa’s Earth Observatory in 2013 and 2020 show heavy deposits of sediment along the edges of the two lakes that are now 13km (8 miles) apart, down from 20km.
A government spokesman says Lake Baringo has expanded from 176 sq km (67 sq miles) to 260 sq km, while Bogoria has expanded from 34 sq km to 45 km sq. “Lake Bogoria National Reserve … has experienced a change in the lake ecosystem, leading to marked reduction in the number of flamingos from 1.5 million to fewer than 100,000.”
Lake Baringo is a freshwater habitat that hosts fish, Nile crocodiles, and hippos. Local people rely on its water for domestic use and farming. Lake Bogoria is alkaline and home to thousands of flamingoes that depend on the blue-green algae thriving in its waters. The hot water geysers and hot springs that used to attract tourists to the region lie buried underneath.
“Should the two lakes ever merge, fresh water from Baringo would dilute the alkali in Bogoria and reduce the growth of algae,” says Mark Boitt, a geographic information system expert. “Several years ago, a similar rise in the waters of Lake Nakuru caused millions of flamingoes to flee the lake for Bogoria. But for how long can they keep on moving? We stand at the threshold of rapid loss of biodiversity around the lakes.”
Already, the rising water levels in Baringo have affected wild animals residing on the lake’s Longcharo island as the waters reduce the size of the island and the areas for them to forage. In September, wildlife authorities relocated ostriches, impalas and warthogs to a conservancy on the mainland. Earlier this month, two of the eight giraffes marooned on the island were also moved to safety.
“Moving a giraffe is a delicate process. We have to survey the habitat and make sure we anchor the barge in a manner that makes it easy for the giraffes to enter without causing them unnecessary stress,” says Jackson Komen, a warden for the Kenya Wildlife Service in Baringo. “It took a whole day just to move one giraffe, with the barge taking at least two hours to get to the mainland. The remaining ones, including some pregnant females, will be moved a little later.”
The government has appointed a multi-agency technical committee to investigate the cause of rising water levels in the lakes, with the final report due for release in the coming days.
Silas Simiyu, a local geologist, says human activity around the water catchment areas is a key reason for the rising water levels.
“We may be talking of increased water volume but forget that it is the lakes’ capacity to hold water that has reduced. Water from underground aquifers has always risen depending on the tectonic movement cycles. But never have the lakes been silted as they are today,” says Simiyu. “Rather than act like deep bowls that can hold more water, the lakes are becoming wide, thin-rimmed pans due to siltation.”
He says: “Some talk of increased rainfall, but the ongoing rains are not the heaviest to be witnessed in these areas. Let us accept that our own activities have exacerbated the problem.”
Susan Jepkemoi, an environmental scientist with the Great Rift Centre for Research and Development, says the population increase has come with demand for more farmland, and more people have settled close to the lakes.
“Change in land use without regard for the environment will have serious climatic consequences on these lakes,” she says. “People around the lakes continue to cut down trees for charcoal burning. This depletes the ground cover leading to flooding. The runoff water takes with it the top soil to the lakes, the lowest points in the Rift Valley, and leads to silting.”
The phenomenon has brought upheaval for local communities. As the water has pushed further inland, grazing fields have continued to shrink and churches, schools and hospitals that were in use at the start of the year now lie in ruins.
“Take a boat ride here and chances are that you will be riding on top of multi-storey buildings, the relics of a lost city,” says Francis Cherutich, a tour guide in Baringo.
For 83-year-old Kangogo Arap Kipotota, his small grocery shop at Kampi Ya Samaki township doubles as his home. His former house lies submerged several miles from the shop. He remembers the lake swelling in 1961, but nowhere near the current levels. Back then, it was a long walk to get to the lake. Now it is almost at his shop. Like other residents, he fears he may have to move to higher ground again.
“The lake was so far out that I would graze our sheep and goats beyond that tree,” he says, pointing to a tree trunk more than 500 metres from his shop. “We would walk in the shallow edges of the lake. You cannot try that now since crocodiles and hippos have become our closet neighbours.”
Both lakes are Important bird areas that attract thousands of ornithologists from all over the world. However, a 2019 assessment of Baringo and Bogoria by BirdLife International put their threat status as “very high”.
The local hospitality industry has also been hit hard by the rising waters. Hotels and lodges that relied on tourism have been either partly or completely submerged. At Soi Safari Lodge in Baringo, the only visible part of a hall styled after the traditional African hut is the roof. As recently as July, the building stood 800 metres away from the original lake’s shoreline.
“Covid-19 took away the hotel business. Now the lake has taken the hotel. And there seems to be no end to the lake’s encroachment on the properties,” says Peter Chebii, a manager at the hotel.
With no sign of the waters receding, Boitt warns: “We have failed to protect the environment and are now reaping the bitter fruits. We either reform or lose our livelihood when the land – laid bare through over-cultivation – fights back using the lakes. Only we can put on the brakes. But can we?”