• The lake has overflown into Lake Nakuru National Park boundary to the West.
• More than 500 households have been affected in Naivasha.
The swelling of Lake Naivasha has been attributed to siltation.
A scientist said people cultivating upstream has loosened the soil, which is swept into the lake by downpours. The lake has overflown into Lake Nakuru National Park boundary to the West.
“Due to poor farming methods, the soils become loose and are swept downstream into the lake,” he told the Star on the phone.
The scientist spoke on condition of anonymity for fear that he would be seen to be painting the authorities in a bad light. He emphasised the need to improve vegetation and build dams to fix the problem.
Even though geologists should confirm why some areas are caving in, the idea that soil has been weakened could be a factor, he said.
The expert said Lake Naivasha water has browned, an indication that turbidity is very high. “The water from upstream needs to be diverted to dams to reduce siltation,” he said.
For his part, however, Lake Naivasha Riparian Association manager Silas Wanjala said the swelling can be attributed to different causes.
“The swelling of the lake as a result of silting is up to a certain extent,” he said.
Wanjala said the lake is silting up at an average of two to three centimetres per year. He said silt does not go deep into the lake as it is prevented by papyrus.
He attributed the rise in water levels to heavy rains, which, he added, are due to the rising heat in the Indian Ocean.
"It is not normal to have rains in January and December,” he said.
Wanjala said rains of up to 1890.75 metres above the sea level were recorded between 1964 and 1965. The trends of the rising water levels in Lake Naivasha have previously been witnessed in 2013, 2016, November 2019.
Already, the weatherman has warned that the rains will continue for two more weeks. The intensity of rains may reduce next month but rains are only expected to cease from May 21, mostly in Eastern Kenya.
“The western parts of Kenya, parts of central Rift Valley (Nakuru, Laikipia, Baringo) and the coastal strip are expected to continue receiving rainfall into June,” said Stella Aura, the Kenya Meteorological Department director.
Wanjala said houses of about 500 families who had encroached on riparian areas have been submerged following the rise in water levels.
“It is a big win for conservationists who have been agitating for the protection of riparian land as water has marked them. Those who had encroached before putting up structures have encountered losses,” Wanjala said.
Siltation is, however, not limited to Lake Naivasha alone. Lake Nakuru faces a similar problem.
On Sunday, Nakuru Governor Lee Kinyanjui said in a statement that heavy rains in the Mau region and the Bahati catchment area had increased water inflows into the two lakes.
The governor issued a red alert to people living near the lake, especially in the Barut area. He said a section of Kihoto area was at high risk of flooding.
"In view of the above, we wish to advise persons living near the two lakes to be extra vigilant and monitor the emerging threat of flooding."
Kinyanjui said effective mitigation measures were being put in place, and the county government would dispatch an emergency response team to map out homes in imminent danger.