- Lake level rise has led to submergence of nearly all riparian land, destruction of crops and structure and displacement of thousands of people.
- In Baringo, schools, hospitals, hotels and roads several kilometres from the shores of Lake Baringo were submerged.
Image: LOISE MACHARIA
About 76,000 families have been displaced by swelling lakes in Rift Valley since the mysterious increase in water bodies started in 2010, a scientist has said.
Thechla Mutia, a senior environment and natural resource scientist, said lake level rise has led to submergence of nearly all riparian land, destruction of crops and structure and displacement of thousands of people. Mutia is attached to the Geothermal Development Company in Nakuru.
Speaking during a recent workshop for journalists organised by Internews’ Earth Journalist Network in collaboration with Egerton University, Mutia said the water rise in lakes and dams in Rift Valley started in September 2010 and significantly spread to many areas in 2013.
“The situation worsened during the 2019 mild El nino periods as per the Kenya Meteorological Department,” she said.
The situation led to the loss of livelihoods, injuries, disease outbreaks, security and safety implications and negative mental, physical and social effects on human lives.
Mutia added that the displacements led to the loss of services, socio-economic disruption and ecological or environmental degradation.
In Baringo, schools, hospitals, hotels and roads, situated within several kilometres from the shores of Lake Baringo, were submerged as residents feared that the fast growing lake might join neighbouring lakes Bogoria and 94.
Previous reports indicated that several islands in Lake Baringo were almost covered up by water, forcing Kenya Wildlife Service to relocate animals living there.
Mutia said an interplay of factors contributed to the increased water levels, among them increased moisture availability as seen in the discharge of rivers feeding the lakes, and increased runoff due to land-use changes.
“Change of land use has over time added to siltation of the lakes as shown by sedimentation and sediment load in the rivers,” she said.
She said the severity of land degradation has resulted in higher rainfall runoff from land and less percolation in groundwater systems, leading to larger volumes of water flowing directly and rapidly from the land surface into the lakes.
Image: LOISE MACHARIA
The scientist said Rift Valley’s geologic structures were also at play in the swelling-lakes mystery, saying the water bodies were in faulted terrains (controlled by geological structures) that were geologically active.
“The geological activities affect water composition and biodiversity, which can explain the absence of flamingoes whose feeding is supported by algae growth, that has been affected by the change in alkalinity of the waters of Lakes Nakuru, Bogoria, Magadi and Elementaita,” she said.
Tabling the extent of the swelling lakes as mapped from the Kenya Topographical sheers and land satellite imaged in 2010, 2014 and 2020, Lake Victoria has also been affected by the phenomenon, having expanded by 542 square kilometres from the original 3971 square kilometres before 2010 to 4572 square kilometres in 2020.
According to the chart presented by Mutia, the expansion has been progressive starting in 2010 where it grew to 4,030 square kilometres, then to 4,421 square kilometres in 2014 and 4,572 in 2020.
Lake Baringo was the second-worst affected as it swelled by more than double its original size from 128 square kilometres in 2010 to 268 square kilometres in 2020 as Lake Olbolosat in Nyandarua expanded from 18 square kilometres in 2010 to 52 square kilometres in 10 years.
Turkwel Dam was not spared as it swelled from 18.97 square kilometres in 2010 to 59.27 in 2020.
Last year, the government issued several alerts for people downstream of the Tukwel dam to relocate to safe grounds as it was on the verge of breaking its bank.
Mutia recommended flood control and catchment-wide conservation practices to reduce the impact of floodwaters on lives, livelihoods and property.
She cited the need to rehabilitate, relocate and restore damaged infrastructure such as water supplies, sewerage plants, health centres, electricity supplies, roads, schools, police stations and posts.
"The government and the relevant agencies should conduct a focused study on hydrochemistry of the lakes, particularly on isotope studies and carbon dioxide saturation monitoring, to understand the lake dynamics, as well as the associated hazards due to swelling,” she said.
Mutia reiterated the need to conduct studies on land use/land cover, as well as water balance studies on all lakes and their respective basins, to inform the establishment of the highest water point under the worst-case scenarios in the history of the lakes.
She said the study would help in defining and demarcating the lake boundaries and urged the government to buy off the affected areas to create a buffer zone.
She added that drilling and installation of groundwater monitoring boreholes would help determine the likelihood of episodic recharge within the aquifers due to heavy rainfall against groundwater saturation potential.
-Edited by SKanyara