Kenyan geologists have launched a fresh assessment of rising water levels in Rift Valley lakes to establish whether geological changes beneath the earth’s surface are contributing to the phenomenon, which has displaced communities, submerged farms and altered wildlife habitats.
The investigation comes as scientists intensify monitoring of the East African Rift, where continuing tectonic activity has raised questions about changes in underground water pathways.
The Geologists Registration Board has in recent weeks examined lakes Baringo, Bogoria, Solai, Nakuru, Elementaita and Naivasha to establish the causes of the rising water levels.
Board registrar and chief executive officer Enock Kipseba said the team was seeking to determine whether geological processes were playing a role alongside rainfall and groundwater recharge. “We want to find out the kind of geological factors contributing to the rising levels of the lakes.”
The scientists are examining several possible explanations, including increased rainfall, groundwater recharge, land degradation and erosion, and movement along active faults associated with the East African Rift.
Board chair Lonjomon Biwott said the investigation was particularly important because the lakes lie within an active geological system undergoing continuous change. “The issue really is the lakes are in the rifts and we are all aware the rifts are undergoing changes.”
One possibility being investigated is whether sections of the rift are subsiding, potentially altering underground channels through which water normally drains.
Biwott said downward movement could tighten faults and restrict groundwater from seeping deeper underground, causing more water to remain within lake basins.
“As it moves down it closes the fault tightly so that the seepage of the groundwater is blocked,” he said, adding that further studies would establish more factors.
Researchers from the University of Nairobi are also conducting seismic analysis using monitoring equipment installed in the Rift Valley to establish the nature and extent of underground movements.
The geologists are collecting water samples to determine whether changes in water composition could provide clues about underground processes.
Scientists caution that tectonic activity is only one of several factors under study.
Rainfall and groundwater remain key considerations, particularly as Kenya approaches the October-November-December wet season, when meteorological authorities expect above-normal rainfall associated with El Niño conditions.
The additional rainfall could worsen flooding around lakes whose levels have risen significantly.
Hydrogeologist Agnes Mbugua, a Ministry of Water official and board member, said Kenya should explore ways of harvesting excess water for use during future dry periods.
She proposed investment in reservoirs and underground aquifers as well as checking dams and possible inter-basin water transfers, saying Kenya should turn the current abundance of water in the Rift Valley into a long-term resource without harming communities or biodiversity.
