Residents living along the River Tana, particularly in Garissa and Tana River counties, have been urged to prepare to move to higher ground as Kenya braces for heavy rains that could increase the risk of flooding downstream.
Water Cabinet Secretary Eric Mugaa said the expected rains, linked to El Niño and the Indian Ocean Dipole, could fill the Seven Forks dams and force operators to release excess water through spillways.
The dams Masinga, Kamburu, Gitaru, Kindaruma and Kiambere form a cascade along the River Tana, with water from one reservoir flowing into the next before eventually returning to the river.
Mugaa warned that the biggest risk would arise if several dams reached capacity and released water at the same time.
“The challenge we risk is that when our dams become full, and water starts passing through the spillways, particularly where dams are arranged in series with one downstream of another, all that water eventually returns to the river course.”
Although the dams are designed to withstand major flood events with return periods of between 25 and 100 years, Mugaa said simultaneous releases could significantly increase the volume of water flowing downstream.
He said low-lying areas were particularly vulnerable because the river becomes flatter downstream, reducing its ability to accommodate large volumes of water.
“We therefore risk flooding downstream, especially in areas where the terrain becomes flatter as the river reaches its mature stage.”
Mugaa urged communities in flood-prone areas to act before water levels rise by moving families, livestock and valuable property to safer, elevated areas.
He said the government’s immediate priority was to ensure any dam releases were safely managed while minimising the impact on communities downstream.
In the longer term, the government plans to expand the country’s water storage capacity through funding from the National Infrastructure Fund. Mugaa said the construction of a single mega-dam could cost between Sh20 billion and Sh40 billion.
The government is also reviving plans to construct a canal that would divert part of the River Tana into an inland swamp, a measure Mugaa described as an important intervention in reducing flood risks.
Meanwhile, the expanded Bura Irrigation Scheme has a canal capable of carrying about 11,000 litres of water per second. Mugaa said the canal could be opened if river levels reach critical levels.
Authorities are therefore urging communities along the River Tana to take early precautions and avoid waiting until flooding begins before moving to safer ground.
