Increased deforestation upstream and land cultivation along river banks are some of the biggest causes of siltation in major rivers across the country as well as Lake Victoria.
The massive silt consignment that has been deposited in the lake in the last decade has drastically reduced the water table and occasionally resulted in floods across the Lake region basin.
Floods witnessed in 2020 and 2021 in Nyatike Sub County have been heavily linked to the rising water table in Lake Victoria.
According to Lake Victoria Basin Eco-Region Research Programme Report-KEFRI (2021), at least three million tonnes of soil gets into the lake annually in Kenya.
Consequently, a None Governmental Organisation (NGO) in Migori County, Green Life, has embarked on an initiative to address the silt problem by planting trees along the Migori river banks to reduce soil erosion and mudslides.
Green Life official Mr. John Bosco says that erosion and mudslides along the major rivers were the principal causes of siltation.
The organisation’s core function is to increase the tree population along the river banks to conserve the environment and curb soil erosion, says Bosco, adding that the initiative aimed at discouraging land cultivation along the river banks.
Through a collaboration with the Kenya Forestry Research Institute (KEFRI), Green Life has been getting professional advice on the type of seedlings to plant along the river banks and other riparian lands within the county.
The Kenyan Law defines riparian land as being a minimum of 6 meters to a maximum of 30 meters on either side of a river bank to curb river bank cultivation.
The conservator called upon the Migori residents to adhere to the government policy of 30 meters of cultivation from the river banks to reduce erosion and farm input chemical pollutants.
Many farmers along the river banks plant eucalyptus trees for commercial purposes but according to Bosco, the trees are heavy consumers of water.
His advice to farmers is to focus on bamboo and acacia trees that could tightly hold the soils together and utilise less water.
By holding the soils together, the trees prevent landslides that are occasioned by the loosening of soils due to wetness below the surface caused by running waters and river engorgement.
“As much as we are trying to address the issues of soil erosion and siltation in our rivers and the lake, we should not plant trees that will end up drying our natural water bodies and wetlands,” Bosco cautioned.
The organisation has highly complemented the Kenya Forest Service (KFS) mandate of sensitising farmers on the importance of planting and conserving trees along the river banks, homesteads, and government forest reserves.
“We have been working with KFS in conserving our river banks more so River Migori to address issues of soil erosion and siltation witnessed both in our rivers and Lake Victoria,” said Bosco.
Migori County KFS Ecosystem Conservator Mr. Joseph Wakiaga says that they have been engaging with various NGOs to ensure forest cover is protected and improved. Since 2013, the county has witnessed an increase in forest cover from 0.6 to 2 per cent.
Wakiaga adds that environmental restoration is a collective responsibility that local residents should embrace with the full support of both the local and national governments.
The conservator assures that the KFS will continue partnering with environmentalists and conservators to ensure that the river banks and other riparian lands are conserved and protected through tree planting.
Although siltation is the biggest culprit of the rising waters in Lake Victoria, the garbage waste has also played a part.
Fisheries Officer Kennedy Omondi acknowledges that in less than 10 years, lake waters have moved more than 50 meters inland.
The officers added that some of the landing sites like Sori in Nyatike have been partially submerged due to the rising waters triggered by siltation and garbage waste in the lake.
Omondi said that if the problem of water siltation and garbage dump is not addressed, residents living along the shores of the lake would keep moving inlands due to water engorgement.
Omondi said that the decline of fish in Lake Victoria has been occasioned by siltation menace that has seen the majority of fish farmers turning to fish caging to sustain their livelihood.
“Fish from shallow waters like Nile Perch cannot be fished because of the rising water table in the lake that has greatly reduced their population, the harvest, and livelihood of our fishermen,” noted Omondi.
By Geoffrey Makokha and George Agimba
