by Dann Okoth and Harold Ayodo
Nam dar (the lake is disappearing). That is how besieged locals sum up the unfolding events on Lake Victoria.
They cannot fathom the hidden forces behind the slow but systematic death of their source of livelihood and heritage.
Pointing to a pile of boulders hanging dangerously on the edge of a hill in the distance, James Mango Mark, 91, shows where the shoreline was when he arrived at Got Kachola beach in Nyatike Migori District in the late 1930s. "If we wound back the hands of time to 1962, we would be standing deep in the lake," he says wryly.
Climate change, invasive plant species, hydroelectric projects and pollution contribute to decline of the water mass |
Mr Maurice Ochieng’, a fisherman for over 30 years, says he can barely make ends meet because fish catches have drastically reduced. "Many of my colleagues have ditched the trade for boda boda (bicycle taxi) business," he says.
According to the National Aeronautics and Space Administration (Nasa) water levels in the lake has dropped by over one metre annually since 2005 but some estimate the drop at three metres.
Receding lake
Evidence that the lake is receding can be seen in most of the over 300 fish jetties that are no longer in use because they now stand on dry land.
Kenya Marine and Fisheries Research Institute principal research officer John Gichuki warns that the lake could dry up within a century. "The lowest water levels in the lake was recorded in 1952 and prevailing trends show it would dry up within 100 years," Dr Gichuki says.
He says the recession of the lake has negatively affected flora and fauna. "We are now forced to fish in the deeper waters," Mark says.
As fishermen complain of reduced catches, researchers attribute the scarcity to destruction of breeding areas following the recession of the lake.
And this has brought conflicts with neighbouring countries. The Kenya Fisheries Department estimates that thousands of Kenyan fishermen have been arrested in Uganda and Tanzania in recent years.
Estimates place the number of people eking their livelihood from Lake Victoria as high as 30 million. Most of them are poor fishermen and subsistence farmers.
Despite its distress, Lake Victoria is stunning at dawn. As the day begins along her shores, fishermen hoist the patchwork canvas sails of their handmade boats to a riot of birdcalls. Hippos break the water’s glassy surface with their broad snouts and snowy white egrets swoop gracefully in the rich golden light.
But beneath the scenic beauty is a grim future looms for this great lake. Rising temperatures, invasive species, hydroelectric projects and millions of poor fishermen all play a part in the environmental crisis that threatens to add Lake Victoria to the growing list of the world’s dying lakes.
Fish stocks
In paper: Status of the Lake Victoria Environment – Trends and Impacts to Fish Stocks researchers say nearly 76 per cent of the water leaves the lake through evaporation from its surface. Another 24 per cent leaves largely by way of the Nile Victoria.
A study by the International Rivers Network say as much as 55 per cent of the lake’s dramatic shrinkage could be attributed to recent hydroelectric dam projects.
Kiira dam, built in 1999 alongside the 1954 Owen Falls dam, uses the lake’s waters to generate power for Uganda and neighbouring nations. Both dams operate at the source of the Nile River.
Experts say Kiira dam draws excessively from the lake even as it falls short of the electricity it was built to produce.
The recent construction of the Bujugali dam to supplement power generation of the Kiira and Owen Falls dams has escalated the water loss. Marine researchers Dr Albert Getabu, Dr Mureithi Njiru and Caroline Lwenya say increased outflows at Jinja for power generation accounted for 45 per cent of the total reduction between 2001 and 2004.
Nasa revealed in 2006, through its Jason-1 satellite that the lake had reached lows not seen since before the Owen Falls Dam was built in 1954. The dramatic drop in water levels was revealed during routine monitoring conducted by the Global Reservoir and Lake Monitor Project.
Experts say the gradual drop is threatening communities that rely on the lake for water, work, power, and food.
But the story told by water levels is complicated. Thirteen years of measurements by satellite radar altimeters combined with historical ground measurements reveal the lake’s volatile past.
river inflows
Researchers say the capacity of water in the lake is mainly regulated by rainfall, catchment river inflows, evaporation and River Nile outflows. "Water levels have fallen as a result of reduced rain, inflows and increased outflows following excess releases at Jinja, Uganda," Lwenya says.
The main rivers that flow into Lake Victoria from Kenya are Sio, Nzoia and Yala, Nyando, Sondu-Mir iu, North Awach, South Awach and Kuja Migori.
Environmental problems at the lake are many. Invasive plants like water hyacinth and hippo grass bloom unchallenged, clogging entire sections of the Kisumu port.
Eroded fertilised soils from agricultural lands around the lake’s catchments flow into the rivers that feed Victoria, which provide the noxious weeds with nutrients, thereby exacerbating the problem
With fishermen reporting shifting weather patterns and receding water, it seems drought and climate change have been added the list of the lake’s ills. But scientists say these meteorological factors aren’t entirely to blame.
A rapid assessment on the impacts of declining levels of the lake found that though Owen falls dam was designed to generate hydropow er without disrupting the natural flow of the water from the lake but problems began in 2002 when Uganda finished building the Kiira hydropower complex in the Eastern town of Jinja. Despite the outcry Uganda has now commissioned the construction of a third dam.
