How climate change threatens Lake Victoria basin

Homa Bay and the neighbouring Kisumu County, which ironically are on the shores of Lake Victoria, and parts of Vihiga and Kakamega counties in western Kenya, have since the beginning of the year been on a drought alert — with little or no rain at all, leading to rivers, boreholes and ponds drying up, and no pastures for animals.

This year’s drought was, ostensibly, an extension of last year’s dry spell which the Food and Agriculture’s Organisation (FAO) declared a “national disaster”. It put some 2.7 million people in dire need — the most vulnerable being the elderly, sick, mothers and children under five.

For Onyango, the rain even did worse. As soon as it started, he turned focus to tilling his 5-acre farm but the floods nearly swept away everything. In October, he was not so sure of what to do next.
“You cannot plant during the dry season. You cannot plant during the rainy season. It is like some of us are cursed,” he says as we walk around his shattered farm.

Officials say for rivers such as Mirui, Kuja, Awach, Mirui, and Nyando that run across the Kisumu and Homa Bay counties and other parts of western and central/rift valley regions of Kenya, some of which drain into Lake Victoria, drying up has become an annual routine.
“…but it is increasingly becoming complex and generating confusion,” says Leonard Omondi Akwany, a coordinator at Ecofinder Kenya, a civil society organisation trying to drum up advocacy to save part of Dunga beach wetland in Kisumu.
“If the rivers are not drying up, they are flooding,” Mr Akwany says, adding: “Extreme weather events such as floods and drought have become prevalent. Previously, communities thought that floods were the most serious but now, the drought is.”
Mr Akwany says when the rivers draining into the lake dry up, the focus turns to the lake.

The causes of the rivers drying up range from encroachment of the river catchment areas for crop cultivation or human settlement to massive deforestation, and changing weather patterns.

Fifteen years ago, 45-year-old Adam Kidega recalls returning to the lake shores at Dunga, a longtime fishing village south of Kisumu Town, after a night fishing with his boat full of fish.
“It was always a bonanza. Today, it is a very different story,” he recalls.

Despite spending a whole night out there on the lake, Kidega says like several other fishermen, one returns to the shore, with a handful of fish if lucky. If you want to be very lucky with the catch, you have to wander a little deeper into the lake, which is problematic, especially at night.

Both Onyango and Kidega’s accounts point to one thing — human activity is squarely to blame for the ever-changing climate.
The Dunga Beach area, like most parts of Kisumu Town bordering Lake Victoria, is heavily colonised by water hyacinth, putrid algae and other invasive aquatic plant that won’t let the fish breed. And they flourish due to the organic pollutant material that are carried by the rivers draining into the lake from near and far in western and central Kenya.

Removing, controlling or even killing the water hyacinth is not an easy process. In fact, in Kavirondo Gulf, which neighbours Dunga Beach to the north, the expanse colonised by water weeds can be easily mistaken for a green park.
The invasive water weeds form a thick green carpet-like layer covering a wider area crippling every activity around, from fishing to transportation.

Uganda has tried to manage its spread over the years, including through the previous LVEMP project in areas such as Kasensero in Rakai District and Port Bell in Luzira in Kampala, which were said to be the worst affected but other menacing activities such as sand mining that also threatens the lake materialised.

Wider water woes
Lake Victoria is considered one of the most important shared natural resources by regional countries; draining an expanse estimated at 194,200 square miles. The lake’s basin is home to more than 40 million people who draw livelihoods directly from the lake, according to the World Bank.

The lake is the main source of water for domestic, industrial, and hydro power generation. It is a climate regulator, a reservoir of biodiversity and a medium for transport across three main basin countries — Uganda, Kenya and Tanzania.

Lake Victoria is also the main surface outflow for the world’s longest river, the Nile. According to the 2017 Lake Victoria Basin Atlas, the largest portion of the lake basin, 44 per cent, lies in Tanzania, followed by Kenya with 22 per cent, while Uganda, Rwanda and Burundi make 16 per cent, 11 per cent, and 7 per cent, respectively. However, only Uganda, Kenya and Tanzania share the lake’s 3,460 km shoreline.

Of the 40 million people estimated by the World Bank to be living in the basin, Kenya, according to the Lake Victoria Basin Commission (LVBC), has the highest population of 15 million in the lake’s catchment area, followed by Tanzania with the main portion of the basin with 7.5 million, and Uganda with 7 million.

The LVBC is an organ of the regional grouping, East African Community, mandated to coordinate sustainable development and management of the Lake Victoria basin.
“The higher the number of people you have in a catchment area, the more the pollution and the more problems you get,” Dr Ally Said Matano, the LVBC executive secretary, says.
“Kenya, with 6 per cent of the lake and a catchment area of 22 per cent, has a population of 15 million. If you take the size of the catchment area, then take the size of the population therein and the extent of socio-economic activities, and also look at the topography of Kenya (mainly hilly catchment areas) and several rivers draining into the lake, which come with a lot of drainage and sewerage, that is why you find that this part of the lake on the Kenyan side is highly polluted,” he says.

Dr Matano reveals that degradation, especially on the lake’s catchment areas and riparian zones, and pollution are the two main challenges threatening the lake, throwing in others such as climate variability, which he said has been materialising intermittently.

“99 per cent of the challenges the lake’s basin face are not lake-based problems. They are problems in the catchment areas, and the drivers of those problems are people — whether the red soils flowing into the lake as a result of improper family methods, sewerage being drained into the lake, open defecating on river banks, name it,” Dr Matano says.

Effects on the lake
In Kavirondo Gulf, for example, studies show that the levels of oxygen in the water is about 3.5 per cent against the normal oxygen levels of 8.6 per cent for fish to breed and survive.

The primary reason is the high concentration of pollutants, including sewerage of all substances carried into area by Kisati river stream that stretches through Ubungo slum, thus making the area highly conducive for water hyacinth.
“So really, there is a big connection between the catchment area and the lake. If we are to save the lake we cannot save the lake from the lake; we have to save the lake from the catchment area,” Dr Matano adds.

According to the atlas, the basin consists of rivers, streams and wetlands. River Kagera, stretching from Burundi and Rwanda, provides the largest inflow into the lake, contributing up to 33 per cent of surface water inflow.

Other major rivers draining into the lake include Bukora and Katonga in Uganda; the Nzoia, Sio Mara, Yala, Awach, Gucha, Migori and Sondu, in Kenya; and the Mori, Simiyu, Grumeti, Mbalageti and Magogo-Moame in Tanzania.

According to the UN Environment Programme, inland freshwater ecosystems or terrestrial water ecosystems provide our water for drinking, food, industry and energy. In addition to their productive uses, freshwater bodies are also essential habitats for biodiversity. Although freshwater makes up only 0.01 per cent of the world’s water, it supports almost 6 per cent of all of its described species.
“Their essential role in society and multiple uses mean freshwater ecosystems are disproportionately important,” says Lis Mullin Bernhardt, freshwater ecosystems expert at UN Environment Programme.
“But unfortunately, they are also disproportionately under threat in that they bear the brunt of human activity, climate changes and a number of other factors,” she says.

Over the past 40 years, freshwater species populations, according to the UN, have declined by 81 per cent – more than double the rates seen in species both on land and in the oceans. At the same time, it is estimated that since 1900, around 70 per cent of inland water bodies have disappeared, with even higher numbers in some regions such as Asia.

The Lake Victoria basin atlas indicates that the entire basin’s ecosystem continues to undergo substantial changes as a result of pollution from industry and agriculture, the proliferation of waterweeds, over-fishing, the introduction of invasive alien species and land degradation.
“Algal blooms are prevalent in the lake to the extent that water transparency declined from five metres in the 1930s to less than one metre in the 1990s. The proliferation of the water hyacinth weed impedes the flow of water for irrigation, hinders navigation and interferes with hydropower schemes. The introduction of the Nile Perch is blamed for the decline in the number of fish species from more than 400 to about 200,” the atlas report notes.

Highly threatened
The Swiss-based International Union for Conservation of Nature and Natural Resources (IUCN) in a 2018 study titled Freshwater biodiversity in the Lake Victoria basin shows that freshwater ecosystems within the region are highly threatened, with current safeguards proving inadequate. The focus of much past and ongoing conservation work in the region is on terrestrial ecosystems.
“Freshwater biodiversity in the Lake Victoria Basin is in decline and the risk of species extinctions is increasing, with the major drivers of threat identified as pollution, biological resource use, primarily overfishing, agriculture, and invasive species, particularly Nile Perch and water hyacinth,” the IUCN study notes.

Climate change is an ongoing and future threat to freshwater species, especially fish, which are shown to be particularly vulnerable, the report indicates.

On the Ugandan side of the lake, the permanent secretary in the ministry of Water and Environment, Mr Alfred Okot Okidi, says the Katonga and Kagera swamps are the most degraded and urgent efforts are needed to “save the situation”.

Out of the $240m (Shs905b), at least $60m (Shs226b) is earmarked for interventions in Uganda, including among others, evicting people from the lake’s key catchment areas and giving them alternative livelihoods in part of south western and eastern Uganda.

The programme is expected to kick off next year in September. However, Mr Okidi reveals that current projections show the situation is worse on the Kenyan side.