Over 40 million people who depend on Lake Victoria for food, water, and livelihoods across East Africa are facing a deepening crisis. A new regional study reveals rising pollution levels in major urban centres around the lake.
Launched on 9 June 2025 in Mwanza, Tanzania, the regional water quality sampling exercise on Lake Victoria, carried out jointly by Kenya, Uganda, and Tanzania, has generated a rich dataset that will serve as the foundation for the upcoming State of the Basin Report. The exercise assessed the extent and sources of pollution in the lake and examined the distribution and impact of invasive species such as water hyacinths.
During the comprehensive survey, a total of 44 sampling stations were covered across nine key locations: Mwanza, Bukoba, Entebbe, Jinja, Busia, Kisumu, Homa Bay, Musoma, and Kirewe. Tanzania recorded the highest number of stations (17), followed by Uganda (15) and Kenya (11). Samples collected from these sites have been dispatched to laboratories in the three countries, where analysis is currently underway.
The monitoring program covered a broad range of parameters, including key nutrients such as nitrogen and phosphorus compounds, silica, alkalinity, and total suspended solids. In-situ measurements, including pH, temperature, turbidity, dissolved oxygen, and photosynthetically active radiation (PAR), were recorded at each sampling site, alongside GPS coordinates and depth data.
Additionally, the survey analysed major ions (including calcium, magnesium, and chloride) and assessed Chemical Oxygen Demand (COD), a critical indicator of organic pollution. Selected sites were also tested for heavy metals such as arsenic, mercury, and lead, with samples collected from both surface and bottom water layers. Further, phytoplankton monitoring was conducted to examine algal composition and abundance, which revealed biological activity and potential risks of harmful algal blooms.
The initiative, led by the Lake Victoria Basin Commission (LVBC) and supported by GIZ under the EAC4Nature project, was successfully concluded on 16 July. It aims to generate credible, science-based data to guide environmental conservation strategies and policymaking in the region, providing a detailed snapshot of Lake Victoria’s chemical, physical, and biological state to support more informed and effective management of one of Africa’s most vital freshwater ecosystems.
LVBC's Executive Secretary Dr Masinde Bwire noted, "We are happy with the effort of our regional experts together with our development partner. The results of this exercise will be crucial to the development and sustainability of various projects and programs within the larger Lake Victoria Basin."
Cosmus Muli, who represented GIZ, emphasised the importance of evidence-based environmental governance. “Science must now inform the next phase of environmental governance to safeguard the lake,” he stated.
Find more information on LVBC here. 
Find more information on EAC4Nature here.
Watch the Ugandan media report revealing urgent concerns about deteriorating water quality in Lake Victoria here.