Water ministry explains foul smell in Lake Victoria

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The ministry of water and environment has attributed the persistent foul smell emanating from bays around Lake Victoria, particularly near Kampala and Entebbe, to severe algal blooms triggered by heavy pollution, wetland degradation and the recent hot, dry conditions.

In a statement issued on Tuesday, February 3, 2026, the ministry explained that studies by its experts and partners show a worrying, ongoing rise in nutrient levels (nitrogen and phosphorus) in the bays, especially the heavily impacted Inner Murchison Bay (IMB) near Kampala.

“These nutrients fuel excessive algal growth, leading to the blooms now visible in the bays,” the statement read. The minister of water and environment is Sam Cheptoris, while the permanent secretary is Dr Alfred Okot Okidi.

Why the lake smells

“The recent dry season and high temperatures over the past month accelerated the blooms through water mixing and intensified the decomposition of dead algae, worsening the stench”.

“The foul odour, often described as rotten-egg-like, stems from decomposing algae that consume oxygen and release noxious gases such as hydrogen sulfide and ammonia. This process depletes oxygen in the water (creating hypoxic “dead zones”), threatening fish and other aquatic life, and recycles nutrients back into the lake fueling a vicious cycle of repeated blooms”.

Lake Victoria, Africa's largest lake, supports over 45 million people across the region as a vital source of drinking water, fisheries, transportation, hydropower, biodiversity, climate regulation, and economic hubs.

In Uganda, key affected areas include the shallow, sheltered Inner Murchison Bay (less than 10 meters deep), along with Kitubulu and Nakiwogo bays in Entebbe, and Napoleon Gulf in Jinja.

These bays bear the brunt of pollution from multiple sources in their catchments that include: silt-laden surface runoff, human and plastic waste, untreated municipal wastewater from suburbs, industrial effluents, and nutrient-rich agricultural runoff. 

The problem has been worsened by the loss of surrounding wetlands, which once naturally filtered nutrients and trapped organic matter before it reached the open lake.

The ministry maintains an active Water Quality Monitoring Network, with 23 stations in Inner Murchison Bay (Kampala area) and 10 in Entebbe Bay. Data collected quarterly informs policy, decision-making, and remedial strategies for the lake's long-term health.

Interventions 

According to the statement, the ministry is implementing several measures, including restoring degraded wetlands to filter incoming waste and wastewater, enforcing a 200-meter buffer zone around the lake to intercept pollutants and protect shorelines, and conducting regular water quality monitoring to guide evidence-based interventions.

The other actions are: supporting industries in adopting cleaner production methods, including wastewater recycling and reduced effluent discharge, strengthening enforcement of effluent discharge permits for industries and municipal plants to ensure compliance with standards and raising public awareness among communities and stakeholders to build support for lake protection.

The ministry also listed the areas "needing stronger action", namely:

Prioritising solid waste management in the lake's catchment to curb nutrient inflows.

Promoting eco-friendly agricultural and land practices to reduce non-point source pollution.

Intensifying the mobilisation of industries for cleaner technologies and wastewater reuse.

Further tightening enforcement of discharge permits and environmental regulations by urban authorities.

Expanding awareness campaigns to foster greater community ownership and collective responsibility.