River Nyakomisaro: Kisii's toxic artery where Bamako promise drowns

The morning sun rises over Kisii town, lighting up the crowded stalls of Daraja Mbili market. Vendors shout, motorbikes weave through traffic, and business hums with energy.

Yet just a few metres away, behind a line of corrugated iron sheet shops, a very different story flows silently. River Nyakomisaro—once a lifeline for households and farmers—has become a toxic artery, carrying oil, heavy metals and untreated waste through the heart of the town.

For hundreds of residents who rely on it, the river now nourishes and poisons in equal measure.

For 42-year-old vegetable farmer Mary Nyanchoka, the river is both sustenance and threat. For 15 years, she has irrigated sukuma wiki, spinach and traditional vegetables along its banks.

Squatting beside her small plot, weeding between rows of greens, she wrinkles her nose.

“Maji siku hizi ina harufu ya petroli—the water now smells like petrol,” she says. “But what choice do I have? Borehole water is too expensive, and this is the only water that reaches my shamba.”

What Nyanchoka does not know is that the river has become a dumping channel for hazardous waste—violating the Bamako Convention, the 1991 African treaty Kenya signed to protect communities from toxic pollution.

Worse still, failures in tracking and reporting hazardous waste mean these violations remain largely invisible to national and regional oversight.

A walk along River Nyakomisaro reveals how contamination happens in plain sight.

Near the main bus station, car wash businesses spray vehicles as soapy water mixed with engine oil flows straight into the river.

Behind roadside mechanic sheds—known locally as jua kali workshops—the riverbank is stained black with oil. Used filters, battery casings and paint cans are scattered in the mud.

Mechanic James Mogaka, 38, drains oil from a matatu into a dented plastic container. Asked where it goes, he shrugs.

“Sometimes we sell it. Sometimes we pour it into the drainage. It all ends up in the river anyway.”

Those discarded batteries contain lead, one of the most toxic substances listed under the Bamako Convention. No authority has ever formally recorded how much lead, oil, or chemical waste enters Nyakomisaro each month.

This data gap is exactly what the Bamako Convention sought to prevent. The treaty required African states to track hazardous waste, share information and coordinate action through a Regional Coordination and Harmonisation Mechanism (RCHM). But in Kisii, waste flows unchecked and unreported.

National Environment Management Authority (NEMA) officer Simion Tonui confirms that Nyakomisaro falls under Class IV–V water quality—heavily polluted and unsafe for domestic use.

“The problem is concentrated in the urban corridor where there is intense human activity and poor waste management,” he says.

However, Kenya lacks a comprehensive national hazardous waste registry—the very system the Bamako Convention requires. There is no reliable record of how much toxic waste is generated, transported, treated, or dumped.

Policy analyst Dennis Anyoka is blunt. Kenya signed the Bamako Convention in 1991, committing to control hazardous waste.

But we have never built the reporting infrastructure to make those commitments real. We cannot even say how many tonnes of lead waste are generated in Kenya annually.”

Without data, the regional mechanism meant to protect communities across Africa is effectively blind.

Back at the riverbank, Nyanchoka’s eight-year-old son Brian suffers from persistent skin rashes and breathing problems. Hospital visits have cost her thousands of shillings, but doctors have found no clear cause.

“They give him medicine, but the problem keeps coming back,” she says softly. “Sometimes I wonder if it’s the water.”

Dr Richard Onkware, Kisii’s public health director, confirms a worrying trend.“We are seeing more unexplained skin conditions, respiratory problems and stomach illnesses, especially among children living near the river.

But we lack the resources to conduct environmental health investigations. We treat symptoms, not the cause.”

The Bamako Convention recognises that toxic waste threatens both human health and the environment. Yet Kenya has no systematic system linking hazardous waste sites to health outcomes, data that could trigger stronger regulation.

Economist Dr Abel Mokoro explains the incentives: “For a small garage, transporting waste to Nairobi for proper disposal can cost tens of thousands of shillings. Dumping it in the river is free and rarely punished.”

Weak enforcement, coupled with poor tracking, has created a culture of impunity.

Not everyone has given up.

Joyce Moraa, 32, of Kisii’s Backstreet Family CBO, organises monthly clean-ups and has petitioned county officials, NEMA, and even protested outside the county assembly.

“We managed to get two car washes shut temporarily and the county promised a proper waste centre—but promises are not action,” she says.

Her biggest frustration is the lack of data. “How do you fight what you cannot measure? There are no records, no reports, no numbers.”

As night falls, Nyanchoka packs her unsold vegetables. Tomorrow, she will return to the same river—because she has no alternative.

The mechanics will drain more oil. More batteries will leak lead into the sediment. And none of it will be properly recorded.

The Bamako Convention was meant to be Africa’s shield against toxic waste.

But in Kisii, that shield has failed. Without transparent reporting from Kenya and other states, the Regional Coordination Mechanism cannot detect patterns, coordinate responses, or protect vulnerable communities.

River Nyakomisaro is therefore more than a local tragedy—it is a test of whether Africa’s environmental treaties are real protections or just paper promises.

The question remains: Will Kenya finally implement the reporting systems it pledged under the Bamako Convention, or will communities like Kisii continue to bear the cost of silence?