Lake Chivero water crisis deepens, cancer risk soars

KUDAKWASHE CHIBVURI

Lake Chivero, once a jewel of Zimbabwe’s natural heritage and a lifeline for Harare’s water supply, is now the epicenter of a worsening public health emergency.

According to startling new research, water from the lake now poses cancer risks 15 times deadlier than HIV, a revelation that has shocked health professionals and environmentalists alike.

Once a bustling recreational site and a sanctuary for wildlife, Lake Chivero today tells a grim tale. Dead fish line the shores, foul odors hang thick in the air, and tourists are increasingly repelled by the toxic blue-green algal blooms that choke the lake. For years, the unchecked discharge of untreated sewage, industrial waste, and agricultural runoff has turned this vital reservoir into a chemical soup.

Despite repeated warnings, the crisis has escalated with little government intervention. In December, a government-imposed fishing ban followed the mysterious deaths of four white rhinos, three zebras, several wildebeests, and scores of fish—tragic casualties attributed to the lake’s contaminated waters.

Professor Hilda Matarira, a Chemical Pathologist at the National Health Laboratories and Parirenyatwa Hospital under the University of Zimbabwe’s College of Health Sciences, has tracked Lake Chivero’s water quality for nearly 25 years. Her verdict is chilling.

“We have researched water quality in Lake Chivero since 2000—nearly 25 years ago. The lake’s contamination is rising each year,” she said.
“Microcystins from blue-green algae are cancer-causing and kill people at rates 15 times higher than HIV.”

The microcystins—potent toxins released by cyanobacteria—are not just a hazard to aquatic life. They infiltrate drinking water, accumulate in fish tissue, and linger in the ecosystem long after visible blooms dissipate.

“This algae chokes the lake of oxygen, leading to the death of fish and other aquatic organisms. Lake Chivero is a crucial water source for Harare, Chitungwiza, and Ruwa,” she warned.

Professor Matarira further cautioned that switching to borehole water—long perceived as a safer alternative—is not necessarily a solution.

“We found 100% E. coli contamination in some boreholes. Heavy metals and nitrates from the lake are serious concerns,” she said.
“Boiling water only kills bacteria—it does nothing for heavy metals. Recent studies show that late rains may wash more chemicals into groundwater.”

She also linked rising pollution levels to Harare’s growing vehicular emissions.

“The influx of around 1.5 million vehicles contributes significantly to air pollution. These emissions contaminate water bodies as particulates drift and settle,” she explained.

Her most ominous warning, however, concerns fish consumption—a major livelihood for many residents around Lake Chivero.

“The worst thing about these particles, besides their consequences in the water, is that while you are unaware, the particles pierce everything—every organ in a human being, animal, whatever,” she said.
“They are one of the major causes of cancer. Some families and even pets are being affected by this pollution.”

She added, “High mercury levels are present in the fish, and unsuspecting consumers are at risk of heavy metal poisoning.”

Ruben Akili, Director of the Combined Harare Residents Association, joined the chorus of concern, urging the City of Harare to take decisive action.

“We need the government to address the ongoing pollution crisis. The deaths of fish and wildlife indicate serious water contamination,” Akili said.
“The local authorities must enforce waste management bylaws to prevent hazardous materials from entering our rivers.”

He emphasized that addressing this crisis requires collaboration across sectors.

“This is a public health issue that requires a multisectoral approach. We must ensure that the water we rely on contributes to food production and human consumption,” he added.

Despite mounting evidence and public outcry, government officials appear largely disengaged from the gravity of the situation. Professor Obert Jiri, Permanent Secretary of the Ministry of Lands, Agriculture, Fisheries, Water, and Rural Development, appeared unaware of the findings.

“I haven’t seen any reports confirming these claims. If you have evidence, please share it with me,” he said.

Meanwhile, Harare City Council’s acting town clerk, Engineer Mabhena Moyo, admitted that industries are polluting Lake Chivero but insisted that action is being taken.

“Yes, there are a lot of industries that are polluting Lake Chivero, and we have been fining them,” Moyo said.

He also defended the city’s water quality measures:
“Water from Lake Chivero is clean and meets WHO standards. We test the water almost hourly before distribution, but I cannot speak to the safety of the fish.”

Efforts to reach the Zimbabwe Parks and Wildlife Management Authority yielded little. Tinashe Farawo, the Authority’s Head of Corporate Communications, declined to comment, stating he was too busy and suggested that queries be directed online.

As the warnings grow louder and the evidence more damning, Lake Chivero’s crisis is no longer just an environmental disaster—it’s a looming catastrophe for public health, livelihoods, and national well-being. Without urgent, coordinated action, Zimbabwe risks turning its primary water source into a toxic relic of inaction.