Fishing in filth — pollution crisis in crucial lake puts Harare’s poor at risk

Along the banks of Lake Chivero, Zimbabwe’s main reservoir, people are casting nets into waters blackened by raw sewage from a broken municipal wastewater system.

The fish they haul out, slick with filth and toxic algae, are crated and ferried by speedboat to an establishment along the lake shore before being sold to unwitting consumers in the capital.

“This is majorly criminal,” says Garry Stafford, who has lived and worked on the lake for decades, running a restaurant and boatyard. “We’ve got video of nets coming out of that sewage absolutely black.

“Those fish are being eaten by poor people who have no idea what they’re consuming. If they go to hospital and die nobody will make the connection.”

Stafford says he has watched with horror as the lake — once a jewel of Zimbabwe’s natural heritage — has been transformed into what he bluntly calls “a sewage pond”. And the problem, he warns, is accelerating.

A lake under siege

Lake Chivero, formerly Lake McIlwaine, was built in 1952 to supply water to a city of half a million people. Today, with Harare’s population exceeding two million, the lake’s health has collapsed under the pressure of untreated sewage, industrial waste and reckless urban development.

The situation is visible to the naked eye. Stafford recounts how, just days ago, his son and a team of water specialists from South Africa surveyed the inlet where two rivers, the Manyame and Marimba, flow into Chivero.

“For three kilometres it was just black, black, black sewage,” Stafford says. “The guys from Acumen, who do water reticulation all over southern Africa, said they had never seen anything so bad in their lives.”

This “blackwater” surge coincides with the lake level dropping by 5m after poor rains, which has concentrated pollutants in the shrinking water body. The result is explosive algae growth, a bloom Stafford says has multiplied fivefold in a week.

Broken systems

The immediate cause of the crisis is Harare’s collapsing wastewater treatment infrastructure. Once, a network of sewage farms processed effluent before releasing greywater onto pasturelands where it was filtered naturally by grasses and wetlands.

Decades of mismanagement have stripped away those safeguards. City officials sold off crucial greenbelt land — including the once-functional Crowborough sewage farm — for housing developments, dismantling the ecological safety net.

Today, says Stafford, “They’re pumping the raw sewage straight through into the lake … from the sewage farm and from whatever house it’s coming from, because they haven’t got the capacity to clean it.”

The Environmental Management Agency of Zimbabwe has admitted that about 415 megalitres of untreated sewage are discharged into the environment nationwide daily, with Harare responsible for about half.

Authorities imposed a ban on fishing on Lake Chivero in December, ostensibly to give the lake time to recover. But Stafford says enforcement is inconsistent at best.

“At the top end of the lake where the sewage is, there are groups netting fish every day,” he says. “One of our neighbours sends a boat over there daily to collect the catch. They bring the fish back to this side, load them on to trucks and take them into Harare’s markets. The people buying them have no idea they were caught in human waste.”

With formal fishing cooperatives now defunct, the lake’s ecosystem has little chance to replenish itself. What was once a sport-fishing haven with 23 fish species has been stripped to just a handful.

Public health time bomb

The consequences for public health are dire. Cyanobacteria — blue-green algae — have bloomed repeatedly in Chivero’s waters, producing toxins that have already killed rhinos, zebras, wildebeest, fish eagles and countless fish.

For humans, these toxins can cause liver damage, gastrointestinal illness and, with long-term exposure, cancer. Yet the city’s poorest residents — those least able to afford bottled water or alternative protein sources — are consuming fish caught in the most contaminated sections of the lake.

“If someone dies from it, it’ll just be another death,” Stafford warns. “It won’t be traced back to toxins in the lake because people don’t have access to medical tests or proper facilities.”

Officials from the Zimbabwe Parks and Wildlife Management Authority were approached, but said we should contact city officials. None replied after a week.

Economic fallout

Lake Chivero’s collapse is not just an environmental disaster but an economic one. The pollution scare has gutted tourism and recreation, forcing Stafford’s business and others along the lake to the brink.

“We lost the whole December, January, February business,” he says. “People didn’t come out because they thought the lake was closed. And who wants to come to a sewage pond for recreation?”

Stafford is suing the City of Harare for loss of earnings and punitive damages, hoping legal pressure will spur action.

Despite years of warnings, Harare’s response has been halting. Mayor Jacob Mafume has said the city needs central government funds to restore proper sewerage systems, particularly for more than 150,000 informal settlements without reticulation.

Earlier this year, Environment, Climate and Wildlife Minister Sithembiso Nyoni announced a plan to create an interministerial committee and a $250-million fund to rehabilitate wastewater management nationwide. But implementation has been slow, and the situation at Chivero continues to worsen.

“Officials are just hoping it’ll disappear,” says Stafford bitterly.

Community mobilisation

Frustrated by government inaction, Stafford has teamed up with local and international partners to push for solutions. These include creating artificial wetlands in abandoned sand quarries to filter effluent naturally, introducing probiotics to break down harmful toxins, and legally challenging those enabling the crisis.

He is also working with environmental lawyers to hold accountable those he accuses of organising commercial fishing in contaminated waters. “They should be brought to task,” he says. “We’ve got pictures of the boat collecting fish — if we publish them, everyone will know who it is.”

The bigger picture

Lake Chivero’s fate is emblematic of a larger national crisis. Across Zimbabwe, ageing infrastructure, rapid urbanisation and a lack of political will have allowed untreated waste to choke waterways. The result is a slow-motion public health emergency that hits the poor first and hardest.

International experts warn that restoring Chivero will require a “whole-of-government and whole-of-society” approach, combining infrastructure investment, enforcement of environmental regulations, and community-driven conservation efforts.

For Stafford, the issue is deeply personal. “I grew up on this lake,” he says. “It was a haven for biodiversity and a hub of recreation. It’s heartbreaking to see it destroyed by neglect and greed.”

He remains determined to keep public attention on the crisis. “The more noise we create, the more chance we have that Harare will fix it,” he says. “Because time is running out — for the lake, for the wildlife and for the people who depend on this water.” DM