Harare Correspondent
HARARE – Recent heavy rains have significantly improved water clarity in Lake Chivero, marking a turnaround from a toxic algal bloom crisis that plagued the reservoir late last year, Zimbabwe Parks and Wildlife Management Authority (ZimParks) officials confirmed.
ZimParks senior terrestrial ecologist Diana Marewangepo highlighted the stark contrast during a recent tour of Ramsar-designated wetland sites.
“Right now, as you can see, the lake is as clean as it can be. But in December, it was dominated by blue-green algae, or cyanobacteria,” she said.
“When concentrations spike, these algae form thick layers. The danger is that some cyanobacteria produce toxins harmful to humans, wildlife, and aquatic ecosystems.”
The algal bloom, linked to nutrient pollution from agricultural runoff and untreated sewage, had raised fears about water quality in the lake, a critical source of Harare’s drinking water.
However, seasonal rains diluted the algae, restoring clarity temporarily.
Responding to concerns, City of Harare spokesperson Stanley Gama emphasized that water from Lake Chivero undergoes rigorous treatment.
“We treat the water thoroughly at our plant until it is 99.99% clean. Regardless of the lake’s condition, we use chemicals to ensure it meets both the Standards Association of Zimbabwe (SAZ) and World Health Organization (WHO) standards,” he said.
“The rains help neutralize pollutants, but our processes guarantee safety year-round.”
Gama acknowledged the City’s reliance on Lake Chivero amid Harare’s persistent water shortages, stating,
“We have nowhere else to source water. This lake is vital, and we monitor it continuously.”
While the rains provided respite, Marewangepo warned that algal blooms could recur without sustainable measures to curb pollution.
“This improvement is seasonal. To protect Lake Chivero, we need to address upstream contamination from fertilizers, industrial waste, and sewage,” she urged.
Environmental groups have long criticized inadequate wastewater treatment infrastructure and lax enforcement of pollution laws, which exacerbate pressure on the lake. Harare’s water treatment plants, strained by aging equipment and chemical shortages, have struggled to maintain consistent supply, fueling public anxiety.
As authorities celebrate the short-term recovery, experts stress that lasting solutions—including upgraded infrastructure and stricter environmental regulations—are essential to safeguard Lake Chivero’s future as a lifeline for millions.
“The rains helped, but they’re not a fix,” Marewangepo said.
“We must act now to prevent another crisis.”
Zim GBC News©️2025