Lake Chivero’s slow, foretold death

LAKE CHIVERO, a reservoir on the Manyame River and Harare’s main water supply dam, is facing a slow but sure death.

A cocktail of siltation, droughts, algae, the destruction of wetlands and the water hyacinth weed is threatening the existence of this important water source which has a carrying capacity of 247 million cubic metres of water.

After announcing a punishing water rationing schedule, the Harare City Council further announced that the capital’s main water source was left with only 18 months stash of water.

The water rationing schedule marked the return of the days when Harare faced acute water shortages.

With the effects of a recent cholera outbreak that claimed the lives of 50 people still fresh in the minds of many, news of the water shortages naturally sends chills down the spine of many.

The Harare City Council is attributing the low water levels in the dam to low rainfall.

“We have problems because of the low amount of rainfall we have received over the years. Normally, the lake would be spilling by end of December up until February. We have so far only had an increase in water levels of three or so metres,” Engineer Mabhena Moyo, the council’s acting director for water, said.

Engineers maintain that the water levels are very low to the extent that contamination levels have doubled, resulting in the jamming of water treatment machinery at Morton Jaffrey.

Although the Harare City Council is attributing the low water levels to droughts, information gathered revealed that 50 years of poor urban planning is behind the alarming water levels. Research also shows that as early as the 1970s, engineers began warning the city of the impending predicament.

A report which was published during the 1970s titled The Impact of Urbanisation on the Water Quality of Lake Chivero foresaw rapid population growth and urbanisation as a danger to the water body.

As recent as 2009, scholar Innocent Nhapi made a similar observation and advised the city to embark on proper and consistent urban planning and infrastructure development policies.

Nhapi argued that authorities had failed to manage the rapid population growth in Harare.

“Often, these problems are attributed to rapid population growth, inadequate maintenance of wastewater treatment plants, expensive technologies and a poor institutional framework.

“Rampant urban agriculture could also result in washing off and leaching of nutrients.”

As such, observers say the drought has only exposed long-term infrastructural and urban planning deficiencies within the Harare City Council.

Those who share this view base their arguments on three realities that council settled people on wetlands, released sewer into the Lake and failed to reign in urban farming activities particularly on the banks of Manyame, Mukuvisi and Marimba Rivers. As a result of the above activities, the depth of the lake has been reduced from 28 meters to 18 metres. The water body has also become a breeding hole for algae, an aquatic organism which has precipitated the rise in the cost of water treatment.

Garry Stafford, who operates Kuimba Shiri-a bird sanctuary located on the shores of the lake said the settling of people on wetlands is the major contributing factor.

“This problem has been foretold a long time ago, so people in Harare have to be used to this fact that if you continue to build on wetlands, if you continue to destroy the wetlands you are going to destroy this lake.

“Wetland holds water over a long period and then release the water slowly and over a long period, resuscitating the lake in the process.

“What has happened is that our previous administrations have gone and built on wetlands and destroyed them and what we are witnessing here at Chivero in the last ten years is what we call flash flooding,” he says.

Stafford said the lake only reaches high water levels briefly during the rainy season because there were no good wetlands to replenish it in the off-season. He said without wetlands and natural green belts, the lake was always going to receive waste and contaminated water.

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