A story is told that when the founders of the city of Harare crossed the Mukuvisi, south of the Kopje, they obtained the services of a guide, and then rode northwards to the headwaters of the dry Gwebi River. The reconnaissance party rode for about five miles downstream towards Mount Hampden before turning northeast to follow the edge of the escarpment overlooking the Mazowe valley.
They concluded in their report, “Finding that the water supply in the Gwebi Valley and at the edge of the plateau was not sufficient for what might eventually be the seat of Government with a considerable population, it was rather better to return to the valley of the Mukuvisi and select a site to camp.”
Over the years, the two rivers Gwebi and the Mukuvisi have become Harare’s most talked about rivers. Starting, of course, from different sources, they both end spilling their precious water into what is Harare’s largest water source, Lake Manyame.
Gwebi, also known as Gwibi, is situated in the northern part of the city, located at an elevation of 1,323 metres above sea level. It starts its journey at a flood plain bordered by Vainona and Borrowdale’s Helensvale area. As rivers go, the Gwebi River is by far the longest river in Harare, not the widest, or the fastest flowing, or the deepest. Yet, if you happen to be looking not for extremes, but for a golden mean, then the Gwebi’s subtle spectrum of smooth beauties approaches perfection. It has no bad patches like gorges, or stagnant areas and there isn’t much human activity that damages the watercourse
The river has been fortunate in the past to have a clean flow from tributaries that are mostly wetlands. Until now, there has been little infrastructure development along its basin.
Though not much industrial activity takes place along Gwebi River, there are fears that the city will expand further north and the river will be squeezed in like the Mukuvisi River. The other worry is the potential of agro-chemicals pollution. Much of Gwebi’s tributaries begin from farmland where conventional agriculture relies heavily on herbicides and pesticides.
Another pollution threat has been the Pomona dumpsite situated at the source of the river. The dumpsite is not properly planned and lined. Fears are that leachates have found their way into the river over the years the city has been dumping there.
Despite this fear, according to Research Fellow at the University of Zimbabwe, Crispen Phiri water quality studies conducted along the river shows much of the Gwebi having fair quality water.
The differences between the Gwebi and the Mukuvisi in terms of the quality of water is down to the human activities on the two rivers, explains Phiri. “Industrial, sewage and domestic pollution has had an adverse effect on the water quality of the Mukuvisi River, while much of Gwebi has fair levels owing to minimal waste discharges into the river.”