How many rivers are left in the city that flow for 100 kilometres and are still as untouched, remote, healthy and scenic as Umwindsi River, asks Isabel Carey, writer and nature lover.
Carey should know. Not only has she lived close to the banks of one of Harare’s most serene rivers for several years, but she is one of the very few who has toured its length.
Sitting at the edge of the river, Isabel and I are watching two fish eagles flying over the Umwindsi River, downstream from her Greystone home. Our guess was that the eagles were probably preying on small mammals for an afternoon meal. These afro-tropical species can be abundant except in waterless areas. Fish eagles are generally resident in one area but can be nomadic in response to resources shortages, drought, flood or prey scarcity and have been recorded travelling up to 200 kilometres.
Carey explains that the species occupies a range of aquatic habitats from sea level to areas of calm water, such as swamps, lakes, flood plains and estuaries.
“I have watched the eagles fly this way many times. This is their time to find a meal,” she says. “Many birds have made their home here, and I believe this length of this river used to sustain even larger animals before we made our flashy homes.”
“We human beings have made our environment worse. We have destroyed the best that nature gave us. As for this river, I would like to believe that controlled development along its basin will keep it the cleanest river in the city,” said Carey.
Umwindsi River is the only major river that flows north from the city. In its long stream northwards, Umwindsi has never been dammed although its flow makes it an attractive candidate for hydro-development. The most recent proposal, Kunzvi dam downstream near Murehwa, has been a talking point for many years and it is believed it would give the city an important alternative source of water.
The Ballantyne Park Wetland is a first order tributary of the Umwindsi River from the west. Another tributary is from Chisipite (translated as ‘spring’ in English). The two connect in the Greystone Park area and flow through a network of wetlands, flood plains and swamps to become part of the Mazowe catchment. Umwindsi forms the headwaters of Nyaguwi River which drains into Kunzvi Dam.
The Umwindsi River has had its fair share of events. Newton Musara, a former resident in Greystone Park recounts that in 2004 a car was swept over the bridge at the end of Exhall Road when the river flooded. The occupants, two children and an adult, died. Four years later a man ended his life tragically when he shot himself alongside the riverbed.
The bridge was condemned by the city council but residents have continued using it despite the warnings and the dangers it poses.
University of Zimbabwe Water Engineer Bekitemba Gumbo says the level of pollution in Umwindsi River is less compared to its city counterparts, the Gwebi and Mukuvisi River. He attributes this to the sparse development in the river’s hinterland.
However he does say that urban agriculture is the chief threat to the Umwindsi riverine system. He points out that as long as there is no policy on urban agriculture, soil erosion and subsequent siltation will alter the river. His respected colleague, Professor Magadza, concurs.
The clean quality of water in Umwindsi is maintained by wetlands that are dotted along its course. “It has been proven scientifically that disturbing wetlands alters their hydrological performance leading to loss of their flow regulation properties, causing excessive runoff,” says Magadza. “The activities are minimal in the Umwindsi river system and provide the answers to why this riverine system still gives clean water.”
Magadza said that ploughing and the burning of grass on wetlands increases erosion risks, as the early rains runoff will not be impeded by ground cover. “As we lose these wetlands, the cost of providing potable water simultaneously increases.”