Clubs dotted along the banks of Harare’s main water source, Lake Chivero, have called for a massive clean up of the lake, as pollution and environmental degradation have continued to increase in and around the lake’s environs.
Shiraz Kassam, Chairman of Lake Chivero Users Association (LCUA) described the problems of pollution and environmental degradation as “very serious.” He said that the problem is worsened by the non-functioning of the Crowborough Sewage Treatment Works that has been discharging raw sewage into the Marimba River, ending up in the lake in its raw state.
Most of City of Harare sewage treatment works are overloaded. For example, as far back as 2004-2005, the Crowborough Sewage Treatment Works, which has a design capacity of 54 megalitres, was receiving 110 megalitres of waste water per day. Nothing has changed, if anything, it is worse.
Addressing a six-weekly meeting of the 25-member Lake Chivero Users Association at Marimba Angling Club, Kassam said a broad based clean up campaign is now needed.
“Lake Chivero is Harare’s major water source. We are looking for like-minded people, associations and non-governmental organisations to partner with us to find solutions for the lake,” said Kassam
Birdlife Zimbabwe Vice-Chairperson Julia Pierini called for unity of purpose to save the lake from demise. She said their organisation has been monitoring changes at the lake and have found that unless efforts are made, human, bird and aquatic life are going to be lost in the not-too-distant future.
“The deteriorating birdlife in the lake is an indicator that all is not well. Islands that have provided sanctuary to bird breeding have been devastated as fish poachers are literally sleeping on the breeding habitats,” said Pierini.
Paul Robertson of Marimba Angling Club said water quality and water hyacinth has certainly become a major challenge.
He said the club has seen a major drop in numbers of anglers coming for their annual angling competitions.
“The algal blooms, which used to be seasonal, are now a permanent feature. Problems are compounded by the discharge of sub-standard effluent into the lake,” said Robertson.
One of the major costs of high organic load on Lake Chivero was massive fish death in 1996. These deaths were credited to deoxygenation of the water body. The likelihood of more fish deaths occurring is high, unless pollution-reducing measures are urgently put in place.
In 1989, the weed situation was so bad that Lake Chivero was declared a national disaster. By covering and choking vast water areas, the waterweed prevents boating, angling and skiing. It also creates ideal conditions for malaria mosquitoes and bilharzia snails to breed. Since 1989 the weed has spread much further.
To control water hyacinth, the plant must be removed faster than the rate of reproduction. Zimbabwe has tried various options to control the weed with little success.
According to Kassam, dredgers were sourced under the World Bank fund last year, but their whereabouts is unknown.
Under mechanical control, mechanical harvesters are designed to float on the water surface or to operate from the shoreline with the objective of collecting the water hyacinth from the infested water body.
“The main advantage of mechanical control is that it is environmentally friendly. The most restrictive factor about this method of control in Zimbabwe is the high cost of machinery,” said Kassam.
Lake Chivero Users Association was formed last year. Working with the Department of National Parks and Wildlife, the Association has put up signs about littering, routes, speed and regulations around the lake
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