3N – Zoo lake (JHB) rehabilitation

Supporting article N: Let’s not just passively ‘look on’ and see our natural systems declining right in front of our own eyes!


Zoo Lake’s clean-up is on the table
Written by Makoena Pabale, Thursday, 22 May 2008

The lake will undergo rehabilitation

THE rehabilitation of Zoo Lake topped the agenda at a section 79 oversight committee meeting for environment held at the Anglogold Ashanti Conference Centre, next to the lion enclosure at Johannesburg Zoo.

The lake, one of Joburg’s most popular parks, is the zoo’s neighbour; the two are divided by the busy Jan Smuts Avenue. And they share more than a name – the Braamfontein Spruit runs through the city, into the zoo, and then into Zoo Lake.

About 40 percent of the water received from the spruit was cleaned by the zoo; the rest was passed on to the lake without being cleaned, according to the zoo’s executive technical manager, Reggie Mokalapa.

He said the volume of water passing through the zoo was too great for it to clean all the water.

At the meeting, the lake was said to be polluted by silt-laden run-off, sewage inflow, solid waste and vegetation litter, soap, oil and grease.

“When the pollutant-rich stream reaches the lake, energy dissipation accelerates sedimentation, physical and biochemical processes that result in, inter alia, pollution retention in the lake,” said Kgomotso Motsepe, from Lekgebeng Water and Environmental Resources Scientists.

Silt and sewage

He said that the lake was “totally silted-up” and that water storage capacity was depleted. The pollutants were mainly silt and sewage, which reached the lake unabated.

Dissolved oxygen depletion had resulted in anaerobic-anoxic conditions, resulting in nuisance and health concerns. Given these issues, the Zoo Lake was no longer a good recreational area, and was suffering ecological degradation.

In a bid to combat this pollution, the City’s environmental department launched a Zoo Lake Rehabilitation Project on 25 February, and Lekgebeng Water Environmental Resources Scientists was contracted to monitor the area.

The project investigates the status quo and determines remedial objectives. It also assesses the hydrological and ecological functioning, such as establishing siltation levels, water quality and aquatic health. This has been up and running for the past three months.

Through the investigation, the stakeholders will be able to establish the lake’s hydrological regime, and assess the sub-catchment areas as pollution sources.

The objectives are to eliminate the risk of outbreaks of waterborne diseases, to ensure the lake conforms to water quality criteria for recreational use and of a desirable ecological reserve, to provide a good environment for eco-recreation and business enterprises and to replenish water storage capacity.

Other issues

Several other environmental issues were also discussed at the meeting, held on 15 May. The deputy director of environmental and natural resource management in the City, Nondokoso Hadebe, spoke about her department’s vision.

It envisaged “an environmentally sustainable city that anticipates, manages and reduces its vulnerability to potential global and local environmental shocks, and works consistently to reduce the impact of its own built environment and urban processes on the broader envelope of natural resources”.

The department had several projects under way to improve air quality and deal with climate change. “We came up with interventions that will help us to improve the quality of air and water in Joburg.”

For example, there was the Basa njengo Magogo emission project set up in Alexandra and Soweto. It involves teaching people to make fires in braziers by placing coal at the bottom, followed by paper and a few sticks of wood.

The paper is lit to burn the wood; once the wood is burning, a few coals are added to the top. The method saves coal and releases less smoke than the usual method of making a fire in a brazier.

The old method is a “bottom-up fire ignition process”, in which the smoke rises through the cold coals and escapes. With the “top-down fire ignition process”, the smoke rises through the hot zone and is burned – and therefore less smoke is released into the atmosphere.

Installing solar water heaters to cut reliance on non-renewable energy sources was another of the department’s projects.

Its key achievements were the clean-up programme on the Upper Jukskei River, which was running smoothly; the rehabilitation of three wetlands; the rezoning of open spaces; and the proclamation of nature reserves.

In addition, more than 700 vehicle licences had been issued to waste service providers to curb illegal dumping. Illegal dumping hotspots had also been cleared and the department had helped to set up recycling centres in Zondi, in Soweto, and Alexandra.
More than 130 tons of recyclable glass, plastic, cans and paper were collected between last year and this year, through waste minimisation initiatives in Region D.

Johannesburg Zoo

The meeting also heard that the Johannesburg Zoo was involved in several conservation programmes, including amphibian conservation and research. Other programmes were Chimpanzee Rescue, Zoo Farm conservation and the Wattled Crane Recovery Programme.

Stephen van der Spuy, the zoo’s chief executive, was seriously concerned about the rapid drop in the frog population. “Around the world we are loosing frogs at a very rapid pace, and this is not good because frogs are an indication of what is happening around us.”

The zoo’s environmental educational programmes were discussed; for example, it participated in World Environment Day, Arbor Day and National Marine Week.
“We were the only zoo that participated in Marine Week last year. We will participate this year as well,” Van der Spuy said.

He emphasised that the primary role of the zoo was to entertain and educate.
The meeting was held on Thursday, 15 May at the Anglogold Ashanti Conference Centre at the Johannesburg Zoo. The zoo’s main public entrance is in Upper Park Drive, in Forest Town.