The Contribution to Closure of Spontaneous Restoration of Industrial Slimes Effluent Dams at the Umbogintwini Industrial Complex near Durban, South Africa

Authors: Lubke, RA Paper is not available for download Contact Us

DOI https://doi.org/10.36487/ACG_repo/852_71

Cite As:
Lubke, RA 2008, 'The Contribution to Closure of Spontaneous Restoration of Industrial Slimes Effluent Dams at the Umbogintwini Industrial Complex near Durban, South Africa', in AB Fourie, M Tibbett, I Weiersbye & P Dye (eds), Mine Closure 2008: Proceedings of the Third International Seminar on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 759-770, https://doi.org/10.36487/ACG_repo/852_71



Abstract:
In the late 1990s the slimes effluent dams at the AECI industrial complex were decommissioned, and there followed an invasion of plants into the still-saturated but somewhat toxic material that had been deposited in the dams over a 40 year period since the early 1960s. This spontaneous restoration of grassland and woody vegetation led to the establishment of the Vumbuka Nature Reserve in the early 2000s, a 20 ha site which currently supports a wide variety of fauna and flora. Additional indigenous trees were introduced, the return of birds and other animals encouraged, and trails and other amenities were laid out for visitors. In order to effect safe closure of these dams, a number of investigations were initiated. The aim of one of these studies is to determine the system water balance and whether the vegetation could function as an evapotranspiration cover (ET cover) in order to negate ground and surface water contamination. To this end, Coastal and Environmental Services (CES) investigated the nature of the plant communities and the contribution to cover of grasses, herbs, and woody plants on four different slimes dams. It was found that the restoration (successional) process was from primary colonizing shrubs, to perennial grasses and creepers, and then to other woody plants. An open forested vegetation formed as woody plants invaded, and as supplementary planting of indigenous tree saplings took place. The natural and augmented forested areas were more abundant on some dams, as the importance of the contribution of woody plant cover and rooting systems to the ET cover was realized. Systematic monitoring of the vegetation was initiated in 2006, and additional studies have been initiated on the reasons for the success of the various plant species on the different dams.

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