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
(https://papers.acg.uwa.edu.au/p/852_71_Lubke/)
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.