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
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.
Aronson, J., Milton, S.J. and Blignaut, J.N. (2007) (eds) Restoring Natural Capital: Science, Business and Practice.
Island Press, Washington.
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program: Phase II Report. University of Wisconsin-Madison, Wisconsin. Geo Engineering Report 01-10.
CES (2006) Evaluation of proposed evapotranspirative cover for the Umbogintwini Industrial Complex: Vegetation and
floristics. Unpublished Report produced for SRK Consulting Engineers & Consultants, Johannesburg. Coastal
and Environmental Services, Grahamstown.
CES (2007) Vegetation and floristics changes on the Vumbuka Nature Reserve, Umbogintwini Industrial Complex:
Unpublished Report produced for SRK Consulting Engineers & Consultants, Johannesburg. Coastal and
Environmental Services, Grahamstown.
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stability and organization. American Naturalist 111, pp. 1119-1144.
CSIR (2006) Evaluation of proposed evapotranspirative cover for the Vumbuka Nature Reserve, Kwa Zulu-Natal:
Modelling the slimes dam water balance under grass- and tree-dominated vegetation. Unpublished Report
produced for SRK Consulting Engineers & Consultants, Johannesburg, NRE, CSIR, Pietermaritzburg.
Hakonson, T.E. (1997) Capping as an alternative for landfill closures-perspectives and approaches. Environmental
Science and Research Foundation. Proceedings Landfill capping in the semi-arid west: Problems, perspectives
and solutions. Grand Teton National Park, Wyoming. May 21-22. ESRF-019, pp. 1-18.
Hauser, V.L., Weand, B.L. and Gill, M.D. (2001) Natural covers for landfills and buried waste. Journal of
Environmental Engineering, pp. 768-775.
Henderson, L. (2001) Alien weeds and invasive plants. Plant Protection Research Institute Handbook No 12.
Agricultural Research Institute, Pretoria.
Kent, M. and Coker, P. (1992) Vegetation Description and Analysis: A Practical Approach. John Wiley & Sons. New
Mucina, L. and Rutherford, M.C. (2006) The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South
African National Biodiversity Institute, Pretoria.
Pisces Conservation (2002) Community Analysis Package (CAP). Pisces Conservation Ltd, UK.
SER (2004) A primer in ecological restoration. Society of Ecological Restoration.
Umbongintwini Land Remediation Project Team (2003) Umbongintwini Industrial Complex; north-west waste site
rehabilitation strategy. AECI Ltd., Umbogintwini. Unpublished Report, June 2003.
U.S. EPA (2003) Evapotranspiration landfill cover systems fact sheet. United States Environmental Protection Agency,
Cincinnati, Ohio. EPA 542-F-03-015.