South Africa’s eutrophication challenges under discussion in Italy

3 September 2014


Eutrophication remains the major threat to stored water supplies

This week sees the hosting of the 15th World Lakes Conference (WLC15) in Perugia, Italy.  One of the discussion themes is that of Wicked Problems, those complex, ever-changing societal and organisational planning problems that evade successful remedial intervention.  The problem of eutrophication is one such problem, for which a group of researchers is now invoking the tool of Morphological Analysis to illustrate their ‘wicked’ nature and, hopefully, underpin a better understanding of what eutrophication management is really all about.

The abstract for one of the three South African papers to be presented on this topic is provided here:


Harding WR, Hart RC and JA Thornton

South Africa’s Hartbeespoort Dam, a reservoir located northwest of the economic centers of Johannesburg and Pretoria, was a focus of concentrated limnological science during the 1970s and 80s.  Between then and now it has progressed from being a notable and famous locus for eutrophication and cyanobacterial research, to notorious for ignoring reservoir management best practices and falling prey to scientifically-invalid solutions and ‘hobbyist’ management, allowing conditions in the impoundment to worsen.

The reservoir receives the bulk of its nutrient load from wastewater effluents from Johannesburg, along with urban runoff and other minor contributions.  Such inputs continue to increase and despite relatively high levels of nutrient removal, vastly exceed its assimilative capacity.  Despite this, efforts to improve water quality have focused on ‘in-lake’ solutions – including top-down biomanipulation – despite scientific evidence disproving the validity thereof.  Substantiated criticism of these remediation efforts has achieved little, apart from attempts to discredit the source of the critique, solicit “sweetheart” peer review and unsubstantiated claims of alleged ‘internationally recognized’ success.

The nett outcome is that little, if anything, has been achieved.  Despite several years of attentive focus/publicity and major financial expenditure, not a single scientific paper has emerged, despite the achievements claimed.  Excessive financial expenditure and the lack of progress to-date have seriously compromised the allocation of funds for other, relevant work.

This presentation analyses Hartbeespoort Dam as a case study of eutrophication as a ‘Wicked Problem’, highlighting where this phenomenon has confounded successful amelioration of several decades of anthropogenic impact.

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