Effective impact prediction: how accurate are predicted impacts in EIAs?

Molefe, Noella Madalo
Journal Title
Journal ISSN
Volume Title
An Environmental Impact Assessment (EIA) is an instrument used to limit unexpected and negative effects of proposed developments on the environment. Much experience has been gained internationally but the lack of follow-up after the EIA is prepared is one of the major weak spots of the assessments. It is therefore very important to follow up on development projects and observe their effects on the environment after the go-ahead has been given, so that the EIA quality may be improved. There is often a significant difference between predicted impacts and actual impacts. Sometimes the predicted impacts do not occur, or new impacts which were not predicted in the Environmental Impacts Assessment Reports (EIRs) arise. The aim of this study was to assess the accuracy of the impacts predicted in the EIRs compiled for three large-scale Eskom projects currently under execution situated in the Mpumalanga, Limpopo and KwaZulu-Natal provinces by comparing them to the actual impacts that occurred on site. The EIA follow-up process was used to assess the influence that the EIA may have on large-scale projects and ultimately assess the effectiveness of the EIA process as a whole. A procedure developed by Wilson (1998) was used to follow up on the selected projects because the method allowed for comparisons between the actual and predicted impacts to be made and for discrepancies in the EIRs to be identified. Recent audit reports, aerial photographs and interviews were all used to identify actual impact occurrence. Of the impacts which actually occurred, 91% occurred as predicted (OP) and 9% occurred but were not predicted (ONP). The majority of impacts omitted from the reports were hydrological (27%) and air quality impacts (25%). These unexpected impacts were most probably overlooked because they are site-specific, temporary in nature and would not cause any significant environmental damage. Of all the impacts predicted in the reports, 85% were accurately predicted and 15% were not. The impacts inaccurately predicted were hydrological impacts (27%), flora and fauna impacts (7%) and 30% other impacts which included soil pollution, fires and loss of agricultural potential. The inaccuracies could be a result of Environmental Impact Assessment Practitioners (EAPs) predicting a large number of impacts with the hopes of lowering the risk of omitting impacts. However, sometimes the impacts predicted do not occur in reality. Overall it can be concluded that the impact prediction accuracy of the three EIRs compiled for Eskom exceeds previous studies conducted nationally. Eskom EIRs are highly accurate with regards to impact prediction with minor discrepancies which can easily be rectified. Key words: Environmental Impacts Assessment (EIA) Environmental Impacts Assessment Reports (EIRs), Environmental Impact Assessment Practitioners (EAPs), EIA follow-up, discrepancies.
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2017.
Molefe, Noella Madalo (2017) Effective impact prediction: how accurate are predicted impacts in EIAs?, University of the Witwatersrand, Johannesburg, <http://hdl.handle.net/10539/23570>